RESEARCH ON THE PROPERTIES OF SORBENTS AND DECONTAMINANTS IN THE PROCESSES WITH SMALL ISOTOPE EFFECTS

The low values of isotope effects in the sorption/decontamination processes make it possible to investigate the properties of the sorbing and decontaminating agents with the use of stable isotope simulators. In the work present-ed here the element content was determined from the characteristic X-ray emission induced by the proton beam (PIXE), by gamma-ray emission from the radioactive source, and by emission from the X-ray tube. Based on the results of efficiency determination for different kinds of sorbents and decontaminants, recommendations have been given for the choice of materials having the wanted performance characteristics.

Study of a single line of sight gamma ray diagnostics for measurements of the absolute gamma ray emission from JET

The fusion power produced in a DT thermonuclear reactor is currently determined by measuring the absolute 14 MeV neutron yield of the D(T, α)n fusion reaction. Measurements of 17 MeV gamma rays born from the much less probable D(T, 5He)γ reaction (branching ratio of ∼10−5) have been proposed as an alternative independent method to validate the neutron counting method and also to fulfill the requests of the nuclear regulator for licensing ITER DT operations. However, the development of absolute 17 MeV gamma ray emission measurements entails a number of requirements, such as: (i) knowledge of the 17 MeV gamma ray to 14 MeV neutron emission branching ratio; (ii) the simulation of the gamma ray transport from the extended plasma source to the gamma ray detectors; (iii) a careful determination of the absolute efficiency of previously calibrated gamma ray spectrometers. In this work, we have studied the possibility to infer the global gamma ray emission rate from measurements made with a 3″ × 6″ LaBr3 spectrometer installed at the end of a collimated tangential line of sight at the JET tokamak and using the neutron emission from deuterium plasmas of the most recent experimental campaigns. Results show that 17 MeV gamma ray fluxes at the end of this tangential line of sight have a weak dependence (less than 5%) on the plasma profile and can therefore be used to infer the total emission from the plasma.

Fermi-LAT Detection of Extended Gamma-Ray Emission in the Vicinity of SNR G045.7-00.4: Evidence of Escaping Cosmic Rays Interacting with the Surrounding Molecular Clouds

We present an analysis of Fermi Large Area Telescope data of the gamma-ray emission in the vicinity of a radio supernova remnant (SNR), G045.7-00.4. To study the origin of the gamma-ray emission, we also make use of the CO survey data of Milky Way Imaging Scroll Painting to study the massive molecular gas complex that surrounds the SNR. The whole size of the gigaelectronvolt emission is significantly larger than that of the radio morphology. Above 3 GeV, the gigaelectronvolt emission is resolved into two sources: one is spatially consistent with the position of the SNR with a size comparable to that of the radio emission, and the other is located outside of the western boundary of the SNR and spatially coincident with the densest region of the surrounding molecular cloud. We suggest that the gigaelectronvolt emission of the western source may arise from cosmic rays (CRs) that have escaped the SNR and illuminated the surrounding molecular cloud. We find that the gamma-ray spectra of the western source can be consistently explained by this scenario with a total energy of ∼1050 erg in escaping CRs assuming the escape is isotropic.