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The Chinese Accelerator Driven Sub-critical system (C-ADS) Injector-I is designed and constructed by the Institute of High Energy Physics (IHEP) of the Chinese Academy of Sciences (CAS) in Beijing, China. The test cryomodule (TCM), housing two 325 MHz spoke cavities and two solenoids and operating at 2 K, has been designed, assembled and commissioned since the beginning of 2012. The C-ADS Injector-I linac with the TCM successfully accelerated the proton beam to 3.68 MeV with the peak current of 10.1 mA in pulse mode. It is the world's first prototype of spoke cavity cryomodule with beam, and is an important step in the qualification of the cryomodule before series productions. This paper describes the detail of the design, operation and thermal performances of the prototype cryomodule. The analysis takes into account the heat loads of the main components (support posts, multilayer insulation and cavities) at various cryogenic temperature levels. The estimated heat loads of the cryomodule have been compared with the available experimental measurements, and the cryogenic deformations by simulation is verified by the experimental measurements by the wire position monitors (WPMs). The operation experiences including the cool down, alignment and heat load measurement are reported. • The 325 MHz spoke cavity prototype cryomodule has been designed, assembled and commissioned. • The thermal performance of the bottom-supported cryomodule has been proved firstly worldwide. • The cryomodule can be in a stable operation at 2 K and 31 mbar with beam. • The operation experiences including the cool down, alignment and measurement of heat loads are reported. • The linac with cryomodule had been accelerated successfully to 3.68 MeV@10.1 mA in pulse mode. [ABSTRACT FROM AUTHOR]

Abstract: A cold neutron radiography/tomography instrument was designed and will soon undergo construction at the Compact Pulsed Hadron Source (CPHS) of Tsinghua University, China. In this paper, we report the physical design of the instrument and propose a scheme to implement several techniques at a later phase to enhance the utilization of the flux on larger samples. This includes code-aperture, grating-based imaging, prompt gamma-ray analysis and 3D emission CT. [Copyright &y& Elsevier]

Abstract: A high power input coupler for a 500MHz superconducting cavity (SCC) of the upgrade project of Beijing Electron Positron Collider (BEPCII) has been developed in China. Several prototypes have been fabricated and tested successfully. A maximum of 420kW continuous wave (CW) RF power in traveling wave (TW) mode was achieved in the high power test. The detailed design, fabrication and test of the coupler are described in this paper. [Copyright &y& Elsevier]

Abstract: Separated Function Radio Frequency Quadrupoles (SFRFQ) structure is a new post accelerator of RFQ, the higher accelerating efficiency and transmission make it become a proper choice for the post acceleration after the integral split ring RFQ (ISR RFQ)-1000 accelerator at Peking University . A novel design strategy is proposed in this paper to avoid the sparking problem and decrease the energy spread at the exit of SFRFQ. Correspondingly, a code SFRFQCODEV1.0 was developed specially for beam dynamic simulations and error studies. A prototype cavity with 14 accelerating gaps has been constructed and tested at low and high RF power successfully. The operating energy region of SFRFQ structure and the results of error study are presented. [Copyright &y& Elsevier]

Abstract: A -delayed neutron detection array composed of a neutron sphere and two neutron walls was constructed in the State Key Laboratory of Nuclear Physics and Technology at Peking University. Recently the performances of this detection array were largely improved and tested with a source, cosmic rays and and radioactive beams. The Tyvek 1056D paper and silicone grease were chosen for the reflection and coupling materials, respectively. For the neutron sphere with large detection solid angle ( of steradian), the intrinsic efficiency is about at a neutron energy of 1MeV and the detection threshold is about 350keV; for the neutron walls with flexible setup, these values are and 200keV, respectively. The combined array of neutron sphere and neutron walls has successfully been applied to measure the -delayed neutrons emitted from neutron-rich unstable nuclei. [Copyright &y& Elsevier]

Abstract: Multi-gap resistive plate chamber (MRPC) is a new kind of gas detector. It has good time resolution and high efficiency and has been adopted to construct the full barrel time-of-flight (TOF) detector for the STAR experiment at RHIC. The high rate TOF of CBM is also proposed to be assembled with MRPCs. Tsinghua University is a collaboration member of the two experiments and has made substantial progress on the R&D and production of MRPC. In this paper, we describe the development of low-resistivity glass and high rate MRPC, and the development of 1m long counter is also described. [Copyright &y& Elsevier]

Abstract: X-ray sources based on Thomson-scattering require strict synchronization between the laser pulse and the electron bunch. Jitter between the laser and the RF phase should be kept within a femtosecond scale to guarantee electron beam quality and the time of flight before impact with the terawatt laser pulse. A laser–RF synchronizer that uses the 36th harmonic of the laser repetition rate was built at Tsinghua University, and it has tested to have a less than 100-fs [10-Hz, 100-kHz] rms time jitter. An RF deflector cavity is used to verify the electron bunch pulse-to-pulse time jitter with respect to the RF accelerating phase in the same condition, and the result shows a 540-fs rms jitter. This paper discusses the synchronization experiment setup, as well as the time jitter measurements under different conditions. [Copyright &y& Elsevier]