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PACS IQR. Mechanical Qualification Status and Plans for PFM. Reinhard Katterloher R. Graue, D. Kampf, R. Hofferbert, M. v.Berg. Overview Mechanical Qualification Status and Plans for PFM. FPU structure - mirrors - baffles - black paint - impact of additional heaters and flashers
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PACS IQR Mechanical Qualification Status and Plans for PFM • Reinhard Katterloher • R. Graue, D. Kampf, R. Hofferbert, M. v.Berg Mech Qual Status
Overview Mechanical Qualification Status and Plans for PFM • FPU structure - mirrors - baffles - black paint - impact of additional heaters and flashers • Filter wheels • Calibration sources • Grating assembly • Chopper • WE units • Delta Cryovibration Qualification Matrix • (PhFPU presented by LR) • (Ge:Ga arrays presented by JS) Mech Qual Status
FPU structure, mirrors, baffles: main data • Total mass allocation in IID-A for PACS is 140 kg,mass requirement is met (margin 13.2 kg), FPU CQM has 74.1 kg • Eigenmodes of complete FPU above 100 Hz,requirement is met for all axes (x,y,z = 188,122,104 Hz)verified by cryogenic vibration of FPU STM • Mirror environmental tests OK, Au coating no concern (initial NCR closed), optical alignment check/stability on FPU CQM not done,after FPU STM cryo-vibration dummies mechanically checked • Baffles structural OK • Upgrades for PFM: none, except- additional baffles required to reduce stray light inside the FPU spectrometer section (see presentation by AP),- modification of detector baffles to carry flashers for curing Mech Qual Status
PACS FPU Architecture – 6 Stand Alone Modular Substructures • Top Optics with Chopper (C.Z.) and 2 Calibration Sources • Image Slicer • Bolometer Optics with Filter Wheel • PhFPU with 0.3 K Cryo-Cooler (CEA) • Collimator with Grating Assembly (CSL) • Spectrometer with Ge:Ga – Photoconductor Arrays (MPE), Filter Wheels, Distribution Boards (Cold Electronics) Level 0 Thermal Links - Thermal Feed Throughs (1.7 K) Mech Qual Status
FPU Analyses All FPU Analyses Performed Mech Qual Status
PACS FPU Structural Verification Similarity • CQM and STM were manufactured parallel with the same drawingsout of the same lot Qualification Tests • STM vibration tests Conclusion: FPFPU Housing is structurally qualified Tests completed Vibration res.src. LHe-Vibration Tests completed Mech Qual Status
FPFPU Qualifikation KT Units Filter Wheels FPFPU FPFPU Calibration Distribution (Bolometer and 2K Therm Strap # Det Suspension # Housing Suspension Source Boards (Blue and Red) Spectrometer #) CQM Similar to CQM Similar to CQM Similar to CQM Similar to CQM Similar to CQM CQM Qualification Tests Qualification Tests Qualification Tests Qualification Tests Qualification Tests Qualification Tests Detector Suspension Qualfiied # Complete Complete Complete Complete Complete Complete Filter Wheels Calibration Source Distribution Boards 2K Straps Housing Qualified Suspension Qualified Qualified # Qualified Qualified Qualified # FPU Cryovibration Qualification Breakdown • All Items Qualified # means remaining problems to be solved resp. delta-vibration to be done Mech Qual Status
Structural Analyses - Status • Evaluation of ambient (STM) and cold vibration tests (Cryo STM) • FEM calibration • Load analyses with calibrated model (cryo-vibration test) • Strength analyses for FPU metallic and CFRP components • Cryogenic material properties analyses • CoG, MoI analyses • Displacement, distortion, deformation analyses All Documentation released Mech Qual Status
Approach to FPU PFM Cryovibration • Protection of sensitive subsystems during acceptance vibration,random loads not to exceed 10 g rms • Dynamic analysis of PACS on CSL shaker performed by ESA- response of red and blue bolometer FPA and their relation with a point on the outside of PhFPU housing determined- mounting of a triplet-accelerometer foreseen • Frequencies and Q-values are to be checked during warm FPU-STM vibration at MPE • Notching at the PACS feet during PFM cryovibration at CSL Mech Qual Status
FPU PFM Test Plan and PFM MAIV Status • Subsystem level (FW, CS, DBs, Substructures) • Mechanical and Thermal Test program as given in Test Plan (similar to CQM) • Outbaking at 80 °C (minimum) • Functional test program as given in test plan (similar to CQM) • Substructures alignment verification -Cryogenic stability tests (tbc) • System level (FPU) • Cryovibration test (KT support at CSL) • Functional test (KT support at MPE) • MAIV Status • Metallic items manufactured • CFRP items manufactured and static load tested • Calibration Sources manufactured and partly assembled • FW assemblies manufactured, pre-tested on motor drive level, partly assembled • Pre-assembly (fit check in progress) Mech Qual Status
FPU Black Paint: main data of KT72 • PACS-RFW-0003 agreed: out-gassing requirements met • Optical performance: satisfying • Adhesion on Al surfaces: satisfying • Particle release below 100ppm, improvement advised:impact of pre-vibration under investigation, additional cryogenic vibration planned in February 2005,CEA: concerned about particle fall-out onto bolometer FPAs,MPE: protection of grating/FW bearings might be advisable • Upgrade for PFM: very likely none Mech Qual Status
Impact of additional Heaters and Flashers For detector curing PACS needs to implement additional heaters and flashers in the FPU. The impact on the mechanical properties of both detector arrays (Upgrade for PFM) is estimated as follows (detailed design in progress): • 2 heater resistors on the red detector array: mass increase 0.2% > no impact on mechanical behaviour • 2 flashers mounted at the end of each detector array baffle:mass increase few % > no impact on mechanical behaviour • Additional wiring inside the FPU required (mass negligible) • Re-routing on both distribution boards required (redesign)mass increase on one board due to a new connector> no impact on structural properties expected Mech Qual Status
FPU Filter Wheels • Photometer FW : OK (initial blocking by a screw resolved) • Spectrometer FW problematic:- during CQM ILT blocked at 4K - during warm-up partial movement at 90K • Currently investigations on CQM wheel at KT in progress:- at 77K higher friction observed- ball bearing sensitive to abrasion during warm vibration?- baffle removed for better inspection of drive - blocking of rotor on one Hall sensor found- new cryogenic verification test planned • Upgrade for PFM: revised tolerance of bearing support Mech Qual Status
Filter Wheel Assembly • Required Torque to Leave the Filter Position : 0.5 Ncm • Maximum Motor Torque Performance : 4.2 Ncm. • Motor & Position Indicator are in Powerless Dormitory Mode between Operations • Position Locking Principle: Contact-less Magnetic System • No Launch Lock Mechanism Required Mech Qual Status
FPU Calibration Sources • Cryogenic qualification on EM during FPU STM vibration • Upgrade for PFM: None Mech Qual Status
Calibration Source Lay-out Wavelength/scattering optimised surfaces • 2 identical Calibration Sources mounted in FPU • Operation at 4 K, Emitter temperature 50 - 100 K • Sphere (inner diameter 51 mm) • Redundant Combined Sensor and Emitter (PT 500) • Circular aperture (diameter 12 mm) with Si lens put in front of aperture • Surface with Lambertian stray light behaviour and high reflectivity (> 0.992) • Emitter suspension: • 4 filigree GFRP struts with 24 x 0.25 x 0.25 mm³ • Titanium coated for 4 wire connection to the source Mech Qual Status
FPU Grating Assembly • Cryogenic vibration qualification on EM plus additional qualification (vibration, cryo-cycling) on CQM incl. launch lock mechanism at subsystem level: OK • Movement quality of grating CQM: OK • Functionality of launch lock mechanism of CQM: OK • Upgrades for PFM:- modified routing of internal harness needed- Inductosyn transformer needs to be mounted inside the grating assembly (for CQM currently on FPU outside)- Fixation of grating plate on axis has to be improved- cleanliness before delivery for integration with FPU to be improved and protection cover advised Mech Qual Status
FPU Chopper • Development performed as specified in IHDR presentation(environmental tests, lifetime test …) • Minor deviations for CQM:- envelope violation of cable housing (solved)- cryovibration done on subunit level at 77K only (agreed) (no LHe vibration with CQM performed) • Upgrades for PFM:- no deviation from MPIA/ZEISS development plan foreseen- Au coating of mirror very likely to be changed (thickness and coating process to be improved) Mech Qual Status
WE Units • AVM / STM WE Unit testing- No structural tests required in general - STM BOLC: Vibration tests done : validation of design > Problem with displacement of boards - STM BOLCPSU sub-unit vibrational tested : OK • CQM / AVM ILT - No structural test on WE Units foreseen • PFM (QM) WE Units - Full environ. test program agreed before FM delivery to MPE - First structural results for QM SPU available (> some NCRs) - New mechanical design for DPU CFM / PFM, will be fully tested • Mass margin for PACS is 13.2 kg in total (DECMEC mass uncertainty not critical in this respect) Mech Qual Status
Delta Cryo-vibration Qualification Matrix of FPU Subunits Unchanged Development Concept & Model Philosophy since IHDR Approval of PACS-RFW-0007 expected ! Mech Qual Status