Paper | Title | Page |
---|---|---|
MOPRO106 | Status of the HZB ERL Prototype BERLinPro | 340 |
|
||
Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association. The Berlin Energy Recovery Linac Prototype BERLinPro is to be constructed at the Helmholtz Zentrum site in Berlin. The aim of the project is to expand the required accelerator physics and technology knowledge mandatory for the generation of a high current (100 mA), high brilliance (norm. emittance below 1 mm mrad) cw electron beam. Since the funding decision in October 2010 the project has entered a phase of detailed planning. Hardware specifications have been defined and various components have been ordered. Furthermore, extensive tests of principal superconducting accelerator components successfully demonstrated the envisaged hardware performance. A summary of the most recent activities together with the details of the project timeline for the coming years are given in this paper. |
||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO106 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
WEPRI005 | Processing and Testing of the SRF Photoinjector Cavity for BERLinPro | 2484 |
|
||
Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association The BERLinPro project is a compact, c.w. SRF energy recovery linac (ERL) that is being built to develop the accelerator physics and technology required to operate the next generation of high current ERLs. The machine is designed to produce a 50 MeV 100 mA beam, with better than 1 mm-mrad emittance. The electron source for the ERL will be a SRF photoinjector equipped with a multi-alkali photocathode. In order to produce a SRF photoinjector to operate reliably at this beam current HZB has undertaken a 3 stage photoinjector development program to study the operation of SRF photoinjectors in detail. The 1.4 cell cavity being reported on here is the second stage of this development, and represents the first cavity designed by HZB for use with a high quantum efficiency multi-alkali photocathode. This paper will describe the work done to prepare the cavity for RF testing in the vertical testing dewar at Jefferson Laboratory as well as the results of these RF tests. |
||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI005 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
WEPRI006 | High Power RF Input Couplers and Test Stand for the BERLinPro Project | 2487 |
|
||
Funding: Work supported by German Federal Ministry of Education and Research, Land Berlin, and grants of the Helmholtz Association The BERLinPro project, under construction at HZB, is a 100 mA, 50 MeV superconducting RF (SRF) energy recovery linac (ERL) being built to study the accelerator physics of operating a high current SRF ERL. For this high current operation, coaxial RF power couplers capable of handling 130 kW of power, c.w. at 1.3 GHz are required for both the SRF gun and booster cavities. In order to achieve this power level a coupler has been designed based on the high power coupler currently in use at the KEK-cERL. A key improvement that was made to the coupler was the modification of the coupler tip, termed a golf-tee. This modification is incorporated so as to achieve the desired coupling, Qext ~105, with minimal coupler penetration into the beampipe. Herein, we discuss the RF design and properties of the high-power coaxial coupler for the gun as well as booster cavity of BERLinPro, along with the design of the test stand for conditioning a pair of couplers. |
||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI006 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
WEPRI007 | Booster Cavity and Fundamental Power Coupler Design Issues for BERLinPro | 2490 |
|
||
Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin and grants of Helmholtz Association HZB has started building the 50MeV, 100mA demonstrator energy-recovery-linac (ERL) facility BERLinPro. The high power injector system needs to deliver this beam at 6.5MeV by combining the energy gain of a 1.4 cell SRF photo-injector and three Cornell style 2-cell booster cavities. One booster cavity will be operated at zero-crossing for bunch energy chirping. Thus two booster cavities have to deliver 2MV each requiring a strong coupling with a loaded Q of 105. To house the two envisaged KEK fundamental power couplers (FPC) with the cavity, the geometry was slightly modified. Further, to increase coupling and reduce transverse kick effects to the beam, a ”golf-tee” antenna tip was designed. This paper summarizes the SRF challenges for the booster cavities, the operational conditions and the modification to the KEK couplers, including tracking calculations to estimate the coupler kick effect to higher order. |
||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI007 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
WEPRI008 | First Cavity Design Studies for the BESSY-VSR Upgrade Proposal | 2493 |
|
||
Funding: Work supported by German Bundesministerium für Bildung und Forschung and Land Berlin Recently HZB proposed an upgrade of the 3rd generation synchrotron light source BESSY II allowing simultanous long and short pulse operation*. For this scheme to work superconducting higher harmonic cavities of the fundamental 500 MHz at two frequencies need to be installed in the BESSY II storage ring. Given an appropiate choice of the higher harmonics the resulting gradient leads to a beating effect of the effective longitudinal focussing voltage at the stable fix points resulting in different bunch lengths in subsequent buckets. This project places stringent requirements on the cavity performance, as high accelerating fields, excellent HOM damping capabilities and high reliability as they will operate in a 300 mA 24/7 user facility. In this paper we describe the requirements for the cavity design and first designs steps. * G. Wüstefeldt et al., Simultaneous Long and Short Electron Bunches in the BESSY II Storage Ring, Proc. of IPAC'11, San Sebástian, Spain |
||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI008 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
THPRO042 | Field Emission Studies of Heat Treated Mo Substrates | 2955 |
|
||
Funding: This work was supported by German Bundesministerium für Bildung und Forschung project 05K13PX2, Land Berlin and grants of Helmholtz Association. Molybdenum can be used as a substrate for the bi-alkali antimonide photocathodes utilized for the generation of high brightness electron beams in a superconducting radio frequency (SRF) photoinjector cavities. Operation at high field strength is required to obtain a low emittance beam, thus increasing the probability of field emission (FE) from the cathode surface. Usually, substrates are heated in situ before alkali de- position to remove oxide layers from the surface. FE on Mo substrates was measured by means of a field emission scanning microscope (FESM). It turned out that in situ heat treatment (HT) of the Mo surface significantly changes the FE behaviour by activation of new emitters. For a better understanding of the mechanism for enhanced emission after in situ heating a witness Mo sample was investigated using x-ray photoelectron spectroscopy. |
||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO042 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |