TY - JOUR

T1 - High-Power Test of Two Prototype X-band Accelerating Structures Based on SwissFEL Fabrication Technology

AU - Millar, William L.

AU - Grudiev, Alexej

AU - Wuensch, Walter

AU - Lasheras, Nuria Catalan

AU - McMonagle, Gerard

AU - Zennaro, Riccardo

AU - Craievich, Paolo

AU - Bopp, Markus

AU - Lucas, Thomas G.

AU - Volpi, Matteo

AU - Paszkiewicz, Jan

AU - Edwards, Amelia

AU - Wegner, Rolf

AU - Bursali, Hikmet

AU - Woolley, Benjamin

AU - Magazinik, Anastasiya

AU - Syratchev, Igor

AU - Vnuchenko, Anna

AU - Pitman, Samantha

AU - Romano, Veronica del Pozo

AU - Caballero, David Banon

AU - Burt, Graeme

PY - 2023/1/31

Y1 - 2023/1/31

N2 - 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.

AB - 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.

KW - Electrical and Electronic Engineering

KW - Nuclear Energy and Engineering

KW - Nuclear and High Energy Physics

U2 - 10.1109/tns.2022.3230567

DO - 10.1109/tns.2022.3230567

M3 - Journal article

VL - 70

SP - 1

EP - 19

JO - IEEE Transactions on Nuclear Science

JF - IEEE Transactions on Nuclear Science

SN - 0018-9499

IS - 1

ER -