Commissioning and first cooldown of XFEL linac

Cryogenic Engineering Conference 2017

材料科学;物理学

Bozhko, Y.^1 ; Escherich, K.^1 ; Jensch, K.^1 ; Petersen, B.^1 ; Schnautz, T.^1 ; Sellmann, D.^1

Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, Hamburg

22607, Germany^1

关键词: Cooldown evolution;    Cryogenic system;    European xfel;    Leak tests;    Remaining component;    Stationary operations;    Thermal loss;    X-ray free electron lasers;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/278/1/012100/pdf
DOI  :  10.1088/1757-899X/278/1/012100

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Beam commissioning of the European X-ray Free Electron Laser (European XFEL project) is ongoing. Commissioning the XFEL cryogenic system has started by cooling down the XFEL injector section in December 2015. The stationary operation was continued until August 2016. After intermediate warming up of the complete XFEL cryogenic system, the commissioning of remaining components including the 1.5 km long superconducting XFEL linear accelerator (linac) has commenced and was completed in beginning of December 2016. After conclusive pressure and leak tests, and flushing the cooldown started on 11 December 2016. Stable 4.5 K operation both for the linac and injector was established on 28 December. In this paper the XFEL cryogenic system is introduced and the first cooldown of the XFEL linac is reported. The cooldown sequences are described and the measured cooldown evolution is presented. Thermal losses of single circuits are given. Preliminary conclusions with the review of critical points are drawn.