Eur. Phys. J. A (2013) 49: 104
https://doi.org/10.1140/epja/i2013-13104-x

Regular Article - Experimental Physics

A prospective pulsed source of ultracold neutrons for experiments in fundamental neutron physics

Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM-II), Lichtenbergstrasse 1, 85747, Garching, Germany

^* e-mail: thorsten.lauer@tum.de

Received: 1 March 2013
Revised: 23 July 2013
Accepted: 26 July 2013
Published online: 15 August 2013

Abstract

Since their discovery, ultracold neutrons (UCNs) have been a unique tool for the investigation of fundamental properties of the free neutron and its interactions. The succesfull installation of a new pulsed superthermal source for ultracold neutrons based on solid deuterium at the TRIGA Mainz reactor is described. In a combination of solid hydrogen acting as pre-moderator and a solid deuterium converter of around 160 cm³, this new UCN source should provide at the experimental area ≥ 370000 UCN to the storage volume with the reactor operated in the pulse mode. In a storage experiment, a UCN density of 18 ± 2 UCN/cm³ was measured applying 1.5 $ pulses with a nominal power of 7 MJ. Assuming a linear behaviour of the UCN output as a function of reactor power this corresponds to a UCN density of 25 ± 3 UCN/cm³ for 2 $ (10 MJ) pulses.