Special Article - New Tools and Techniques
Ultracold neutron storage in a bottle coated with the fluoropolymer CYTOP
Institut Laue-Langevin, 38042, Grenoble, France
2 University of Illinois Urbana-Champaign, 61801, Urbana, IL, USA
3 University of Bristol, BS8 1TL, Bristol, UK
4 Universität Heidelberg, 69120, Heidelberg, Germany
5 Technische Universität München, 80805, Garching, Germany
Accepted: 11 July 2022
Published online: 30 July 2022
The fluoropolymer CYTOP was investigated in order to evaluate its suitability as a coating material for ultracold neutron (UCN) storage vessels. Using neutron reflectometry on CYTOP-coated silicon wafers, its neutron optical potential was measured to be 115.2(2) neV. UCN storage measurements were carried out in a 3.8 l CYTOP-coated aluminum bottle, in which the storage time constant was found to increase from 311(9) s at room temperature to 564(7) s slightly above 10 K. By combining experimental storage data with simulations of the UCN source, the neutron loss factor of CYTOP is estimated to decrease from 1.1(1) to 2.7(2) at these temperatures, respectively. These results are of particular importance to the next-generation superthermal UCN source SuperSUN, currently under construction at the Institut Laue-Langevin, for which CYTOP is a possible top-surface coating in the UCN production volume.
© The Author(s) 2022
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