Since synchrotron radiation sources have many advanced characteristics such as high radiation power, high brightness, broad spectral range, transverse coherence, and excellent time structure, they have become powerful tools for exploring microscopic material structures. With the growing demand for industrial researches, several dedicated industrial light sources are under operation or...
Currently, a conventional local bump injection system with four pulsed dipole kicker magnets is adopted in the HLS-II storage ring to achieve top-off operation. Due to the nonlinear magnetic elements between the kickers in the HLS-II storage ring, the local bump injection presents technical challenges in forming a perfect closed bump, which causes the oscillation of the stored beam. In order...
A novel wireless method for beam coupling impedance measurements is currently under development, with preliminary measurements on beam pipes serving as proof of concept for its validity. This innovative approach overcomes the limitations of existing methods by not only evaluating impedance with high accuracy but also enabling the characterization of an unknown Device Under Test (DUT) as it...
In this paper we present the development of a 1-meter high-efficiency C-band travelling wave (TW) accelerating structure for the proposed Jinhua Light Source (JHLS) project including the design and cold test. This C-band structure works at a mode of 3π/4 with a relatively low group velocity varying from 0.016c to 0.009c. It employs a cell shape with elliptical irises and circular arc tops to...
In this paper, a multi-layer ionization chamber is designed for the measurement of 250MeV proton beam profile. The chamber is equipped with 128 X and Y channels, allowing for high-resolution profiling of the proton beam across both transverse axes. Each channel is capable of detecting ionization events, providing precise dose measurements and spatial distribution information. The design...
A novel travelling-wave (TW) deflector with variable polarization has been proposed and studied by researchers at CERN, DESY and PSI. The dual polarization mode coupler is the key component generating circular polarization TE11 mode into the structure from axis. In this paper, a design of side-coupling TW deflector with variable polarization realized by a phase shifter and E-hybrid is proposed...
This paper presents the design, fabrication and cold-test of a C-band spherical pulse compressor for the proposed Jinhua Light Source (JHLS) project. It utilizes a spherical resonant cavity working with two orthogonal polarized TE114 modes for storing energy, and a novel mode coupler for transferring power and converting modes. This pulse compressor is expected to achieve an average power gain...
Higher-Order Modes (HOMs) in superconducting radiofrequency (SRF) cavities are traditionally considered detrimental to efficient operation. They are often associated with beam instabilities and are actively damped. However, these “harmful” HOMs, if used strategically, can be transformed into a tool for providing extra control over the beam, which can introduce new opportunities that are not...
In this paper we desgin a X-band two-stage pulse compression system based on barrel open cavity (BOC), which is driven by a 6-MW X-band klystron. By utilizing numerous coupling holes surrounding the resonant cavity, a rotating-wave-like mode is excited in BOC, thereby enabling an extremely high Q-factor over 2.3×10$^5$ at 11.424 GHz. A RF pulse can be flattened through the employment of the...
Capability for generating an attosecond bunch can provide interesting opportunities to wakefield accelerator research. We have been studying requirements and challenges in beam dynamics to produce an attosecond bunch using an existing beamline at Argonne Wakefield Accelerator (AWA) facility. One unavoidable limitation of this study is that conventional C-typed chicane is not available. Thus, a...
