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Dal Molin A, Marcer G, Nocente M, Rebai M, Rigamonti D, Angelone M, Bracco A, Camera F, Cazzaniga C, Craciunescu T, Croci G, Dalla Rosa M, Giacomelli L, Gorini G, Kazakov Y, Khilkevitch EM, Muraro A, Panontin E, Perelli Cippo E, Pillon M, Putignano O, Scionti J, Shevelev AE, Žohar A, Tardocchi M. Measurement of the Gamma-Ray-to-Neutron Branching Ratio for the Deuterium-Tritium Reaction in Magnetic Confinement Fusion Plasmas. PHYSICAL REVIEW LETTERS 2024; 133:055102. [PMID: 39159102 DOI: 10.1103/physrevlett.133.055102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 05/14/2024] [Indexed: 08/21/2024]
Abstract
At present, magnetic confinement fusion devices rely solely on absolute neutron counting as a direct way of measuring fusion power. Absolute counting of deuterium-tritium gamma rays could provide the secondary neutron-independent technique required for the validation of scientific results and as a licensing tool for future power plants. However, this approach necessitates an accurate determination of the gamma-ray-to-neutron branching ratio. The gamma-ray-to-neutron branching ratio for the deuterium-tritium reaction ^{3}H(^{2}H,γ)^{5}He/^{3}H(^{2}H,n)^{4}He was determined in magnetic confinement fusion plasmas at the Joint European Torus in predominantly deuterium beam heated plasmas. The branching ratio was found to be equal to (2.4±0.5)×10^{-5} over the deuterium energy range of (80±20) keV. This accurate determination of the deuterium-tritium branching ratio paves the way for a direct and neutron-independent measurement of fusion power in magnetic confinement fusion reactors, based on the absolute counting of deuterium-tritium gamma rays.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - A E Shevelev
- Scientist from St. Petersburg, Russian Federation
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Putignano O, Croci G, Muraro A, Cancelli S, Caruggi F, Gorini G, Grosso G, Kushoro MH, Marcer G, Nocente M, Cippo EP, Rebai M, Rigamonti D, Tardocchi M. Conceptual design of a GEM (gas electron multiplier) based gas Cherenkov detector for measurement of 17 MeV gamma rays from T(D, γ) 5He in magnetic confinement fusion plasmas. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:013501. [PMID: 36725552 DOI: 10.1063/5.0101761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 11/28/2022] [Indexed: 06/18/2023]
Abstract
The only method for assessing the fusion power throughput of a deuterium-tritium (DT) reactor presently relies on determining the absolute number of 14 MeV neutrons produced in the DT plasma. An independent method, developed and investigated during the recent DT campaign at the Joint European Torus, is based on the absolute counting of 17 MeV gamma rays produced by the competing T(D, γ)5He reaction that features a very weak branching ratio (about 3-6 × 10-6) when compared to the main T(D, n)4He reaction. The state-of-the-art spectrometer used for gamma-ray measurements in magnetic confinement fusion plasmas is LaBr3(Ce) scintillator detectors, although they require significant neutron shielding to extract a relatively weak gamma-ray signal from a much more abundant neutron field. A better approach relies on a gamma-ray detector that is intrinsically insensitive to neutrons. We have advanced the design of a gamma-ray counter based on the Cherenkov effect for gamma-rays whose energy exceeds 11 MeV, optimized to work in the neutron-rich environment of a steady-state, magnetically confined fusion plasma device. The gamma-rays interact with an aluminum window and extract electrons that move into the radiator emitting photons via the Cherenkov effect. Since the Cherenkov light consists of few photons (25 on average) in the far UV band (100-200 nm), a pre-amplifier is required to transport the photons to the neutron-shielded location, which may be a few meters away, where the readout elements of the detector, either a silicon or standard photomultiplier tube, are placed. The present work focuses on the development of a scintillating GEM (Gas Electron Multiplier) based pre-amplifier that acts as a Cherenkov photon pre-amplifier and wavelength shifter. This paper presents the result of a set of Garfield++ simulations developed to find the optimal GEM working parameters. A photon gain of 100 is obtained by biasing a single GEM foil to 1 kV.
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Affiliation(s)
- O Putignano
- Dipartimento di Fisica "G. Occhialini," Università Degli Studi di Milano-Bicocca, Milano, Italy
| | - G Croci
- Dipartimento di Fisica "G. Occhialini," Università Degli Studi di Milano-Bicocca, Milano, Italy
| | - A Muraro
- Istituto per la Scienza e Tecnologia dei Plasmi, CNR, Milano, Italy
| | - S Cancelli
- Dipartimento di Fisica "G. Occhialini," Università Degli Studi di Milano-Bicocca, Milano, Italy
| | - F Caruggi
- Dipartimento di Fisica "G. Occhialini," Università Degli Studi di Milano-Bicocca, Milano, Italy
| | - G Gorini
- Dipartimento di Fisica "G. Occhialini," Università Degli Studi di Milano-Bicocca, Milano, Italy
| | - G Grosso
- Istituto per la Scienza e Tecnologia dei Plasmi, CNR, Milano, Italy
| | - M H Kushoro
- Dipartimento di Fisica "G. Occhialini," Università Degli Studi di Milano-Bicocca, Milano, Italy
| | - G Marcer
- Dipartimento di Fisica "G. Occhialini," Università Degli Studi di Milano-Bicocca, Milano, Italy
| | - M Nocente
- Dipartimento di Fisica "G. Occhialini," Università Degli Studi di Milano-Bicocca, Milano, Italy
| | - E Perelli Cippo
- Istituto per la Scienza e Tecnologia dei Plasmi, CNR, Milano, Italy
| | - M Rebai
- Istituto per la Scienza e Tecnologia dei Plasmi, CNR, Milano, Italy
| | - D Rigamonti
- Istituto per la Scienza e Tecnologia dei Plasmi, CNR, Milano, Italy
| | - M Tardocchi
- Istituto per la Scienza e Tecnologia dei Plasmi, CNR, Milano, Italy
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Guan X, Hu H, Song Z, Han H. Experimental study on the fluorescence spectrum in the near-ultraviolet and visible regions of a carbon dioxide gas Cerenkov medium. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:113105. [PMID: 27910536 DOI: 10.1063/1.4967421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We investigated the faint fluorescence spectrum of carbon dioxide in the near-ultraviolet and visible regions using an intense relativistic electron beam accelerator with an energy of 0.2-0.3 MeV. Monte Carlo simulations were carried out in advance to maximize the signal-to-noise ratio and a self-normalization pulse experimental layout was designed to overcome the shot-to-shot fluctuations in different pulses of the accelerator. Ultimately, the relative proportion sequences in the near-ultraviolet and visible regions of a carbon dioxide fluorescence spectrum were successfully obtained for the first time. The result shows that there exists distinct difference between fluorescence spectrum and Cerenkov spectrum, which can therefore provide basic support for selectively reducing the unwanted below-threshold fluorescence response of a carbon dioxide gas Cerenkov medium.
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Affiliation(s)
- Xingyin Guan
- School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Huasi Hu
- School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Zhaohui Song
- Northwest Institute of Nuclear Technology, Xi'an 710024, China
| | - Hetong Han
- Northwest Institute of Nuclear Technology, Xi'an 710024, China
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Navrátil P, Quaglioni S. Ab initio many-body calculations of the (3)H(d,n)(4)He and (3)He(d,p)(4)He fusion reactions. PHYSICAL REVIEW LETTERS 2012; 108:042503. [PMID: 22400830 DOI: 10.1103/physrevlett.108.042503] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Indexed: 05/31/2023]
Abstract
We apply the ab initio no-core shell model combined with the resonating-group method approach to calculate the cross sections of the (3)H(d,n)(4)He and (3)He(d,p)(4)He fusion reactions. These are important reactions for the big bang nucleosynthesis and the future of energy generation on Earth. Starting from a selected similarity-transformed chiral nucleon-nucleon interaction that accurately describes two-nucleon data, we performed many-body calculations that predict the S factor of both reactions. Virtual three-body breakup effects are obtained by including excited pseudostates of the deuteron in the calculation. Our results are in satisfactory agreement with experimental data and pave the way for microscopic investigations of polarization and electron-screening effects, of the (3)H(d,γn)(4)He bremsstrahlung and other reactions relevant to fusion research.
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Affiliation(s)
- Petr Navrátil
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
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Mack J, Berggren R, Caldwell S, Christensen C, Evans S, Faulkner Jr. J, Griffith R, Hale G, King R, Lash D, Lerche R, Oertel J, Pacheco D, Young C. Remarks on detecting high-energy deuterium–tritium fusion gamma rays using a gas Cherenkov detector. Radiat Phys Chem Oxf Engl 1993 2006. [DOI: 10.1016/j.radphyschem.2005.12.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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