1. Space environment and detection : lessons learned from PLANCK/HFI François PAJOT Institut d'Astrophysique Spatiale François PAJOT Institut d'Astrophysique Spatiale Beyond CoRE, June 26 th 2012

2. F. Pajot – CoRE 2012 Introduction  Planck/HFI first mission with  NEP ~10 -17 WHz -1/2 bolometers  100 mK uninterrupted operation for nearly 30 months  0.01 Hz- 100 Hz flat noise requirement  polarization sensitive bolometers  high precision calibration  at SE Lagrangian L2  Outline  cosmic rays interactions  impact on design and tests  EMI/EMC  note on ground calibrations (spectral, ADC,...)

3. F. Pajot – CoRE 2012 Glitches

4. F. Pajot – CoRE 2012 Planck/HFI data processing glitches templates 1 sglitches removal

5. F. Pajot – CoRE 2012 High glitch rate on bolo and thermo 100/mn

6. F. Pajot – CoRE 2012 Cosmic ray impact on HFI  CR on detectors  thermometer  grid  wafer  CR on 100 mK plate  CR secondary and showers  higher energy CR interacting with HFI or satellite then with bolometers or 100 mK plate  correlated events on many bolometers, big events on the 100 mK plate (elephants: still lacking an interpretation)

7. F. Pajot – CoRE 2012 CR on bolometers  Cosmic Rays primary and secondary, hits thermometer, grid and wafer  NEP ~10 -17 WHz -1/2 means sensitivity down to a few 10 eV on grid or thermometer, but tens of keV on the wafer

8. F. Pajot – CoRE 2012 CR on bolometers total long very long short

9. F. Pajot – CoRE 2012 CR hits impact on 100 mK stage  Low frequency thermal fluctuations  CR hits on bolometer housing (many s)  CR hits and showers on bolometer cold plate (10 s and more)  CR hits on thermometers used by the PIDs (depends on PID)

10. F. Pajot – CoRE 2012 Cosmic ray hits on 100 mK stage: long term trend bolometer plate PID bolometer plate dilution plate PID SREM count (AU)  Solar activity minimum means higher CR rate below ~500 MeV

11. F. Pajot – CoRE 2012 Cryochain stability: long term trend  About 4 nW power change on 100mK bolometer plate / 2 years PID bolo PID dilution PID 1.6K PID 4K EOL The power follows the Helium pressures at the pressure regulators 30 nW correlated with SREM data (ie: sun waking up) SCS switch over

12. F. Pajot – CoRE 2012 Cosmic ray energy distribution -> solar maximum -> solar minimum est.

13. F. Pajot – CoRE 2012 Planck/HFI noise PSD

14. F. Pajot – CoRE 2012 Impact on design and tests  Minimize detector sensitivity to CR  minimize cross section to CR for absorber (grid,..) and thermometer  minimize beams / frame thermal coupling to thermometer  fast time response  differential measurements  model and test under representative environment (instrument + high energy particles : proton accelerators up to few 100 MeV – on going work in Orsay IAS and Grenoble LPSC & INéel)  Cryochain design  passive / active thermal regulation  need design sub-K stages more immune to cosmic rays showers.

15. F. Pajot – CoRE 2012 EMI/EMC  Strict EMI/EMC design of Planck  no pertubation from transmitters  no perturbation from other subsystems  except from known 4K cooler drive electronics  synchronization with modulation of bolometer readout gives very narrow lines  requires design at system level (ex SPICA/SAFARI)

16. F. Pajot – CoRE 2012 Thoughts on ground calibrations  Temporal response  direct impact on C(l)  more characterisations  ADC calibration  large dynamics, but usefull range on a few bits  Spectral transmission calibration  the best achievable on ground may not be enough  check with multiband sky measurement  Polarization calibration...

17. F. Pajot – CoRE 2012 Thank You !

18. F. Pajot – CoRE 2012 The results presented here are a product of the Planck Collaboration, including individuals from more than 50 scientific institutes in Europe, the USA and Canada Planck is a project of the European Space Agency -- ESA -- with instruments provided by two scientific Consortia funded by ESA member states (in particular the lead countries: France and Italy) with contributions from NASA (USA), and telescope reflectors provided in a collaboration between ESA and a scientific Consortium led and funded by Denmark.