Presentation on theme: "Space environment and detection : lessons learned from PLANCK/HFI François PAJOT Institut d'Astrophysique Spatiale François PAJOT Institut d'Astrophysique."— Presentation transcript:
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
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,...)
F. Pajot – CoRE 2012 Planck/HFI data processing glitches templates 1 sglitches removal
F. Pajot – CoRE 2012 High glitch rate on bolo and thermo 100/mn
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)
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
F. Pajot – CoRE 2012 CR on bolometers total long very long short
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)
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
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
F. Pajot – CoRE 2012 Cosmic ray energy distribution -> solar maximum -> solar minimum est.
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.
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)
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...
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.