An upgrade of the Near Detector of the T2K long baseline neutrino oscillation experiment, ND280, has been proposed. This upgrade will include two new Time Projection Chambers, each equipped with 16 ...resistive Micromegas modules for gas amplification. A first prototype of resistive Micromegas has been designed, built, installed in the HARP field cage, and exposed to a beam of charged particles at CERN. The data have been used to characterize the performances of the resistive Micromegas module. A spatial resolution of 300 μm and a deposited energy resolution of 9% were observed for horizontal electrons crossing the TPCs at 30 cm from the anode. Such performances fully satisfy the requirements for the upgrade of the ND280 TPC.
Preliminary design of the COMPASS upgrade tokamak Vondracek, P.; Panek, R.; Hron, M. ...
Fusion engineering and design,
August 2021, 2021-08-00, 20210801, 2021-08-01, Letnik:
169, Številka:
C
Journal Article
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COMPASS Upgrade is a new medium size, high magnetic field tokamak (R = 0.9 m, Bt = 5 T, Ip = 2 MA) currently under design in the Czech Republic. It will provide unique capabilities for addressing ...some of the key challenges in plasma exhaust physics, advanced confinement modes and advanced plasma configurations as well as testing new plasma facing materials and liquid metal divertor concepts.
This paper contains an overview of the preliminary engineering design of the main systems of the COMPASS Upgrade tokamak (vacuum vessel, central solenoid and poloidal field coils, toroidal field coils, support structure, cryostat, cryogenic system, power supply system and machine monitoring and protection system). The description of foreseen auxiliary plasma heating systems and plasma diagnostics is also provided as well as a summary of expected plasma performance and available plasma configurations.
Abstract
The European Spallation Source (ESS) project currently enters the final stage of installation. Since 2017, a group of engineers and technicians from The Henryk Niewodniczanski Institute of ...Nuclear Physics Polish Academy of Science (IFJ PAN) are involved in the project. The contribution to the project can be divided into three main tasks: Radio Frequency Distribution System (RFDS), RF (Radio Frequency) Power Stations and Cryomodules.
The RFDS in ESS project is one of the largest installations of this type consisting of 155 RF high power systems. Engineers and technicians from IFJ PAN were responsible for preparation, installation and RF measurements of the above-mentioned system. The team is also involved in preparation and conducting low and high power tests of the RF stations.
The IFJ PAN team is also responsible for the preparation as well as vacuum and cryogenic tests for 9 Medium and 21 High Beta Cryomodules, before they are installed in the tunnel.
The advanced quality control and quality assurance were mandatory for this work because the costs of failures, as well as potential delays, would have a huge impact in the project realisation. Therefore dedicated methods and approaches have been adapted to this work using experience gained by the IFJ PAN team on previous projects like LHC, XFEL and W7X.
An upgrade of the near detector of the T2K long baseline neutrino oscillation experiment is currently being conducted. This upgrade will include two new Time Projection Chambers, each equipped with ...16 charge readout resistive Micromegas modules.
A procedure to validate the performance of the detectors at different stages of production has been developed and implemented to ensure a proper and reliable operation of the detectors once installed. A dedicated X-ray test bench is used to characterize the detectors by scanning each pad individually and to precisely measure the uniformity of the gain and the deposited energy resolution over the pad plane. An energy resolution of about 10% is obtained.
A detailed physical model has been developed to describe the charge dispersion phenomena in the resistive Micromegas anode. The detailed physical description includes initial ionization, electron drift, diffusion effects and the readout electronics effects. The model provides an excellent characterization of the charge spreading of the experimental measurements and allowed the simultaneous extraction of gain and charge spreading information of the modules.
In this paper we describe the performance of a prototype of the High Angle Time Projection Chambers (HA-TPCs) that are being produced for the Near Detector (ND280) upgrade of the T2K experiment. The ...two HA-TPCs of ND280 will be instrumented with eight Encapsulated Resistive Anode Micromegas (ERAM) on each endplate, for a total of 32 ERAMs. This innovative technique allows the detection of the charge emitted by ionization electrons over several pads, improving the determination of the track position.
The TPC prototype has been equipped with the first ERAM module produced for T2K and with the HA-TPC readout electronics chain and it has been exposed to an electron beam at DESY in order to measure spatial and dE/dx resolution. In this paper we characterize the performances of the ERAM and, for the first time, we compare them with a newly developed simulation of the detector response.
Spatial resolution better than 800 μm and dE/dx resolution better than 10% are observed for all the incident angles and for all the drift distances of interest. All the main features of the data are correctly reproduced by the simulation and these performances fully fulfill the requirements for the HA-TPCs of T2K.
The paper presents an overview of the design status of the Radial Neutron Camera (RNC), that, together with the Vertical Neutron Camera, will provide, through reconstruction techniques applied to the ...measured line-integrated neutron fluxes, the time resolved measurement of the ITER neutron and α-source profile (i.e. neutron emissivity, neutrons emitted per unit time and volume). The RNC is composed of two subsystems, the In-Port RNC and Ex-Port RNC located, respectively, inside and outside the Plug of Equatorial Port #01. The In-Port subsystem is in a more advanced design stage since it has recently undergone the Final Design Review in the ITER procurement process. The paper describes the diagnostic layout, the interfaces, the measurement capabilities and the main challenges in its realization. Prototyping and testing of neutron detectors and electronics components were carried out and led to the choice of the component solutions that can match the environmental and operational constraints in terms radiation hardness, high temperature and electromagnetic compatibility. The performance of the RNC in terms of neutron emissivity measurement capability was assessed through 1D and 2D reconstruction analysis. It is proven that the neutron emissivity can be reconstructed in real-time within the measurement requirements: 10% accuracy, 10 ms time resolution and a/10 (a = plasma minor radius) space resolution.
The European X-ray Free Electron Laser (XFEL) is in operation at DESY. The superconducting XFEL linac will produce pulsed electron beam at an energy of 17.5 GeV. The linac consists of 768 ...superconducting niobium 1.3 GHz nine cell cavities and 96 superconducting magnet packages assembled in 96 cryomodules. Each cryomodule is 12 m long and includes a 2 K helium II bath circuit for the cavities, and 5/8 and 40/80 K thermal radiation shields. Before being installed in the XFEL linac tunnel all cryomodules were tested in the Accelerator Module Test Facility (AMTF.) In this paper methods and results of static and dynamic heat load measurements of all XFEL cryomodules are reported. A comparison with first integral heat load measurements in the XFEL linac is given.
In order to produce pulsed electron beam with the energy of 17.5 GeV, the XFEL linear accelerator is under construction. After the assembly but before being installed in the accelerator tunnel, 100 ...accelerator modules have to be tested in Accelerator Module Test Facility (AMTF). Two vertical cryostats and three horizontal test benches are devoted to the testing of cavities and cryomodules as well as two other cold boxes and liquid helium (LHe) storage tank are installed to enable their operation. This paper describes our experience with cryogenic operation of AMTF after two years of operation.
•The STUMM is a module dedicated to the commissioning and testing phase of the IFMIF-DONES facility.•STUMM is developed to characterize the neutron flux and verify the radiation and thermal ...conditions adjacent to the neutron source.•Detection systems dedicated for STUMM have to be characterized by a high radiation resistance and a relatively small radiation sensitivity (to avoid detector saturation).•Dedicated detection systems have been proposed which are known to operate well and are tested in reactor conditions, such as: MFC, IC, SPND, gamma thermometers, thermocouples and rabbit systems.•Thermo-hydraulic analysis have shown that the considered cooling system based on helium flow, is able to provide appropriate thermal conditions for the proper operation (up to 250 °C) of the proposed number and arrangement of detectors.•Full elasto-plastic analysis was performed in order to check the extend of possible yielding, and it turned out to be almost negligible with the maximum plastic strain below 0.5% for considered flow directions, thus ensuring safety of the structure even for the conservative thermal assumptions.
International Fusion Materials Irradiation Facility — DEMOOriented Neutron Source (IFMIF-DONES) is a planned powerful neutron source, which will generate an intense flux of neutrons (up to ∼1015n/s/cm2) with a fusion-relevant energy spectrum. It will be an accelerator source based on deuteron beam - lithium target reactions. The engineering design of IFMIF-DONES is elaborated in the frame of the Early Neutron Source work package of the EUROfusion consortium. The facility will be dedicated to the irradiation of suitable structural materials planned for the construction of future fusion reactors such as DEMO (Demonstration Fusion Power Plant). Start-up Monitoring Module (STUMM) is designed to monitor radiation and thermal conditions during the commissioning phase of IFMIF-DONES, characterize the produced neutron flux and validate neutronic modeling of the facility. The conceptual design of STUMM is prepared by a team of physicists and engineers from the Institute of Nuclear Physics Polish Academy of Sciences (IFJ PAN) and the National Centre for Nuclear Research (NCBJ), Poland. This paper presents the concept of STUMM, the proposed design of the module, and selected measuring systems.
In order to produce short pulsed electron beam of 17.5 GeV energy, the XFEL linear accelerator is being built at DESY in Hamburg. Before being installed in the accelerator tunnel, 103 accelerator ...modules have to be tested in Accelerator Module Test Facility (AMTF). Cavities and cryomodules are tested at two vertical cryostats and three horizontal test benches. Two valve boxes and a liquid helium (LHe) storage tank are installed to enable cryogenic operation of AMTF. This paper describes our experience of three years cryogenic operation of AMTF. All 800 cavities and almost all cryomodules have been tested. The test results and lessons learned are also summarized
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