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Elastic Recoil Detection Analysis
Published in Zeev B. Alfassi, Max Peisach, Elemental Analysis by Particle Accelerators, 2020
If the incident projectile is a charged particle and the host substrate is thin compared with the range of this projectile in the substrate material, a considerable improvement in detection sensitivity can be achieved by the use of the kinematic coincidence technique (KCT). In this technique, both the recoil light nucleus and the scattered projectile are detected in coincidence at their respective correlated recoil and scattered angles. The summed energy of the pair must be a constant and the coincidence must be prompt.2 This technique can improve the sensitivity of the elastic recoil method by up to four orders of magnitude in favorable circumstances. This makes it one of the most powerful analytical tools for trace analysis of light elements such as hydrogen isotopes, helium isotopes, and lithium isotopes.2
Preliminary Estimation of Tritium Migration for A-FNS Lithium Target System
Published in Fusion Science and Technology, 2021
Makoto Oyaidzu, Masayuki Ohta, Kentaro Ochiai, Atsushi Kasugai
Fusion-relevant neutron sources are required to research and develop the materials, devices, and so on for the DEMO reactor, and validation studies for some key issues have been conducted in the Engineering Validation and Engineering Design Activities (EVEDA) for the International Fusion Materials Irradiation Facility (IFMIF) under Broader Approach (BA) Activities implemented by Japanese and European governments for early realization of fusion energy. Based on the results of the IFMIF/EVEDA project, the conceptual design of the Advanced Fusion Neutron Source (A-FNS), where fusion-relevant neutron irradiation data will be obtained for the DEMO design, has just been completed by the National Institute for Quantum and Radiological Science and Technology in Japan, which plans to construct the A-FNS in Japan.1 Since no fewer than a few grams of tritium will be generated in the A-FNS and relevant neutron sources every year, it is necessary to assess the tritium behavior and to design a series of detritiation systems as preliminary ones for IFMIF (Ref. 2) and a present one for IFMIF-DEMO-Oriented Neutron Source (Ref. 3). The tritium source terms are considered to be nuclear reactions of (1) energetic deuteron with lithium as the deuteron beam target, (2) energetic deuteron with deuterium and constituent materials of the accelerator in the accelerator cavity, (3) energetic neutron with coolant water, and (4) neutron with materials in the test cell, including neutron irradiation experiments, where it is considered that a source term (1) with the tritium generation rate of 3.5 g/full power year, which corresponds to half that of the IFMIF of 7 g/year (Ref. 4), should make up most of all of tritium generation in A-FNS. Furthermore, liquid lithium, including tritium, will be circulated with the temperature from 523 to 573 K in the lithium target system to remove the heat of 5 MW induced by the deuteron beam with the energy of 40 MeV and the ion current of 125 mA, while hydrogen isotopes in lithium will be removed in the lithium purification system. Therefore, it is considered that the tritium behavior into and out of the lithium target system should be clarified in the design of the detritiation system for the A-FNS. In the present study, a preliminary estimation of tritium migration in the A-FNS lithium target system under normal operation of the A-FNS is performed to obtain preliminary requirements for the A-FNS detritiation system based on our previous study, where a purification scenario with suggested impurity limits is discussed.5