Search

The Cosmic Ray Energetics And Mass experiment for the International Space Station (ISS-CREAM) was installed on the ISS to measure high-energy cosmic-ray elemental spectra for the charge range Z = 1 to 26. The ISS-CREAM instrument includes a tungsten scintillating-fiber calorimeter preceded by a carbon target for energy measurements. The carbon target induces hadronic interactions, and showers of secondary particles develop in the calorimeter. The energy deposition in the calorimeter is proportional to the particle energy. As a predecessor to ISS-CREAM, the balloon-borne CREAM instrument was successfully flown seven times over Antarctica for a cumulative exposure of 191 days. The CREAM calorimeter demonstrated its capability to measure energies of cosmic-ray particles, and the ISS-CREAM calorimeter is expected to have a similar performance. Before the launch, an engineering-unit calorimeter was shipped to CERN for calibration and performance tests. This beam test included position, energy, and angle scans of electron and pion beams together with a high-voltage scan for calibration and characterization. Additionally, an attenuation effect in the scintillating fibers was studied. In this paper, beam test results, including corrections for the attenuation effect, are presented. [ABSTRACT FROM AUTHOR]

• Design proposal for the coils and power supplies for the SMART tokamak. • Dimensioning of coils by analytical thermal model in transitory scenarios. • Modular power supplies by the parallelization of H-bridges and supercapacitors banks. • Design of auxiliary circuit for central solenoid power supply for plasma breakdown. • Preliminary analysis of power supplies with MATLAB Simulink to prove feasibility. A new spherical tokamak, the SMall Aspect Ratio Tokamak (SMART), is currently being designed at the University of Seville. The goal of the machine is to achieve a toroidal field of 1 T, a plasma current of 500 kA and a pulse length of 500 ms for a plasma with a major radius of 0.4 m and minor radius of 0.25 m. This contribution presents the design of the coils and power supplies of the machine. The design foresees a central solenoid, 12 toroidal field coils and 8 poloidal field coils. Taking the current waveforms for these set of coils as starting point, each of them has been designed to withstand the Joule heating during the tokamak operation time. An analytical thermal model is employed to obtain the cross sections of each coil and, finally, their dimensions and parameters. The design of flexible and modular power supplies, based on IGBTs and supercapacitors, is presented. The topologies and control strategy of the power supplies are explained, together with a model in MATLAB Simulink to simulate the power supplies performance, proving their feasibility before the construction of the system. [ABSTRACT FROM AUTHOR]

● The evaluation method of beam energy fraction using MLR with numerous calorimetric results from the ion dump is developed. ● Through the MLR method, the energy fraction of the dump ions, source ions, and neutral particles before tokamak injection can be obtained. ● The beam energy fraction representing 1-year NBI-1 injection results of KSTAR was obtained using the MLR method. ● The beam energy fraction change caused by magnetic geometry change from the exchange of ion buckets of NBI-1A and NBI-1C of KSTAR in 2020 is well reflected in the MLR method's result. A new method of calculating the beam energy fraction using multiple linear regression (MLR) to ion dump calorimetric data is proposed in Korea Superconducting Tokamak Advanced Research (KSTAR). MLR was applied by collecting the cooling water temperature data from an ion dump calorimeter, where the beam energy fraction directly affects. Through the MLR method, the power delivered to the ion dump can be separated by the beam energy and the beamline A, B, and C, respectively. This power can be converted to the ratio of full, half, and one-third energy particles. By considering the neutralization efficiency, the energy fraction of the source ions and the neutrals can be finally calculated. The beam energy fraction results of the 2019 and 2020 campaign were obtained through this method. For the 2019 campaign, the results were compared with the beam energy fraction obtained using the Doppler shift spectroscopy (DSS) measurement. A notable difference in the first beam energy fraction exists between 2019 and 2020, where A decreases and C increases. This difference in the neutral particle fraction has been understood by the exchange between A and C's ion buckets. [ABSTRACT FROM AUTHOR]

Highlights: [•] A small plasma gun is constructed to study edge localized mode. [•] A plasma jet ejected from the gun is characterized with a quadruple Langmuir probe. [•] The device and diagnostics are suitable for research about the control of plasma jet. [Copyright &y& Elsevier]

The time dependence of the relative light emission of Eljen Technology EJ-200 polyvinyltoluene-based plastic scintillator was measured between 1 and 10 μ s after the passage of a particle shower, a singly charged particle (atmospheric muon), and with a UV LED exciting the fluor. This was compared in magnitude to the integrated response for the prompt light (within 500 ns of excitation). A model with a time-dependent yield consisting of three exponentially decaying components (fast, medium, and slow) was developed to fit the data. Note that the exact time structure of early (< 1 μ s) light emission was not measured for individual components, only for all three components together This model assumes all three components share the same rise time. The decay time constants of the fast, medium and slow components are, respectively, 7.8 ns, 490 ns, and 2370 ns. The relative total normalized yields for each component are: fast 95.8%, medium 2.2%, and slow 2.0%. [ABSTRACT FROM AUTHOR]