• D. Reggiani, M. Daum, P.-A. Duperrex, G. Dzieglewski, U.P. Frei, T. Korhonen, A.C. Mezger, U. Muller, U. Rohrer
  PSI, Villigen

At PSI, a new and very intensive Ultra-Cold Neutron (UCN) source based on the spallation principle will start operation at the end of 2009. From then on, two neutron spallation sources - the continuous wave SINQ and the macro-pulsed UCN source will be running concurrently at PSI. The 590 MeV, 1.2 MW proton beam will be switched towards the new spallation target for about 8 s every 800 s. This operation can be accomplished by means of a fast kicker magnet with a rise-time shorter than 1 ms. A beam dump capable of absorbing the full-intensity beam for a few milliseconds has been installed after the last bending magnet so that the kicking process and the beam diagnostic can be checked well before the UCN facility will be ready for operation. Recent tests have demonstrated the capability of switching the 1.2 MW beam with negligible losses and to center it through the beam line by using fast beam position monitors. Much longer beam pulses (up to 6 seconds) with reduced beam intensity have also been performed successfully.

• Y. Lee, P.-A. Duperrex, D.C. Kiselev, U. Muller
  PSI, Villigen

The Paul Scherrer Institute (PSI) operates a high power proton accelerator for the research projects in physical and medical sciences. Currently, a proton beam current of 2mA with a beam power of 1.2MW is routinely used. In the future, the ring cyclotron with new cavities will make a proton beam current of 3mA possible. The enhanced beam power will generate higher thermal and mechanical loads to different accelerator components. In this paper, a simulation based study of a new current monitor designed to sustain the 3mA beam operation is presented. The monitor is located behind the second graphite target and exposed to scattered particles and their secondaries. The thermal energy deposition in the current monitor has been calculated by the Monte-Carlo particle transport code MARS. The calculated power source has been used for the the coupled flow, heat and radiation simulations, for the prediction of the operating temperature. The effect of the newly introduced water cooling system and the surface blackening has been analyzed by using CFX. The thermal properties of the monitor system have been measured by laboratory experiments, and a simulation validation study is presented.