Fast injection and extraction kicker system design for High rEpetition rate Muon Source at CSNS

Abstract

A non-parasitic muon production facility (HEMS, abbreviation of High rEpetition rate Muon Source) at China Spallation Neutron Source (CSNS) is proposed. HEMS will extract a 500 MeV proton beam from a proton storage ring with a circumference of 80 m to bombard a target on a linear section at a repetition rate of 100 Hz. After bombarding the target, the beam will be injected back into the proton storage ring. The proton beam will be extracted and injected repeatedly to the proton storage ring 20 times within 20 ms. For injection and extraction kicker system, the repetition rate of pulser should be as high as 1 kHz. In addition, to achieve a large kick angle with a high magnet gap aperture in a relatively small beam lattice, kicker pulser is required to generate a large excitation current. The primary challenge is to build a high repetition rate, high current, and fast injection and extraction kicker system. To achieve these requirements, a 6.25 Ω impedance matching kicker system, mainly composed of a twin-C transmission line kicker magnet and inductive adder, is developed. In this paper, we report the conceptual design of the kicker magnet and kicker pulser for HEMS. K: Instrumentation for particle accelerators and storage rings -high energy (linear accelerators, synchrotrons); Instrumentation for synchrotron radiation accelerators; Targets (spallation source targets, radioisotope production, neutrino and muon sources)

A low characteristic impedance quasi-rectangular pulser based on solid-state inductive adder for High rEpetition rate Muon Source at CSNS

“…Furthermore, a life test was conducted on the pulser, with a charging voltage of 700 V and a pulse burst repetition frequency of 1 kHz. The specific timing is the same as figure 2 in reference [1]. After 3 hours of continuous operation, the pulser did not experience any malfunction, and the jitter of the pulse generator was less than 1 ns.…”

“…The exchange of the beams between the storage ring and the linear section depends on the injection and extraction system. Transmission line kicker with a twin-C structure based on distributed L-C cells has been selected as the injection and extraction kicker magnet for the HEMS muon source [1]. To provide sufficient deflection impact and avoid disturbing adjacent cyclic beams, it is required that: (1) The pulser has a pulse power density of tens of megawatts.…”

“…Transmission line kicker with a twin-C structure based on distributed L-C cells has been selected as the injection and extraction kicker magnet for the HEMS muon source [1]. To provide sufficient deflection impact and avoid disturbing adjacent cyclic beams, it is required that: (1) The pulser has a pulse power density of tens of megawatts. (2) The pulser can generate a precise high-voltage and high-current pulse, which imposes extremely stringent requirements on the pulse front/back edge, pulse width, and pulse repetition rate.…”

“…Additionally, pulse transformer is commonly used in unipolar applications, and the magnetic flux density does not fully collapse to zero due to the magnetic core remanence, necessitating the implementation of a reset circuit. In this paper, a DC biasing circuiti is used to reset the magnetic cores [1]. For a pulse transformer, the influence of magnetizing inductance on output pulse signal should be given careful considered.…”

“…A non-parasitic muon production facility, the High rEpetition rate Muon Source (HEMS), has been proposed for construction at the China Spallation Neutron Source (CSNS) for new discoveries in particle physics and material science [1]. One of the main advantages of HEMS is its high beam-target repetition rate.…”