1) Conceptual design for a high-gradient, high-heat load quadrupole and
possible application for ILC final focus -- Peter McIntyre (Texas A&M
2) Energy deposition and residual activation in elements for 20-mrad extraction line -- Mikhail Kostin
Peter presented conceptual design of SC magnets based on Nb3Sn technology, which are based on special structured cable, where six strands of Nb3Sn are placed around a hollow Inconel tube and then this assembly is sheathed in an outer armor that is drawn onto the 6-on-1 configuration. The hollow inner tube acts as a spring and provide stress reduction. The interior of the cable is not impregnated and serves for volumetric cooling to handle heating from particle losses. Peter has started to look into possible application of this technology for ILC QD0 quad. Peter also presented other ideas, potentially applicable for ILC, e.g. SC dipole with levitating pole where SC pole is isolated from the main iron body, which can be at room temperature, thus can handle high beam loads.
Mikhail presented calculations of energy deposition in the 20mrad extraction line, including residual activation of elements. High luminosity 500GeV CM case was considered. For the activation, with 30days run time and 1 day cool-down, the desirable dose on contact of < 1 mSv/hr can be achieved for the nominal head-on beam collisions. The energy deposition effects are generally ~10 times higher for 120 nm offset of the beams. The dynamic heat load looks similar to the STRUCT calculations. The stress and temperature seems to be OK in hot elements.
Andrei Seryi, 07/19/05