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[en] The new 9 inch hemispherical photomultiplier tubes (PMTs) produced by Hainan Zhanchuang Photonics Technology Co.Ltd (HZC) have been studied. The tube shows good transit time spread (FWHM=2.35 ns), nonlinearity (5% to 750 photoelectrons), good charge resolution with single photoelectron (PE) and high stable operation gain (1× 10⁷). Totally 13 tubes are measured for a prototype detector of JUNO at IHEP, China.

[en] With more and more large-scale scientific facilities are built, more and more HPC requirements are needed in IHEP. RDMA is a technology that allows servers in a network to exchange data in main memory without involving the processor, cache or operating system of either server, which can provide high bandwidth and low latency. There are two RDMA technologies which were InfiniBand and a relative newcomer called RoCE – RDMA over Converged Ethernet. This paper introduces the RoCE technology, we research and compare the performance of both IB and RoCE in IHEP data center, and we also evaluate the application scenarios of RoCE which can support our future technology selection in HEPS. In the end, we present our future plan.

[en] The Data Centre is part of the Nuclear Spectroscopy Laboratory in the Neutron Research Department of the Petersburg Nuclear Physics Institute (PNPI), and covers the work of three physicists and one mathematician. Our main activity is connected with information support of fundamental research nuclear reactor technologies, and the evaluation of nuclear data for nuclear spectroscopy.

[en] HTCondor was adopted to manage the High Throughput Computing (HTC) cluster at IHEP in 2016. In 2017 a Slurm cluster was set up to run High Performance Computing (HPC) jobs. To provide accounting services for these two clusters, we implemented a unified accounting system named Cosmos. Multiple workloads bring different accounting requirements. Briefly speaking, there are four types of jobs to account. First of all, 30 million single-core jobs run in the HTCondor cluster every year. Secondly, Virtual Machine (VM) jobs run in the legacy HTCondor VM cluster. Thirdly, parallel jobs run in the Slurm cluster, and some of these jobs are run on the GPU worker nodes to accelerate computing. Lastly, some selected HTC jobs are migrated from the HTCondor cluster to the Slurm cluster for research purposes. To satisfy all the mentioned requirements, Cosmos is implemented with four layers: acquisition, integration, statistics and presentation. Details about the issues and solutions of each layer will be presented in the paper. Cosmos has run in production for two years, and the status shows that it is a well-functioning system, also meets the requirements of the HTCondor and Slurm clusters.

[en] The test stand of CADS Injector I is built at the Institute of High Energy Physics (IHEP). The 3.2 MeV, 10 mA beam from the RFQ will be transported and matched by medium energy transport line (MEBT1) to the superconductive accelerating section. To minimize the beam loss from mismatch, the Twiss parameters at the exit of RFQ should be got. The method of scanning quadrupole strength with wire scanner is used in CADS Injector I. As to the data process, the traditional method based on matrix will bring errors for high intensity accelerators, especially at low energy when the space charge force is very strong. This paper introduces the traditional method and the new method considering space charge effect, which is based on MOGA. The result proves that the space charge should be considered when calculating the Twiss parameters for high intensity low energy accelerators. (authors)

[en] A typical HEP Computing Center normally runs at least one batch system. As an example, at IHEP (Institute of High Energy Physics, Chinese Academy of Sciences), we’ve used three batch systems: PBS, HTCondor and SLURM. After running PBS as a local batch system for 10 years, we replaced it by HTCondor (for HTC) and SLURM (for HPC). During that period, problems came up on both user and admin sides. Introduction of the new batch systems implies necessity for users to acquire additional knowledge specific for every batch system, in particular, batch commands. In some cases, users have to use both HTCondor and SLURM in parallel. Furthermore, HTCondor and SLURM provide more functionality, which means more complicated usage mode, compared to the simple PBS commands. On admin side, HTCondor gives more freedom to users, which brings an additional challenge to site administrators. Site administrators have to find the solutions for many problems: preventing users from requesting the resources they are not allowed to use, checking if the required attributes are correct, deciding where requested resources are located (SLURM cluster, the cluster of the virtual machines, the remote sites, etc). To meet the above requirements, HepJob was designed and developed. HepJob provides a set of simple user commands, for example: hep_sub, hep_q, hep_rm, etc. In the submission process, HepJob checks all the attributes and ensures all attributes are correct; assigns proper resources to users (the user and group info is obtained from the management database); routes jobs to the target site; performs other steps as required. Users can start with HepJob very easily and administrators can take the necessary management actions in HepJob.

[en] The C-ADS Inject-I test facility is under construction in IHEP. An interlock system based on redundancy PLC is developed for machine protection and personnel safety. Device status, radiation dose, temperature of cavities and chambers are collected for machine state judge and interlock . A MPS (Machine Protection System) are working together with the interlock system in the control loop, and protect the machine in Four levels for different situations. (author)

[en] HTCondor has been widely adopted by HEP clusters to provide high-level scheduling performance. Unlike other schedulers, HTCondor provides loose management of the worker nodes. We developed a maintenance automation tool called “HTCondor MAT” that focuses on dynamic resource management and automatic error handling. A central database records all worker node information, which is sent to the worker node for the startd configuration. If an error happens for the worker node, the node information stored in the database is updated and the worker node is reconfigured with the new node information. The new configuration stops the startd from accepting error-related jobs until the worker node recovers. The MAT has been deployed in the IHEP HTC cluster to provide a central way to manage the worker nodes and remove the impacts of errors on the worker nodes automatically.

[en] Studies on the steering of particle beams using channeling in aligned bent crystals have been performed at IHEP for many years. Different types of extraction schemes with bent crystals and technical equipment have been developed for experiments to test new crystal devices and to study beam collimation processes. A special apparatus has been designed to control the crystal extraction system. In this article, we describe the crystal devices and in-vacuum goniometers, the beam diagnostic tools (intensity and profile measurements), and the beam feedback system.