Related papers: Investigations on the multi-sector hard X-Band Str…
High-gradient linacs of next generation require novel accelerating structures which are compact, robust and cost-effective. Dedicated research and development have been launched in the linear-collider community. This paper focuses on the…
We report the results of high gradient testing of two single cell off axis coupled standing wave accelerating structures. Two brazed standing wave side coupled structures with the same geometry were tested one made of pure copper Cu and one…
High-gradient acceleration is a key research area that could enable compact linear accelerators for future colliders, light sources, and other applications. In the pursuit of high-gradient operation, RF breakdown limits the attainable…
In the development of high efficiency and high gradient RF-accelerators, RF waveguides and cavities have been designed with Photonic Band Gap (PBG) and fishnet- metamaterial structures. The designed structures are comprised of a…
Conditioning of a metal structure in a high-voltage system is the progressive development of resistance to vacuum arcing over the operational life of the system. This is, for instance, seen during the initial operation of radio frequency…
Tsinghua University has designed an X-band (11.424 GHz) slow-wave parallel-coupling accelerating structure, and demonstrated the high performance of the over-coupled structure operating with ultrashort pulse. In this study, we redesigned a…
The cw CCL being designed for the Accelerator Production of Tritium (APT) project accelerates protons from 96MeV to 211MeV. It consists of 99 segments each containing up to seven accelerating cavities. Segments are coupled by intersegment…
The development of Ultra-High Frequency (UHF) linear accelerators via Metal Additive Manufacturing (MAM) is a strategic research focus of the RACERS team at GSI. The 704.4 MHz Crossbar H-mode (CH) cavity, proposed in 2021 to facilitate…
Dielectric disk accelerating (DDA) structures are being studied as an alternative to conventional disk-loaded copper structures. This paper investigates numerically an efficient X-band DDA structure operating at a higher order mode of…
Use of a traveling wave (TW) accelerating structure with a small phase advance per cell instead of standing wave may provide a significant increase of accelerating gradient in a superconducting linear accelerator. The TW section achieves an…
The technological and metallurgical requirements of material for highgradient superconducting cavities are described. High-purity niobium, as the preferred metal for the fabrication of superconducting accelerating cavities, should meet…
Two standing-wave single-cell choke-mode damped structures with different choke dimensions which worked at 11.424 GHz were designed, manufactured and tuned by accelerator group in Tsinghua University. High power test was carried out to…
We present the electromagnetic design study of a multi cell, \beta_g= 0.9, 650 MHz elliptic superconducting radiofrequency cavity, which can be used for accelerating H- particles in the linear accelerator part of a Spallation Neutron…
Normal conducting linear particle accelerators consist of multiple rf stations with accelerating structure cavities. Low-level rf (LLRF) systems are employed to set the phase and amplitude of the field in the accelerating structure, and to…
Presently, the manufacturing of active RF devices like klystrons is dominated by expensive and time consuming cycles of machining and brazing. In this article we characterize the RF properties of X-band klystron cavities and an integrated…
Recent developments in superconducting radio-frequency (SRF) research have focused primarily on high frequency elliptical cavities for electron accelerators. Advances have been made in both reducing RF surface resistance and pushing the…
Nb3Sn is a promising next-generation material for superconducting radiofrequency cavities, with significant potential for both large scale and compact accelerator applications. However, so far, Nb3Sn cavities have been limited to cw…
Conductor materials with good mechanical performance as well as high electrical- and thermal-conductivities are particularly important to break through the current bottle-neck limit ($\sim 100$ T) of pulsed magnets. Here we perform…
RF processing studies of 1.8-m X-band (11.4 GHz) traveling wave structures at the Next Linear Collider Test Accelerator (NLCTA) have revealed breakdown-related damage at gradients lower than expected from earlier tests with standing wave…
X-band accelerator structures meeting the Next Linear Collider (NLC) design requirements have been found to suffer vacuum surface damage caused by radio frequency (RF) breakdown, when processed to high electric-field gradients. Improved…