Design of a novel compact neutron collimator

TL;DR

This paper introduces a compact, multi-channel neutron collimator with a novel design that decouples field-of-view from collimation power, enhancing neutron imaging for small to medium sources.

Contribution

It proposes a scalable, multi-sector collimator with a unique geometry and borated polymer components, improving neutron beam collimation and imaging capabilities.

Findings

Design achieves a 50x50 mm2 field of view.

L/D ratio of 40 provides effective collimation.

Compact structure suitable for small neutron sources.

Abstract

In this work the concept of a novel slow neutron collimator and the way to operate it are presented. The idea is based on the possibility to decouple the device field-of-view from its collimation power. A multi-channel geometry is proposed consisting of a chess-board structure where highly neutron-absorbing channels are alternated to air channels. A borated polymer was purposely developed to produce the attenuating components in the form of square-sectioned long rods. A scalable structure consisting of multiple collimation sectors can be arranged. The geometrical parameter LD, corresponding to the ratio between the length of a channel and its width, defines the collimation power. Several sectors can be arranged one after the other to reach relevant collimation powers. Each sector, 100 mm long, is composed by several channels with D = 2.5 mm corresponding to an L/D coefficient of 40. The target field of view is 50x50 mm2. This novel collimator, developed inside the INFN-ANET collaboration, due to its intrinsic compactness, will be of great importance to enhance the neutron imaging capability of small to medium-size neutron sources.