Progress Towards A Permanent Octupole Magnetic Ultra-Cold Neutron Trap for Lifetime Measurements

TL;DR

This paper reports progress on developing a permanent octupole magnetic trap for ultra-cold neutrons to improve neutron lifetime measurements by reducing losses and enabling in-situ decay detection.

Contribution

It introduces a novel Ioffe-type trap using a Halbach permanent octupole magnet for ultra-cold neutrons, advancing neutron lifetime measurement techniques.

Findings

Reduced neutron loss channels through vacuum extraction

Successful in-situ detection of neutron decay protons

Progress towards a reliable neutron lifetime measurement

Abstract

The current knowledge of the neutron $\beta$-decay lifetime has come under scrutiny as of late due to large disagreements between recent precise measurements. Measurements using magnetically trapped Ultra-Cold Neutrons (UCNs) offer the possibility of storage without spurious losses which can provide a reliable value for the neutron lifetime. The progress towards realizing a neutron lifetime measurement using a Ioffe-type trap made with a Halbach-type permanent octupole magnet is presented here. The experimental procedure extracts a gas of UCNs into vacuum, which reduces many known channels of neutron losses, and detects the neutron decays via in-situ detection of the produced protons.