| Paper | Title | Page |
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| MOPKF014 | Emittance Compensation of a Superconducting RF Photoelectron Gun by a Magnetic RF Field | 330 |
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| For compensation of transverse emittance in normal conducting RF photoelectron guns a static magnetic field is applied. In superconducting RF guns the application of a static magnetic field is impossible. Therefore we put instead of a static field a magnetic RF field (TE - mode) together with the corresponding accelerating mode into the superconducting cavity of the RF gun. For a 3 _ cell cavity of the superconducting gun with frequencies f = 1.3GHz for the accelerating mode and f = 3.9 GHz for the magnetic mode and a bunch charge of 1 nC a transversal emittance of 0.5 mm mrad has been obtained. In this case the maximal field strength on the axis were Ez = 50 MV/m for the accelerating mode and Bz = 0.34 T for the magnetic mode.(This corresponds to Bs(max) = 0.22T on the surface of the cavity). Possibilities for the technical realization (input of RF power for the TE mode, tuning of two frequencies in one cavity, phase stability) are discussed. | ||
| MOPKF015 | A Superconducting Photo-Injector with 3+1/2- Cell Cavity for the ELBE Linac | 333 |
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After successful tests of an SRF gun with a superconducting half-cell cavity [*], a new SRF photo-injector for CW operation at the ELBE linac has been designed. In this report the design layout of the SRF photo-injector, the parameters of the superconducting cavity and the expected electron beam parameters are presented. The SRF gun has a 31/2-cell niobium cavity working at 1.3 MHz and will be operated at 2 K. The three full cells have TESLA-like shapes. In the half-cell the photocathode is situated which will be cooled by liquid nitrogen.
* D. Janssen et. al., First operation of a superconducting RF-gun, Nucl. Instr. and Meth. A507(2003)314 |
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| MOPLT092 | Single Mode RF Cavity for VEPP-2000 Storage Ring Based Collider | 752 |
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| Accelerating cavity 172 MHz with strong damped higher-order modes (HOM) for VEPP-2000 electron-positron collider have been made in Novosibirsk. Resonance frequences and Q values of cavity HOMs are measured and analysed. Most of HOMs have Q values less than 300. We compare these results with computer calculations of HOM. | ||
| THPLT095 | Nuclotron Extracted Beam Spill Control | 2715 |
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| The first experiments with the Nuclotron Beam Slow Extraction System (BES) were carried out in December 1999. After the BES commissioning, the development of the system was continued together with experiments on relativistic nuclear physics. To realize the constant-current-beam or the constant-time-length spill and to suppress the low frequency spill structure in the range up to several hundred hertz, a spill control subsystem was designed and put into operation. It consists of a feedback loop in parallel with a feed-forward control. In the feedback loop the extracted particle flux is measured with beam current monitor and is compared with the request flux. The resulting error signal is fed into a feedback controller. The controller is an analog unit in which integration, differentiation and gain can be adjusted separately. The output control signal is added to the extraction quadrupoles power supply pattern generated by the corresponding function generator. The beam spill control subsystem has been improved in stages since its commissioning in 2000. The beam spill duration of more than 10s and the beam spill uniformity of about 0.9 were achieved in recent Nuclotron runs. |