1996, was the first, and is still the strongest, of its kind. It delivers a continuous neutron flux of 1014 n cm−2s−1. In SINQ the protons from the large particle accelerator strike a lead target and knock the neutrons out of the lead nuclei, making them available for experiments. In addition to thermal neutrons, a moderator made of liquid deuterium also enables the production of slow neutrons, which have a lower energy spectrum. The MEGAPIE Target (Megawatt Pilot-Experiment) came into operation in summer 2006. By replacing the solid target with a target made of a lead-bismuth eutectic, the neutron yield could be increased by about another 80%. Since it would be very costly to dispose of the MEGAPIE target, PSI decided in 2009 not to produce another such target and instead to develop the solid target further as it had already proven its worth. Based on the findings from the MEGAPIE project, it was possible to obtain almost as large an increase in neutron yield for operation with a solid target. SINQ was one of the first facilities to use specially developed optical guide systems to transport slow neutrons. Metal-coated glass conduits guide neutrons over longer distances (a few tens of metres) by means of total reflection, analogous to the light guidance in glass fibres, with a low loss of intensity. The efficiency of these neutron guides has steadily increased with advances in manufacturing technology. This is why PSI decided to carry out a comprehensive upgrade in 2019. When SINQ goes back into operation in summer 2020, it will be able to provide, on average, five times more neutrons for experiments, and in a special case, even 30 times more. SINQ's 15 instruments are not only used for PSI research projects but are also available for national and international users. Ultracold Neutron Source (UCN) Since 2011, PSI has also been operating a second spallation neutron source for the generation of ultracold neutrons (UCN). Unlike SINQ, it is pulsed and uses HIPA's full beam, but normally only for 8 seconds every 5 minutes. The design is similar to that of SINQ. In order to cool down the neutrons, however, it uses frozen deuterium at a temperature of 5 Kelvin (corresponding to -268 degrees Celsius) as a cold moderator. The UCN generated can be stored in the facility and observed for a few minutes in experiments. COMET cyclotron This superconducting 250 MeV