PAC2013 - List of Authors (Brandon, J.F.)

Paper	Title	Page
MOPMA20	Phase Stability of the RF Reference Line for the FRIB Linac	342
	Q. Zhao, J.F. Brandon NSCL, East Lansing, Michigan, USA D. Morris, Y. Yamazaki FRIB, East Lansing, Michigan, USA
	Funding: supported by the US Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 The phase stability of rf reference line is usually quite restricted in a high energy linac (very long linac, very high frequency). Due to the change of the ambience temperature in the linac tunnel, the electrical length of reference rf cables may change significantly, which results in unacceptable phase changes in cavities. So, sometimes the reference line is very expensive, for example, made of optical fiber housed in a lengthy thermostatic chamber. The frequencies of FRIB linac cavities are 80.5 and 322 MHz (not very high). We also take advantage of the double-folded linac geometry and feed the reference line in the center of the linac to effectively reduced the reference line by 6 times. Our studies show that the FRIB linac can tolerate up to 12ps phase stability of the rf reference line. Therefore, no special treatment is needed for the reference line.

Paper

Title

Page

Phase Stability of the RF Reference Line for the FRIB Linac

342

Q. Zhao, J.F. Brandon
NSCL, East Lansing, Michigan, USA
D. Morris, Y. Yamazaki
FRIB, East Lansing, Michigan, USA

Funding: supported by the US Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
The phase stability of rf reference line is usually quite restricted in a high energy linac (very long linac, very high frequency). Due to the change of the ambience temperature in the linac tunnel, the electrical length of reference rf cables may change significantly, which results in unacceptable phase changes in cavities. So, sometimes the reference line is very expensive, for example, made of optical fiber housed in a lengthy thermostatic chamber. The frequencies of FRIB linac cavities are 80.5 and 322 MHz (not very high). We also take advantage of the double-folded linac geometry and feed the reference line in the center of the linac to effectively reduced the reference line by 6 times. Our studies show that the FRIB linac can tolerate up to 12ps phase stability of the rf reference line. Therefore, no special treatment is needed for the reference line.