C. Caso & F. Gastaldo/INFN-Genova
hybrid stave equipped with 8 temperature sensors (3 wire reading Pt100) on "silicon side"
operations in a cold isolated box (ambient temperature ~ -9 ± 1 °C. For an ambient temperature of +8 °C results get worse by ~ 1 °C.)
1 differential gauge pressure sensor (RS)
across the stave
2 absolute pressure sensors across the cold box
2 Pt100 INSIDE the cooling tube (input/output: ice conc.)
MINCO heaters (to simulate the nominal 80 W pixel sensor heating) powered in parallel
1 mm grease hybrid prototype started giving anomalous results (positive temperatures when heated) after 1 week of operation. Stave open.
Test of failure on 0.1 mm grease prototype
coolant turned off whit power on
silicon side --> + 90 °C
power off, let it cool down and coolant turned on
Tests of thermal shock on different greases.
Grease samples hosted in a stave put in a oven at 100, 150, 170 °C (~ 5 min). Put in a freezer at -28 °C (~ 20 min).
Visual inspections.