750 MHz inter-digital H-mode drift tube linac (IH-DTL) with the capability to accelerate protons from 3 to 10 MeV was proposed for the compact therpy linac that now under development in the institute of Modern Physics, Chinese Academy of Science (IMP, CAS). Four drift tube sections were housed in a single vacuum chamber and coupled with three large drift tubes which housing focusing triplet...
Linear Accelerators (LINACs) technology is evolving towards compactness and high intensity. As a consequence, these devices are becoming suitable for several industrial and medical applications, such as the upgrade of light sources to the so-called 4-th generation or the design of high-dose rate radio-therapy facilities. In such scenarios, intensity-dependent collective effects can arise and...
To reduce energy consumption and cost has become a prime objective of the development and operation of high energy particle accelerators. RF sources are major energy consumption components of any RF system for the particle colliders. The 30 GeV injector linear accelerator (LINAC) for the CEPC (Circular Electron and Positron Collider) requires S-band klystrons with higher efficiency to reduce...
Nowadays, production of ultrashort and high-current electron bunches of few fs to hundred fs with several pc charge is a very attractive subject in the context of many recent applications, specially, in light sources, free electron lasers and plasma wake field accelerators. In the light sources and free electron lasers, the radiation gain is directly proportional to the beam pick current and...
Dielectric Assist Accelerating (DAA) structures based on ultralow-loss ceramic are being studied as an alternative to conventional disk-loaded copper cavities. This accelerating structure consists of dielectric disks with irises arranged periodically in metallic structures working under the TM02$-\pi$ mode.
Here, the numerical design of an S-band DAA structure for low beta particles, such as...
The THz-frequency range could provide the accelerating gradients needed for next generation accelerators with compact, GV/m-scale devices. One of the most promising THz generation techniques for accelerator applications is optical rectification in lithium niobate using the tilted pulse front method. Current THz accelerators are limited by significant losses during transport of THz radiation...
After years of development, the phase-locked loop technology has gradually tended to maturate. The photoelectric phase-locked loop based on an optical-microwave phase detector can meet the high-precision synchronization requirements of scientific facilities such as UED, XFEL. Whereas, several kinds of noise introduced in the phase detection process will reduce the integrity of the original...
High gradient RF cavities, especially those at frequencies above S-band, are critical in several concepts for future electron linacs such as the ultra-compact X-ray free electron laser (UCXFEL) and the Cool Copper Collider ($C^3$). These two designs in particular rely on the cryogenic operation of RF cavities, taking advantage of several complementary physical effects. It is then advantageous...
The CLARA accelerator (Compact Linear Accelerator for Research and Applications) located at Daresbury Laboratory in the UK has a new 1.5 cell S-band photoinjector designed by ASTeC (Accelerator Science and Technology Centre). The photoinjector underwent RF conditioning between October last year and March this year to obtain a peak E-field of 70MV/m and a pulse length of 2µs. This was carried...
One of the key aspects to provide on chip acceleration in Dielectric Laser Accelerators (DLA) from tens of keV up to MeV energies is the phase velocity tapering.
In this paper, we present simulated performance of sub-relativistic structures, based on tapered slot waveguides and tapered electromagnetic band bap (EBG) waveguides, where we engineered channel/defect modification in order to...
Conditioning of a metal surface in a high-voltage system is the progressive development of resistance to vacuum arcing over the operational life of the system. This is relevant for accelerator cavities where high level of performance is only achievable after long conditioning period. Beyond the accelerator research field, this is an important topic for any technology where breakdowns can cause...
With high shunt impedance and expected gradient, cryogenic structure has the ability to reduce accelerators' length and has the potential to operate at a higher repetition rate. In SSRF/SXFEL, the scheme and preliminary experimental studies about the cryogenic RF structure have been developed. Foremost, theoretical and experimental studies of the RF characteristics in cryogenic environments...
S-band high-gradient accelerating structures were proposed to accelerate protons from 30MeV to 230MeV for a compact therapy Linac in IMP. A backward traveling wave structure and a high gradient standing wave structure were developed, and the differences between the two types of structures were analyzed. In this paper, A new-shaped accelerating structure with reduced coupling holes and thermal...
The occurrence of breakdown events is a primary limiting factor for future accelerator applications aiming to operate under high field-gradient environments. Experimental evidence often leads to a hypothesis that breakdown events are accompanied by elevated temperature and dark current spike due to high asperity nano-structure formation which significantly enhances the local electric field....
Currently SSRF/SXFEL is ongoing to develop the advanced transverse deflecting structure TTDS（Two-mode operation transverse deflecting structure) to carry out variable polarization based on the design of dual-mode RF structure. Driven by two different RF power sources, this novel TDS can work on both HEM11 and HEM12 modes in vertical and horizontal deflecting directions simultaneously, and...
