Operating the LCLS Gas Attenuator and Gas Detector System with Apertures of 6 mm Diameter

Ryutov, D D ; Bionta, R M ; Hau-Riege, S P ; Kishiyama, K I ; Roeben, M D ; Shen, S ; Stefan, P M

关键词: APERTURES;    MODIFICATIONS;    PERFORMANCE;    PUMPING;    VELOCITY;   

DOI  :  10.2172/945806
RP-ID  :  LLNL-TR-408303
PID  :  OSTI ID: 945806
Others  :  TRN: US200904%%157

学科分类：物理（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

The possibility of increasing the apertures of the LCLS gas attenuator/gas detector system is considered. It is shown that increase of the apertures from 3 to 6 mm, together with 4-fold reduction of the operation pressure does not adversely affect the vacuum conditions upstream or downstream. No change of the pump speed and the lengths of the differential pumping cells is required. One minor modification is the use of 1.5 cm long tubular apertures in the end cells of the differential pumping system. Reduction of the pressure does not affect performance of the gas attenuator/gas detector system at the FEL energies below, roughly, 2 keV. Some minor performance degradation occurs at higher energies.