1. Spectrometer Solenoid Lead Testing Update S. Virostek and Mike Zisman Lawrence Berkeley National Lab MICO Meeting January 19, 2010

2. Virostek/Zisman -- Lawrence Berkeley National Laboratory -- January 19, 2010 Spectrometer Solenoid Lead Testing Update Page2 Magnet Lead Test HTS lead 1 st stage plate Thermal connection

3. Virostek/Zisman -- Lawrence Berkeley National Laboratory -- January 19, 2010 Spectrometer Solenoid Lead Testing Update Page3 Initial Test Results (1) Tests began on January 14, 2010 – at initial equilibrium (no current), leads gave ~10 W heat load into cooler stage 1 temperature at top of leads was below freezing cooler temperatures: 33.8 K (stage 1); 3.5 K (stage 2) – next, powered leads to 275 A voltage drops on leads were 99 and 95 mV, respectively – means about 27 W per lead…unexpectedly high  leads too long for their cross-sectional area temperature at top of leads was 350 K (hot!) cooler temperatures: 42.4 K (stage 1); 3.5 K (stage 2)

4. Virostek/Zisman -- Lawrence Berkeley National Laboratory -- January 19, 2010 Spectrometer Solenoid Lead Testing Update Page4 Initial Test Results (2) Added 20 W to shield (stage 1 load) with 275 A in leads – results: cooler temperatures: 56 K (stage 1); 3.9 K (stage 2) lead voltage drops increased to 104 and 101 mV, respectively – because leads now running hotter than before  T between stage 1 and copper plate (across plug-in joint): 1.1 K at 33.8 K, 2.4 K at 42.4 K, and 1.4 K at 56 K – grease probably more conductive at higher temperature means that “plug-in” aspect working as expected Next, will increase cross section and decrease L of leads – then retest next week

5. Virostek/Zisman -- Lawrence Berkeley National Laboratory -- January 19, 2010 Spectrometer Solenoid Lead Testing Update Page5 Modifying lead assembly to improve IL/A Adding temperature monitors to top of HTS leads Changes will delay resumption of tests for a few days (maybe a week) After testing, install leads in Magnet 2, complete turret welds, leak check, and begin cool-down This procedure will take ~2 weeks...if we’re lucky Magnet 2 test results will be used to assess the degree of modification required for Magnet 1 Summary