Author: Hoffstaetter, G.H.
Paper Title Page
MOIDCC004
CBETA, a 4-Turn ERL With FFAG Arc  
 
  • G.H. Hoffstaetter
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Cornell University has been pioneering Energy Recovery Linacs (ERLs) technology that is essential for any high brightness electron ERL. This includes a DC electron source and an SRF injector Linac with world-record current and normalized brightness in a bunch train, a high-current linac cryomodule, and a high-power beam stop, and several diagnostics tools for high-current and high-brightness beams. All these are now being used to construct a novel one-cryomodule ERL in Cornell's Wilson Lab. BNL has designed a multi-turn ERL for eRHIC, where beam is transported more than 20 times around the 4km long RHIC tunnel. The number of transport lines is minimized by using two arcs with strongly-focusing permanent magnets that can control many beams of different energies. A collaboration between BNL and Cornell has been formed to investigate this multi-turn eRHIC ERL design by building a 4-turn, one-cryomodule ERL at Cornell. It also has a return loop built with strongly focusing permanent magnets and is meant to accelerate 40 mA beam to 150 MeV. This high-brightness beam will have applications beyond accelerator research, in industry, in nuclear physics, and in X-ray science.  
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TUIBCC003
Applications for CBETA at Cornell  
 
  • G.H. Hoffstaetter
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  At Cornell, a 4-turn ERL with FFAG return loop is being constructed by a collaboration of Cornell and BNL. It is designed to produce a high-current (up to 40mA) CW beam of moderate energy (150MEV). For after successful commissioning, several applications of CBETA have been envisioned and are being analyzed, these include (a) a dark-photon search, (b) a Compton-Backscattering hard-x-ray source, (c) a Terahertz FEL, (d) a facility or ERL accelerator physics studies, and (e) a test facility with CW beam to test, for example, SRF cryomodules for eRHIC or for industrial isotope production  
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TUICCC003
Cornell ERL CM Performance  
 
  • F. Furuta, J. Dobbins, R.G. Eichhorn, M. Ge, G.H. Hoffstaetter, M. Liepe, T.I. O'Connell, P. Quigley, D.M. Sabol, J. Sears, E.N. Smith, V. Veshcherevich
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • D. Gonnella
    SLAC, Menlo Park, California, USA
 
  The main linac prototype cryomodule (MLC) is a key component for the Cornell-BNL ERL Test Accelerator (CBETA) project, which is a 4-turn FFAG ERL under construction at Cornell University. This novel cryomodule is the first SRF module ever to be fully optimized simultaneously for high efficient SRF cavity operation and for supporting very high CW beam currents. After the success of the initial MLC testing, the MLC had been moved into the final location for the first MLC beam test. Cornell ERL high voltage DC gun and Injector Cryomodule were connected to MLC via the entry beam line; the beam stop assembly was also installed as the exit line. In this paper, we summarize the performance of this novel ERL cryomodule including the results of the first beam test and the additional tests focused on RF field stability and cavity microphonics.  
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WEIBCC001
Beam Dynamics Issues for Multi-Pass ERLs  
 
  • G.H. Hoffstaetter
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Several labs have proposed multi-turn ERLs as electron-drivers for major experiments. The beam dynamics of the 4-turn ERL CBETA will be studied in detail to understand the beam-dynamic issues for these electron drivers. These issues include: (a) current limits by the recirculative beam-breakup instability(BBU) and its control by HOM damping, optics adjustments, and optical coupling, (b) ions attracted to the electron beam and their control by clearing electrodes, current modulations, and beam shaking, (c) loss mechanism including Touschek scattering, gas scattering, field emission, ghost pules, and spurious emotions from the cathode, (d) high-chromaticity operation, orbit and optics controls of superimposed beams, coherent synchrotron radiation, micro-bunching, and longitudinal space charge, and (e) low energies space charge and emittance control  
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THIBCC002
Microphonics Analysis of ERL Cryomodule  
 
  • F. Furuta, N. Banerjee, J. Dobbins, R.G. Eichhorn, M. Ge, G.H. Hoffstaetter, M. Liepe, P. Quigley, J. Sears, V. Veshcherevich
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  The main linac prototype cryomodule (MLC) is a key component for the Cornell-BNL ERL Test Accelerator (CBETA) project, which is a 4-turn FFAG ERL under construction at Cornell University. After the success of the initial MLC test, the MLC has been moved into the final location for the initial beam test into the MLC. The levels of microphonic in the MLC cavities without fast tuner compensation were measured at the initial and the final location, confirming that these should not limit the CBETA requirement of a nominal energy gain of 36 MeV per pass. Nevertheless, a further reduction of microphonics is desirable for improved energy stability and reduced RF power demand. The cryogenic gas line to the MLC was optimized to reduce vibrations. A piezoelectric-driven fast tuner is installed on each MLC cavity, and its usefulness in compensating cavity microphonics was studied. Here we report details from these tests and summarize results.  
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FRIBCC003 ERL17 Workshop, WG3 Summary: Test Facilities Around the World 80
 
  • A. Stocchi
    LAL, Orsay, France
  • G.H. Hoffstaetter
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  This contribution has not been submitted.  
slides icon Slides FRIBCC003 [5.375 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2017-FRIBCC003  
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