pacs iqr estec 13 january 2005 mech qual status 1 pacs iqr mechanical qualification status and plans...

Mech Qual Status 1

PACS IQR ESTEC 13 January 2005

PACS IQR

Mechanical Qualification Status and Plans for PFM

Reinhard KatterloherR. Graue, D. Kampf, R. Hofferbert, M.

v.Berg

Mech Qual Status 2


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 3


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 4


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 5


FPU Analyses

Physical Analyses Optical Analyses Thermal

Analyses Mechanisms

Analyses Structural Analyses

Tolerancing Analyses/ Budgets

Straylight Analysis

Strength Analysis

Deformation/ Distortion Analysis

Load Analysis

Ray Tracing ,

Spot Diagram Quasi Static

Analysis Functional Analysis

Natural Modes Analysis

Mass Properties Analysis

All FPU Analyses Performed

Mech Qual Status 6


PACS FPU Structural Verification

Reduced Functional Test

Functional Test(LHe)

Vibration Test - tbc(LHe)

Ambient VibrationTest (Qualification )

Physical Measurement

Functional Tests

Prel. OpticalPerformance Tests *

CQM

Vibration Test(LHe - tbc)

Vibration Test(ambient)


Mass / StructuralDummy


Functional Test(LHe)

Cold Vibration Test

Ambient VibrationTest (Acceptance)


Functional Tests


PFM


Functional Tests(LHe)

Ambient VibrationTest (Acceptance)


Functional Tests


FS

F PF PU Test Pro g ra m

Tests completed

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

LHe-VibrationVibration res.src.

Mech Qual Status 7


FPU Cryovibration Qualification Breakdown

FPFPU QualifikationKT Units

Filter Wheels(Bolometer andSpectrometer #)

DistributionBoards (Blue and Red)

2K Therm Strap #FPFPU

SuspensionFPFPU

HousingDet Suspension #

Similar to CQM

Qualification TestsComplete

Housing Qualified

Similar to CQM


Suspension Qualified

Similar to CQM


Filter WheelsQualified #

Similar to CQM


Distribution BoardsQualified

CQM


CQM

Detector Suspension Qualfiied #

CalibrationSource

Similar to CQM


Calibration SourceQualified

2K StrapsQualified #

All Items Qualified# means remaining problems to be solved resp. delta-vibration to be

done

Mech Qual Status 8


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 9


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 10


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 11


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 12


Impact of additional Heaters and Flashers

• 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

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):

Mech Qual Status 13


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 14


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 15


FPU Calibration Sources

• Cryogenic qualification on EM during FPU STM vibration

• Upgrade for PFM: None

Mech Qual Status 16


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 17


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 18


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 19


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 BOLC PSU 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 20


Delta Cryo-vibration Qualification Matrix of FPU Subunits

ILT phase

AVM CQM PFM FS

FPU STM CQM PFM CQM refurb.

DPU AVM AVM PFM QM

SPU AVM AVM PFM EM

DECMEC AVM EM PFM QM+

BOLC BOLCSIM QM1 (QM2) PFM

QM2

WIH AVM AVM PFM QM

EGSE ILT ILT ILT ILT

FPU Subunit Delta cryovibration

qualification

Scheduled

PhFPU(bolom.+cooler)

Done(upgraded STM)

October 04

Ge:Ga-array internal cooling link with I/Fs

Open(STM housing + FM components)

March 05

Ge:Ga-array suspension strut electr. insulation

Open(STM housing + FM components)

March 05

Grating assembly CQM incl. L Lock

Done(CQM)

February 04

Unchanged Development Concept & Model Philosophy since IHDRApproval of PACS-RFW-0007 expected !

pacs iqr estec 13 january 2005 mech qual status 1 pacs iqr mechanical qualification status and plans...

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