D0 Central Tracking Solenoid Energizatino, Controls, Interlocks and Quench Protection Initial Validation Procedures

This note presents the inspection and tests to be performed on the DZERO solenoid energization, controls, interlocks and quench protection system before it is energized for the first time. This test is to be performed with a 5000A jumper at the end of the bus instead of the solenoid. This system is based in DZERO room 511. A copy of this note shall be annotated, signed and dated by the person coordinating the procedure; and filed with the system maintenance records. Annotations shall include comments about any aspect of the procedure that is abnormal or unsuccessful. The following inspections and tests shall be performed by persons knowledgeable about the system. Each individual test step should be reviewed and understood before proceeding with that step

A system to test the effects of materials on the electron drift lifetime in liquid argon and observations on the effect of water

A materials test system (MTS) has been developed at FNAL to assess the suitability of materials for use in a large liquid argon time projection chamber. During development of the MTS, it was noted that controlling the cryostat pressure with a 'raining' condenser reduced the electron drift lifetime in the liquid argon. The effect of condensing has been investigated using a series of passive materials to filter the condensate. We report the results of these studies and of tests on different candidate materials for detector construction. The inferred reduction of electron drift lifetime by water concentrations in the parts per trillion is of particular interest

Towards a liquid Argon TPC without evacuation: filling of a 6 m^3 vessel with argon gas from air to ppm impurities concentration through flushing

In this paper we present a successful experimental test of filling a volume of 6 m$^3$ with argon gas, starting from normal ambient air and reducing the impurities content down to few parts per million (ppm) oxygen equivalent. This level of contamination was directly monitored measuring the slow component of the scintillation light of the Ar gas, which is sensitive to {\it all} sources of impurities affecting directly the argon scintillation.Comment: 9 pages, 6 figures, to appear in Proc. 1st International Workshop towards the Giant Liquid Argon Charge Imaging Experiment (GLA2010), Tsukuba, March 201

A Regenerable Filter for Liquid Argon Purification

A filter system for removing electronegative impurities from liquid argon is described. The active components of the filter are adsorbing molecular sieve and activated-copper-coated alumina granules. The system is capable of purifying liquid argon to an oxygen-equivalent impurity concentration of better than 30 parts per trillion, corresponding to an electron drift lifetime of at least 10 ms. Reduction reactions that occur at about 250 degrees Celsius allow the filter material to be regenerated in-situ through a simple procedure. In the following work we describe the filter design, performance, and regeneration process.Comment: 12 pages with 9 figure