Development of the Quasi-monoenergetic Neutron Calibration Fields of Several Tens of MeV at TIARA

Abstract

Development of three calibration fields for 45, 60 and 75 MeV neutrons has been in progress at Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) of JAEA-Takasaki. Achievement of the neutron calibration fields requires establishment of both measurement of neutron fluence and its monitoring technique. In order to measure the neutron fluence of main energy peak especially at a reference point on low fluence condition, a proton recoil counter telescope with high efficiency has been developed. The design of relatively large telescope components brought a high detection efficiency at the reference point with wide irradiation area at a long distance. Effective and precise measurement of the neutron fluence could be performed with uncertainties less than 6.5 % (standard deviation). For detecting neutrons without scattering near the target, a transmission type neutron fluence monitor has been newly developed to measure the neutron fluence directly at the collimator exit. Its performance such as counting rates was tested for various beam intensities.

Time-of-Flight Measurements for Low-Energy Components of 45-MeV Quasi-Monoenergetic High-Energy Neutron Field from <formula formulatype="inline"><tex Notation="TeX">${^7{\rm Li}({\rm p}, {\rm n})}$</tex></formula> Reaction

“…A -glass scintillation detector GS20 was used for the keV-region TOF measurements, in addition to an organic liquid scintillation detector BC501A for the MeV region. A transmission type fluence monitor based on a plastic scintillator developed by JAEA [11] was placed on the outlet of the collimator for normalization across the measurements.…”

A new irradiation facility for neutron-induced Single Event Effect studies at LNL

“…Quasi-monoenergetic neutrons are also available at Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) where new calibration fields (45, 60 and 75 MeV neutrons) are under development for the intercomparison of the TIARA fields with those of international facilities in a similar energy range [7].…”