Journal of Neutron Research - Volume 26, issue 2-3

Authors: Wilcox, Dan | Gallimore, Stephen | Probert, Molly | Jones, Leslie | Skoro, Goran | Quintieri, Lina | Densham, Chris | Loveridge, Peter

Article Type: Research Article

Abstract: A new design of spallation target has been installed and operated at the first target station of the ISIS Neutron and Muon Source (ISIS TS-1), as part of the recently completed “TS-1 Project”. Detailed Finite Element Analysis (FEA) simulations were used to guide the design process and predict target performance. Since the TS-1 Project target began operation in November 2022, operating data has been collected and used to validate the target simulation approach. Measured temperatures of 9 out of 10 target plates showed good agreement with FEA simulations of both steady-state and transient behaviour. However, the front target plate temperature …was elevated compared to predictions. Because the installed target was now too radioactive to permit hands-on inspection, FEA simulations became an indispensable tool to understand the possible causes and safety implications of this anomalous behaviour. The anomalous elevated temperature appears to be highly localised; a combination of simulations and experiments indicates the mostly likely cause is poor thermal contact between the thermocouple and the bulk of the target plate. In all other respects the target is operating as predicted, and is running reliably at up to 120 kW. Show more

Keywords: Spallation, target, ISIS, TS-1, simulation, operation, validation

DOI: 10.3233/JNR-240007

Citation: Journal of Neutron Research, vol. 26, no. 2-3, pp. 47-58, 2024

Authors: Yamamoto, Kazami | Moriya, Katsuhiro | Okita, Hidefumi | Yamada, Ippei | Chimura, Motoki | Saha, Pranab Kumar | Shobuda, Yoshihiro | Tamura, Fumihiko | Yamamoto, Masanobu | Morishita, Takatoshi | Hotchi, Hideaki | Liu, Yong

Article Type: Brief Report

Abstract: The linac and the 3 GeV rapid-cycling synchrotron (RCS) at the Japan Proton Accelerator Research Complex (J-PARC) were designed to provide 1-MW proton beams to the following facilities. Due to the improvement of the accelerator system, we accelerated a 1-MW beam with a small beam loss. The lack of anode current in the radiofrequency (RF) cavity, rather than beam loss, limits the RCS beam power. Recently, we developed a new acceleration cavity that can accelerate a beam with a low anode current. This new cavity enables us to reduce the requirement for the anode power supply and accelerate a beam of …more than 1 MW. We considered how to achieve beam acceleration beyond 1 MW. So far, a beam of up to 1.5 MW is expected to be accelerated after replacing the RF cavity. We also studied to achieve an up to 2 MW beam in J-PARC RCS. Show more

DOI: 10.3233/JNR-240003

Citation: Journal of Neutron Research, vol. 26, no. 2-3, pp. 59-67, 2024

Authors: Teshigawara, Makoto | Ikeda, Yujiro | Muramatsu, Kazuo | Sutani, Koichi | Fukuzumi, Masafumi | Noda, Yohei | Koizumi, Satoshi | Saruta, Koichi | Otake, Yoshie

Article Type: Research Article

Abstract: We have been developing nanosized graphene, called graphene flower, as a material that induces coherent scattering very cold neutrons. Previous experiments have found that the seed part of the graphene flower is more effective than the petal part in increasing the coherent scattering. Based on these results, we found that further modification of the graphene flower to increase the seed portion increased the total cross-section, although it did not reach the level of nanodiamonds.

Keywords: Nanosized material, graphene aggregation, neutron reflector, cold neutrons, very cold neutrons, neutron sources

DOI: 10.3233/JNR-240002

Citation: Journal of Neutron Research, vol. 26, no. 2-3, pp. 69-74, 2024

Authors: Nirei, Masami | Kofu, Maiko | Nakajima, Kenji | Kikuchi, Tatsuya | Ohira-Kawamura, Seiko | Murai, Naoki | Harada, Masahide | Inamura, Yasuhiro

Article Type: Research Article

Abstract: We investigated neutron flux at a sample position and energy resolution of a direct-geometry disk-chopper spectrometer AMATERAS under various chopper conditions and compared them with simulations and calculations. The measured flux was comparable to that of similar high-flux spectrometers. The resolution when using a pulse-shaping chopper correlated well with the analytical calculations, including the thickness of the disk chopper, the sample size, and the penetration depth into the detector. The results show that the chopper, placed at the intermediate distance of the primary spectrometer, functions as a pulse shaper that optimizes the flux and resolution below the incident energy of …10 meV. Show more

Keywords: Disk-chopper spectrometer, AMATERAS, J-PARC

DOI: 10.3233/JNR-230013

Citation: Journal of Neutron Research, vol. 26, no. 2-3, pp. 75-82, 2024

Authors: Stefanescu, Irina | Guérard, Bruno | Hall-Wilton, Richard | Jackson, Andrew | Khaplanov, Anton | Klein, Martin | Lai, Chung-Chuan | Piscitelli, Francesco | Raspino, Davide | Schmidt, Christian J. | Schweika, Werner | Svensson, Per-Olof

Article Type: Research Article

Abstract: The development of detectors for the European Spallation Source is an important parallel element to the effort put into the design and construction of the neutron source and instruments. The 10 Boron-film-based detector developments that started over a decade ago as basic detector concepts have now reached technical maturity after intense prototyping work and numerous testing campaigns. Several of the ESS beamlines that will soon enter the commissioning phase started welcoming the detector systems built with the 10 B-film converter technology. The real-size demonstrators evolved in the last 2–3 years into a diverse suite of gas proportional counters for use …in diffraction, reflectometry and small-angle scattering studies in spite of the operational complexity posed by the requirements for large-area coverage, low material budget and robustness for operation in the high-flux and high-radiation environment of ESS. The detectors are now being shipped to ESS or undergoing the last performance and calibration tests before being handed over to the instrument teams for installation in the host beamlines. A common feature of these detector systems is the very large number of readout channels that they are instrumented with in order to fulfill the demanding requirements for sensitivity, spatial resolution and count-rate capability. Across all of the detector types that will operate at ESS, the integration, testing and commissioning of the read-out technologies and software tools for data reduction, calibration and analysis are the focus of the detector and integration teams. These will yield a wealth of knowledge about their operation as well as initial results on the in-situ performance, a very important asset to ensure rapid commissioning of the detectors when neutrons from the ESS source become available. In this paper we will give an overview of the 10 B-film-based detector technologies included in the ESS detector suite that are currently facing the transition from the production phase to installation and integration with the other beamline components, which comes with its own specific challenges of both organizational and technical nature. Show more

Keywords: Neutron detectors (cold, thermal), instrumentation for neutron sources, solid converters, 10B4C, gaseous detectors

DOI: 10.3233/JNR-230012

Citation: Journal of Neutron Research, vol. 26, no. 2-3, pp. 83-109, 2024

Authors: Hu, Peng | Wang, Li | Tang, Ming | Li, Yakang | Chen, Juan | Hu, Hao | Wang, Haofan | Zhuang, Bo | Qi, Fazhi | Zhang, Junrong

Article Type: Research Article

Abstract: At the second stage of China Spallation Neutron Source (CSNS-II), it is predicted that 2 PB raw experimental data will be produced annually from twenty instruments. Scientific computing puts forward higher requirements for data sharing, utilization, retrieval, analysis efficiency, and security. However, the existing data management system (DMS) based on ICAT has several limitations including poor scalability of metadata database, imperfect data-management lifecycle and inflexible API. To ensure the accuracy, usability, scalability and efficiency of CSNS-II experimental data, a new scientific data management system is therefore designed based on the DOMAS framework developed by the Computing Center of IHEP. The …data acquisition, transmission, storage and service systems are re-designed and tailored specifically for CSNS-II. Upon its completion, the new DMS will overcome the existing challenges and offer functions such as online display, search functionality and rapid download capabilities for metadata, raw data and analyzed data; flexible and user-friendly authorization; and data lifecycle management. Ultimately, the implementation of the new Data Management System (DMS) is expected to enhance the efficiency of experimental data analysis, propelling CSNS-II to achieve international advanced standards. Furthermore, it aims to reinforce self-reliance and technological strength in the field of science and technology at a high level in China. The development and deployment of the new DMS begin at the end of 2023. Show more

Keywords: Data management, metadata, DOMAS, CSNS

DOI: 10.3233/JNR-230014

Citation: Journal of Neutron Research, vol. 26, no. 2-3, pp. 111-115, 2024