2011 Particle Accelerator Conference - List of Authors (Fuerst, J.D.)

Paper

Title

Page

RF and Structural Analysis of the 72.75 MHz QWR for the ATLAS Upgrade

1325

T. Schultheiss, J. Rathke
AES, Medford, NY, USA
J.D. Fuerst, M.P. Kelly, P.N. Ostroumov
ANL, Argonne, USA

Funding: This work was supported by Argonne National Lab under contract # 0F-32381 & 0F32422
An energy upgrade to the heavy-ion accelerator ATLAS at Argonne Lab is progressing*,**. The plans include replacing split-ring cavities with high performance quarter wave resonators. The new 72.75 MHz resonators are designed for optimum ion velocity β=.077 and a record high accelerating voltage of 2.5 MV by modifying the top geometry and reducing the peak surface fields. This new cavity has a longer center conductor than the 10⁹ MHz cavities previously built by ANL with AES assistance, this and the other geometry changes add new engineering requirements to the design. This paper presents the engineering studies that were performed to resolve new issues. These studies include determining structural frequencies of the center conductor and stiffening methods, resonator frequency sensitivity to helium pressure fluctuations, and determining stress levels due to pressure and slow tuning. Evaluation of fast piezoelectric tuner frequency shift to tuner load was also performed and the local cavity shape was optimized based on these results.
* P.N. Ostroumov, et.al, “A New Atlas Efficiency and Intensity Upgrade Project,” SRF2009, tuppo016
** P.N. Ostroumov, et.al., “Efficiency and Intensity Upgrade of the Atlas Facility,” LINAC 2010, MOP045

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]

Paper	Title	Page
TUP270	RF and Structural Analysis of the 72.75 MHz QWR for the ATLAS Upgrade	1325
	T. Schultheiss, J. Rathke AES, Medford, NY, USA J.D. Fuerst, M.P. Kelly, P.N. Ostroumov ANL, Argonne, USA
	Funding: This work was supported by Argonne National Lab under contract # 0F-32381 & 0F32422 An energy upgrade to the heavy-ion accelerator ATLAS at Argonne Lab is progressing,. The plans include replacing split-ring cavities with high performance quarter wave resonators. The new 72.75 MHz resonators are designed for optimum ion velocity β=.077 and a record high accelerating voltage of 2.5 MV by modifying the top geometry and reducing the peak surface fields. This new cavity has a longer center conductor than the 10⁹ MHz cavities previously built by ANL with AES assistance, this and the other geometry changes add new engineering requirements to the design. This paper presents the engineering studies that were performed to resolve new issues. These studies include determining structural frequencies of the center conductor and stiffening methods, resonator frequency sensitivity to helium pressure fluctuations, and determining stress levels due to pressure and slow tuning. Evaluation of fast piezoelectric tuner frequency shift to tuner load was also performed and the local cavity shape was optimized based on these results. P.N. Ostroumov, et.al, “A New Atlas Efficiency and Intensity Upgrade Project,” SRF2009, tuppo016 ** P.N. Ostroumov, et.al., “Efficiency and Intensity Upgrade of the Atlas Facility,” LINAC 2010, MOP045

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]