SINQ—Performance of the New Neutron Delivery System. Issue 2 (3rd April 2021) - Geue, Thomas
Abstract : The Swiss spallation neutron source SINQ at Paul Scherrer Institute (PSI) has been in operation since 1996 using an optical guide system to transport low-energy neutrons from the source to the neutron beam lines. Clear signs of degradation in the guide system motivated us to redesign all neutron guides, which were then replaced in 2019–2020. All instruments received new tailored guides and SINQ operation was resumed in July 2020. Neutron flux measurements before and after the upgrade show that the expected instrument-dependent flux gain of a factor 2–10 was achieved. Furthermore, the fast-neutron background in the guide hall could be suppressed with an improved shielding in the guide bunker. The upgrade was completed with a slight delay due to the corona pandemic and in full compliance with the financial budget.