One of the approaches to power distribution system of a superconducting proton linac that is under discussion at Fermilab requires development of a fast-action, megawatt-range phase shifter. Using two phase shifters with a waveguide hybrid junction can allow independent control of phase and amplitude of RF power at the input of each superconducting cavity of the linac. This promises significant saving in number of klystrons and modulators required for the accelerator. A prototype of a waveguide version of a phase shifter that uses Yttrium-Iron Garnet (YIG) blocks was developed and tested. This report presents design concept of the device and main results of simulation and proof-of-principle tests.

A discrete event simulation methodology was developed to assist in managing test wafer usage in semiconductor fabs. The purpose of modeling test wafer usage is to predict the number of new test wafers required, test wafer WIP levels, and how to downgrade test wafers to reduce costs of purchasing new test wafers. The test wafer simulation methodology is a detailed yet accurate way to predict test wafer consumption. The methodology has been implemented in a 200" development facility resulting in considerable cost savings by reducing the overall WIP levels of test wafers.

No abstract