Thermal Analysis and Loss in Shunt Impedance of the LEP Accelerating Cell

Basic formulae governing thermal flow in water-cooled solids are qiven. By calculating the heat dissipation at room temperature of the LEP accelerating cell with the program SUPERFISH and then using this as input to the thermal analysis program DOT, the surface temperatures and losses at full power have been estimated. Good agreement is obtained when these LEP results are scaled and compared with measurements made on similar accelerating structures in PEP and PETRA. The calculated decrease in shunt impedance of 4.2% with respect to the room temperature value has been stubstantiated by experimental measurements on a prototype LEP cavity.