A short calculation was done to check the attachment method of the radiation shield to it's LN2 cooling tubes. The case considered was only for the obround chimney section. The proposed attachment method was to use 1/8-inch plug welds spaced every 5-inch along the length of the shield. The calculations were done conservatively for 6-inch spacing between plug welds. The criteria used was that the LN2 shield warmest temperature be less than 2 K above the temperature of the LN2 fluid. Using a very conservative heat transfer model. the calculations predict that the warmest temperature on the radiation shield will be < 1.4 K warmer than the LN2 fluid temperature.

This engineering note documents the calculations done to determine the chimney heat loads. These heat load numbers were reported in the D0 solenoid upgrade design report. The heat loads to the LN2 circuit were done by Andrew Stefanik, RDIMechanical Systems group. They were part of his LN2 shield calculations dated 2/23/93. Pages 1 thru 3 of his calculations that apply to the chimney are attached. The heat loads to the LHe circuit were done originally on 12/16/92 and then revised on 12/23/92 to be more conservative. The raw calculations are attached. I include both the original 12/16 version and the 12/23 revised version to document the amount of conservativeness added.

This engineering note contains miscellaneous information about the rectangular liquid helium supply tube for the D-Zero solenoid. The information is fairly superficial, but could be used as a starting point for a future engineer who is going to specify and puchase the tubing. The chimney contains 4 conductors attached to an aluminum liquid helium supply tube. Because good thermal contact is desired, the tube will have flat sides. Aluminum is chosen to match the thermal contraction coefficient of the superconductor's aluminum stabilizer. The type of aluminum is chosen as 6061-T6 because it's allowable stress in ANSI/ASME B31.3 is higher than for other alloys. A different alloy could be chosen for extrusion reasons. The highest pressures this tubing should see will be during a quench. Current calculations predict the peak pressure during a quench to be 520 psi a for one-way relieving and 250 psia for two way relieving. Whatever the final alloy selection, the tubing needs to have a high enough allowable working pressure. There is very little room in the obround section of the chimney. In that portion the shape is rectangular, 12.7 mm (0.50-inch) x 31.8 mm (1.25-inch). A drawing shows the flow path cross section. This also …

This engineering note documents the calculations done to determine the relief capacity of the solenoid vacuum pumping line. The calculations were done by David Bell, a co-op student from the University of Wisconsin. The calculations are attached. The conclusion is that the vacuum pumping line has a venting capacity of 129 g/s warm helium or 298 g/s warm nitrogen. Both of these capacities are much larger than the expected operating mass flow rates of the liquid helium (5 to 15 g/s) or liquid nitrogen (2 or 3 g/s) circuits. The calculations assume the solenoid vacuum vessel is at 3 psig and the relief plate is set at 1.5 psig. Additional calculations were done to prove that the venting capacity of the vacuum pumping line exceeded flowrates due to a failure mode. These calculations are attached. Since the system is not finalized, (pipe sizes not determined, components sized...) the calculations were done by first picking reasonable line sizes based on known allowed pressure drops in the system and then doing a maximum delivery rate calculation if a line was completely severed in the vacuum space of the solenoid/control dewar. The numbers from these calculations say that failure mode flow rates are …

A plasma coating system has been developed for induction melting zirconium at 1900 C using a graphite crucible. This laminated coating system consists of plasma spraying the following materials onto the graphite: (1) molybdenum or tungsten, (2) a 50% blend by weight of the metal powder and calcia-stabilized zirconium oxide, and (3) calcia-stabilized zirconia followed by painting a final coating of nonstabilized zirconia on top of the plasma-sprayed coating system. Zirconium was melted in argon using both laminating systems without any degradation of the graphite crucible and with only a minimal amount of carbon absorption. This novel approach that is being proposed as an alternative method of melting zirconium alloys offers substantial cost savings over the standard practice of electric arc melting using a consumable electrode.

The majority of this research has been in developing a model to describe the magnetostrictive properties of Terfenol-D, Tb{sub 1{minus}x}Dy{sub x}Fe{sub y} (x = 0.7-0.75 and y = 1.8--2.0), a rare earth-iron alloy which displays much promise for use in device applications. In the first chapter an introduction is given to the phenomena of magnetization and magnetostriction. The magnetic processes responsible for the observed magnetic properties of materials are explained. An overview is presented of the magnetic properties of rare earths, and more specifically the magnetic properties of Terfenol-D. In the second chapter, experimental results are presented on three composition of Tb{sub 1{minus}x}Dy{sub x}Fe{sub y} with x = 0.7, y= 1.9, 1.95, and x= 0.73, y= 1.95. The data were taken for various levels of prestress to show the effects of composition and microstructure on the magnetic and magnetostrictive properties of Terfenol-D. In the third chapter, a theoretical model is developed based on the rotation of magnetic domains. The model is used to explain the magnetic and magnetostrictive properties of Terfenol-D, including the observed negative strictions and large change in strain. The fourth chapter goes on to examine the magnetic properties of Terfenol-D along different crystallographic orientations. In the fifth …

The March seminar, ``Military and Diplomatic Roles and Options`` for managing and responding to proliferation, featured three presentations: the military and diplomatic implications of preemptive force as a counterproliferation option; an in-depth assessment of the threat posed by biological weapons; and, a new proposed US counterproliferation policy.

Letter opinion issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Dan Morales, regarding a legal question submitted for clarification: Whether a home-rule city may reimburse its officials in a fixed amount for expenses incurred (ID# 20029)