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PACS Thermal Behaviour Tests T. M üller, H. Feuchtgruber, A. Contursi, Cs. Kiss, Sz. Csizmadia. Available Reports. Thermal Behaviour Tests During EQM IMT: SPEC & PHOT , PACS-ME-TR-067, issue 1.0 Blue Spectrometer Temperature Sensor Variation – EQM IMT PACS-ME-TR-066, issue 1.0
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PACS Thermal Behaviour TestsT. Müller, H. Feuchtgruber, A. Contursi,Cs. Kiss, Sz. Csizmadia PACS Thermal Behaviour
Available Reports • Thermal Behaviour Tests During EQM IMT: SPEC & PHOT , • PACS-ME-TR-067, issue 1.0 • Blue Spectrometer Temperature Sensor Variation – EQM IMT • PACS-ME-TR-066, issue 1.0 • Comparison of the nominal and the PACS/SPIRE parallel mode cooler • Recycling procedures • Cooler Holdtimes of the Photometer Focal Plane Unit, PICC-KO-TR-004, • Draft 0.1 • As part of the PACS ILT report: • Cooler Recycling Procedure of the Photometer Focal Plane Unit • AVM/CQM ILT • Thermal Behaviour Tests during CQM ILT: SPEC & PHOT PACS Thermal Behaviour
PACS EQM Cryostat Environment To be compared with IST and TV/TB Environment PACS Thermal Behaviour
FM IST Cryostat Environment Closed ! (drifting) Tilt may affect Red Ge:Ga strap Full PACS Thermal Behaviour
FM TV/TB Cryostat Environment Tilt may affect Red Ge:Ga strap Empty PACS Thermal Behaviour
In-Flight Cryostat Environment Empty PACS Thermal Behaviour
Thermal Behaviour Test: Spectroscopy (1) • Problems: • He leak • Bugs in the script • Blue detector temperature sensors where not functional • Remarks: • - Two cover heat-up activities took place during the test, • causing some impact on L1 temperatures • - General upward drift of L1 temperatures, probably due to • cryostat operations • - Significant increase of Red detector temperature in second • half of the test probably due to the He-leak effects and • combined with the cryostat operations. • - The internal calibration sources were not switched-on due to • a bug in the command script PACS Thermal Behaviour
Thermal Behaviour Test: Spectroscopy (2) PACS Thermal Behaviour
Thermal Behaviour Test: Spectroscopy (3) PACS Thermal Behaviour
Blue Detector Heating in Spectroscopy Iheater=200µA After Recovery of Temperature Sensor: DECB_TS_2_3 Iheater=100µA Input to thermal shimming for FM PACS Thermal Behaviour
Thermal Behaviour Test: Photometry (1) • Problems: • He leak • Bugs in the script • excessive dissipation by bolometer group 5 (PACS-ME-NCR-163) • Timing FPGA parameters problem DMC (PACS-ME-NCR-159) • DPU CFM generated corrupted data • Remarks: • - Executed 4 times (2 with leak, 1 without, 1 parallel mode) • - Ideally, more time would be required to see stabilization of CSs • The PACS/SPIRE parallel mode worked from the thermal point of view, • at the He-mass flow given during EQM IMT. PACS Thermal Behaviour
Thermal Behaviour Test: Photometry (2) PACS Thermal Behaviour
Thermal Behaviour Test: Photometry (3) without Bias group 5 problem, during parallel mode with Bias group 5 problem PACS-ME-NCR-163 PACS Thermal Behaviour
Cooler hold Time with He-leak End of 2h10m Recycling Procedure PACS Thermal Behaviour
Cooler hold Time without He-leak End of 2h10m Recycling Procedure only little detector operation during cooler hold time ! ~40 hours PACS Thermal Behaviour
Thermal Behaviour Conclusions • Do not run a test with a He-Leak. Consequence: Non-Nominal He- • flow scheme due to main tank leak • Absolute L1 He-flow more than a factor 10 larger than specified for FM • [spec. (IID-A) = 2.1 mg/s ; actual >25 mg/s] • L1 temperatures became stable only towards the end of the test phase • Photometry: bias group 5 problem caused anomalous heat dissipation • Overall thermal behaviour of PACS was within expectations • and comparable to ILT • Cooler hold time too short, even with little bolometer operations: • Recy. Opt. + improved cooler filling; Cover-T ? L1-T ? Straps ? Leak ? • Cryo-cover, L2, L1 and L0 temperatures should be kept constant during • thermal behaviour tests • The malfunction of at least one blue spectroscopy detector could be • recovered to obtain the required FM design information. • Stabilized value of DM_CAL_SRC temperature not visible due to time • constraint • Steep learning curve for implementation of related commanding scripts PACS Thermal Behaviour