TAILIEUCHUNG - Determination of γ-rays relative intensities from the 35Cl(n, γ)36 reaction on filtered thermal neutron beam
The neutron flux and Cdratio are × 106 −2 .s−1 and 134, respectively, determined by the gold foil activation method. A new PGNAA system with a HPGe detector of 58% relative efficiency and a digital spectrometer was used to detect prompt gamma rays from the 35Cl(n, γ) 36Cl reaction. In this work, relative intensities of 23 prompt γ-rays have been determined on the filtered thermal neutron beam. The present results are in good agreement with literature values and data from previous measurements. | Communications in Physics, Vol. 25, No. 4 (2015), pp. 367-373 DOI: DETERMINATION OF γ-RAYS RELATIVE INTENSITIES FROM THE 35 Cl(n, γ)36 Cl REACTION ON FILTERED THERMAL NEUTRON BEAM TRAN TUAN ANH AND PHAM NGOC SON Nuclear Research Institute, Dalat VUONG HUU TAN Vietnam Agency for Radiation and Nuclear Safety, Hanoi, Vietnam Received 24 October 2015 Accepted for publication 24 December 2015 E-mail: ttanhfr@ Abstract. The relative intensities of prompt γ-rays from the 35 Cl(n, γ)36 Cl reation with thermal neutron have been used as secondary γ-ray intensity standards for the prompt gamma neutron activation analysis (PGNAA) and for nuclear data measurements due to a high capture cross section. The filter neutron technique was applied for producing a thermal neutron beam at the neutron channel No . 4 of the Dalat nuclear research reactor. The neutron flux and Cdratio are × 106 −2 .s−1 and 134, respectively, determined by the gold foil activation method. A new PGNAA system with a HPGe detector of 58% relative efficiency and a digital spectrometer was used to detect prompt gamma rays from the 35 Cl(n, γ)36 Cl reaction. In this work, relative intensities of 23 prompt γ-rays have been determined on the filtered thermal neutron beam. The present results are in good agreement with literature values and data from previous measurements. Keywords: relative intensity, filtered thermal neutron beam, Dalat research reactor. I. INTRODUCTION The energies and emmission probabilities (intensities) of prompt γ-rays in the high energy region are very important for spectrometer calibration and for nuclear data measurements due to the experiments are only carried out by (n, γ) reaction. The 14 N(n, γ)15 N reaction is usually a primary γ-ray source for high energy and efficiency calibrations of detectors in PGAA [1–4]. However, this reaction has a small cross section (75 mbarns), hence it is difficult to detect prompt γ-rays of 15 N in a low .
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