High resolution measurements of theAm241(n,2n

Abstract

Measurements of the 241 Am(n,2n) reaction cross section have been performed at the Joint Research Centre (JRC) Geel in the frame of a collaboration between the European Commission (EC) JRC and French laboratories from CNRS and the Commissariatà L'Energie Atomique (CEA) Cadarache. Raw material coming from the Atalante facility of CEA Marcoule has been transformed by JRC Karlsruhe into suitable 241 AmO 2 samples embedded in Al 2 O 3 matrices specifically designed for these measurements. The irradiations were carried out at the 7-MV Van de Graaff accelerator. The 241 Am(n,2n) reaction cross section was determined relative to the 27 Al(n,α) 24 Na standard cross section. The measurements were performed in four sessions, using quasi-monoenergetic neutrons with energies ranging from 8 to 21 MeV produced via the 2 H(d,n) 3 He and the 3 H(d,n) 4 He reactions. The induced activity was measured by standard γ -ray spectrometry using a high-purity germanium detector. Below 15 MeV, the present results are in agreement with data obtained earlier. Above 15 MeV, these measurements allowed the experimental investigation of the 241 Am(n,2n) reaction cross section for the first time. The present data are in good agreement with predictions obtained with the TALYS code that uses an optical and fission model developed at CEA.

Experimental Nuclear Reaction Data Uncertainties: Basic Concepts and Documentation

“…So, the "hand calculation" provided in Example 14 actually corresponds to applying Eqs. (79) and (80).…”

Americium-241 integral radiative capture cross section in over-moderated neutron spectrum from pile oscillator measurements in the Minerve reactor

“…Some of them were previously irradiated at EC-JRC for the measurement of the 241 Am(n,2n) cross section [5] and at the nToF facility at CERN for radiative capture measurements [6].…”

“…This experiment made use of 7 americium samples manufactured by ITU Karlsruhe in the framework of a previous collaboration between EC-JRC and CEA [5]. Measurements setup was based on the reactivity oscillator technique commonly implemented in Minerve [7].…”

Experimental Uncertainty and Covariance Information in EXFOR Library

“…2. This sample shows a compilation of the 241 Am(n,2n) 240 Am cross section measured at the IRMM Van de Graaff laboratory [17,21]. In this example, the total uncertainty and 9 partial uncertainties (MONIT-ERR, ERR-1, ERR-2 « ERR-8) are defined under the keyword ERR-ANALYS with their correlation properties (F, U, P).…”