Fast neutron induced gamma rays from (n,n’), (n,p) and (n,α) reactions on CaCO3

Abstract

Emission of prompt gamma rays following (n,n’), (n,p) and (n,α) reactions induced by irradiation of a calcium carbonate (CaCO3) sample with a beam of fission neutrons was investigated with a modified version of the FaNGaS (Fast Neutron-induced Gamma-ray Spectrometry) instrument operated at the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching. The neutron spectrum has an average energy of 2.30 MeV and at sample position the fast neutron flux was (1.13 ± 0.04) × 108 cm−2 s−1. The measurement was performed at an angle of 90° between neutron beam and detector. In total, we claim the identification of 38 prompt gamma lines, from which we have assigned 12 to the (n,n’) reaction in calcium (7 for 40Ca, 1 for 42Ca and 4 for 44Ca), 1 to the 12C(n,n’)12C reaction, and 2 to the (n,n’) reaction in oxygen (1 for 16O and 1 for 18O). The other observed gamma lines are attributed to the 40Ca(n,p)40K reaction (20 lines) and to the 40Ca(n,α)37Ar reaction (3 lines). Relative intensities and fast neutron spectrum averaged partial cross sections of the gamma lines are presented and compared with available literature data. Our results were found to be in good agreement with available literature data but also improved and complemented it, as we have pointed out possible errors and identified new lines. Additionally, for a counting time of 12 h the detection limits of calcium, carbon and oxygen were determined as 5, 13 and 64 mg, respectively.

Gamma emission from interaction of fission neutrons on nickel and zirconium

“…Here, the value of B E was extracted from the beam background spectrum measured with the new version of the FaNGaS instrument [3] which delivers a fast neutron flux at sample position of 1.13 × 10 8 cm −2 s −1 . In this case, the smallest amounts of nickel and zirconium that can be detected are 0.7 mg and 1.4 mg, respectively.…”

“…The FaNGaS (Fast Neutron induced Gamma-ray Spectrometry) instrument [1][2][3] installed at Heinz Maier-Leibnitz Zentrum (MLZ) offers the possibility to perform non-destructive elemental analysis of samples of various sizes origins by means of Prompt Gamma Analysis based on Inelastic Neutron Scattering PGAINS as we are going to call the method from now on. This analytical technique focuses on the measurement of prompt gamma radiation emitted from inelastic scattering of fission neutrons, i.e.…”

“…Such data are also required in other fields of nuclear science and technology [4]. With the aim of developing a comprehensive database on (n,n′γ) reactions, prompt gamma rays induced by fission neutrons on carbon, oxygen, aluminum, chlorine, calcium, titanium, iron, copper, indium, cerium and terbium were measured with the FaNGaS instrument and their associated fissionneutron spectrum-averaged production cross sections were determined [2,3,[5][6][7][8]. Relative intensities of the gamma rays were found to agree reasonably with the values provided by the only existing database for (n,n′γ) reactions: the "Atlas of Gamma-ray spectra from the Inelastic Scattering of Reactor Fast Neutrons" published by Demidov et al in 1978 [9].…”