1. 1DSM/DAPNIA/SAp – J. MartignacPACS - IHDR - MPE – Nov. 12 – 13, 2003 PACS – IHDR PhFPU Design J. Martignac CEA/DSM/DAPNIA Service d’Astrophysique

2. 2DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 INTRODUCTION PhFPU Requirements BFP & PhFPU : - Design -Thermal & Grounding Scheme - Validation & Qualification Critical Items

3. 3DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 PhFPU Requirements Mass around 7 kg. External Envelope & Mechanical I/F according to the Doc. : PACS-KT-ID-005-iss.4 Admissible Load according to the Doc : PACS-KT- AN-005-iss.2 Thermal Consumption : -  to 12µW at 300mK -  to 4,3mW at 2K without the Cooler

4. 4DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 BFP : Design The BFP is mainly composed by 5 Sub-assemblies: the mechanical structure, the focal plane at 300 mK, the 300mK thermal strap the 2K circuit buffer, the envelope.

5. 5DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 BFP : Design Review BFP SpecificationsBFP Design Dimensions Mass 90x90x80 500g / BFP 86x86x70 (without 2K shield Cone) B-BFP : 630g included 2K shield Cone R-BFP : 550g included 2K shield Cone Thermal Load on 300mkMech. Structure < 1µW Elect. Connections < 1µW Mechanical Structure : 0,6 µW Elec. Connect. : 0,66 µW Eigenfrequencies Admissible Loads Transv. mode : > 150Hz Axial mode : > 150Hz Transverse mode : 200 Hz Axial mode : 500 Hz Thermal Load on 2K (through 2K/4K Rib. Cabl.) <5.10 -4 WPower ON: 4.10 -4 W (calculated) Power OFF: 2,4.10 -4 W (calculated) Spectral BandsB-BFP: 60-90 µm 90-130 µm R-BFP: 130-210 µm HP filter : High Pass 60 µm + AG filter : Low Pass 130 µm Two Band Pass HP filters on a 2K filter wheel (not SAp delivery) : 60-90µm / 90-130 µm HP filter : High Pass 130 µm + AG filter : Low Pass 210 µm One Band Pass HP filter at the end of the 2K shield Cone located at the pupil Stray LightFIR Black Coating on critical areas

6. 6DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 4K Structure Connector Panel Cooler Harness Holder PhFPU : Design The PhFPU is mainly composed of 8 Sub-assemblies: the 4K Structure,

7. 7DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 R & B BFPs Holder Stainless Steel Insulating Tubes Voltalef Insulating Spacers PhFPU : Design the 2K Structure,

8. 8DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 R BFP B BFP R&B BFP Filters Boxes R&B 2K/4K Ribbon Cables PhFPU : Design the two BFPs Red & Blue,

9. 9DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 3He Cooler 3He Cooler Harness L0 Straps Baffling Shield Covers PhFPU : Design the 3He sorption Cooler

10. 10DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 300mK Thermal Strap Kevlar wires suspension to the 4K 3He Cooler Thermal Interface R&B BFPs Thermall I/F R&B Copper Braid Kevlar wires suspension to the 2K Copper Braid Stray light Baffling PhFPU : Design the PhFPU 300mK Thermal Strap from the cooler to the BFPs

11. 11DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 2K Feedthrough (by KT) R&B BFP L0 I/F L0 Strap I/F Copper Braids Stray Light Baffle PhFPU : Design the 2K Thermal Strap,

12. 12DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 2K Baffle 4K Baffle PhFPU : Design & the Baffles.

13. 13DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 PhFPU : Design PhFPU assembly Status: Mechanical I/F: OK Optical I/F: SOAM (KT) Parts Manufacturing: OK Integration Tools: OK Black Paint: in progress Full Assembly: First Time Thermal: to be validated

14. 14DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 PhFPU Thermal Equivalent Scheme R3 R1 Rc3 R6 Rc1 Rc4 PhFPU 2K I/F PhFPU 4K Structure  PhFPU  élec =2,8mW (B&R BFP)  flex =0,5mW  struct =0,8mW  Feedth. =0,5mW TBC by KT Evap. Switch I/F T  2K R2 Rc2 Pump Switch I/F h  0,12W.K -1  Evap.  Pump. h  0,075W.K -1 Global Thermal budget on the L0 level: - 4,1mW + 0,5mW* *:(TBC by KT) L0 Straps manufacturing is under responsibility of Astrium

15. 15DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 PhFPU Grounding scheme Pump Evap. Cooler Structure @ 4K Space Scraft L0 Thermal Straps He Tank Optical Bench PhFPU Structure @ 4K BFP Housing @ 2K The PhFPU grounding configuration is like represented: - one shield @ 2K close to the bolometers and signal - one shield @ 4K performed by the outer PhFPU and Cooler Structure - the electrical insulation between the two shields are performed by: - Voltalef parts at the Structure level - 0,1mm layer of STYCAST 1266 between copper foils at the Thermal Strap level (300mK & 2K)

16. 16DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 Validation & Qualification Succesful Warm vibrations have been done : - on a BFP Structure alone - at the PhFPU level - & at the Instrument level A new PhFPU SM has been build for the Cold vibration campaign at CSL. The BFP Kevlar suspensions only survived to the first two axis (Y & Z), and a breakage occured at the beginning of the third run (X). But higher input levels than specified in the IIDA was applied.

17. 17DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 BFP : Validation & Qualification – Future Tests Cold vibrations are planed : - on a BFP Structure alone - on a BFP equiped with detectors and its complete readout circuit to validate all the interconnections from the detectors to the end of the 2K/4K Ribbon Cable. New stiffness measurements at 4K will be done on a BFP Structure in two directions : - axial (applied load  to the focal plane) - transverse ( // to the focal plane) These tests should be repeated 2 or 3 times on the same Structure to study the thermal cycling influence on the Kevlar wire suspensions.

18. 18DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 PhFPU : Validation & Qualification – Future Tests A complete PhFPU FEM is complete now with the Cooler & the BFP Kevlar suspensions Warm vibrations will be done at the PhFPU level to investigate potential coupling between the PhFPU 4K Structure and 3He Cooler: Cooler SM refurbished with a Titanium core and a functionnal switch linked to a representative L0 Strap: TBC!). New cold vibrations campaign under negociation (ESA/Inst).

19. 19DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 PhFPU Critical Items Critical: Qualification at Cold temperature BFP Kevlar wire suspension Mechanical load on the Cooler thermal switches I/F To be validated: 0,3K Strap thermal behaviour (without & with electrical insulating parts. Cooler behaviour mounted on the PhFPU (thermal environment)

20. 20DSM/DAPNIA/SAp – J. Martignac PhFPU Design PACS - IHDR - MPE – Nov. 12 – 13, 2003 Progress since IBDR 3 models of the PhFPU have been built: SMKT, SMKT2 & SOAM Warm vibrations done succesfully passed at sub-assembly and at instrument level BFP assembly & integration is now completely stabilised 2K/4K ribbon cables manufacturing is now under control PhFPU design is complete, all the parts for the QM are manufactured