Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-24T16:36:36.839Z Has data issue: false hasContentIssue false
  • English
  • Français

Effects of Structural Behavior on Electromagnetic Resonance Frequency of a Superconducting Radio Frequency Cavity

Published online by Cambridge University Press:  05 May 2011

M.-C. Lin ,
Ch. Wang ,
L.-H. Chang ,
M.-K. Yeh  and
F.-S. Kao
M.-C. Lin*
Affiliation:
Light Source Division, National Synchrotron Radiation Research Center, Hsinchu, Taiwan 30076, R.O.C.
Ch. Wang*
Affiliation:
Light Source Division, National Synchrotron Radiation Research Center, Hsinchu, Taiwan 30076, R.O.C.
L.-H. Chang*
Affiliation:
Light Source Division, National Synchrotron Radiation Research Center, Hsinchu, Taiwan 30076, R.O.C.
M.-K. Yeh*
Affiliation:
Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan 30013, R.O.C.
F.-S. Kao*
Affiliation:
Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan 30013, R.O.C.
*
*Associate Scientist
**Scientist
*Associate Scientist
***Professor
****Master student
Get access

Abstract

During operation, a superconducting radio frequency cavity is cooled down to below critical superconducting temperature by liquid helium. Thus it is under external pressure by liquid helium while an ultrahigh vacuum inside. Being a niobium-made shell structure, the SRF cavity's shape and consequently the electromagnetic resonance frequency are sensitive to external load variations. A CESR-III 500MHz superconducting radio frequency cavity is illustrated to investigate this relationship. A simulation that links the calculations on mechanical structure and radio frequency electromagnetic field with the finite element code ANSYS® is demonstrated herein. The changes of electromagnetic resonance frequency associated with external loads and mechanical properties of niobium are studied systematically. A complete understanding on the mechanism is thus achieved. The computed results also indicate that the electromagnetic resonance frequency increases as the cavity is either cooled to cryogenic temperature or stretched longitudinally, while the reduction of the helium vessel pressure also raises the resonance frequency. Besides, the electromagnetic resonance frequency shift is ruled by the coefficient of thermal expansion when the cavity is cooled from room temperature to liquid helium temperature. Young's modulus and thickness of the cavity wall dominate the structure stiffness and thus also affect the frequency shift.

Keywords

SRF cavityResonance frequencyShellCryogenic temperature.
Type
Articles
Information
Journal of Mechanics , Volume 23 , Issue 3 , September 2007 , pp. 187 - 196
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Padamsee, H., Barnes, P., Chen, C., Hartung, W., Kirchgessner, J., Moffat, D., Ringrose, R., Rubin, D., Samed, Y., Saraniti, D., Sears, J., Shu, Q. S. and Tigner, M., “Design Challenges for High Current Storage Rings,” Part. Accel., 40, pp. 17–41 (1992).Google Scholar
2.Wang, Ch., Chang, L. H., Chang, S. S., Hsiao, F. Z., Lin, M. C., Luo, G. H., Yang, T. T., Yeh, M. S., Kuo, C. C., Sah, R. and Chen, C. T., “Superconducting RF Project at the Synchrotron Radiation Research Center,” Proc. 10th Workshop on RF Superconductivity, Tsukuba, Japan, pp. 34–38 (2001).Google Scholar
3.Dallin, L. O., Blomqvist, I., de Jong, M., Hallin, E., Lowe, D. S. and Silzer, R. M., “The Canadian Light Source: An Update,” Proc. PAC 2001, Chicago, USA, pp. 2680–2682 (2001).Google Scholar
4.Rao, M. G. and Kneisel, P., “Mechanical Properties of High RRR Niobium,” Adv. Cryo. Eng., 40, pp. 1383–1390(1994).Google Scholar
5.Ishio, K., Kikuchi, K., Kusano, J., Mizumoto, M., Mukugi, K., Naito, A., Ouchi, N., Tsuchiya, Y. and Saito, K., “Fracture Toughness and Mechanical Properties of Pure Niobium and Welded Joints for Superconducting Cavities at 4K,” Proc. 9th Workshop on RF Superconductivity, Santa Fe, New Mexico, USA, pp. 319–323 (1999).Google Scholar
6.Buhler, S., “Supplement of Worksheets and Useful Data,” Materials of Short Course in Cryogenics, Hsinchu, Taiwan, May (1999).Google Scholar
7.Chen, C. H. and Hsu, S. Y., “Equivalent Fixed-Base Model for Soil-Structure Interaction Analysis,” Journal of Mechanics 22, pp. 167–180 (2006).CrossRefGoogle Scholar
8.Hasheminejad, S. M., “Acoustical Scattering by a Fluid-Encapsulating Spherical Viscoelastic Membrane Including Thermoviscous Effects,” Journal of Mechanics, 21, pp. 205–215(2005).CrossRefGoogle Scholar
9.Rimmer, R. A., Koehler, G., Li, D., Hartman, N., Folwell, N., Hodgson, J., Ko, K., and McCandless, B., “PEP-II RF Cavity Revisited,” LBNL Report, No. LBNL-45136, SLAC Report No. LCC-0032 (1999).CrossRefGoogle Scholar
10.Rimmer, R. A., Corlett, J. N., Koehler, G., Li, D., Hartman, N., Rasson, J. and Saleh, T., “RF Cavity R” FY1999, SLAC Report No. LCC-0033 (1999).Google Scholar
11.Lin, M. C., Wang, Ch., Chang, L. H., Luo, G. H., Chou, P. J. and Huang, M. J., “A Coupled-Field Analysis on RF Cavity,” Proc. PAC 2001, Chicago, USA, pp. 1207–1209 (2001).Google Scholar
12.Lin, M. C., Wang, Ch., Chang, L. H., Luo, G. H., Kao, F. S., Yeh, M. K. and Huang, M. J., “A Coupled-Field Analysis on a 500MHz Superconducting Radio Frequency Niobium Cavity,” Proc. EPAC 2002, Paris, France, pp. 2259–2261 (2002).Google Scholar
13.Lin, M. C., Yeh, M. K., Kao, F. S., Wang, Ch. And Chang, L. H., Proc. 26th Conf. on Theo. And Appl. Mech.Taiwan, ROC, paper ID O003 (2002).Google Scholar
14.Lin, M. C., Wang, Ch., Chang, L. H., Luo, G. H. and Yeh, M. K., “Effects of Material Properties on Resonance Frequency of a CESR-III Type 500 MHz SRF Cavity,” Proc. of 2003 Part. Accel. Conf., Portland, Oregon, USA, pp. 1372–1373 (2003).Google Scholar
15.Losito, R. and Marque, S., “Coupled Analysis of Electromagnetic, Thermo-Mechanical Effects on RF Accelerating Structures,” Proc. EPAC 2002, Paris, France, pp. 2166–2168 (2002).Google Scholar
16.ANSYS Element Reference, 000853, Ninth Ed., SAS IP Inc. (1997).Google Scholar
17.ANSYS Theory Reference, 000855, Eighth Ed., SAS IP, Inc. (1996).Google Scholar
18.Chang, D. K., Field and Wave Electromagnetics, 2nd Ed., Addison-Wesley (1989).Google Scholar
19.Kirchgessner, J., “Thoughts on the Very High Value of dF/dP or Pressure Sensitivity of the B Cell Cavity in the MTM Cryostat,” CESR Report SRF-940321–01, Cornell University (1994).Google Scholar
20.Padamsee, H., Knobloch, J. and Hays, T., RF Superconductivity for Accelerators, John Wiley & Sons, Inc., New York (2000).Google Scholar
21.Pekeler, M., “Factory Acceptance Test of First Superconducting 500 MHz Module for SRRC,” ACCEL Report, No. A-BP-1201-A, Oct. (2002).Google Scholar
22.Flynn, T., Cryogenic Engineering, Marcel Dekker, (1997).Google Scholar
23.HEPAK, A Commercial Available Computer Program, CRYODATA, Inc., Louisville Colorado, USA.Google Scholar