The epoch of first star formation in the early Universe was dominated by simple atomic and molecular species consisting mainly of two elements: hydrogen and helium. Gaining insight into this constitutive era requires a thorough understanding of molecular reactivity under primordial conditions. We used a cryogenic ion storage ring combined with a merged electron beam to measure state-specific rate coefficients of dissociative recombination, a process by which electrons destroy molecular ions. We found a pronounced decrease of the electron recombination rates for the lowest rotational states of the helium hydride ion (HeH+), compared with previous measurements at room temperature. The reduced destruction of cold HeH+ translates into an enhanced abundance of this primordial molecule at redshifts of first star and galaxy formation.

The High-Brilliance Neutron Source (HBS) project aims to design a scalable compact accelerator driven neutron source (CANS) which is competitive and cost-efficient. The concept allows one to optimize the whole facility including accelerator, target, moderators and neutron optics to the demands of individual neutron instruments. Particle type, energy, timing, and pulse structure of the accelerator are fully defined by the requirements of a given neutron instrument. In the following, we present the current status of the HBS project.

Nuclear reaction and target for primary neutron generationThe neutron production at an accelerator driven compact neutron source is based on nuclear reactions in a suit-

The High-Brilliance Neutron Source project (HBS) aims at developing a medium-flux accelerator-driven neutron source based on a 70 MeV, 100 mA proton accelerator. The concept optimizes the facility such that it provides high-brilliance neutron beams for instruments operating at different time structures. This can be realized by generating an interlaced proton pulse structure, which is unraveled and sent to three different target stations by a multiplexer system. In the following we present the developments of a multiplexer system at the JULIC accelerator at Forschungszentrum Jülich GmbH (FZJ), which serves as test facility for HBS. The main components of the JULIC multiplexer system are designed to be scalable to the HBS parameters.