# The aCORN Backscatter-Suppressed Beta Spectrometer

## TL;DR

This paper introduces a novel backscatter-suppressed beta spectrometer designed to improve measurements in neutron beta decay experiments by reducing errors caused by electron backscatter.

## Contribution

It presents the design, construction, and calibration of a new spectrometer with backscatter suppression features for precise beta decay measurements.

## Key findings

- Effective backscatter suppression achieved
- Improved energy resolution in beta detection
- Enhanced accuracy in neutron decay experiments

## Abstract

Backscatter of electrons from a beta spectrometer, with incomplete energy deposition, can lead to undesirable effects in many types of experiments. We present and discuss the design and operation of a backscatter-suppressed beta spectrometer that was developed as part of a program to measure the electron-antineutrino correlation coefficient in neutron beta decay (aCORN). An array of backscatter veto detectors surrounds a plastic scintillator beta energy detector. The spectrometer contains an axial magnetic field gradient, so electrons are efficiently admitted but have a low probability for escaping back through the entrance after backscattering. The design, construction, calibration, and performance of the spectrometer are discussed.