• C. C. Drennan
  
• M. Ball, A. R. Franck, D. J. Harding, P. A. Kasley, G. E. Krafczyk, M. J. Kucera, J. R. Lackey, D. McArthur, J. R. Misek, W. Pellico, E. Prebys, A. K. Triplett, D. Wolff
  Fermilab, Batavia, Illinois

To better control the beam position, tune, and chromaticity in the Fermilab Booster synchrotron, a new package of six corrector elements has been designed, incorporating both normal and skew orientations of dipole, quadrupole, and sextupole magnets. The devices are under construction and will be installation in 48 locations in the Booster accelerator. Each of these 288 corrector magnets will be individually powered. Each of the magnets will be individually controlled using operator programmed current ramps designed specifically for the each type of Booster acceleration cycle. This paper provides an overview of the corrector magnet installation in the accelerator enclosure, power and sensor interconnections, specifications for the switch-mode power supplies, rack and equipment layouts, controls and interlock electronics, and the features of the operator interface for programming the current ramps and adjusting the timing of the system triggers.

• D. J. Harding
  
• J. DiMarco, C. C. Drennan, V. S. Kashikhin, S. Kotelnikov, J. R. Lackey, A. Makarov, A. Makulski, R. Nehring, D. F. Orris, E. Prebys, P. Schlabach, G. Velev, D. G.C. Walbridge
  Fermilab, Batavia, Illinois

To better control the beam position, tune, and chromaticity in the Fermilab Booster synchrotron, a new package of six corrector elements has been designed, incorporating both normal and skew orientations of dipole, quadrupole, and sextupole magnets. The devices are under construction and installation at 48 locations is planned. The density of elements and the rapid slew rate have posed special challenges. The magnet construction is presented along with DC measurements of the magnetic field.

• D. J. Harding
  
• C. L. Bartelson, B. C. Brown, J. A. Carson, W. Chou, J. DiMarco, H. D. Glass, D. E. Johnson, V. S. Kashikhin, I. Kourbanis, W. F. Robotham, M. Tartaglia
  Fermilab, Batavia, Illinois

During the design of the Fermilab Main Injector synchrotron it was recognized that the aperture was limited at the beam transfer and extraction points by the combination of the Lambertson magnets and the reused Main Ring quadrupoles located between the Lambertsons. Increased intensity demands on the Main Injector from antiproton production for the collider program, slow spill to the meson fixed target program, and high intensity beam to the high energy neutrino program have led us to replace the aperture-limiting quadrupoles with newly built magnets that have the same physical length but a larger aperture. The magnets run on the main quadrupole bus, and must therefore have the same excitation profile as the magnets they replaced. We present here the design of the magnets, their magnetic performance, and the accelerator performance.

• M. Hu
  
• D. R. Broemmelsiek, B. Chase, J. L. Crisp, N. E. Eddy, P. W. Joireman, K. Y. Ng
  Fermilab, Batavia, Illinois

• V. S. Kashikhin
  
• R. P. Johnson, S. A. Kahn, T. J. Roberts
  Muons, Inc, Batavia
• V. Kashikhin, M. J. Lamm, G. Romanov, K. Yonehara, A. V. Zlobin
  Fermilab, Batavia, Illinois

MANX is a 6-dimensional muon ionization-cooling experiment that has been proposed to Fermilab to demonstrate the use of a Helical Cooling Channel (HCC) for future muon colliders and neutrino factories. The HCC for MANX has solenoidal, helical dipole, and helical quadrupole magnetic components which diminish as the beam loses energy as it slows down in a liquid helium absorber inside the magnets. Two superconducting magnet system designs are described which use quite different approaches to providing the needed fields. Additional magnets that provide emittance matching between the HCC and upstream and downstream spectrometers are also described as are the results of G4Beamline simulations of the beam cooling behaviour of the complete magnet and absorber system.

• V. Kashikhin
  
• A. V. Zlobin
  Fermilab, Batavia, Illinois

After LHC operates for several years at nominal parameters it will need an upgrade to higher luminosity. Replacing the low-beta insertions with a higher performance design based on advanced superconducting magnets is a straightforward step in this direction. One of the approaches being considered for the new LHC IRs is a "dipole-first: option with two separation dipoles placed in front of the focusing quadrupoles. It reduces the number of parasitic collisions with respect to the "quadrupole-first" option and allows independent field error corrections for each beam. Most of key magnet designs for the "dipole-first" option including high-field large-aperture dipoles (D1) and 2-in-1 quadrupoles have already been studied and reported. This paper focuses on design studies of the 2-in-1 separation dipole (D2) located between D1 and the quadrupoles. High operation field of the same polarity in large adjacent apertures imposes limitations on the maximum field, field quality and mechanics for this magnet. This paper analyses possible D2 magnet designs based on Nb3Sn superconductor and compares them in terms of the aperture size, maximum field, field quality and Lorents forces in the coil.

• E. Prebys
  
• C. C. Drennan, D. J. Harding, V. S. Kashikhin, J. R. Lackey, A. Makarov, W. Pellico
  Fermilab, Batavia, Illinois

The Fermilab neutrino program places unprecedented demands on the lab's 8 GeV Booster synchrotron, which has not changed significantly since it was built almost 35 years ago. In particular, the existing corrector system is not adequate to control beam position and tune throughout the acceleration system, and provides limited compensation for higher order resonances. We present an ambitious ongoing project to build and install a set of 48 corrector packages, each containing horizontal and vertical dipoles, normal and skew quadrupoles, and normal and skew sextupoles. Space limitations in the machine have motivated a unique design, which utilizes custom wound coils around a 12 pole laminated core. Each of the 288 discrete multipole elements in the system will have a dedicated power supply, the output current of which is controlled by an individual programmable ramp. This provides for great flexibility in the system, but also presents a challenge in terms of designing the control hardware and software in such a way that the system can be operated in the most efficacious way.

• J. Ruan
  
• H. Edwards, R. P. Fliller, J. K. Santucci
  Fermilab, Batavia, Illinois

The current Fermilab A0 Photoinjector laser system includes a seed laser, a flashlamp pumped multipass amplifier cavity, a flashlamp pumped 2-pass amplifier system followed by an IR to UV conversion stage. However the current system can only deliver up to 800 pulses due to the low efficiency of Nd:Glass used inside multi-pass cavity. In this paper we will report the effort to develop a new multi pass cavity based on Nd:YLF crystal end-pumped by diode laser. We will also discuss the foreseen design of the laser system for the NML accelerator test facility at Fermilab.

• I. Terechkine
  
• V. Kashikhin, T. M. Page, M. Tartaglia, J. C. Tompkins
  Fermilab, Batavia, Illinois

• G. Velev
  
• J. DiMarco, D. J. Harding, V. S. Kashikhin, M. J. Lamm, P. Schlabach, M. Tartaglia, J. C. Tompkins
  Fermilab, Batavia, Illinois

A method for measurement of rapidly changing magnetic fields has been developed and applied to the testing of new room temperature corrector packages designed for the Fermilab Booster Synchrotron. The method is based on fast digitization of a slowly rotating tangential coil probe, with analysis combining the measured coil voltages across a set of successive magnet current cycles. This paper presents results on the field quality measured for normal and skew dipole, quadrupole, and sextupole magnets in several of these corrector packages.

• M. Votava
  
• B. Chase, M. Wendt
  Fermilab, Batavia, Illinois

The major controls and instrumentation systems for the ILC test areas and the NML test accelerator at Fermilab are discussed. The test areas include 3 separate areas for Vertical Superconducting RF Cavity Testing, Horizontal Cavity Testing, and NML RF and beam test area. A common control infrastructure for the test areas including a controls framework, electronic logbook and cavity database will be provided, while supporting components supplied by collaborators with diverse areas of expertise (EPICS, DOOCS, LabVIEW, and Matlab). The discussions on the instrumentation systems are focused on overview and requirements.

• A. V. Zlobin
  
• G. Ambrosio, N. Andreev, E. Barzi, R. Bossert, R. H. Carcagno, G. Chlachidze, J. DiMarco, SF. Feher, V. Kashikhin, V. S. Kashikhin, M. J. Lamm, A. Nobrega, I. Novitski, D. F. Orris, Y. M. Pischalnikov, P. Schlabach, C. Sylvester, M. Tartaglia, J. C. Tompkins, D. Turrioni, G. Velev, R. Yamada
  Fermilab, Batavia, Illinois

Accelerator magnets based on Nb3Sn superconductor advances magnet operation fields above 10T and increases the coil temperature margin. Development of a new accelerator magnet technology includes the demonstration of main magnet parameters (maximum field, quench performance, field quality, etc.) and their reproducibility using short models, and then the demonstration of technology scale up using long coils. Fermilab is working on the development of Nb3Sn accelerator magnets using shell-type dipole coils and react-and-wind method. As a part of the first phase of technology development Fermilab built and tested six 1-m long dipole models and several dipole mirror configurations. The last three dipoles and two mirrors reached their design fields of 10^-11 T. Reproducibility of magnet field quality was demonstrated by all six short models. The technology scale up phase has started by building 2m and 4m dipole coils and testing them in a mirror configuration. This effort complements the Nb3Sn scale up work being performed in the framework of US LHC Accelerator Research Program (LARP). The status and main results of the Nb3Sn accelerator magnet development at Fermilab are reported.

• S. De Santis
  
• T. Naito, J. Urakawa
  KEK, Ibaraki

We present the final results of a study for the design of a fast extraction kicker to be installed in the Accelerator Test Facility ring at KEK. The purpose of this project is to test the technologies to be used in the design of the extraction kickers for the International Linear Collider damping rings. The kicker's rise and fall times are important parameters in the final configuration of the rings, since they constrain the minimum distance between bunches and ultimately define a lower limit for the rings length. We investigated a stripline kicker composed of several 65-cm long sections, grouped in two different locations in the ATF damping ring. An analytical study of the kicker's parameter and extensive computer simulations using Microwave Studio* point out the ambitious requirements on the pulsers, in order to be able to satisfy the design specifications. We also investigated the use of a single kicker module, together with a close orbit bump near the extraction septum.

* http://www.cst.com

• S. Marks
  
• K. Kennedy, D. W. Plate, D. Schlueter, M. S. Zisman
  LBNL, Berkeley, California

The positron and electron damping rings for the ILC (International Linear Collider) will contain long straight sections consisting of twenty wiggler/quadrupole pairs. The wigglers will be based upon the CESR-C superconducting design* . There are a number of challenges associated with the design of the wiggler straight vacuum system, in particular, the absorption of photon power generated by the wigglers. This paper will present the overall conceptual design of the wiggler straight vacuum system developed for the ILC RDR. Particular emphasis will be placed on photon power load calculations and the absorber design.

* A. Mihailichenko, Optimized Wiggler Magnet for CESR, Proceedings of PAC2001, Chicago, Il, June 18-22, 2001

• N. V. Mokhov
  
• P. Ferracin, G. L. Sabbi
  LBNL, Berkeley, California
• V. Kashikhin, M. Monville
  Fermilab, Batavia, Illinois

At the LHC upgrade luminosity of 10³⁵ cm^-2 s^-1, collision product power in excess of a kW is deposited in the inner triplet quadrupoles. The quadrupole field sweeps secondary particles from pp-collisions into the superconducting coils, concentrating the power deposition at the magnetic mid-planes. The local peak power density can substantially exceed the conductor quench limits and reduce component lifetime. Under these conditions, block-coil geometries may result in overall improved performance by removing the superconductor from the magnetic mid-planes and/or allowing increased shielding at such locations. First realistic energy deposition simulations are performed for an interaction region based on block-coil quadrupoles with parameters suitable for the LHC upgrade. Results are presented on 3-D distributions of power density and accumulated dose in the inner triplet components as well as on dynamic heat loads on the cryogenic system. Optimization studies are performed on configuration and parameters of the beam pipe, cold bore and cooling channels. The feasibility of the proposed design is discussed.

• J. W. Staples
  
• J. M. Byrd, R. B. Wilcox
  LBNL, Berkeley, California

Long-term phase drifts of less than a femtosecond per hour have been demonstrated in a 2 km length of single-mode optical fiber, stabilized interferometrically at 1530 nm. Recent improvements include a wide-band phase detector that reduces the possibility of fringe jumping due to fast external perturbations of the fiber and locking of the master CW laser wavelength to a molecular absorption line. Mode-locked lasers may be synchronized using two wavelengths of the comb, multiplexed over one fiber, each wavelength individually interferometrically stabilized.

• S. P. Virostek
  
• M. A. Green, D. Li, M. S. Zisman
  LBNL, Berkeley, California

The Muon Ionization Cooling Experiment (MICE) will demonstrate ionization cooling in a short section of a realistic cooling channel using a muon beam at Rutherford Appleton Laboratory (RAL) in the UK. A five-coil, superconducting spectrometer solenoid magnet at each end of the cooling channel will provide a 4 T uniform field region for the scintillating fiber tracker within the magnet bore tubes. The tracker modules are used to measure the muon beam emittance as it enters and exits the cooling channel. The cold mass for the 400 mm warm bore magnet consists of two sections: a three-coil spectrometer magnet and a two-coil matching section that matches the uniform field of the solenoid into the MICE cooling channel. The detailed design and analysis of the two spectrometer solenoids has been completed, and the fabrication of the magnets is in its final stages. The primary features of the spectrometer solenoid magnetic and mechanical designs are presented along with a summary of key fabrication issues and photos of the fabrication process.

• M. A. Green
  
• X. L. Guo, G. Han, L. Jia, L. K. Li, S. Y. Li, C. S. Liu, X. K. Liu, L. Wang, H. Wu, F. Y. Xu
  ICST, Harbin
• S. P. Virostek
  LBNL, Berkeley, California

The Muon Ionization Cooling Experiment (MICE) will demonstrate ionization cooling in a short section of a realistic cooling channel using a muon beam at Rutherford Appleton Laboratory (RAL) in the UK. The MICE RF and Coupling Coil Module comprises a superconducting solenoid mounted around four normal conducting 201.25-MHz RF cavities. Each cavity has a pair of thin curved beryllium windows to close the conventional open beam irises. The coil package that surrounds the RF cavities is to be mounted on the outside of a 1.4 m diameter vacuum vessel. The coupling coil confines the beam in the cavity module and, in particular, within the radius of the cavity beam windows. The two MICE coupling solenoids will be operated in series using a 300 A, 10 V power supply. The maximum longitudinal force that will be carried by the cold mass support system is 0.5 MN during the expected operating and failure modes of the experiment. The detailed design and analysis of the two coupling coils has been completed, and the fabrication of the magnets is under way. The primary magnetic and mechanical design features of the coils are presented along with a summary of key fabrication issues.

• J. M. Weber
  
• M. J. Chin, CA. Timossi, E. C. Williams
  LBNL, Berkeley, California

The emergence of Field Programmable Gate Arrays (FPGAs) with embedded processors and significant progress in their development tools have contributed to the realization of system-on-a-chip networked front-end systems. Embedded processors are capable of running full-fledged Real-Time Operating Systems (RTOSs) and serving channels via Ethernet while high speed hardware functions, such as digital signal processing and high performance interfaces, run simultaneously in the FPGA logic. Despite significant advantages of the system-on-a-chip implementation, engineers have shied away from designing such systems due to the perceived daunting task of integrating software to run a RTOS with custom hardware. However, advances in embedded development tools considerably reduce the effort required for software/hardware integration. This paper will describe the implementation and integration of software and hardware in an FPGA embedded processor system as illustrated by the design of a new control system module for the ALS.

• P. Messmer
  
• J. G. Power
  ANL, Argonne, Illinois
• V. H. Ranjbar, D. J. Wade-Stein
  Tech-X, Boulder, Colorado
• P. Schoessow
  Euclid TechLabs, LLC, Solon, Ohio

Field Programmable Gate Arrays (FPGAs) offer a powerful alternative to ASICs or general purpose processors in accelerator control applications. Software development for these devices can be awkward and time consuming, however, when using low level hardware design languages. To facilitate the use of FPGAs in control systems we are developing a library of software tools based on ImpulseC, a high level subset of the C language specifically designed for FPGA programming. Development and testing of the software will be performed on a Xilinx Virtex-4 FPGA demo board. We will present timing benchmarks for common control functions (PID feedback loops, FIR and Kalman filters) and present plans for the development of a controller for the Argonne Wakefield Accelerator high current photoinjector based on this work.

• C. Wu
  
• E. Abed, G. Bai, B. L. Beaudoin, S. Bernal, I. Haber, R. A. Kishek, P. G. O'Shea, M. Reiser, D. Stratakis, D. F. Sutter, K. Tian, M. Walter
  UMD, College Park, Maryland

Beam based alignment and control has been a critical issue for many accelerators. In this paper, we've developed a new approach that can correct the beam orbit using a systematic quad-scan method, where there is an insufficient number of beam position monitors. In this approach, we've proposed a calibrated response matrix. This matrix takes consideration of the different sensitivities of different quadrupoles in the lattice. With the calibrated response matrix, we can greatly enhance our ability to control the beam centroid motion and reduce the control effort.

• P. M. McIntyre
  
• A. D. McInturff, A. Sattarov
  Texas A&M University, College Station, Texas

The block coil geometry utilized in recent high-field dipole development has significant benefit for applications requiring rapid cycling, since it intrinsically suppresses coupling currents between strands. A conceptual design for a 6 Tesla dipole has been studied for such applications, in which the intra-strand losses are minimized by using bronze-process Nb3Sn superconducting wire developed for ITER. That conductor provides isolated fine filaments and optimum matrix resistance between filaments. The block-coil geometry further accommodates placement of He cooling channels inside the coil, so that heat from radiation and from AC losses can be removed with minimum temperature rise in the coil. The design could be operated with supercritical helium cooling, and should make it possible to operate with a continuous ramp rate of 5-10 T/s.

• S. M. Hartman
  
• S. F. Mikhailov, V. Popov, Y. K. Wu
  FEL/Duke University, Durham, North Carolina

At Duke University, a booster synchrotron was recently commissioned as part of the HIGS upgrade. For the ramping magnet power supply controls, a scheme was developed to present the high level operator interface in terms of the physics quantities of the accelerator, i.e. the effective focusing strength of the magnets. This scheme allows for the nonlinearities of the magnets – a result of the extremely compact footprint of this booster – to be incorporated into the low level software. This facilitates machine studies and simplifies use of physics modeling. In addition, it simplifies operation, allowing the booster to ramp to any energy from the 0.27 GeV of the injector linac to the 1.2 GeV maximum of the Duke Storage Ring. The high level of flexibility of this system if further advanced by incorporating the level of tunability typically found in a storage ring control system. Tuning changes made during steady-state operation are automatically propagated to the waveforms which make up the booster ramp. This approach provides a good match to the wide operation modes of the Duke Storage Ring and its associated free electron laser, and may useful for other compact booster synchrotrons.

• Y. Kim
  
• M. D. Busch, P. Wang, W. Wu, Y. K. Wu
  FEL/Duke University, Durham, North Carolina
• J. Choi, I. S. Ko, I. S. Park
  PAL, Pohang, Kyungbuk
• D. Teytelman
  Dimtel, Redwood City, California

• V. Popov
  
• M. D. Busch, S. M. Hartman, S. F. Mikhailov, O. Oakeley, P. W. Wallace, Y. K. Wu
  FEL/Duke University, Durham, North Carolina

A booster synchrotron has been recently commissioned at Duke University as part of the High Intensity Gamma-ray Source (HIGS) upgrade. All dipole and quadrupole magnets are fed by the same power supply in order to facilitate synchronization. A 500kW retired thyristor controlled power supply has been completely rebuilt to provide high accuracy ramping of current in the range between 150A and 700A in a 1.3 sec repetition cycle. Reproducibility of current at extraction energy is better than 0.1% for entire operational range of energy. Conflict of a fast ramping operation and a magnet protection in the case of emergency shutdown was resolved using additional thyristor switches. All trim power supplies involved in ramp have been matched with the main power supply for the time response and voltage range. The injection and extraction schemes require rapidly ramping Y-correctors. The required peak power about 4 kW in these correctors is provided by a combining a low voltage DC power supply and a pulse boosting circuit. We present the challenges of designing and developing booster power supply system. And also we report measured performance and operational experience in this paper.

• S. Chouhan
  
• E. Barzi
  Fermilab, Batavia, Illinois
• G. Bollen, C. Guenaut, D. Lawton, F. Marti, D. J. Morrissey, J. Ottarson, G. K. Pang, S. Schwarz, B. Sherrill, A. Zeller
  NSCL, East Lansing, Michigan

We present the design of a superferric cyclotron gas stopper magnet that has been proposed for use at the NSCL/MSU to stop the radioactive ions produced by fragmentation at high energies (~140 MeV/u). The magnet is a gradient dipole with three sectors ( B~2.7 T at the center and 2 T at the pole-edge. The magnet outer diameter is 3.8 m, with a pole radius of 1.1 m and B*rho=1.7 T-m). The field shape is obtained by extensive profiles in the iron. The coil cross-section is 64 cm*cm and peak field on the conductor is about 1.6 T. The upper and lower coils are in separate cryostat and have warm electrical connections. We present the coil winding and protection schemes. The forces are large and the implication on the support structure is presented.

• P. Quigley
  
• S. A. Belomestnykh, M. Liepe, V. Medjidzade, J. Sears, V. Veshcherevich
  CLASSE, Ithaca

Cornell is building a 1.3 GHz Injector Cryomodule for an ERL prototype. The cryomodule consists of five two-cell niobium cavities each cavity having two coaxial power input couplers. Cavity and coupler pairs will require acceptance testing at high power prior to assembly in the injector cryomodule. A liquid nitrogen cryostat for testing the couplers at high power has been built and the first input coupler test is complete. In addition, a Horizontal Test Cryostat (HTC) is being built to test input coupler pairs and cavities as a set. The first HTC test is scheduled for spring 2007. Details for instrumentation of the Coupler Test Cryostat (CTC) and HTC are presented.

• D. G. Ouzounov
  
• I. V. Bazarov, B. M. Dunham, C. K. Sinclair
  Cornell University, Department of Physics, Ithaca, New York
• F. W. Wise, S. Zhou
  Cornell University, Ithaca, New York

Cornell University is developing a high brightness, high average current electron source for the injector of an ERL based synchrotron radiation source. The source is a DC electron gun with a negative electron affinity photoemission cathode. The photocathode is illuminated by a 1300 MHz CW train of optical pulses to produce a 100 mA average current beam. The optical pulse train is generated by frequency doubling the output of a diode-pumped, mode-locked Yb-fiber oscillator-amplifier system. The 50 MHz fundamental frequency oscillator is locked on its 26th harmonic to produce the 1300 MHz train. The oscillator output is amplified in three stages and doubled to give 26 W in the green. The doubled beam is diffraction limited (M2 = 1.08) with a pulse width of 2.5 ps. This pulse is split and differentially delayed in a series of birefringent crystals to produce a flat top temporal profile with fast rise and fall times. The final pulse shape is measured by cross-correlation. The pulses are spatially shaped by a commercial aspheric lens system. A full power system operating at 50 MHz is in routine use for electron beam measurements. Detailed laser performance information will be presented.

• M. Shverdin
  
• S. G. Anderson, C. P.J. Barty, M. Betts, D. J. Gibson, F. V. Hartemann, J. Hernandez, M. Johnson, I. Jovanovic, D. P. McNabb, M. J. Messerly, J. A. Pruet, C. Siders, A. M. Tremaine
  LLNL, Livermore, California

The fiber-based, spatially and temporally shaped, picosecond UV laser system described here has been specifically designed for advanced rf gun applications, with a special emphasis on the production of high-brightness electron beams for free-electron lasers and Compton scattering light sources. The laser pulse can be shaped to a flat-top in both space and time with a duration of 10 ps FWHM and rise and fall times under 1 ps. The pulse energy is 100 micro-joules at 261.75 nm and the spot size diameter of the beam at the photocathode measures 2 mm. A fiber oscillator and amplifier system generates a chirped pump pulse at 1047 nm; stretching is achieved in a chirped fiber Bragg grating. A single multi-layer dielectric grating based compressor recompresses the input pulse to 250 fs FWHM and a two stage harmonic converter frequency quadruples the beam. A custom-designed diffractive optic reshapes the input pulse to a flat-top. Temporal shaping is achieved with a Michelson-based ultrafast pulse stacking device with nearly 100% throughput. The integration of the system, as well as preliminary electron beam measurements will be discussed.

• M. J. Borden
  
• J. F. O'Hara, E. M. Perez, B. J. Roller, V. P. Vigil, L. S. Walker
  LANL, Los Alamos, New Mexico

Large maintenance dose burdens have necessitated the development of radiation resistant water manifolds for use on DC magnets in the Proton Storage Ring, at the Los Alamos Neutron Science Center (LANSCE) accelerator. This paper will describe dose measurements and the mechanical design of radiation resistant water manifolds used in PSR.

• M. J. Borden
  
• C. A. Chapman, C. T. Kelsey, J. F. O'Hara, J. Sturrock
  LANL, Los Alamos, New Mexico

Dose rate modeling and post irradiation measurements of the Isotope Production Facility beamline, at the Los Alamos Neutron Science Center (LANSCE) accelerator, have determined that a radiation shielding shutter is required to protect personnel from shine from irradiated targets for routine beam tunnel entries. This paper will describe radiation dose modeling, shielding calculations and the failsafe mechanical shutter design.

• J. T. Bradley III
  
• C. J. Andrews, L. F. Fernandez, M. F. Fresquez, W. Reass, W. Roybal, J. B. Sandoval
  LANL, Los Alamos, New Mexico

The proton beam in the LANSCE accelerator is guided and focused almost exclusively by electromagnets. Magnet hysteresis has had significant impacts on the tuning of the LANSCE accelerator.* Magnet hysteresis can also have an impact on Magnet Power Supply (MPS) control, regulation and repeatability requirements. To date, MPS performance requirements have been driven by the requirements on the magnetic fields as determined by the accelerator physicists. Taking hysteresis effects into account can significantly change MPS requirements, as some requirements become more stringent and some are found to be overspecified. Overspecification of MPS requirements can result in significant increases in MPS cost. Conversely, the use of appropriate MPS requirements can result in significant cost savings. The LANSCE accelerator's more than three decades of operation provide a wide variety of magnet power supply technologies and operational experience. We will survey the LANSCE magnet power supply history and determine how performance specifications can be refined to both reduce costs and improve the operators abilities to control the magnetic fields.

*R. McCrady, "Mitigation Of Magnet Hysteresis Effects at LANSCE", LINAC 2006, August, 2006.

• S. S. Kurennoy
  

* S. S. Kurennoy and J. F. Power, EPAC 2000 (Vienna, Austria, 2000), 336.

• R. C. McCrady
  
• S. Assadi, C. Deibele, S. Henderson, M. A. Plum
  ORNL, Oak Ridge, Tennessee
• J. M. Byrd
  LBNL, Berkeley, California
• S.-Y. Lee
  IUCF, Bloomington, Indiana
• R. J. Macek, S. B. Walbridge, T. Zaugg
  LANL, Los Alamos, New Mexico
• M. T.F. Pivi
  SLAC, Menlo Park, California

A prototype of an analog, transverse (vertical) feedback system for active damping of the two-stream (e-p) instability has been developed and successfully tested at the Los Alamos National Laboratory Proton Storage Ring (PSR). This system was able to improve the instability threshold by approximately 30% (as measured by the change in RF buncher voltage at instability threshold). Evidence obtained from these tests suggests that further improvement in performance is limited by beam leakage into the gap at lower RF buncher voltage and the onset of instability in the horizontal plane, which had no feedback. Here we describe the present system configuration, system optimization, results of several recent experimental tests, and results from studies of factors limiting its performance.

• E. R. Olivas
  

Thin windows are devices required by some particle accelerator physics experiments. These windows must be thin and light enough so they have a minimum effect on the beam. However, due to the boundary and loading conditions a window might observe; nonlinear structural behavior can occur from a number of different causes, such as geometric and material nonlinearities. If a structure experiences large plastic deformation, its changing geometric relationship can cause the structure to respond in a nonlinear manner. Material nonlinearities occur when the material's stress-strain relation depends on the load history as in plasticity models. The method of analysis for this study entails an FEA analysis, in which the stress and displacement are solved for a metallic membrane; these results are then compared to results obtained from an iterative process in relating the stress and strain with respect to the deformed geometry of the membrane. In addition, multiple experimental tests will be carried out to determine the membrane displacement from a prescribed load. Also included in this test will be the burst pressure or failure point of the membrane. The study is conducted on 1100 series Al.

• M. Pieck
  
• E. Bjorklund, G. P. Carr, J. A. Faucett, J. O. Hill, D. M. Kerstiens, P. S. Marroquin, P. McGhee, M. A. Oothoudt, S. Schaller
  LANL, Los Alamos, New Mexico

• T. Tajima
  
• M. J. Borden, A. Canabal, J. P. Chamberlin, S. Harrison, F. R. Olivas, M. A. Oothoudt, J. J. Sullivan
  LANL, Los Alamos, New Mexico

• C. Goodzeit
  
• M. J. Ball, R. B. Meinke
  Advanced Magnet Lab., Inc, Melbourne, Florida

This work is partially supported under U. S. Department of Energy grant : DoE SBIR DE-FG02-06ER 84492

• A. Chan
  
• P. Bellomo, G. R. Crane, P. Emma, E. Grunhaus, K. Luchini, I. A. MacGregor, D. S. Marsh, R. Pope, P. L. Prickett, E. Rago, K. Ratcliffe, T. Shab
  SLAC, Menlo Park, California

Changes to beamline optics may effect many engineering processes downstream. In the past, we incorporated these changes manually into disparate engineering spreadsheets. At LCLS, database applications have been developed in order to compare and clearly display differences amongst various versions of beamline optics files. These applications also incorporate the changes into engineering databases, after they have been validated by the engineers. This allows the engineers to be notified, and modifications to be made if beamline optics changes require corresponding adjustments of engineering elements. This paper will describe how this streamlines the workflow, and also provides greater reliability in how beamline optics changes are integrated into engineering databases (such as cabling, power supplies, inventory). The paper includes a description of the related LCLS inventory system, which also serves as a repository for quality assurance documents. The underlying database schemas and applications will be outlined.

• W. Wittmer
  
• W. S. Colocho, G. R. White
  SLAC, Menlo Park, California

The controls software in use at PEP II had originally been developed in the eighties. The functionality and maturity of the applications in that system have made it very successful in routine operation, but this same longevity and orientation toward fixed requirements, make it largely unsuitable for rapid machine development and ad-hoc online experimentation. A successful recent trend at light sources has been to use the so called MATLAB Middle Layer (MML). This package abstracts each underlying control system framework to which it is connected, such as Channel Access. We describe the middle layer implementation for PEP II and LCLS based on AIDA (described elsewhere in these proceedings), which is unusual in that it provides access to the high level functionality of the legacy control system, as well as to a very large assortment of useful data in addition to channel access read and control. The MML had to be adapted for the implementation at PEP II since colliders differ significantly from light sources by scale and symmetry of the lattice, and PEP II is the first collider at which such an implementation is being done.

• B. Lam
  
• P. Bellomo, D. Macnair, A. C. de Lira
  SLAC, Menlo Park, California

In 2008 KEK is commissioning ATF2 - an extension to the existing ATF. ATF2 is a mockup of the final focus test beam accelerator envisioned in the ILC. SLAC is designing the power supply systems for the dc magnets in the ATF2, which will require 38 power supplies ranging from 1.5 to 6 kW, currents from 50 to 200 A, all rated at output voltages not higher than 30 V. Because of the extensive quantities of magnets required for the ILC, high availability is paramount to its successful operation, so the power supply topology chosen for the ATF2 uses N+1 redundancy, with 50-A power modules to construct each power supply. These power modules are current-mode buck regulators, which operate in parallel with each other and one redundant module. One bulk power supply provides off-the-line regulated dc input to a number of the power supplies. Current stability requirements for the magnets range from 10 to 10⁰⁰ ppm. A precision current transductor and a recently developed SLAC-built 20-bit Ethernet Power Supply Controller will provide the current regulation required. In this paper we present the conceptual design, prototype results, and the status of the power supply systems for the ATF2.

• C. H. Rivetta
  
• R. Akre, P. Cutino, J. C. Frisch, K. D. Kotturi
  SLAC, Menlo Park, California

The LCLC RF gun requires a water cooling thermal system to tune the resonance frequency of the cavity to 2856.03MHz. The RF system operates in pulsed mode with bursts of 2.5usec at a repetition rate of 30-120Hz. The thermal system operates in combination with the low-level RF system to set the operation point of the cavity. The Low-Level RF system controls the magnitude and phase of the cavity voltage and define slow signals to the thermal system. The thermal system operates by pre-heating / pre-cooling the water and mixing both channels to achieve the optimal temperature to control the cavity resonant frequency. The tune control of the RF gun include two systems with different dynamics. The dynamics of the thermal system is slow while the RF system is fast. Additionally, different actuators in the system present limits that introduce non-linearities to be taking into account during the start up process . Combining these characteristics, a controller is designed for the resulting hybrid system that allows convergence in large for all the operation conditions and achieve the performance in the magnitude and phase of the cavity voltage required around the operation point.

• T. Mastorides
  
• J. D. Fox, C. H. Rivetta, D. Teytelman, D. Van Winkle
  SLAC, Menlo Park, California

PEP-II operations will increase the beam currents to 4A for LER and 2.2A for HER to achieve the final goal in luminosity. These magnitudes are challenging in part because they will push toward the limit the longitudinal low-order mode (LOM) beam stability due to beam loading. To analyze the behavior of both rings at high currents and understand the limits in the longitudinal feedback systems a simulation tool has been developed at SLAC. This tool is based on a reduced model of the longitudinal LOM dynamics of the beam interacting with the effective impedance presented by RF station. Simulations and measurements of the longitudinal beam behavior in both rings have been performed to understand the ultimate limit of the system. These studies have defined the impact of control loop parameters in the longitudinal beam dynamics, identified the poor performance of RF devices affecting the optimal performance of the RF stations and quantified the behavior of the longitudinal LOM beam dynamics. Results of sensitivity to parameter variations in the beam dynamics and limits in the maximum current that LER/HER can achieve based on the longitudinal beam stability are reported in this paper.

• J. E. Spencer
  

We consider optimization of the generalized luminosity per unit cost of a linear collider in this ES&H era. Examples running over the length of the LC, starting at the source and ending at the dump, suggest that both costs (capital and operating) and environmental issues can be improved in a compatible way. Thus, a RoHS by any other name (WEES or OSHA) need not present thorny problems requiring unexpected R&D but a push to leverage many recent advances that might otherwise be overlooked or avoided. The physics is interesting and the true amortized cost may be seriously underestimated by ignoring such issues. For example, the entire, interior surface of a laser driven RF gun involves interesting materials science where the space requires continuous UHV to sustain stable, acceptable quantum efficiency as well as avoid RF breakdown damage in an environment that is also subject to radiation damage. All of these can seriously reduce a gun's output and LCs luminosity. Intelligent design of rad-hard systems can approach the ideal of bug-proof software that needn't produce overly slow or ponderous systems while providing opportunities to innovate that justify the costs.

• J. E. Spencer
  
• S. D. Anderson, Z. R. Wolf
  SLAC, Menlo Park, California
• M. Boussoufi
  UCD/MNRC, McClellan, California
• G. Gallagher, D. E. Pellet
  UCD, Davis, California
• J. T. Volk
  Fermilab, Batavia, Illinois

Many materials and electronics need to be tested for the radiation environment expected at linear colliders (LC) to improve reliability and longevity since both accelerator and detectors will be subjected to large fluences of hadrons, leptons and gammas. Examples include NdFeB magnets, considered for the damping rings, injection and extraction lines and final focus, electronic and electro-optic devices to be utilized in detector readout, accelerator controls and the CCDs required for the vertex detector, as well as high and low temperature superconducting materials (LTSMs) because some magnets will be superconducting. Our first measurements of fast neutron, stepped doses at the UC Davis McClellan Nuclear Reactor Center (UCD MNRC) were presented for NdFeB materials at EPAC04 where the damage appeared proportional to the distances between the effective operating point and Hc. We have extended those doses, included other manufacturer's samples and measured induced radioactivities. We have also added L and HTSMs as well as a variety of relevant semiconductor and electro-optic materials including PBG fiber that we studied previously only with gamma rays.

• D. Teytelman
  
• W. X. Cheng, J. W. Flanagan, T. Naito, M. Tobiyama
  KEK, Ibaraki
• A. Drago
  INFN/LNF, Frascati (Roma)
• J. D. Fox
  SLAC, Menlo Park, California

Damping ring at the Accelerator Test Facility (ATF) is a storage ring with 714 MHz RF frequency and harmonic number of 330. The ring is used in both single and multibunch regimes. In both cases significant longitudinal dipole motion has been observed in the ring. A prototype longitudinal feedback channel using a Gproto baseband processing channel and a set of horizontal striplines has been constructed for the machine. The prototype allowed both suppression of the longitudinal motion and studies of the motion sources. In this paper we present the results of these studies including measurements of steady-state oscillation amplitudes, eigenmodal patterns, and growth and damping rates. Using measured growth rates we estimate the driving impedances. We also present the effect of the longitudinal stabilization on the energy spread of the extracted beam as documented by a screen monitor.

• M. Yeddulla
  
• S. G. Tantawi
  SLAC, Menlo Park, California

*S. G. Tantawi et al., Physical Review Special Topics – Accelerator and Beams. 8, 042002 (2005)

• A. C. de Lira
  
• P. Bellomo, K. Luchini, D. Macnair
  SLAC, Menlo Park, California

The LCLS injector at SLAC requires 100+ dc-magnet power supply systems for its operation. Power supplies are divided into two main groups: intermediate rack-mounted type for output powers up to 20 kW at 375 A, and bipolar units rated 6 A, 12 A, and 30 A for corrector magnets and small quadrupoles. The intermediate power supplies are controlled by a 20-bit Ethernet power supply controller, specially developed at SLAC to be used in this project. The bipolar units are controlled via 12-bit DACs and ADCs housed in a VME crate. EPICS is the controls interface to all systems. For all systems, stability requirements are better than 10⁰⁰ ppm. The Power Conversion Department at SLAC, in close cooperation with the LCLS Controls group, was responsible for defining the major characteristics of the power supply systems, their specification, procurement, installation, and commissioning. In this paper we describe the main characteristics of the power supply systems for the LCLS injector, including results from their successful commissioning early this year.

• L. Bees
  
• L. Simpson, A. Tydeman
  Lambda, Neptune, New Jersey

• V. P. Yakovlev
  
• J. L. Hirshfield
  Omega-P, Inc., New Haven, Connecticut
• A. Kanareykin
  Euclid TechLabs, LLC, Solon, Ohio
• S. Kazakov
  KEK, Ibaraki
• E. Nenasheva
  Ceramics Ltd., St. Petersburg
• S. V. Shchelkunov
  Columbia University, New York

Fast, electrically-controlled ferroelectric RF vector modulators are under development for different accelerator applications in the frequency range 0.4 - 1.3 GHz. The exact design of a vector modulator depends on the electrical parameters of particular ferroelectric material to be used, namely its dielectric constant, loss tangent and tunability. The exact values of these parameters were unknown in this frequency domain for low loss BST material that is planned to be used. A special two-disc test cavity has been designed and built that allows direct measurements of these parameters for large (100 mm in diameter) ferroelectric rings that are to be used in vector modulators. The results of measurements are presented.

• V. P. Yakovlev
  
• J. L. Hirshfield
  Omega-P, Inc., New Haven, Connecticut
• A. Kanareykin
  Euclid TechLabs, LLC, Solon, Ohio
• S. Kazakov
  KEK, Ibaraki
• E. Nenasheva
  Ceramics Ltd., St. Petersburg

A fast, electrically-controlled phase shifter is described with parameters suitable for operation with the SC acceleration structure of the electron cooling system of Relativistic Heavy Ion Collider (RHIC) at BNL. The phase shifter is a key element of the external RF vector modulator that is capable of fast tuning of the cavities against microphonics, Lorentz force and beam instabilities in a way that can possibly lead to an order of magnitude reduction in the required RF power. The phase shifter is based on a shortened low-impendence coaxial line with ferroelectric rings. The dielectric constant of the ferroelectric rings is altered by applying a 4.2 kV voltage that provides an RF phase shift from 0 to 180 deg.

• G. H. Biallas
  
• N. T. Belcher
  The College of William and Mary, Williamsburg
• D. Douglas, T. Hiatt, K. Jordan
  Jefferson Lab, Newport News, Virginia

Two styles of Panofsky Quadrupoles with integral corrector dipole windings are in use in the electron beam line of the Free Electron Laser at Jefferson Lab. We combined the functions into single magnets, adding hundreds of Gauss-cm dipole corrector capability to existing quadrupoles because space is at a premium along the beam line. Superposing high quality dipole corrector field on a high quality, weak (600 to 1'000 Gauss) quadrupole is possible because the parallel slab iron yoke of the Panofsky Quadrupole acts as a window frame style dipole yoke. The dipole field is formed when two current sources, designed and made at Jlab, add and subtract current from the two opposite quadrupole current sheet windings parallel to the dipole field direction. The current sources also drive auxiliary coils at the yoke's inner corners that improve the dipole field. Magnet measurements yielded the control system field maps that characterize the two types of fields. Details of field analysis using OPERA, construction methods, wiring details, magnet measurements and the current sources are presented.

• G. Cheng
  
• E. Daly, R. A. Rimmer, M. Stirbet, L. Vogel, H. Wang, K. Wilson
  Jefferson Lab, Newport News, Virginia

For an ongoing high current cryomodule project, a total of 5 higher order mode (HOM) absorbers are required per cavity. The load is designed to absorb RF heat induced by HOMs in a 748.5MHz cavity. Each load is targeted at a 4 kW dissipation capability. Embedded cooling channels are employed to remove the heat generated in ceramic tiles and by surface losses on the waveguide walls. A sequentially coupled RF-thermal-structural analysis was developed in ANSYS to optimize the HOM load design. Frequency dependent dielectric material properties measured from samples and RF power spectrum calculated by the beam-cavity interaction codes were considered. The coupled field analysis capability of ANSYS avoided mapping of results between separate RF and thermal/structural simulation codes. For verification purposes, RF results obtained from ANSYS were compared to those from MAFIA, HFSS, and Microwave Studio. Good agreement was reached and this confirms that multiple-field coupled analysis is a desirable choice in analysis of HOM loads. Similar analysis could be performed on other particle accelerator components where distributed RF heating and surface current induced losses are inevitable.

• J. Musson
  
• J. M. Grames, J. Hansknecht, R. Kazimi, M. Poelker
  Jefferson Lab, Newport News, Virginia

Recent upgrades to the CEBAF Polarized Source include a fiber-based seed laser, capable of producing pulses with frequency centered at 499 MHz. Combined with the existing three-beam Chopper, an aliasing, or beat frequency technique is used to produce long time intervals between individual electron microbunches (tens of nanoseconds) by merely varying the nominal 499 MHz drive laser frequency by <20%. This RF Laser modulator uses a divider and heterodyne scheme to maintain coherence with the accelerator Master Oscillator, while providing delay resolution in increments of 2ns. Laser repetition frequencies producing bunch repetition rates between 20 MHz and 100 MHz are demonstrated, resulting in time delays between 50 and 10 ns, respectively. Also, possible uses for such a beam are discussed as well as intended development. Authored by Jefferson Science Associates, LLC under U. S. DOE Contract No. DE-AC05-06OR23177

• H. Ma
  
• M. S. Champion, M. T. Crofford, T. W. Hardek, K.-U. Kasemir, M. F. Piller, Y. Zhang
  ORNL, Oak Ridge, Tennessee

The proposed upgrade plan for RF control of the Spallation Neutron Source (SNS) accumulator ring requires that the new digital field control module (FCM) support both the conventional narrow-band feed forward control and a new beam-based feed forward control. Both are necessary for compensating the heavy beam loading in SNS ring. The ring FCM also has the integrated control and monitoring features for the cavity bias, cavity resonance, and tetrode grid boost. A user-friendly Epics GUI for all these FCM functionalities is also a part of the requirement. The ring FCM under development is being implemented on the hardware of the proven FCM of SNS Linac. Both the controller architecture and the design code of the digital hardware for the Linac system will be largely reused in the ring system.

• M. P. McCarthy
  
• D. E. Anderson, I. E. Campisi, F. Casagrande, R. I. Cutler, G. W. Dodson, J. Galambos, D. P. Gurd, Y. W. Kang, K.-U. Kasemir, S.-H. Kim, H. Ma, B. W. Riemer, J. P. Schubert, M. P. Stockli
  ORNL, Oak Ridge, Tennessee

Increasing the pulse repetition rate (PRR) of the SNS Linac to its designed maximum of 60 Hz to provide 1.4 MW of beam on target is in progress. Operation above 60 Hz in the future to provide beam to a second target is also being considered. Increasing the PRR to 80 Hz would allow the additional pulses to be diverted to a second target. This paper discusses the impact of increasing the PRR on the SNS infrastructure including Radio Frequency (RF) systems and structures, the ion source, cryogenics, controls and the target.

• A. K. Polisetti
  
• S. Assadi, C. Deibele, J. C. Patterson
  ORNL, Oak Ridge, Tennessee
• R. C. McCrady
  LANL, Los Alamos, New Mexico
• M. J. Schulte
  UW-Madison, Madison, Wisconsin

• R. W. Shaw
  
• M. J. Borden, T. Spickermann
  LANL, Los Alamos, New Mexico
• C. S. Feigerle
  University of Tennessee, Knoxville, Tennessee
• Y. Irie
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• M. A. Plum, L. L. Wilson
  ORNL, Oak Ridge, Tennessee
• I. Sugai, A. Takagi
  KEK, Ibaraki

Diamond stripping foils are under development for the SNS. Free-standing, flat 350 microgram/cm² foils as large as 17 x 25 mm have been prepared. These nano-textured polycrystalline foils are grown by microwave plasma-assisted chemical vapor deposition in a corrugated format to maintain their flatness. They are mechanically supported on a single edge by a residual portion of their silicon growth substrate; typical fine foil supporting wires are not required for diamond foils. Six foils were mounted on the SNS foil changer in early 2006 and have performed well in commissioning experiments at reduced operating power. A diamond foil was used during a recent experiment where 12 microCoulombs of protons, approximately 40% of the design value, were stored in the ring. A few diamond foils have been tested at LANSCE/PSR, where one foil was in service for a period of five months (820 Coulombs of integrated injected charge) before it was replaced. Diamond foils have also been tested in Japan at KEK (650 keV H-) where their lifetimes slightly surpassed those of evaporated carbon foils, but fell short of those for Sugai's new hybrid boron carbon (HBC) foils.

• D. Stout
  
• S. Assadi, I. E. Campisi, F. Casagrande, M. T. Crofford, W. R. DeVan, X. Geng, T. W. Hardek, S. Henderson, M. P. Howell, Y. W. Kang, W. C. Stone, W. H. Strong, D. C. Williams, P. A. Wright
  ORNL, Oak Ridge, Tennessee

The SNS project was completed with only limited SRF facilities installed as part of the project, namely a 5 MW, 805 MHz RF test stand, a fundamental power coupler processing system, a concrete test cave shell, and temporary cleaning/assembly facilities. A concerted effort has been initiated to install the infrastructure and equipment necessary to maintain and repair the superconducting Linac, and to support power upgrade R&D. Installation of a Class10/100/10,000 cleanroom and outfitting of the test cave with RF, vacuum, controls, personnel protection and cryogenics systems is underway. A horizontal cryostat, which can house a helium vessel/cavity and fundamental power coupler for full power, pulsed testing, is being procured. Equipment for cryomodule assembly/disassembly and cavity processing also is being designed. This effort, while derived from the experience of the SRF community, will provide a unique high power test capability as well as long term maintenance capabilities. This paper presents the current status and the future plans for the SNS SRF facilities.

• J.-G. Wang
  

3D computing simulations have been performed to study the magnetic field distribution of the SNS ring extraction Lambertson septum magnet. The magnetic field for extracted beams is fully characterized in all the aspects. The stray field on the circulating beam line and the effect of a shielding box up-stream and a shielding cap down-stream is investigated. In addition, the magnetic interference between the Lambertson and an adjacent quadrupole has been studied. The simulations have provided valuable information for the SNS ring commissioning and operation. This paper reports our simulation techniques and the major results.

• D. C. Williams
  
• X. Geng, P. Ladd
  ORNL, Oak Ridge, Tennessee

The superconducting linac of the Spallation Neutron Source (SNS) has 23 cryomodules each of which incorporate either 3 or 4 niobium cavities. These cavities are submerged in a bath of liquid helium and maintained at an operating temperature of ~ 2K. This bath is surrounded by heat shields and a multilayer blanket within the cryomodule shell. The pressure in this area needs to be maintained at <5·10^-5 torr to limit heat leak due to gas convection. Some cryomodules have developed helium leaks into this vacuum cavity and now need to be actively pumped. This paper provides an overview of the Insulating Vacuum System (IVS) that has been installed for this purpose.

• A. Grassellino
  
• J. K. Keung, F. M. Newcomer
  University of Pennsylvania, Philadelphia, Pennsylvania
• N. Lockyer
  TRIUMF, Vancouver

• A. Kanareykin
  
• A. Dedyk
  Eltech University, St. Petersburg
• E. Nenasheva
  Ceramics Ltd., St. Petersburg
• V. P. Yakovlev
  Omega-P, Inc., New Haven, Connecticut

We present recent results on development of a BST(M) ferroelectric composition synthesized for use in advanced technology components for X-band and Ka-band RF systems in high gradient accelerators and offer significant advantages for high power RF manipulation in the 300-1'000 MHz frequency range as well. These low loss ferroelectric materials can be used as key elements of both tuning and phase shifting components. We have identified BST ferroelectric-oxide compounds as suitable materials for a fast electrically-controlled 700 MHz, 50 kW tuner for ERL (BNL) and for high-power fast RF phase shifters to be used for SNS vector modulation applications. We have also developed large diameter (11 cm) BST(M)-based ferroelectric rings planned to be used at high average power (10 kW range) for L-band phase-shifters intended for the ILC. This phase shifter will allow coupling adjustment and control of the power consumption during the process of SC cavity filling.

• D. Bruno
  
• G. Ganetis, W. Louie, J. Sandberg
  BNL, Upton, Long Island, New York

The two rings in the Relativistic Heavy Ion Collider (RHIC) were originally constructed with 24 sextupole power supplies, 12 for each ring. Before the start of Run 7, 24 new sextupole power supplies were installed, 12 for each ring. Individual sextupole power supplies are now each connected to six sextupole magnets. A superconducting snake magnet and power supplies were installed in the Alternating Gradient Synchrotron (AGS) and commissioned during RHIC Run 5, and used operationally in RHIC Run 6. The power supply technology, connections, control systems and interfacing with the Quench Protection system for both these systems will be presented.

• D. Bruno
  
• G. Ganetis, G. Heppner, W. Louie, J. Sandberg, C. Schultheiss
  BNL, Upton, Long Island, New York

The two rings in the Relativistic Heavy Ion Collider (RHIC) require a total of 933 power supplies to supply current to highly inductive superconducting magnets. Failure statistics for the RHIC power supplies will be presented for the last three RHIC runs. The failures of the power supplies will be analyzed. The statistics associated with the power supply failures will be presented. Comparisons of the failure statistics for the last three RHIC runs will be shown. Improvements that have increased power supply availability will be discussed. Further improvements to increase the availability of the power supplies will also be discussed.

• P. He
  
• M. Anerella, S. Aydin, G. Ganetis, M. Harrison, A. K. Jain, B. Parker
  BNL, Upton, Long Island, New York

The conceptual design of compact superconducting magnets for the International Linear Collider final focus is presently under development at BNL. A primary concern in using superconducting quadrupoles is the potential for inducing additional vibrations from cryogenic operation. We have employed a Laser Doppler Vibrometer system to measure the vibrations at resolutions ~1 nm (at frequencies above ~8 Hz) in a spare RHIC quadrupole coldmass under cryogenic conditions. Some preliminary results of these studies were presented at the Nanobeam 2005 workshop*. These results were limited in resolution due to a rather large motion of the laser head itself. As a first step towards improving the measurement quality, an actively stabilized isolation table was used to reduce the motion of the laser holder. The improved set-up will be described, and vibration spectra measured at cryogenic temperatures, both with and without helium flow, will be presented.

*A. Jain, et al., Nanobeam 2005, Kyoto, Japan, Oct.17-21, 2005; paper WG2d-05; available at http://wwwal.kuicr.kyoto-u.ac.jp/NanoBM .

• H. G. Kirk
  
• J. R.J. Bennett
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon
• O. Caretta, P. Loveridge
  STFC/RAL, Chilton, Didcot, Oxon
• A. J. Carroll, V. B. Graves, P. T. Spampinato
  ORNL, Oak Ridge, Tennessee
• I. Efthymiopoulos, A. Fabich, F. Haug, J. Lettry, M. Palm
  CERN, Geneva
• K. T. McDonald
  PU, Princeton, New Jersey
• N. V. Mokhov, S. I. Striganov
  Fermilab, Batavia, Illinois

• C. J. Liaw
  
• R. Schroeder, R. Sikora
  BNL, Upton, Long Island, New York

• I. Marneris
  
• S. V. Badea, R. Bonati, T. Roser, J. Sandberg
  BNL, Upton, Long Island, New York

The Brookhaven AGS Main Magnet Power Supply (MMPS) is a thyristor control supply rated at 5500 Amps, ±9000 Volts. The peak magnet power is 50 MWatts. The power supply is fed from a motor/generator manufactured by Siemens. The generator is 3 phase 7500 Volts rated at 50 MVA. The peak power requirements come from the stored energy in the rotor of the motor/generator. The motor generator is about 45 years old and Siemens is not manufacturing similar machines in the future. We are therefore investigating different ways of storing energy for future AGS MMPS operation. This paper will present simulations of a power supply where energy is stored in capacitor banks. Two dc to dc converters will be presented. The switching elements would be IGCT's made by ABB. The simulation program used is called PSIM Version 6.1. The control system of the power supply will also be presented. The average power from the Long Island Power Authority (LIPA) into the power supply will be kept constant during the pulsing of the magnets at ±50 MW. The reactive power will also be kept constant below 1.5 MVAR. Waveforms will be presented.

• W. Meng
  
• G. Ganetis, A. K. Jain, D. Kayran, V. Litvinenko, C. Longo, G. J. Mahler, E. Pozdeyev, J. E. Tuozzolo
  BNL, Upton, Long Island, New York

In this paper we describe unique features of magnets for R&D ERL, which is under construction in Collider-Accelerator Department, BNL. The R&D ERL serves as a test-bed future BNL ERLs, such as electron-cooler-ERL for RHIC and 20 GeV ERL for future electron-hadron, eRHIC. We present selected designs of various dipole and quadrupole magnets, which are used in Z-bend merging systems and the returning loop, 3-D simulations of the fields in these magnets, particle tracking and analysis of magnet's influence on the beam parameters. We discuss an uncommon method of setting requirements on the quality of magnetic field and transferring them into measurable parameters as well as into manufacturing tolerances. We compare selected simulation with results magnetic measurements.

• J. Niedziela
  
• W. Fu, M. Harvey, G. J. Marr, T. Satogata, V. Schoefer
  BNL, Upton, Long Island, New York

Centralization of information pertaining to accelerators can benefit accelerator operation and development. Further, retention and the changeable nature of information present challenges to accelerator operation, particularly in instances of turnover. MediaWiki is free, server-based software licensed under the GNU General Public License that uses PHP to render data stored in a MySQL database as interactive web documents, and is designed to produce collaborative documentation. The MediaWiki engine was implemented at BNL, and this paper describes the first year of use by the Operations, Controls, and RF groups at the Collider-Accelerator Department, including code modifications, common practices, and the use of the wiki as a training tool.

• I. Pinayev
  

• N. Tsoupas
  
• R. Heese, R. Meir, I. Pinayev, J. Rose, T. V. Shaftan, C. Stelmach
  BNL, Upton, Long Island, New York

The proposed NSLS II light source* to be built at Brookhaven National Laboratory utilizes a LINAC and a Booster with a Storage-ring which share the same tunnel, but at different horizontal planes. The Booster which accepts beam from the LINAC, accelerates the electron beam to an energy of 3.0 GeV and the beam is extracted to the Booster_to_Storage_Ring(BtS) transport line. The BtS line transports the beam and injects it into the Storage ring . In order to facilitate the design of the BtS transfer line, the line has been partitioned in three sections which can be considered as independent. The function of each the three sections will be discussed in details and the procedure for the design of the BtS line and other details about the optics and the magnetic elements of the line will be presented in the paper. The LINAC to Booster beam transfer line will also be discussed.

*NSLS II CDR BNL

• P. I. Pavlishin
  
• M. Babzien, I. Pogorelsky, D. Stolyarov, V. Yakimenko
  BNL, Upton, Long Island, New York
• M. S. Zolotorev
  LBNL, Berkeley, California

Optical stochastic cooling for the Relativistic Heavy Ion Collider (RHIC) based on optical parametric amplification was proposed by M. Babzien et al., Phys. Rev. ST Accel. Beams v.7, 012801, (2004). According to this proposal a CdGeAs2 nonlinear crystal is used as an active medium for the optical parametric amplifier because of extremely large nonlinear coefficient, wide transparency range, and possibility to be phase matched over the required spectral range. We discuss experimental results of the parametric amplifier gain and coherency for the conditions applicable to optical stochastic cooling for RHIC.

• W. Zhang
  
• I. Marneris, J. Sandberg
  BNL, Upton, Long Island, New York

Large accelerator main magnet system consists of hundreds, even thousands, of dipole magnets. They are linked together under selected configurations to provide highly uniform dipole fields when powered. Distributed capacitance, insulation resistance, coil resistance, magnet inductance, and coupling inductance of upper and lower pancakes make each magnet a complex network. When all dipole magnets are chained together in a circle, they become a coupled pair of very high order complex ladder networks. In this study, a network of more than thousand inductive, capacitive or resistive elements are used to model an actual system. The circuit is a large scale network. Its equivalent polynomial form has several hundred degrees. Analysis of this high order circuit and simulation of the response of any or all components is often computationally infeasible. We present methods to use frequency decomposition approach to effectively simulate and analyze magnet configuration and power supply topologies.

• W. Zhang
  
• I. Marneris, J. Sandberg
  BNL, Upton, Long Island, New York

A main magnet chain forms a pair of transmission lines. Pulse-reflection-caused voltage and current differentiation throughout the magnet chain can have adverse effect on main magnet field quality. This effect is associated with magnet system configuration, coupling efficiency, and parasitic parameters. A better understanding of this phenomenon will help us in new design and existing system upgrade. In this paper, we exam the transmission line effect due to different input functions as well as configuration, coupling, and other parameters.