# A versatile UHV transport and measurement chamber for neutron reflectometry under UHV conditions

## TL;DR

This paper introduces a compact UHV chamber enabling transfer and measurement of samples, like Co thin films, under ultra-high vacuum conditions for neutron reflectometry, preventing contamination and expanding experimental capabilities.

## Contribution

The development of a versatile mini UHV chamber that allows sample transfer and measurement without air exposure, facilitating advanced neutron reflectometry studies.

## Key findings

- Co thin films remain uncontaminated during UHV neutron measurements
- The chamber successfully performs polarized neutron reflectivity in UHV conditions
- Demonstrates new possibilities for neutron measurements under ultra-high vacuum

## Abstract

We report on a versatile mini ultra-high vacuum (UHV) chamber which is designed to be used on the MAgnetic Reflectometer with high Incident Angle of the J\"ulich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum in Garching, Germany. Samples are prepared in the adjacent thin film laboratory by molecular beam epitaxy and moved into the compact chamber for transfer without exposure to ambient air. The chamber is based on DN 40 CF flanges and equipped with sapphire view ports, a small getter pump, and a wobble stick, which serves also as sample holder. Here, we present polarized neutron reflectivity measurements which have been performed on Co thin films at room temperature in UHV and in ambient air in a magnetic field of 200 mT and in the Q-range of 0.18 \AA$^{-1}$. The results confirm that the Co film is not contaminated during the polarized neutron reflectivity measurement. Herewith it is demonstrated that the mini UHV transport chamber also works as a measurement chamber which opens new possibilities for polarized neutron measurements under UHV conditions.