2011 Particle Accelerator Conference - List of Authors (Wu, G.)

Paper

Title

Page

Status of the Short-Pulse X-ray Project (SPX) at the Advanced Photon Source (APS)

1427

R. Nassiri, N.D. Arnold, G. Berenc, M. Borland, D.J. Bromberek, Y.-C. Chae, G. Decker, L. Emery, J.D. Fuerst, A.E. Grelick, D. Horan, F. Lenkszus, R.M. Lill, V. Sajaev, T.L. Smith, G.J. Waldschmidt, G. Wu, B.X. Yang, A. Zholents
ANL, Argonne, USA
J.M. Byrd, L.R. Doolittle, G. Huang
LBNL, Berkeley, California, USA
G. Cheng, G. Ciovati, J. Henry, P. Kneisel, J.D. Mammosser, R.A. Rimmer, L. Turlington, H. Wang
JLAB, Newport News, Virginia, USA

Funding: Work at Argonne is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11354.
The Advanced Photon Source Upgrade project (APS-U) at Argonne includes implementation of Zholents’* deflecting cavity scheme for production of short x-ray pulses. This is a joint project between Argonne National Laboratory, Thomas Jefferson National Laboratory, and Lawrence Berkeley National Laboratory. This paper describes performance characteristics of the proposed source and technical issues related to its realization. Ensuring stable APS storage ring operation requires reducing quality factors of these modes by many orders of magnitude. These challenges reduce to those of the design of a single-cell SC cavity that can achieve the desired operating deflecting fields while providing needed damping of all these modes. The project team is currently prototyping and testing several promising designs for single-cell cavities with the goal of deciding on a winning design in the near future.
*A. Zholents et al., NIM A 425, 385 (1999).

Slides WEOBS5 [1.730 MB]

WEOCS7

Crab Cavity and Cryomodule Prototype Development for the Advanced Photon Source

1472

H. Wang, G. Cheng, G. Ciovati, W.A. Clemens, J. Henry, P. Kneisel, P. Kushnick, K. Macha, J.D. Mammosser, R.A. Rimmer, G. Slack, L. Turlington
JLAB, Newport News, Virginia, USA
R. Nassiri, G.J. Waldschmidt, G. Wu
ANL, Argonne, USA

Funding: Work is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11354.
Two single-cell, superconducting, squashed elliptical crab cavities with waveguides to damp Higher Order Modes (HOM) and Lower Order Mode (LOM) have been designed and prototyped for the Short Pulse X-ray (SPX) project at the Advanced Photon Source (APS). The Baseline cavity with LOM damper on the beam pipe has been vertically tested and exceeded its performance specification with over 0.5MV deflecting voltage. The Alternate cavity design which uses an “on-cell” waveguide damper is preferred due to its larger LOM impedance safety margin. Its prototype cavity has been fabricated by a Computer Numerical Controlled (CNC) machine and is subject to further testing. The conceptual design, layout and analysis for various cryomodule components are presented.

Slides WEOCS7 [7.008 MB]

TUP066

Three-cell Traveling-wave Superconducting Test Structure

940

P.V. Avrakhov, A. Kanareykin
Euclid TechLabs, LLC, Solon, Ohio, USA
S. Kazakov, N. Solyak, G. Wu, V.P. Yakovlev
Fermilab, Batavia, USA

Use of a superconducting traveling wave accelerating (STWA) structure* with a small phase advance per cell rather than a standing wave structure may provide a significant increase of the accelerating gradient in the ILC linac. For the same surface electric and magnetic fields the STWA achieves an accelerating gradient 1.2 larger than TESLA-like standing wave cavities. The STWA allows also longer acceleration cavities, reducing the number of gaps between them. However, the STWA structure requires a SC feedback waveguide to return the few hundreds of MW of circulating RF power from the structure output to the structure input. A test single-cell cavity with feedback was designed, manufactured and successfully tested** demonstrating the possibility of a proper processing to achieve a high accelerating gradient. These results open the way to take the next step of the TW SC cavity development: to build and test a traveling-wave three-cell cavity with a feedback waveguide. The latest results of the single-cell cavity tests are discussed as well as the design of the test 3-cell TW cavity.
* P. Avrakhov, et al, Phys. of Part. and Nucl. Let, 2008, Vol. 5, No. 7, p. 597
** G. Wu, et al, IPAC 2010, THPD048

TUP032

Development of 1.3 GHz Prototype Niobium Single Cell Superconducting Cavity Under IIFC Collaboration

871

A. Puntambekar, M. Bagre, J. Dwivedi, P.D. Gupta, R.K. Gupta, S.C. Joshi, G.V. Kane, R.S. Sandha, S.D. Sharma, P. Shrivastava
RRCAT, Indore (M.P.), India
C.A. Cooper, M.H. Foley, T.N. Khabiboulline, C.S. Mishra, J.P. Ozelis, A.M. Rowe, G. Wu
Fermilab, Batavia, USA
V. Jain
IIT, Mumbai, India
D. Kanjilal, K.K. Mistri, P.N. Potukuchi, J. Sacharias
IUAC, New Delhi, India
V.C. Sahni
Homi Bhbha National Institute (HBNI), DAE, Mumbai, India

Under Indian Institutions Fermilab collaboration (IIFC), Raja Ramanna Centre for Advanced Technology (RRCAT) Indore, Inter University Accelerator Centre (IUAC) New Delhi and Fermi National Accelerator Laboratory (FNAL) have developed two prototype 1.3 GHz niobium single cell superconducting cavities. Development of forming tools, forming of half cells, machining of components, development of welding fixtures along with RF & vacuum qualification were carried out at RRCAT. The electron beam welding was carried out at IUAC. The fabricated prototype cavities were tested for RF and vacuum leak tightness up to 77 K at RRCAT before shipment to FNAL. Processing, consisting of CBP, EP, and heat treatment was carried out jointly by FNAL and Argonne National Laboratory in USA. Both the prototype cavities were tested at 2 K in the VTS facility at FNAL and have achieved the accelerating gradient of ~ 19 to 21 MV/m with Q > 1.5 ·10⁺¹⁰. This paper will report the developmental efforts carried out in tooling, forming, machining, welding & various qualification procedures adopted. The paper will also present the processing and the 2 K test results.

FROBS5

1.3 GHz Superconducting RF Cavity Program at Fermilab

2586

C.M. Ginsburg, T.T. Arkan, S. Barbanotti, H. Carter, M.S. Champion, L.D. Cooley, C.A. Cooper, M.H. Foley, M. Ge, C.J. Grimm, E.R. Harms, A. Hocker, R.D. Kephart, T.N. Khabiboulline, J.R. Leibfritz, A. Lunin, J.P. Ozelis, Y.M. Pischalnikov, A.M. Rowe, W. Schappert, D.A. Sergatskov, A.I. Sukhanov, G. Wu
Fermilab, Batavia, USA

Funding: Work supported by Fermi Research Alliance, LLC under contract DE-AC02-07CH11359 with the U.S. Department of Energy.
At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules, for Project X, an International Linear Collider, or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described.

Slides FROBS5 [3.749 MB]

Paper	Title	Page
WEOBS5	Status of the Short-Pulse X-ray Project (SPX) at the Advanced Photon Source (APS)	1427
	R. Nassiri, N.D. Arnold, G. Berenc, M. Borland, D.J. Bromberek, Y.-C. Chae, G. Decker, L. Emery, J.D. Fuerst, A.E. Grelick, D. Horan, F. Lenkszus, R.M. Lill, V. Sajaev, T.L. Smith, G.J. Waldschmidt, G. Wu, B.X. Yang, A. Zholents ANL, Argonne, USA J.M. Byrd, L.R. Doolittle, G. Huang LBNL, Berkeley, California, USA G. Cheng, G. Ciovati, J. Henry, P. Kneisel, J.D. Mammosser, R.A. Rimmer, L. Turlington, H. Wang JLAB, Newport News, Virginia, USA
	Funding: Work at Argonne is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11354. The Advanced Photon Source Upgrade project (APS-U) at Argonne includes implementation of Zholents’* deflecting cavity scheme for production of short x-ray pulses. This is a joint project between Argonne National Laboratory, Thomas Jefferson National Laboratory, and Lawrence Berkeley National Laboratory. This paper describes performance characteristics of the proposed source and technical issues related to its realization. Ensuring stable APS storage ring operation requires reducing quality factors of these modes by many orders of magnitude. These challenges reduce to those of the design of a single-cell SC cavity that can achieve the desired operating deflecting fields while providing needed damping of all these modes. The project team is currently prototyping and testing several promising designs for single-cell cavities with the goal of deciding on a winning design in the near future. *A. Zholents et al., NIM A 425, 385 (1999).
	Slides WEOBS5 [1.730 MB]

WEOCS7	Crab Cavity and Cryomodule Prototype Development for the Advanced Photon Source	1472
	H. Wang, G. Cheng, G. Ciovati, W.A. Clemens, J. Henry, P. Kneisel, P. Kushnick, K. Macha, J.D. Mammosser, R.A. Rimmer, G. Slack, L. Turlington JLAB, Newport News, Virginia, USA R. Nassiri, G.J. Waldschmidt, G. Wu ANL, Argonne, USA
	Funding: Work is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11354. Two single-cell, superconducting, squashed elliptical crab cavities with waveguides to damp Higher Order Modes (HOM) and Lower Order Mode (LOM) have been designed and prototyped for the Short Pulse X-ray (SPX) project at the Advanced Photon Source (APS). The Baseline cavity with LOM damper on the beam pipe has been vertically tested and exceeded its performance specification with over 0.5MV deflecting voltage. The Alternate cavity design which uses an “on-cell” waveguide damper is preferred due to its larger LOM impedance safety margin. Its prototype cavity has been fabricated by a Computer Numerical Controlled (CNC) machine and is subject to further testing. The conceptual design, layout and analysis for various cryomodule components are presented.
	Slides WEOCS7 [7.008 MB]

TUP066	Three-cell Traveling-wave Superconducting Test Structure	940
	P.V. Avrakhov, A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio, USA S. Kazakov, N. Solyak, G. Wu, V.P. Yakovlev Fermilab, Batavia, USA
	Use of a superconducting traveling wave accelerating (STWA) structure* with a small phase advance per cell rather than a standing wave structure may provide a significant increase of the accelerating gradient in the ILC linac. For the same surface electric and magnetic fields the STWA achieves an accelerating gradient 1.2 larger than TESLA-like standing wave cavities. The STWA allows also longer acceleration cavities, reducing the number of gaps between them. However, the STWA structure requires a SC feedback waveguide to return the few hundreds of MW of circulating RF power from the structure output to the structure input. A test single-cell cavity with feedback was designed, manufactured and successfully tested** demonstrating the possibility of a proper processing to achieve a high accelerating gradient. These results open the way to take the next step of the TW SC cavity development: to build and test a traveling-wave three-cell cavity with a feedback waveguide. The latest results of the single-cell cavity tests are discussed as well as the design of the test 3-cell TW cavity. * P. Avrakhov, et al, Phys. of Part. and Nucl. Let, 2008, Vol. 5, No. 7, p. 597 ** G. Wu, et al, IPAC 2010, THPD048

TUP032	Development of 1.3 GHz Prototype Niobium Single Cell Superconducting Cavity Under IIFC Collaboration	871
	A. Puntambekar, M. Bagre, J. Dwivedi, P.D. Gupta, R.K. Gupta, S.C. Joshi, G.V. Kane, R.S. Sandha, S.D. Sharma, P. Shrivastava RRCAT, Indore (M.P.), India C.A. Cooper, M.H. Foley, T.N. Khabiboulline, C.S. Mishra, J.P. Ozelis, A.M. Rowe, G. Wu Fermilab, Batavia, USA V. Jain IIT, Mumbai, India D. Kanjilal, K.K. Mistri, P.N. Potukuchi, J. Sacharias IUAC, New Delhi, India V.C. Sahni Homi Bhbha National Institute (HBNI), DAE, Mumbai, India
	Under Indian Institutions Fermilab collaboration (IIFC), Raja Ramanna Centre for Advanced Technology (RRCAT) Indore, Inter University Accelerator Centre (IUAC) New Delhi and Fermi National Accelerator Laboratory (FNAL) have developed two prototype 1.3 GHz niobium single cell superconducting cavities. Development of forming tools, forming of half cells, machining of components, development of welding fixtures along with RF & vacuum qualification were carried out at RRCAT. The electron beam welding was carried out at IUAC. The fabricated prototype cavities were tested for RF and vacuum leak tightness up to 77 K at RRCAT before shipment to FNAL. Processing, consisting of CBP, EP, and heat treatment was carried out jointly by FNAL and Argonne National Laboratory in USA. Both the prototype cavities were tested at 2 K in the VTS facility at FNAL and have achieved the accelerating gradient of ~ 19 to 21 MV/m with Q > 1.5 ·10⁺¹⁰. This paper will report the developmental efforts carried out in tooling, forming, machining, welding & various qualification procedures adopted. The paper will also present the processing and the 2 K test results.

FROBS5	1.3 GHz Superconducting RF Cavity Program at Fermilab	2586
	C.M. Ginsburg, T.T. Arkan, S. Barbanotti, H. Carter, M.S. Champion, L.D. Cooley, C.A. Cooper, M.H. Foley, M. Ge, C.J. Grimm, E.R. Harms, A. Hocker, R.D. Kephart, T.N. Khabiboulline, J.R. Leibfritz, A. Lunin, J.P. Ozelis, Y.M. Pischalnikov, A.M. Rowe, W. Schappert, D.A. Sergatskov, A.I. Sukhanov, G. Wu Fermilab, Batavia, USA
	Funding: Work supported by Fermi Research Alliance, LLC under contract DE-AC02-07CH11359 with the U.S. Department of Energy. At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules, for Project X, an International Linear Collider, or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described.
	Slides FROBS5 [3.749 MB]