Progress and Experiences of Series Production of Helium Tanks With DESY as a Subcontractor for RI

DESY act as a subcontractor for helium tanks, for one of the cavity manufacturer in charge, for the XFEL cavity production. Here the full responsibility of production, quality and warranty of these parts is at DESY. Therefore on 400 out of the total of 800 helium tanks, DESY has to set up a logistic of incoming inspection, documentation, storage and distribution. Special effort is made to archive a free of doubts interconnection and integration of the cavity into the helium tank. After more than 300 units produced a review and statistic is provided. INTRODUCTION For the European XFEL project two companies are in charge to provide 824 superconducting cavities, 412 cavities each [1]. The complete fabrication and surface treated of these cavities is done by industry according to XFEL specification. After finalizing the surface treatment and integration into the helium tank, the resonators are handed out to DESY in the status ready for acceptance test and string assembly. The two companies, contracted for fabrication and surface treatment are E. Zanon S.p.A. in Schio Italy (EZ) and Research Instruments in Bergisch Gladbach Germany (RI). One step of the cavity production line is the completion of the cavity with the helium tank. E. Zanon was contracted to manufacture also the helium tanks for their own cavity production. For the RI cavity production the helium tanks are provided by DESY. Basing on a European call for tender; DESY ordered in total 272 helium tanks at the company C.S.C S.p.A. in Schio Italy (CSC) and 146 helium tanks at EZ. INCOMING INSPECTION From April 2012 to September 2013, 300 so called helium tank kits (HTkit) consisting of helium tank (HT), bellow unit (BU), reduction ring (RR), sliding collar (SC) and adapter (AD) were manufactured. After delivery the components of the helium tank kit are tested on a special designed control device at DESY. After the incoming inspection the helium tanks are stored or supplied directly to RI. Due to the complicated measurement, the big amount of captured parameters and a requested production rate of up to 28 units per month, the quality control department of DESY, responsible for all DESY incoming inspections of mechanical products, were not able to cover these additional inspections. Therefore the workshop of the DESY department MKS-3 carried out the work of receiving, storage, testing and prepare for shipment of helium tanks. Control Device To minimize the cost and time for measuring a special control device (CD) (Fig. 1) is developed in cooperation with “Horst Witte Gerätebau Barskamp KG”. The incoming inspection, as designed by DESY, can be done by semi-skilled worker within half an hour. For application of a 3D measuring device people need to be trained very well and approximately 2 hours are needed for this measurement. The CD fixes the helium tank at the machined diameters at the end of the tank tube and gives the reference for the measurement. Four dial gauges at each bracket measure the correct position. For testing the parallelism and evenness of the bracket the dial gauges can slide back and forth. Errors at the parallelism or evenness result in a movement of the index of the dial gauge. Figure 1: Control device with helium tank on place . The correct position of projecting edges, ribs and pins can be measured by sliding a wheel with dial gauges and gauging jigs onto the welded attachments of the helium tank (Fig: 2 and 3). If the parts are on correct position the wheel can be moved without stagnating. For parts that are displaced, the jig will stagnate at the wrong position of the attachment. Also for the helium service pipe gauging jigs show if the position is correct or displaced. Figure 2 and 3: Wheel with dial gauges and gaunging jigs. Proceedings of SRF2013, Paris, France MOP049 09 Cavity preparation and production K. Technical R&D Large scale fabrication ISBN 978-3-95450-143-4 231 C op yr ig ht c ○ 20 13 by th e re sp ec tiv e au th or s