Neutron source back to operation

Antares new The new green ANTARES in the experimental hall.

The new green ANTARES in the experimental hall.

The scientific instruments, the irradiation facilities for isotopes and the tumour treatment facility are available again after having partly been remodeled. A new thimble for the production of molybdenum-99 for tumour diagnostics has been built.

The power of the neutron source has slowly been risen during the restart from 200 kW to the full power at 20 MW. During the single steps, the new facilities and the safety systems have been tested and the scientists adjusted their instruments.

Now all instruments are again available for international users. Japanese neutron researchers got special beam time because their facilities were destroyed by the tsunami in March 2011.

The long maintenance break has been planned routinely after six years of routine operation. The reactor operation staff as well as the scientists had to test or replace systems. For the first time, the moderator tank containing heavy water has been emptied completely, two larger heat exchangers were built expecting more and more scientific instruments.

Other tasks to fulfill included the exchange of neutron guides or the reconstruction of scientific instruments. The neutron optics group has exchanged the cold neutron guides 3, 4, 5 and 6, which feed 2/3 of the instruments in the neutron guide hall west from boron-containing glass to boron-free glass. The radiography and tomography facility ANTARES has been equipped with a completely new shielding and has moved to make room for the neutron guide to the neutron guide hall east. The bushings in the moderator cooling system have been reconstructed with a new material to make them resistant to corrosion. The authority and its experts have approuved the solution.

The insertion of the new thimble for the production of molybdenum-99 has been successfully completed. Furthermore the beam tube of the positron source NEPOMUC has been exchanged. The beam port of the hot source has been divided to feed the new polarized hot neutron diffractometer POLI. The spectrometer TOFTOF has doubled its detector and thus reduced the time to measure a sample.