NSRRC Activity Report 2022

098 NSRRC ACTIVITY REPORT 2022 References 1. C. W. Chen, H. Chen, J. C. Huang, C.-S. Hwang, Phys. Open 11 , 100108 (2022). 2. R. W. Warren, Nucl. Instrum. Methods Phys. Res. A 272 , 257 (1988). 3. D. Arbelaez, T. Wilks, A. Madur, S. Prestemon, S. Marks, R. Schlueter, Nucl. Instrum. Methods Phys. Res. A 716 , 62 (2013). 4. C.-K. Yang, C.-H. Chang, J.-C. Huang, C.-S. Hwang, T.-Y. Chung, IEEE Trans. Appl. Supercond. 24 , 9001205 (2014). Development of an EPU Vacuum System Using Lumped NEG-Ion Combination Pumps N onevaporable getter (NEG) coatings and NEG strips 1 have been extensively used as pumping solutions in synchrotron facilities to address the problem of conductance limitation on pumping speeds in small-aperture insertion device (ID) vacuum chambers. Applying an NEG coating to accelerators is a complex technique that requires technical expertise and substantial upfront investment for the manufacture and operation of a NEG-coated vacuum system; for example, technical expertise is necessary for determining the cleaning processes, coating parameters, activation methods, and neon venting for interventions. For NEG strips ( Fig. 1 ), the beam duct must be equipped with an antechamber that houses the NEG strips and their accessories for activation ( i.e. , alumina supports, aluminum supports, and electrical feedthroughs). A narrow antechamber hinders NEG strip installation, which may generate microparticles caused by friction during NEG strip insertion into the antechamber. To simplify the design and manufacture of ID vacuum chambers and to facilitate installation and maintenance tasks, this study developed a new vacuum design 2 that entails the use of five small lumped ZAO NEG pumps (CapaciTorr Z 200 × 2 and Fig. 2 : NEG cartridge-type vacuum system (5-m length) and cross-sectional views of the NEXTorr and CapaciTorr pumps. [Reproduced from Ref. 2] Fig. 1 : NEG strip-type vacuum system (5-m length) and its inside view. [Reproduced from Ref. 2]