| Paper | Title | Page |
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| TUPB01 | A Fiber Profile Monitor for low Beam Intensities. | 51 |
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| A scintillating Fiber Profile Monitor (FPM) has been prototyped, built and tested for the new low intensity Meson Test (M-Test) beamline at Fermilab. The beamline has the following beam parameters: E = 1-120 GeV, I from a few hundreds to 700,000 particles/spill, and the spill length is 4.5 seconds. Segmented Wire Ion Chambers (SWICs) and Proportional Wire Chambers (PWCs) do not display the beam profile accurately below about 10,000 particles. For the prototype FPM detector a modified SWIC vacuum can was used. An (x, y) array of fibers replaced the chamber containing windows, gas, and AuW wires soldered on a ceramic substrate. The fibers were purchased from Saint Gobain and are of the type BCF-12 MC, 420 nm wavelength They have a diameter of 0.75 mm and are coated with black EMA for optical isolation. The 64 channel fibers are positioned and then epoxied in a vacuum feed-thru “cookie” to match a Burle 64 channel multianode microchannel plate PMT of the type Planacon # 85011-501. The gain of the Planacon PMT is 800,000 at –2400 Volts. Unlike SWICs or PWCs, this device will allow for vacuum continuity. Comparative data with PWCs will be presented. | ||
| TUPB02 | Stripline Transversal Filter Techniques For Sub-Picosecond Bunch Timing Measurements | 54 |
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Measurement of time of arrival of a particle bunch is a fundamental beam diagnostic. The PEP-II/ALS/BESSY/PLS longitudinal feedback systems use a planar stripline circuit structure to convert a 30 ps beam BPM impulse signal into a 4 cycle tone burst at the 6th harmonic of the accelerator RF frequency (roughly 3 GHz). A phase-detection technique is used to measure the arrival time of these BPM impulses with 180 fs rms single-shot resolution (out of a 330 ps dynamic range). Scaled in frequency, this approach is directly applicable to LCLS, FEL and other sub-fs regime pulse and timing measurements. The transversal circuit structure is applicable to measurement of microbunches or closely spaced bunches (the PEP-II examples make independent measurements at 2 nS bunch spacing) and opens up some new diagnostic and control possibilities. This paper reviews the principles of the technique, and uses data from PEP-II operations to predict the limits of performance of this measurement scheme for arrival phase measurement. These predictions are compared with results in the literature from electro-optic high-resolution sub-picosecond beam timing and phasing diagnostics.
* Briggs, et al, "Prompt Bunch by Bunch Synchrotron Oscillation Detection by a Fast Phase Measurement", Proceedings of the IEEE Particle Accelerator Conference, 5/91, 1404-1406 |
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| TUPB03 | Precision Beam Position Monitor for EUROTeV | 57 |
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| For future linear colliders (ILC, CLIC) a new Precision Beam Position Monitor (PBPM) has been designed within the framework of EUROTeV. The design goals are a resolution of 100nm and an overall precision of 10μm, in a circular vacuum chamber of 6mm in diameter. The required bandwidth is 100 kHz-30MHz. The PBPM is based on an inductive type BPM which measures the image current in four electrodes located outside the vacuum tube, from which the position is derived. In this paper, the design of the PBPM is presented together with the first bench measurements, where twoμmovers and a rotational stage, installed on a vibration damped table, have been used to characterize the PBPM. | ||
| TUPB04 | BPM detectors upgrade for the ELETTRA Fast Orbit Feedback | 60 |
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| The project of a fast feedback system to stabilize the closed orbit of the Elettra storage ring is in an advanced stage. All of the existing BPMs have been equipped with new digital detectors in order to provide precise and high-rate position measurements to the feedback system. A new beam position interlock system has also been installed to protect the vacuum chamber from synchrotron radiation produced by insertion devices. This paper presents features and performance of the new orbit measurement system and reports some preliminary results of the feedback commissioning. | ||
| TUPB05 | A Tagged Photon Source at the Frascati Beam-Test Facility (BTF) | 63 |
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The DAΦNE Beam Test Facility, operating at the Frascati National Laboratory of INFN, provides electron or positron beams with tunable energy from 25 MeV to 750 MeV, while the intensity can be varied from 1010/pulse@ 0-50Hz down to a single particle per pulse. Recently a tagged photon source has been designed, built and tested. The photons are produced by bremsstrahlung of electrons with a maximum momentum of 750 MeV/c on a pair of x-y silicon micro-strip chambers(1), placed before the last bending magnet of the BTF transfer line. The photons are tagged in energy using the same bending dipole, whose internal walls have been covered by 10 modules of silicon micro-strip detectors. Depending on the energy loss in the photon production, the electrons impinge on a different strip once the dipole current has been set to the nominal value. The correlation between the directions on the electron measured by silicon chambers and the impinging position on the tagging module inside the magnet allows the tagging on the photons. In this paper the configuration of the system is presented with some results obtained during the latest test-beams.
(1)Profile monitors for wide multiplicity range electron beams. Proceeding DIPAC 2005 Lyon, France,pp166-168. |
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| TUPB06 | First Tests with the Sis18 Digital BPM System* | 66 |
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In this paper we describe new approaches for BPM (Beam Position Monitor) measurements, needed in hadron accelerators which have strongly varying beam parameters, such as intensity, accelerating frequency and bunch length. After the data collection and offline evaluation in 2005, first FPGA implementations of algorithms were completed in 2006 and tested at SIS18 and CERN PS. Main aspect of the first tests was the proof of concept in terms of online calculation feasibility. This includes online calculation of the needed integration windows as well as the baseline restoration algorithms. The realization of the hardware and the data handling are discussed. Least squares techniques were used for parametric fitting to gain bunch signal properties which can be used to monitor beam position.
*Founded by EU FP6-Design Studies |
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| TUPB07 | Electric -In-Air-X-Ray- Detectors for high Resolution Vertical Beam Position Measurement at the ESRF | 69 |
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| The tiny fraction of the very hard X-rays that fully penetrate the dipole absorber structure and enter the free air space behind it can be detected in different ways to yield precise information on the vertical characteristics of the electron beam. In addition to a system of imaging detectors to measure the emittance, a 2nd detector type was developed that yields a direct electric signal. It consists of a high-Z blade in conjuction with a small In-Air ionization slot that generates a direct strong electric signal allowing for nanometer resolution measurements of vertical beam motion in a spectrum upto 1KHz. The high resolution performance of this detector type is explained by the fact that it touches the heart and center of the beam whereas other devices (X-BPMs or e-BPMs) have to work on the edges or tails of the beam or feel the beam indirectly by wall-current pick-ups. The results obtained with prototypes will be presented together with the prospects of an installation of 8 units in 2007. The intrinsic advantages of this In-Air detector like costs and simplicity, thanks to a total absence of cooling and UHV requirements, will be emphasized. | ||
| TUPB08 | Measurement of Vertical Emittance with a system of Six -In-Air-X-Ray- Projection Monitors at the ESRF | 72 |
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| The ESRF Storage Ring is now equiped with a system of 5 independent imaging monitors that measure the vertical emittance of the electron beam in the middle of the bending magnet through the very hard X-rays that fully traverse the 40mm thick Copper dipole absorbers and enter the free air space behind it. The tiny power that leaks through the absorber, and carried by X-rays of ~160KeV of very narrow vertical divergence, is simply projected onto a scintillator screen at ~1.8m from the source-point and imaged by optics & camera. These inexpensive and compact detectors are fully operated in free air and can be easily installed and maintained without any vacuum intervention. They now work reliably in routine fashion and have demonstrated their high precision and resolution of the ESRF’s vertical emittance. These results will be presented in this paper together with the underlying principles of the projection detector, aswell as the practical design solutions applied to obtain the high spatial resolution, to make the system resistant to the hostile radiation environment behind the absorber, and to reduce its sensitivity to stray signals generated at this point. | ||
| TUPB09 | Digital Beam Trajectory and Orbit System, for the CERN Proton Synchrotron | 75 |
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| A new trajectory and orbit measurement system using fast signal sampling and digital signal processing in an FPGA is proposed for the CERN PS. The system uses a constant sampling frequency while the beam revolution frequency changes during acceleration. Synchronization with the beam is accomplished through a numerical PLL algorithm. This algorithm is also capable of treating RF gymnastics like bunch splitting or batch compression with the help of external timing signals. Baseline correction as well as position calculation is provided in the FPGA code as well. After having implemented the algorithms in C and MatLab and tested them with data from a test run at the PS they have now been implemented in the FPGA for online use. Results of measurements on a single beam position monitor in the CERN PS and the SIS-18 at GSI will be presented. | ||
| TUPB10 | Proposed Beam Position and Phase Measurements for the LANSCE Linac | 78 |
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| There is presently an ongoing effort to develop beam position and phase measurements for the Los Alamos Neutron Science Center (LANSCE) linac associated with an improvement project known as the LANSCE Refurbishment. This non-interceptive measurement’s purpose is to provide both beam measurements of phase for determining rf-cavity phase and amplitude set points, and position measurements for determining the 805-MHz linac input transverse position and trajectories. The measurement components consist of a four-electrode beam position and phase monitor (BPPM), a cable plant that transports the 201.25-MHz signals, electronics capable of detecting phase and amplitude signals, and associated software that communicates with a mature LANSCE control system. This paper describes measurement requirements, proposed beam line device and some initial device bench measurements, initial designs of the associated electronics, and some of the difficulties developing these beam measurements in an operational facility. | ||
| TUPB11 | A laserwire beam profile measuring device for the RAL Front End Test Stand | 81 |
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| The Front End Test Stand at the Rutherford Appleton Laboratory (RAL) is being developed to demonstrate a chopped H- beam of 60 mA at 3 MeV with 50 pps and sufficiently high beam quality for future high-powered proton accelerators. As such, it requires a suite of diagnostic instruments to provide detailed measurements of the ion beam. Due to the high beam brightness and a desire to be able to have online instrumentation, a series of non-intrusive and non-destructive diagnostics based on laser-detachment are being developed. The progress that has been made towards construction of a laserwire instrument that can measure the beam profile at an arbitrary angle are described. In particular, the principle behind the instrument, the simulation and design of it and the vacuum vessel in which it will be mounted are given. In addition, the reconstruction software that will be used to reconstruct the 2D transverse beam density distribution from the profiles of the beam is described. | ||
| TUPB12 | BPMs for the XFEL Cryo module | 84 |
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| The European XFEL is based on superconducting accelerator technology developed in the context of the TESLA collaboration. The accelerator itself consist of cryo modules each equipped with 8 cavities, followed by a quadrupole/steerer package, a BPM and a HOM absorber. This contribution will present the layout of the BPM system for the cryo modules, describing the monitor itself, its integration into the cryo module. Additionally, the electronics concept will be discussed. Finally the results of beam measurements at FLASH using prototypes of the monitor and the electronics will be presented. | ||
| TUPB13 | Design Considerations of a Spectrometer Dipole Magnet for the Photo Injector Test facility at DESY in Zeuthen (PITZ) | 87 |
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| The goal of the Photoinjector Test Facility at DESY in Zeuthen (PITZ) is to test and optimise electron guns for FELs like FLASH and XFEL at DESY in Hamburg and study emittance conservation by using a matched booster cavity. The physical specifications of a second spectrometer for measurements after the booster cavity at the beam momentum range from 4 to 40 MeV/c will be described. It will be used for measurements of the momentum distribution and the longitudinal phase space using two methods. The first method combines the dipole magnet with a RF transverse deflecting cavity, the second combines it with a Cherenkov radiator whose light is measured by a streak camera. Especially the first method is aiming for a good resolution in order to determine slice momentum spread. The design has to meet the demands of all these techniques for a measurement with high resolution and a bunch train containing 7200 pulses of 1nC charge and a repetition rate of 10Hz. Since there is not enough space for a separate beam dump after the dispersive section the beam has to be transported to the dump of the main beamline. | ||
| TUPB14 | Test of a Silicon Photomultiplier for Ionization Profile Monitor Applications | 90 |
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| A sample of SiPM (silicon photomultiplier) has been tested as an elementary light detector for accelerated beam fast profile evolution observation by using it in residual gas ionization profile monitors. A noise, sensitivity, dynamic range and timing parameters tests of SiPM were performed. A procedure of the data acquisition and following signal reconstruction is discussed. A special attention has been paid to the fine time resolution counting mode with single photon detection. A dedicated signal normalizing and time-to-digit converter design was prototyped and tested. In addition some different modes of operation and optical schemes are discussed in this paper. It is shown that fast optical detectors like SiPMs also could be used for high performance profile measurements with spatial resolution compatible with CCD sensors. | ||
| TUPB15 | Beam Position Monitors Using a Re-entrant Cavity | 93 |
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| Two designs of high resolution beam position monitor, based on a radiofrequency re-entrant cavity, are developed at CEA/Saclay. The main radio-frequency modes excited by the beam in the cavity are monopole and dipole modes. The first monitor is developed in the framework of the European CARE/SRF program. It is designed to work at cryogenic temperature, in a clean environment and to get a high resolution and the possibility to perform bunch to bunch measurements. Two prototypes with a large aperture (78 mm) are installed in the FLASH linac, at DESY. The other design with an aperture of 18 mm and a large frequency separation between monopole and dipole modes, as well as a low loop exposure to the electric fields is developed for the CTF3 probe beam CALIFES at CERN. It is operated in single bunch and multi-bunches. This paper presents the mechanical and signal processing designs of both systems. Simulation and experimental results will be discussed. | ||
| TUPB16 | Optimization of the Linear-cut Beam Position Monitors Based on Finite Element Methods | 96 |
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| This contribution presents simulations of the Beam Position Monitors (BPMs) for the FAIR project that were performed using CST Studio Suite 2006B. The linear-cut BPMs based on a metal-coated ceramics were considered as the only solution that meets the required mechanical stability under cryogenic conditions. The essential BPM features like position sensitivity or linearity of position determination were compared for two geometries. In these geometries, in both cases based on elliptically shaped ceramic pipe, the vertical and horizontal electrode pairs were either mounted subsequently in series or were spirally shaped and combined alternatively within one unit. It is shown that optimization of BPM design increases position sensitivity by more than a factor of two. The frequency dependence of the position sensitivity and an offset of electrical center of BPM in respect to its geometrical center were analyzed in the bandwidth of 200 MHz. In a frequency range up to 100 MHz (i.e. typical for the BPM applications) calculated variations of the displacement sensitivity are smaller than 1%; the careful design of a guard ring configuration allows keeping the offset consistent with zero. | ||
| TUPB17 | Diagnostics for the CTF3 Probe Beam Linac CALIFES | 99 |
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| CALIFES is the probe beam linac developed by the CEA/DAPNIA and LAL in the frame of the CFT3 collaboration at CERN. Its objective is to "mimic" the main beam of CLIC in order to measure the performances of the 30 GHz CLIC accelerating structures. The requirements on the bunched electron beam in terms of emittance, energy spread and bunch-length are quite stringent and lead to use the most advanced techniques: laser triggered photo-injector, velocity bunching, RF pulse compression… In order to tune the machine and assess its performances before delivering the beam to the test stand a complete suit of diagnostics is foreseen including charge monitor, beam position and video profile monitors, deflecting cavity, RF pick-up and analysis dipole. All these diagnostics will be interfaced to the CERN command/control network. A special effort has been done on the Video Profile Monitors that make use of both scintillation and OTR (Optical Transition Radiation) screens and are fitted with 2 optical magnifications to fulfill field of view and resolution performances (<20μm). Their performances can be checked via an integrated resolution pattern. | ||
| TUPB18 | Measurement of Electron Beam Charge in the ESRF Accelerator Complex for Absolute and Injection Efficency Measurements Using an FPGA Based Digital BPM Electronics | 102 |
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| A Beam Position Monitor (BPM) using Virtex II pro FPGAs (‘Libera Electron’ from Instrumentation Technologies) has been programmed with an alternative firmware in order to determine the charge by measuring integrated RF amplitude, over an adjustable time window, of signals from 4 strip lines. These strip lines are located on the transfer line from the linac to the booster, on the booster ring, on the transfer line from the booster to the storage ring and on the storage ring. By calibrating the RF loss in all the cables, knowing the geometry of the strip lines and using the crossbar switching before the 4 RF ADCs of the Libera, the charge/current can be compared in order to determine the efficiency of transfer at various locations during injection. Since the current in the storage ring is known to a high accuracy using a parametric current transformer (from Bergoz Instrumentation), the absolute charge can be determined at all locations. | ||
| TUPB19 | Signal Level Calculation for the PETRA-III Beam Position Monitor System | 105 |
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| Starting mid 2007 the PETRA accelerator at DESY in Hamburg (Germany) will be converted into a new high brilliance light source. For measurement and control of the PETRA-III closed orbit with a resolution of better than 1 micrometer (rms) it is planned to install about 220 button type beam position monitors (BPMs). To guarantee a good performance of the BPM electronics, the button signals have to meet several criteria in time and frequency domain. Therefore signal levels for the monitor types included for installation have been estimated. The results of these calculations will be presented together with a comparison of monitor signals from accelerators in operation, and the expected position resolution will be discussed for a certain type of BPM electronics. | ||
| TUPB20 | Large Horizontal Aperture BPM and Precision Bunch Arrival Pickup | 108 |
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| The large horizontal aperture chicane BPM and the precision bunch arrival monitor at FLASH will be important tools to stabilize the arrival-time of the beam at the end of the linac. The pickups for these monitors will be paired with front-ends that sample the zero-crossing of the beam transient through the use of electro-optical modulators and sub-picosecond-long laser pulses delivered by the master-laser oscillator. The design of pickups for this front-end requires the consideration of the beam transient shape as well as the amplitude. Simulations and oscilloscope traces from pickups that use or will use the EOM based phase measurement and the expected limitations and benefits of each pickup are presented. In particular, the design for a 5 um resolution BPM with a 10 cm horizontal aperture is demonstrated in terms of its capability to measure the beam energy and its sensitivity to the shape and orientation of the beam. | ||
| TUPB21 | Experience with Libera Beam Position Monitors at DELTA | 111 |
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| Libera beam posiotion monitor electronics have been installed at the electron storage ring Delta in order to extend the capabilities of the BPM system to turn-by-turn orbit measurements. This report covers the integration of Liberas into the beam diagnostics infrastructure at DELTA and its control system EPICS. Prior to their application in user runs the devices have undergone characterization measurements in a BPM teststand and during machine runs for accelerator physics. Results of these measurements are compared to measurements with DELTAs standard BPM electronics. The necessary clock and trigger signals are provided by a low-cost signal distribution device developed at DELTA. | ||
| TUPB22 | Renewal of BPM Electronics of SPring-8 Storage Ring | 114 |
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| The signal processing electronics of the SPring-8 Storage Ring BPM were replaced during the summer shutdown period of the year 2006. Since then, the new electronics have been put into operation for user experiment runs. The purpose of the renewal was to upgrade the performance of the position measurement system, i.e. the position resolution, speed of the measurement, etc. The position resolution of them in the real operation condition was estimated by using the stored beam in the same condition as the operations for user experiments, in the following way. The closed orbit distortions (COD) were repeatedly measured with the interval of 4 seconds in order to obtain the root mean square (r.m.s.) values of differences between two consecutive measurements. Since the obtained r.m.s. values included the intrinsic resolution of the position measurement system and the effect of the beam motion, the effect of the beam motion was separated from the obtained r.m.s. data by assuming that the effect of the beam motion was proportional to the betatron function values at the BPM locations. As a result, the intrinsic resolution was estimated to be 0.1μmeters. | ||
| TUPB23 | Design Considerations for Phase Space Tomography Diagnostics at the PITZ Facility | 117 |
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| A major goal of the Photo Injector Test Facility at DESY in Zeuthen (PITZ) is to build and to optimise high brightness electron sources for SASE FELs where the detailed knowledge of the phase-space density distribution of the electron beam is very important. The current upgrade of the machine includes a diagnostic section suitable for transverse phase space tomography and multiscreen emittance measurement. The designed module should be capable of operation over a range of beam momenta between 15 and 40MeV/c. It mainly consists of four observation screens with three FODO cells in between them. An upstream section of a number quadrupoles is used to match the electron beam Twiss parameters to the tomography section. The design considerations of the tomography section and results from numerical simulations will be presented in this contribution. | ||
| TUPB24 | First Results from the LEIR Ionisation Profile Monitors | 120 |
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| The role of the Low Energy Ion Ring, LEIR is to transform long pulses of lead ions from the Linac 3 to short dense bunches for transfer to the LHC. This is accomplished by the accumulation of up to 4 Linac pulses by electron cooling. In order to non-destructively monitor the cooling performance and determine the accumulated beam characteristics, two prototype ionisation profile monitors have been built and were tested during the LEIR commissioning runs with O4+ and Pb54+ ions in 2006. In this paper we present the results obtained with the prototype monitors, the problems encountered and describe the modifications made for the final design. The modified monitors have been installed on the LEIR machine and are waiting for the next ion run planned in August. | ||
| TUPB25 | Beam Profile Measurement with Optical Fiber Sensors at FLASH | 123 |
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| The measurement setup is based on wire scanners, optical fibers mounted symmetrically around the beam line over the full length (30 m) of the undulator section, a signal conditioning unit and a data acquisition system. The fiber sensors along the beam line allow the measurement of the spatial distribution of the scattered beam caused by the wire scanner. At each increment of the wire scanner, the generated Cherenkov light in the fiber sensors - which is proportional to the intensity of the scattered electron shower - is measured. As an improvement, the shower is not only measured at a singular location but over the entire length of the undulator section. Each integral of the generated Cherenkov light along the beam line gives one point of the transversal beam profile. Accomplishing an x-y-scan leads to a two dimensional profile of the beam. The synchronisation with the beam trigger allows the characterization of each bunch. The measured data are visualized in real time and stored in a log file for extended evaluation. The high sensitivity of the system allows an accurate monitoring of the beam profile as well as HALO measurement. | ||
| TUPB26 | Characterisation of the Systematic Effects of the Insertion Devices with Photon Beam Position Monitors | 126 |
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| The X-ray photon monitors at Swiss Light Source are used for beam-position stabilisation down to sub-micron level. The beam position changes are mainly induced by changing the insertion device (ID) settings. An ID correction scheme involves both digital beam-position monitors (DBPM) located inside the storage ring and analog photon monitors (XBPM) located inside beamline front-ends. However, a beam-position correction scheme optimised for the electron beam is not automatically optimal for the photon beam. A sub-micron stability of the photon beam by changing the ID-settings is possible only if the XBPM readouts are well characterised for each considered ID-setting. We account for some limitations of the XBPM readouts as well as for examples where a sub-micron stability for all considered ID-settings is achieved. | ||
| TUPB27 | Recent Results from the Electron Beam Profile Monitor at the Swiss Light Source | 129 |
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| Two different methods of beam profile measurements using a) visible-to-UV range synchrotron radiation and b) X-ray synchrotron radiation have been realized in a single diagnostics beam line at the Swiss Light Source (SLS). In the visible-to-UV case the vertically polarized synchrotron radiation renders an image heavily influenced by inherent emission and diffraction effects of synchrotron radiation. This nevertheless turns out to be an advantageous influence when determining rms beam profiles below 10 μm. However, high-precision wave-optics based calculations of the synchrotron light characteristics need to be performed (SRW-code) to ensure correct interpretation of the measured profiles. The visible-to-UV branch has a few built-in features allowing numerous cross-checks of the SRW-model. Surprisingly, wave-optics based calculations are also applicable, and required, for the X-ray pinhole camera setup. We briefly discuss the advantage of applying two different measuring techniques at the same source point. In total, for standard user operation at the SLS, the beam line has helped to establish a vertical emittance below 10 pmrad. | ||
| TUPB28 | A Large Scintillating Screen for the LHC Dump Line | 132 |
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| 7 TeV proton beam from the LHC is ejected through a long transfer line to a beam dump block. Approximately 100 m downstream of the ejection septa, a series of dilution kicker magnets provide a sweeping deflection spreading the extracted beam over a 40 cm diameter area on the face of the beam dump core. During normal operation, the quality of each dump event must be recorded and verified. The so called “Post-Mortem” data-set will include information from the beam dumping system as well as from the beam diagnostics along the extraction line. For this purpose, a profile monitor in front of the dump block is permanently available during machine operation. With more than 1014 protons stored in LHC, the thermal properties of the screen have to be considered as beam energy deposition becomes an issue. This paper presents the design of this device, which is original due to its very large size. We introduce the different technical considerations involved in the design of the system and present the complete layout of its installation with a special emphasis on the mechanical design, the screen assembly and the choice of the radiation-hard video camera used to capture the image. | ||
| TUPB29 | Experimental Optimization of the Cathode Laser Temporal Profile | 135 |
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| Producing a flat-top temporal intensity profile of the cathode laser pulse is a key issue for the XFEL photo injector. The photo injector test facility at DESY in Zeuthen (PITZ) serves as a test bench for FEL photo injectors. The PITZ cathode laser contains a pulse shaper to produce flat-top temporal pulse profiles. Based on birefringent filters the pulse shaper includes four degrees of freedom to achieve a pulse profile with parameters closer to the required XFEL photo injector specifications (20 ps FWHM, 2 ps rise/fall time). A procedure for experimental temporal laser profile optimization is presented in this paper. The laser profile is measured using a streak camera. The four parameters - pulse length (FWHM), rise and fall time as well as modulation of the flat-top which are obtained from a flat-top fit of the measured profile - are used in the profile evaluation. Utilizing results of beam dynamics simulations for various cathode laser profiles a single value of the goal function – the expected emittance growth due to measured imperfections of the profile - can be obtained. The procedure of the goal function minimization has been implemented and tested at PITZ. | ||
| TUPB30 | Applications of IEEE-1394 and GigE Vision Digital Camera in the TLS | 138 |
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| Digital cameras comply with IEEE-1394 and GigE Vision standard are applied for beam diagnostic applications at NSRRC. These cameras provide low distortion for image transmission over long distance and flexible camera parameters adjustment with remote interface. These digital interfaces include of FireWire and gigabit Ethernet. The wide bandwidth bus can reduce latency time and timing jitter effectively and provides high quality image transportation. It also provides lossless compressed image with high update rate. Experiences accompany with both kind of cameras will be summarized. System integration with control system, analysis and application will also include in the report. | ||
| TUPB31 | The Beam Position System of the CERN Neutrino to Gran Sasso Proton Beam Line | 141 |
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| The CERN Neutrino to Gran Sasso (CNGS) experiment uses 400GeV protons extracted from the SPS, which travel along 825 meters of beam line before reaching the CNGS target. This beam line is equipped with 23 BPMs capable of measuring both the horizontal and vertical position of the beam. The final BPM is linked to the target station and due to radiation constraints has been designed to work in air. This contribution will give an overview of the BPMs used in the tansfer line. It will also provide a detailed explanation of their logarithmic amplifier based acquisition electronics, which consists of an auto-triggered sequencer controlling an integrator, the A/D conversion and the Manchester encoded transmission of the digital data to the surface. At the surface the digital data is aquired using the Digital Acquisition Board (DAB) developed by TRIUMF (Canada) for the LHC BPM system. Results from both laboratory measurements and beam measurements during the 2006 CNGS run will also be presented. | ||
| TUPB32 | An RF Deflector for the Longitudinal and Transverse Beam Phase Space Analysis at PITZ | 144 |
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| A detailed characterization of the longitudinal and transverse phase space of the electron beam provided by the Photo Injector Test Facility at DESY in Zeuthen (PITZ) is required to optimize photo injectors for Free-Electron Laser (FEL) applications. By means of a RF deflector the transverse slice emittance and the longitudinal phase space can be analysed. In this paper we present the status of the RF deflector design. The analysis of the prospect diagnostics shows the possibility to achieve a time resolution of about 0.5 ps, and a longitudinal momentum resolution of 10-4. The influence of the deflector on the beam longitudinal and transverse phase space is analysed. |