Target studies for the neutrino factory at the Rutherford Appleton laboratory

Target studies at the Rutherford Appleton Laboratory have concentrated on s tudies of a solid heavy metal target. The suggestion to use a radiatively c ooled target which rotates in beam was made shortly after the first NuFact workshop as a means of dissipating large amounts of power at a high tempera ture, and as an alternative to the proposed water-cooled rotating band and liquid metal jet targets. This paper examines the proposed drive scheme for the target ring, which uses induced currents and magnetic forces to both l evitate and drive the target. Estimates of the power required to levitate a nd drive the target ring and the forces exerted on the moving ring as it en ters the target capture solenoid are given. One of the principle concerns in the operation of a solid target is the sev ere shock stress experienced due to the impact of an intense energetic prot on beam in a short time compared to the transit time of sound in the materi al. Calculations of the stresses induced in the target ring and their evolu tion with time as well as an initial estimation of the expected power densi ties and stresses in an existing high power density target are presented. ( C) 2001 Elsevier Science B.V. All rights reserved.