SRF2011 - List of Authors (Boulware, C.H.)

Paper

Title

Page

Commercial Superconducting Electron Linacs

33

T.L. Grimm, C.H. Boulware, J.L. Hollister
Niowave, Inc., Lansing, Michigan, USA

Industry now has the capability to design, build and commission superconducting electron linacs. This capability includes the integration of the liquid helium refrigerator and the license to operate a radiation generating device. Niowave offers a broad range of commercial turnkey superconducting electron linacs with beam energies from 0.5 to 50 MeV and average beam powers from 1 W to 1 MW. The commercial linacs operate at 4.5 K with helium refrigerator loads typically less than 100 W. Operation at 4.5 K uses niobium cavities with frequencies less than about 700 MHz. The types of electron source used depend on the application and include DC, copper RF and SRF guns with cathodes based on photoemission, thermionic and field emission. There are many applications with a diverse range of uses from ultrafast electron microscopes to free electron laser to advanced x-ray sources and isotope production. Commercial developments and plans to date will be presented.

Poster MOPO001 [0.324 MB]

MOPO050

Design of a 1500 MHz Bunch Lengthening Cavity for NSLS-II

210

J. Rose, N.A. Towne
BNL, Upton, Long Island, New York, USA
C.H. Boulware, T.L. Grimm
Niowave, Inc., Lansing, Michigan, USA

The NSLS-II is a new third generation light source being constructed at > BNL. In order to increase the Touschek lifetime and third harmonic bunch > lengthening cavity is required. A 1500 MHz passive third harmonic cavity has > been designed and fabricated. It is a coupled two-cell HOM damped SRF cavity > that can provide 1 MV of voltage in a single cryomodule. The two cell design > allows for a single tuner mechanism outside the cryostat while the room > temperature ferrite HOM dampers provide damping of all but the fundamental > zero and pi modes. Since the unwanted zero mode is strongly coupled to the > pi mode it tracks the pi mode tuning which is required for the beam induced > excitation. The design allows for the tuning of the pi mode between minimum > and required field excitation while keeping the zero mode excitation below > allowable limits. Design and initial cold test results are presented.

MOPO054

Superconducting 112 MHz QWR Electron Gun

223

S.A. Belomestnykh, I. Ben-Zvi, X. Chang, X. Liang, T. Rao, J. Skaritka, R. Than, Q. Wu, T. Xin
BNL, Upton, Long Island, New York, USA
C.H. Boulware, T.L. Grimm, B. Siegel, M.J. Winowski
Niowave, Inc., Lansing, Michigan, USA

Funding: Work is supported at BNL by BSA, LLC under U.S. DOE Contract No. DE-AC02-98CH10886, at Stony Brook University by U.S. DOE grant DE-SC0005713, at Niowave by U.S. DOE SBIR contract No. DE-FG02-07ER84861
Brookhaven National Laboratory and Niowave, Inc. have designed and fabricated a superconducting 112 MHz quarter-wave resonator (QWR) electron gun. The first cold test of the QWR cryomodule has been completed at Niowave. The paper describes the cryomodule design, presents the cold test results, and outline plans to upgrade the cryomodule. Future experiments include studies of different photocathodes and use for the coherent electron cooling proof-of-principle experiment. Two cathode stalk options, one for multi-alkali photocathodes and the other one for a diamond-amplified photocathode, are discussed.

Poster MOPO054 [3.299 MB]

TUPO035

Cryogenic Test of a Two-Cell Passive SRF Cavity for NSLS-II

459

C.H. Boulware, T.L. Grimm, C. Krizmanich, B. Kuhlman, N. Miller, B. Siegel, M.J. Winowski
Niowave, Inc., Lansing, Michigan, USA
W.K. Gash, B.N. Kosciuk, V. Ravindranath, J. Rose, S.K. Sharma, R. Sikora, N.A. Towne
BNL, Upton, Long Island, New York, USA

Funding: The work at Niowave has been funded by DOE SBIR grant DE-FG02-08ER85014.
In collaboration with Brookhaven National Lab (BNL), Niowave, Inc. has built and performed the first cryogenic test on a two-cell passive SRF cavity for controlling electron bunch lengths at NSLS-II, the new 3rd generation synchrotron under construction at BNL. The structure is resonant at 1500 MHz, the third harmonic of the accelerating RF frequency. Because the cavity is powered by the beam itself, however, many frequencies could potentially be excited and higher-order modes must be strongly damped. Further, only one of the two cavity fundamental modes is used for the bunch length control, and the other mode has been carefully tuned so that it will be minimally excited by the electron bunches. The first cryogenic test has been performed to demonstrate a successful cooldown of the cavity in its cryomodule and to show that the cavity can be tuned to its operating frequency while the proper spacing between the two fundamental modes is maintained. A brief discussion of the cavity design will be presented along with some results from the cavity tuning and cryotest.

Poster TUPO035 [1.092 MB]

Paper	Title	Page
MOPO001	Commercial Superconducting Electron Linacs	33
	T.L. Grimm, C.H. Boulware, J.L. Hollister Niowave, Inc., Lansing, Michigan, USA
	Industry now has the capability to design, build and commission superconducting electron linacs. This capability includes the integration of the liquid helium refrigerator and the license to operate a radiation generating device. Niowave offers a broad range of commercial turnkey superconducting electron linacs with beam energies from 0.5 to 50 MeV and average beam powers from 1 W to 1 MW. The commercial linacs operate at 4.5 K with helium refrigerator loads typically less than 100 W. Operation at 4.5 K uses niobium cavities with frequencies less than about 700 MHz. The types of electron source used depend on the application and include DC, copper RF and SRF guns with cathodes based on photoemission, thermionic and field emission. There are many applications with a diverse range of uses from ultrafast electron microscopes to free electron laser to advanced x-ray sources and isotope production. Commercial developments and plans to date will be presented.
	Poster MOPO001 [0.324 MB]

MOPO050	Design of a 1500 MHz Bunch Lengthening Cavity for NSLS-II	210
	J. Rose, N.A. Towne BNL, Upton, Long Island, New York, USA C.H. Boulware, T.L. Grimm Niowave, Inc., Lansing, Michigan, USA
	The NSLS-II is a new third generation light source being constructed at > BNL. In order to increase the Touschek lifetime and third harmonic bunch > lengthening cavity is required. A 1500 MHz passive third harmonic cavity has > been designed and fabricated. It is a coupled two-cell HOM damped SRF cavity > that can provide 1 MV of voltage in a single cryomodule. The two cell design > allows for a single tuner mechanism outside the cryostat while the room > temperature ferrite HOM dampers provide damping of all but the fundamental > zero and pi modes. Since the unwanted zero mode is strongly coupled to the > pi mode it tracks the pi mode tuning which is required for the beam induced > excitation. The design allows for the tuning of the pi mode between minimum > and required field excitation while keeping the zero mode excitation below > allowable limits. Design and initial cold test results are presented.

MOPO054	Superconducting 112 MHz QWR Electron Gun	223
	S.A. Belomestnykh, I. Ben-Zvi, X. Chang, X. Liang, T. Rao, J. Skaritka, R. Than, Q. Wu, T. Xin BNL, Upton, Long Island, New York, USA C.H. Boulware, T.L. Grimm, B. Siegel, M.J. Winowski Niowave, Inc., Lansing, Michigan, USA
	Funding: Work is supported at BNL by BSA, LLC under U.S. DOE Contract No. DE-AC02-98CH10886, at Stony Brook University by U.S. DOE grant DE-SC0005713, at Niowave by U.S. DOE SBIR contract No. DE-FG02-07ER84861 Brookhaven National Laboratory and Niowave, Inc. have designed and fabricated a superconducting 112 MHz quarter-wave resonator (QWR) electron gun. The first cold test of the QWR cryomodule has been completed at Niowave. The paper describes the cryomodule design, presents the cold test results, and outline plans to upgrade the cryomodule. Future experiments include studies of different photocathodes and use for the coherent electron cooling proof-of-principle experiment. Two cathode stalk options, one for multi-alkali photocathodes and the other one for a diamond-amplified photocathode, are discussed.
	Poster MOPO054 [3.299 MB]

TUPO035	Cryogenic Test of a Two-Cell Passive SRF Cavity for NSLS-II	459
	C.H. Boulware, T.L. Grimm, C. Krizmanich, B. Kuhlman, N. Miller, B. Siegel, M.J. Winowski Niowave, Inc., Lansing, Michigan, USA W.K. Gash, B.N. Kosciuk, V. Ravindranath, J. Rose, S.K. Sharma, R. Sikora, N.A. Towne BNL, Upton, Long Island, New York, USA
	Funding: The work at Niowave has been funded by DOE SBIR grant DE-FG02-08ER85014. In collaboration with Brookhaven National Lab (BNL), Niowave, Inc. has built and performed the first cryogenic test on a two-cell passive SRF cavity for controlling electron bunch lengths at NSLS-II, the new 3rd generation synchrotron under construction at BNL. The structure is resonant at 1500 MHz, the third harmonic of the accelerating RF frequency. Because the cavity is powered by the beam itself, however, many frequencies could potentially be excited and higher-order modes must be strongly damped. Further, only one of the two cavity fundamental modes is used for the bunch length control, and the other mode has been carefully tuned so that it will be minimally excited by the electron bunches. The first cryogenic test has been performed to demonstrate a successful cooldown of the cavity in its cryomodule and to show that the cavity can be tuned to its operating frequency while the proper spacing between the two fundamental modes is maintained. A brief discussion of the cavity design will be presented along with some results from the cavity tuning and cryotest.
	Poster TUPO035 [1.092 MB]