| Paper | Title | Page |
| MOHP01 |
Normal-Conducting Separation and Compensation Dipoles for the LHC Experimental Insertions
The experimental insertions of the LHC employ normal-conducting magnets to provide for part of the beam separation and to compensate the effect of two large spectrometer dipoles. In the interaction regions IR1 for the ATLAS experiment and IR5 for the CMS experiment, each of the optical elements D1 for beam separation on either side of the experiment consist of 6 MBXW dipoles. Each magnet has a core length of 3.4 m, a large single aperture with a gap height of 63 mm and will operate in the field range up to 1.5 T. The MBXWT and MBXWS magnets are shorter versions of the MBXW magnet and will be used as vertical and horizontal compensation dipoles for the spectrometer dipoles in IR2 for the ALICE and in IR8 for the LHCb experiments respectively. The MBXWT and MBXWS have a core length of 1.5m and 0.75m respectively. Additionally on MBXW magnet serves as a main compensator for the LHCb experiment. The magnet design was done in collaboration between CERN and BINP and the dipole magnets are produced by BINP. So far all three MBXWS, all three MBXWT and thirteen of twenty-nine MBXW magnets including spares have been manufactured and delivered to CERN. The report presents the main design issues and results of the acceptance tests including mechanical, electrical and magnetic field measurements |
281 |
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MOHP02 |
The Vacuum System of the VEPP-2000 Storage Ring
Perimeter of VEPP-2000 is 24.4m only and the average density of SR flux is 1.2*1019 photon/s per meter and SR power is 1000W per meter at maximum design currents Ie-=Ie+=200mA. Special SR receivers are used along the total length of the ring except interaction regions and RF cavity. An intense gas load due to photon stimulated desorption should be compensated by high enough molecular pumping speed. VEPP-2000 high vacuum system consists from different parts: 8 vacuum chambers inside the dipole magnets, vacuum chambers of the solenoids, experimental and technical straight sections and vacuum chamber of the RF cavity. VEPP-2000 high vacuum pump system consists from 16 ports with ion-getter pumps PVIG-100 situated on the bending magnets vacuum chambers edges; ion- getter pump PVIG-250 connected with resonator area; 4 cryopumps presented by solenoid cold surface. To prevent SR heating of cryosurface at T=4.2 K a perforated cooper liner have been made that is cooled by liquid nitrogen. Slits in the liner should provide linear pump speed at rate of 5 l/sec/cm for nitrogen. Cold surface at 4.2 K is the ideal pump for all residual gases except hydrogen, since after adsorption more than one monolayer of hydrogen at T=4.2 K saturated vapor pressure the one reaches 5*10-7 Torr. In spite of such circumstances calculations showed the beam lifetime will be determined of CO residual pressure. By now the vacuum system has been made, assembled, pumped and baked in-situ at 200Ñ. The obtained average pressure in vacuum chamber of storage ring is better than 10-9 Torr. But pressure is about 10-9 Torr inside resonator vacuum chamber baked in-situ at 120C. |
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| MOHP04 |
The Modulator for the 10 MeV 2 kA Inductive Accelerator Pulse Power Supply
For the 10 MeV 2 kA electron inductive accelerator pulse power supply the modulator prototype operating in two-pulse regime has been developed. The modulator is used for the resistively-inductive load supplying with the pulse voltage 20 kV, current up to 10 kA, 300 ns pulse duration. The data obtained at the nominal modulator operation regime are presented. The basic technical developments of the modulator parts and the modulator design are described. |
284 |
| MOHP05 |
Vacuum System of FEL
In this article is described the vacuum system of the powerful terahertz free electron laser constructed in the Siberian Center for Photochemical Research. Vacuum system of FEL contains the new technological decisions: standby blocks - power supply of pumps; hardware and software intended for the vacuum's monitoring and ensuring the protection of some technological units of FEL in case of vacuum's downturn |
287 |
| MOHP06 |
Superferric Magnets for Super-FRS and Storage Rings of FAIR
The Super Fragment Separator (Super-FRS) is conceived as a large acceptance fragment separator, with three branches serving different experimental areas, including a new storage ring complex. Rare isotopes of all elements up to uranium can be spatially separated by the Super-FRS. Unique studies with these isotopes and antiprotons will be performed in the Ring Branch, consisting mainly of a Collector Ring (CR), the New Experimental Storage Ring (NESR), and the Recycled Experimental Storage Ring (RESR). A common requirement for the magnets of these systems is a large acceptance at moderate fields, which can be fulfilled by superferric magnets with wide apertures. Similar requirements for the Super-FRS and CR magnets allow using the same magnet designs for both systems, yielding a reduction of costs and development time. Rare ions and anti-protons will be decelerated in the NESR and RESR, thus requiring pulsed magnets. This requires a coil design different from CR and Super-FRS. The cryostat design has to prevent large eddy current losses. This paper describes the status and development of the aforementioned superferric magnets. Differences and common features will be clarified. |
289 |
| MOHP07 |
High-Voltage Nanosecond Generators System For Injections - Extraction Kickers of FEL Complex DUKE University
Booster-synchrotron of the maximum energy of 1.2 GeV has been created to increase the current in the Storage Ring electron bunches. The Storage Ring is expected the operating modes of 2, 4 and 8 bunches. The booster will be used to accelerate 19 electron bunches with the possibility of their extraction in SR FEL at the frequency of 25 Hz. This system allows to inject the bunch from linear accelerator into the booster with the minimal loss of particles and then to realize bunch-by-bunch extraction into the main ring in the energy range of 250 MeV-1.2 GeV. |
292 |
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MOHP08 |
Experimental Study Of The Stripping Target With Differential Pumping For 10 mA, 1.25 MeV Ion Beam
An electrostatic tandem-accelerator with 2.5 MeV 10 mA proton beam is under development at BINP. One of the accelerator important parts is a target that converts the half energy accelerated negative hydrogen ions into the proton beam. To reduce argon flux from the target to accelerator gaps a gas recirculation by turbomolecular pump installed in high voltage electrode is provided. To study the argon recirculation and the plasma production in the stripping cell an experimental test stand is prepared. Results of experimental modeling of differential pumping with different length of tubes for ion beam pass are presented. Ionization of the target by 500 eV electrons is studied by injecting a corresponding electron beam. |
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| MOHP11 |
Multipole Magnets For The Metrology Light Source (PTB, Berlin)
The Metrology Light Source (MLS), a specialized synchrotron radiation source (electron energy up to 600 MeV) being built at the PTB in Germany. The multipole magnets of the Storage Ring consist of 24 quadrupoles, 24 sextupoles and 4 octupoles manufactured by Budker INP. The quadrupole magnets of 165 mm length have gradient of 13 T/m and aperture of 70 mm. The sextupole magnets of 80 mm length have strength of 280 T/m2 and aperture of 76 mm. The octupole magnets of 80 mm length have strength of 2400 T/m3 and aperture of 86 mm. The main features of magnetic modeling and manufacture are described in the paper. The multipoles were magnetically measured by Rotating Coil System and main results of the magnetic measurements are also presented. |
295 |
| MOHP12 |
Permanent Magnet Quadrupole For The 1-St Tank of LINAC-4
Rare-earth 60 mm diameter, 45 mm long quadrupole for the LINAC-4 focusing channel on the integrated gradient of 2.3 T is described. The thin side washers are used for tuning the quad into specified gradient integral with 0.5 % accuracy. The single washer contribution calculations are discussed. A method of the magnetic axis offset in the REPM quad decreasing down to 30 mm is discussed to exclude its compensation by the outer diameter machining before inserting into the drift tube. Nonlinearity of the field is less than 1 % in the reference range of 75% of beam aperture at the central cross-section near the quad axis. The angular quadrupole arrangement in the drift tube will be provided by machining the main groove on the quad surface in the median plane with 1 mrad accuracy. Calculations of the longitudinal gradient distribution between two closer quadrupoles showed that some percents should be added to the nominal gradient in the beginning of the LINAC-4 focusing channel because of partial field compensation. |
298 |
| MOHP13 |
High-Voltage Source With Output Voltage Up To 60 kV with Power up to 15 kW
The presented report contains the description of a high-voltage source with output voltage up to 60 kV with power up to 15 kW. The source consist of the converter whit IGBT switches, working with a principle of pulse-width modulation on 20 kHz frequency, and high voltage sectioned transformer with the rectifier. The schematic configuration and the optimal matching of the rectifier to the load has allowed minimizing the energy stored at the reactive components of the high-voltage stage at the level less than 15 J for 60 kV operation. The design of the high-voltage transformer provides preservation of working capacity at voltage up to 100 kV. A nominal output voltage of the source is 60 kV. The efficiency of system is more than 80% at the nominally output power. The controller of the source is developed with DSP and PLM, which allows optimizing operations of the source. For control of the source serial CAN-interface is used. The description of the source and the test results are presented. |
301 |
|
MOHP14 |
A Pulsed Modulator To Energize The Secondary-Emission Electron Source Of The Technological Accelerator
Experiments were made to investigate a pulsed modulator intended to energize the electron accelerator based on the secondary-emission electron source. The accelerator with a great pulse length (8 - 40 mks) and a pulse repetition rate up to 10 Hz is designed for material-surface treatment. To form long pulses in the modulator (with reservoir capacitor discharge through a step-up transformer), the nonlinear properties of the pulse-transformer core material are used, while the top of the pulse is formed through summation of a short spike and a flat-topped long-duration pulse. At a load resistance of 4300 Ohm; a voltage pulse with a spike amplitude of ~ 150 kV and a flat-topped pulse with an amplitude of ~ 130 kV of ~ 16 mks duration and a repetition frequency of 3 Hz were obtained. During formation of the beam with a current of ~ 100A the amplitude of the flat part of cathode voltage made ~ 100 kV. |
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| MOHP15 |
High Voltage Decoupled High-Current Power Supply
10 kW power supply (PS) with smooth adjustment of a load current from zero up to 2 êÀ is described. Depending on the load requirements operating modes with stability of a load current from 5% to 0.1% and long-term instability of 0.01% are possible. Power mains isolation is up to 35 kV. PS includes the high-frequency inverter, transformer-rectifier module and the control block. The high-frequency inverter is performed on progressive ZCZVS-PS-FB (Zero Cur-rent Zero Voltage Switching - Phase Shifted - Full Bridge) topology. It provides a full range load regulation with the minimal power losses. Dynamic losses of the inverter switching do not exceed 6%. The step-down transformer secondary winding has the form of a solid turn that allows to receive low leakage inductance and high working frequency. Rectifier block is based on the current symmetric doubler circuit. Total power losses of the transformer-rectifier module is about 15%. Thus, the high-frequency conversion and doubling of a load current allow to reach high power and low weight parameters of the device. The power supply control circuit is realized on an CPLD base by "ALTERA" firm. The intellectual algorithm of inverter management provides soft switching in a full range of load variations and precision stabilization of a load current. The remote control is carried out through the CAN-interface. Oscillograms of a power supply operating modes are presented, the received results are discussed. |
304 |
| MOHP16 |
Plasma Lens Investigation For The Heavy Ion Accelerator AT ITEP
The problem of transportation and focusing of an intense heavy-ions beam is an important issue for heavy ion beam-driven inertial confinement fusion and for investigation of high energy densities (HED) in matter produced by heavy ion beam. A plasma lens application has a number of essential advantages in comparison with traditional focusing system on a quadruple lenses basic [1]. Description of the plasma lens with the maximum of the current discharge in 250 kA for HED research on the heavy ion accelerator-accumulated facility TWAC-ITEP is presented [2]. The minimum beam spot size on a target which will get by using this plasma lens is 300 mm for 300MeV/u ion energy and the beam emittance 40 mm·mrad. The investigation of plasma discharge dynamic and a plasma parameters diagnostic in temporal and spatial resolution are reported. References [1] E. Boggasch, B. Heimrich, D.H.H. Hoffmann, Nucl. Instr.Meth.336 (1993), p.438-41. [2] B.Yu. Sharkov et al., Nucl. Instr.Meth. A464 (2001), p.1-5. |
307 |
|
MOHP17 |
Experiments with TiZrV Non-Evaporated Getter at BINP.
The aim of the presentation is a summary of Synchrotron Radiation experiments made at BINP (Novosibirsk, Russia) in 90K - 300K temperature range with TiZrV coated vacuum chambers. The sensitivity of applied method, the problem with scattered photons and photoelectrons, photon stimulated desorption, cleaning and pumping is under detailed discussion. The presentation includes the first results of XRF, XRD, EXAFS, SEY experiments and future proposed investigations. |