학술논문
High-Power Test of Two Prototype X-Band Accelerating Structures Based on SwissFEL Fabrication Technology
Document Type
Periodical
Author
Millar, W.L.; Grudiev, A.; Wuensch, W.; Lasheras, N.C.; McMonagle, G.; Zennaro, R.; Craievich, P.; Bopp, M.; Lucas, T.G.; Volpi, M.; Paszkiewicz, J.; Edwards, A.; Wegner, R.; Bursali, H.; Woolley, B.; Magazinik, A.; Syratchev, I.; Vnuchenko, A.; Pitman, S.; Romano, V.d.P.; Caballero, D.B.n.; Burt, G.
Source
IEEE Transactions on Nuclear Science IEEE Trans. Nucl. Sci. Nuclear Science, IEEE Transactions on. 70(1):1-19 Jan, 2023
Subject
Language
ISSN
0018-9499
1558-1578
1558-1578
Abstract
This article presents the design, construction, and high-power test of two $X$ -band radio frequency (RF) accelerating structures built as part of a collaboration between CERN and the Paul Scherrer Institute (PSI) for the compact linear collider (CLIC) study. The structures are a modified “tuning-free” variant of an existing CERN design and were assembled using Swiss free electron laser (SwissFEL) production methods. The purpose of the study is two-fold. The first objective is to validate the RF properties and high-power performance of the tuning-free, vacuum brazed PSI technology. The second objective is to study the structures’ high-gradient behavior to provide insight into the breakdown and conditioning phenomena as they apply to high-field devices in general. Low-power RF measurements showed that the structure field profiles were close to the design values, and both structures were conditioned to accelerating gradients in excess of 100 MV/m in CERN’s high-gradient test facility. Measurements performed during the second structure test suggest that the breakdown rate (BDR) scales strongly with the accelerating gradient, with the best fit being a power law relation with an exponent of 31.14. In both cases, the test results indicate that stable, high-gradient operation is possible with tuning-free, vacuum brazed structures of this kind.