Slotted Rotatable Target Assembly Used In a Search for Possible Long Range Spin Dependent Interactions From Vector Boson Exchange Using Polarized Slow Neutrons

TL;DR

This paper presents a novel nonmagnetic target array design for neutron polarimetry aimed at detecting exotic spin-dependent interactions at sub-millimeter scales, utilizing a rotatable slot assembly to enhance sensitivity.

Contribution

The study introduces a new target array with a rotatable, slot-based design optimized for detecting spin-dependent forces from vector boson exchanges at micron to millimeter ranges.

Findings

Designed a target array with optimized atom density gradients.

Implemented a rotatable slot mechanism for systematic error reduction.

Achieved sensitivity to exotic spin-dependent interactions.

Abstract

We discuss the design and construction of a novel target array of nonmagnetic test masses used in a neutron polarimetry measurement made in search for new possible exotic spin dependent neutron-atom interactions of Nature at sub\,-$mm$ length scales. This target was designed to accept and efficiently transmit a transversely polarized slow neutron beam through a series of long open parallel slots bounded by flat rectangular plates. These openings possessed equal atom density gradients across the slots from the flat test masses with dimensions optimized to achieve maximum sensitivity to an exotic spin-dependent interaction from vector boson exchanges with ranges in the millimeter to micron regime. The parallel slots were oriented differently in four quadrants that can be rotated about the neutron beam axis using a Geneva drive. The spin rotation signals from the 4 quadrants were measured using a segmented neutron ion chamber in parallel to suppress possible systematic errors from stray magnetic fields in the target region. Design constraints and systematic effects are discussed.