Measuring light-ion production and fission cross sections versus elastic np-scattering at the upcoming NFS facility

TL;DR

This paper discusses the design and simulation of an upgraded Medley detector setup for measuring light-ion production and fission cross sections at the new NFS neutron facility, emphasizing high temporal resolution and detector enhancements.

Contribution

The paper presents a new design and simulation of Medley's upgrade, including the integration of PPACs for improved detection at the NFS facility.

Findings

Simulations show effective detector coverage and resolution.

PPACs are suitable for fission fragment detection.

Design adaptations enable measurements with a white neutron beam.

Abstract

The Medley setup is planned to be moved to and used at the new neutron facility NFS where measurements of light-ion production and fission cross-sections are planned at 1-40 MeV. Medley has eight detector telescopes providing Delta E-Delta E-E data, each consisting of two silicon detectors and a CsI(Tl) detector at the back. The telescope setup is rotatable and can be made to cover any angle. Medley has previously been used in many measurements at The Svedberg Laboratory (TSL) in Uppsala mainly with a quasi-mono-energetic neutron beam at 96 and 175 MeV. To be able to do measurements at NFS, which will have a white neutron beam, Medley needs to detect the reaction products with a high temporal resolution providing the ToF of the primary neutron. In this paper we discuss the design of the Medley upgrade along with simulations of the setup. We explore the use of Parallel Plate Avalanche Counters (PPACs) which work very well for detecting fission fragments but require more consideration for detecting deeply penetrating particles.