First Measurement of the Total Neutron Cross Section on Argon between 100 and 800MeV.

B Bhandari,S Locke,N Dokania,A Olivier,S Martynenko,C Callahan,Y Wang,J Mirabal-Martinez,W Ketchum,C Taylor,D Walker,E Guardincerri,N Kamp,N Walsh,C Thorn,H Chen,M Rosen,V Radeka,A Higuera,J Medina,J Maricic,E Pantic,D Cline,M Gold,Q Liu,S Glavin,A Mills,A Manalaysay,I Stancu,C Mauger,S Gardiner,J Chaves,B Philipbar,J Yoo,C Mcgrew,A Teymourian,H Wang,F Giuliani,K Rielage,R Svoboda,D Lee,C Yanagisawa,J Ramsey,M Tzanov,G Sinnis,Michael J Martínez ,Antonio Rodríguez Sánchez ,L W Koerner ,Arthur Karlin ,J.i Shin ,W E Sondheim ,S M Fernandes ,C S Pitcher ,J G Bian ,T J Haines ,S R Elliott ,Kyuho Lee ,Y K Sun ,A K Yarritu ,R W Kadel ,Catherine E Grant ,Julie Y Ji ,K J Bilton ,Patrice Medina ,G B Mills ,M B Smy ,W C Louis ,D.l Danielson ,V M Gehman ,R L Cooper ,G T Garvey ,Carol Endler Sterbenz ,J.r Danielson ,R G Van De Water ,E C Martin ,C E Tull

doi:10.1103/physrevlett.123.042502

Abstract

We report the first measurement of the neutron cross section on argon in the energy range of 100-800MeV. The measurement was obtained with a 4.3-h exposure of the Mini-CAPTAIN detector to the WNR/LANSCE beam at LANL. The total cross section is measured from the attenuation coefficient of the neutron flux as it traverses the liquid argon volume. A set of 2631 candidate interactions is divided in bins of the neutron kinetic energy calculated from time-of-flight measurements. These interactions are reconstructed with custom-made algorithms specifically designed for the data in a time projection chamber the size of the Mini-CAPTAIN detector. The energy averaged cross section is 0.91±0.10(stat)±0.09(syst) b. A comparison of the measured cross section is made to the GEANT4 and FLUKA event generator packages, where the energy averaged cross sections in this range are 0.60 and 0.68b, respectively.

Highlights

We report the first measurement of the neutron cross section on argon in the energy range of 100–800 MeV
The total cross section is measured from the attenuation coefficient of the neutron flux as it traverses the liquid argon volume
A set of 2631 candidate interactions is divided in bins of the neutron kinetic energy calculated from time-of-flight measurements. These interactions are reconstructed with custom-made algorithms designed for the data in a time projection chamber the size of the Mini-CAPTAIN detector

Summary

Published by the American Physical Society

Many liquid argon detectors use a time projection chamber (TPC) to measure the trail of ionization electrons left by a charged particle as it travels through the argon volume. The PDS provided a more precise measure of the beginning of the drift time for the tracks in the argon than the time inferred from TPC data. Hits from the same PMT were combined if they were closely correlated inside a time window of 16 ns Both photons and neutrons are produced at the beam target and produced scintillation signals visible to the PDS. The PDS hits were associated with tracks in the TPC data if the times of the rf signals were within Æ100 ms of each other. On the collection plane, which is used to directly determine the starting point of a track along the beam, 101 of 334 log(Charge)

Collection Plane Wire Number

Findings

Number of tracks