LINAC2014 - List of Authors (Davis, G.K.)

Paper	Title	Page
MOPP134	Superconducting Accelerating Cavity Pressure Sensitivity Analysis and Stiffening	373
	J. Rodnizki, Y. Ben Aliz, A. Grin, Z. Horvitz, A. Perry, L. Weissman Soreq NRC, Yavne, Israel G.K. Davis JLab, Newport News, Virginia, USA J.R. Delayen ODU, Norfolk, Virginia, USA
	The SARAF Prototype Superconducting Module (PSM) houses six 176 MHz Half Wave Resonators(HWR). The PSM accelerates protons and deuterons from 1.5 MeV/u to 4 and 5.6 MeV. The HWRs are highly sensitive to the coolant liquid Helium pressure fluctuations which limit the available beam power to 2kW per cavity out of 4kW RF amplifier and coupler and so might limit the available beam current to 2mA depending on the output energy. The flat shape of the cavity along the beam line in the area of the high electric field generates the high sensitivity of the Eigen mode frequency to helium pressure. The evaluated cavity sensitivity is full consistent with the measured values. It was explored that the tuning system (the fog structure) has a significant contribution to the cavity sensitivity. By using ribs or by modifying the rigidity of the fog we may reduce the HWR sensitivity by a factor of 3. This analysis is applied to study the stresses on the cavity during cool down and warm up to avoid plastic deformation as the Niobium yield is an order of magnitude lower in room temperature.

Paper

Title

Page

Superconducting Accelerating Cavity Pressure Sensitivity Analysis and Stiffening

373

J. Rodnizki, Y. Ben Aliz, A. Grin, Z. Horvitz, A. Perry, L. Weissman
Soreq NRC, Yavne, Israel
G.K. Davis
JLab, Newport News, Virginia, USA
J.R. Delayen
ODU, Norfolk, Virginia, USA

The SARAF Prototype Superconducting Module (PSM) houses six 176 MHz Half Wave Resonators(HWR). The PSM accelerates protons and deuterons from 1.5 MeV/u to 4 and 5.6 MeV. The HWRs are highly sensitive to the coolant liquid Helium pressure fluctuations which limit the available beam power to 2kW per cavity out of 4kW RF amplifier and coupler and so might limit the available beam current to 2mA depending on the output energy. The flat shape of the cavity along the beam line in the area of the high electric field generates the high sensitivity of the Eigen mode frequency to helium pressure. The evaluated cavity sensitivity is full consistent with the measured values. It was explored that the tuning system (the fog structure) has a significant contribution to the cavity sensitivity. By using ribs or by modifying the rigidity of the fog we may reduce the HWR sensitivity by a factor of 3. This analysis is applied to study the stresses on the cavity during cool down and warm up to avoid plastic deformation as the Niobium yield is an order of magnitude lower in room temperature.