The city of Mainz is to become an international center of UCN research for five days

Johannes Gutenberg University Mainz expects physicists from Germany and abroad at its workshop on the current status of ultracold neutron physics at Waldthausen Castle

Mainz, 5 April 2016

About 70 physicists from around the world will be gathering in Mainz in the middle of April to participate in a workshop relating to research with ultracold neutrons. Ultracold neutrons or UCNs are free neutrons that travel at a speed of only about 5 meters per second after extreme cooling and can thus be stored in suitable bottles. Participants will be debating current and future experiments with ultracold neutrons at the workshop. The workshop will also serve to present the UCN facilities of the Institute of Nuclear Chemistry at Johannes Gutenberg University Mainz (JGU) to an international public. 

Ultracold neutrons were first generated at Mainz University some ten years ago. In the meantime, two UCN sources have been set up at the TRIGA Mainz research reactor. Its results are excellent, and Mainz is now one of the leading producers of UCNs worldwide. The ultracold neutrons are required for various experiments, for example, to determine the lifetime of the free neutron and in the search for the electrical dipole moment (EDM) of the neutron. At their meeting in Mainz, the 70 physicists from Germany and other countries will also discuss progress made on the various UCN sources and the related equipment.

“Research with ultracold neutrons started about 50 years ago. It was only during the course of the 1970s, however, that new ideas emerged about how larger amounts could be generated so that UCNs could be made available in sufficient quantities for experimental purposes,” explained Professor Werner Heil, who has helped to establish UCN production in Mainz and who is one of the organizers of the international workshop. “Due to our ten years of experience, we are now in a position to provide sufficient ultracold neutrons for major high-accuracy experiments.” Free neutrons played an important role in the creation of the first elements immediately following the Big Bang. Accurately determining the lifetime of the neutron could provide information about the element composition of the universe in its early stages. The physicists are also concerned with the question of the neutron EDM, which is an indicator of the distribution of positive and negative charges in what appears to be a ‘neutral’ neutron. Finding evidence of a neutron EDM is the key to solving one of the great mysteries of cosmology and particle physics: Why does the universe today consist of matter alone, why is there no anti-matter?

“At the JGU Institute of Nuclear Chemistry, the TRIGA Mainz research reactor provides us with an excellent source of neutrons. A user facility here was created within the PRISMA Cluster of Excellence. This is not only available to university personnel but also to external researchers,” added Professor Norbert Trautmann, manager of the TRIGA Mainz research reactor for 15 years. The Precision Physics, Fundamental Interactions and Structure of Matter (PRISMA) Cluster of Excellence, composed mainly of particle and hadron physicists, is one of the world’s foremost research organizations.

The international workshop entitled "Probing Fundamental Symmetries and Interactions with UCNs" will be held at Waldthausen Castle in Budenheim near Mainz from April 11 to 15, 2016.