Updated calibration designs and EUSO calibration DB

1. Updated calibration designsand EUSO calibration DB Emanuele Pace INFN – Firenze (Italy)XUVLab – Dip. Astronomia e Scienza dello Spazio Università di Firenze (Italy)

2. Calibration Definition “Calibration” is measurements to determine the transfer function to get the incident photon flux from the photo-electron signal. Calibration concerns: Fresnel lenses Phocal surface detectors / Filters / Optical adapters FE electronics and trigger Calibration involves: sub-systems pre-flight on orbit ground-based in flight EUSO General Meeting, Munchen 17-20 November 2003

3. Requirements • Spectro-radiometry in the range 330 nm ÷ 400 nm • Photon counting (support DC mode and Pulse mode) • Time resolution (pulse mode): 20 ns • Background: less than 104 photons / (pixel s) • Uncertainty of absolute light intensity: < 10% • Light intensity range • DC mode: 0.01photo-electron ~ 0.1 photo-electron • Pulse mode: 0.1photo-electron ~ 100 photo-electron • Very low impact on the mass budget • Low power consumption • No movable components • Monitoring function for the light source intensity • Fitting the EUSO structure EUSO General Meeting, Munchen 17-20 November 2003

4. In orbit calibration system • Light Source • Type: LED • Single/Multiple • Multi-wavelength emission • Monitor Detectors • Photon counting / analog regime • Optical configuration and arrangement • Mass & power budget • Ground based calibration / cross measurements EUSO General Meeting, Munchen 17-20 November 2003

5. Calibration design in the Red Book Flux on FS = 5 x 109 ph/s = 950 ph on FS = 0.2 ph / MAPMT ~10-2 ph / px EUSO General Meeting, Munchen 17-20 November 2003

6. Electronics box 30 mm 50 mm Multiple-LED source EUSO General Meeting, Munchen 17-20 November 2003

7. Calibration design in the Red Book EUSO General Meeting, Munchen 17-20 November 2003

8. Diffuser on the lid + single source EUSO General Meeting, Munchen 17-20 November 2003

9. Diffuser on the lid + multiple source 4 LEDs 5 LEDs EUSO General Meeting, Munchen 17-20 November 2003

10. After ESA Review • Questions from the review panel: • Prototype of the source-detector system • Calibration of the OM EUSO General Meeting, Munchen 17-20 November 2003

11. Possible solutions Detectors on the FS Embedded detectors on the lid EUSO General Meeting, Munchen 17-20 November 2003

12. 6 LEDs on FL2 EUSO General Meeting, Munchen 17-20 November 2003

13. Ray tracing of 6 LEDs on FL2 EUSO General Meeting, Munchen 17-20 November 2003

14. EUSO Calibration Databases Getting Started... From M.C. Espirito Santo

15. Context • Archives and databases (DB) have been identified as one of the issues to be addressed in priority when planning the EUSO data handling system, in the context of the SODC • The reconstruction/analysis modules of ESAF are being build and the need to access different types of external information is one of the main issues (DB I/F expected to represent large fraction of code) ... the problem should likely be addressed as one and soon • Gain experience and perform relevant tests rather early • Modularity and growing capability required EUSO General Meeting, Munchen 17-20 November 2003

16. EUSO DB: form & contents Questions for the time being... • Probably Several DB (info inter-relation, common interface) • Which type of DB ? Which SW and access tools? • Organisation/inter-relations are crucial point! And highy dependent on • contents specification • Which information do we want to store? • Which parameters do we need to get for reconstruction? • I/F with end-to-end simulation and reconstruction • Accessing different types of info with single tool (external DB) EUSO General Meeting, Munchen 17-20 November 2003

17. Detector calibration DB Requires some basic assumptions... • How does the trigger and readout electronics work ? • Data contents • Trigger: basic scheme and tunable parameters • Which calibration information will we have? • Collected information • Information to be used on reconstruction • Information used to generate configuration parameter for uploading Some Information on the RedBook preliminary issue EUSO General Meeting, Munchen 17-20 November 2003

18. Calibration • Pre-flight absolute calibration @ 3 different wavelengths Gains (G) and pedestals (p) Single p.e. peak • On-board: relative calibration (stability) • Stable illumination of full FS (~1s, daily basis ) • Threshold scan => p.e. signal discriminator level • Separate monitoring of the OM? One complete FS threshold scan every 2 months Illumination of the FS daily? EUSO General Meeting, Munchen 17-20 November 2003

19. Calibration DB – Info for reconstruction Digital: Npe = (signal – pedestal) x inneficiency correction • Pedestal map (analog and digital) • Also computed from event itself (other GTU) • Dead pixel map • Spatial proximity... • Inneficiency correction map • If threshold high w.r.t. p.e. Peak • pileup • Analog: Q to Npe gain factor Analog: Npe = (Q – pedestal) x Gain factor Ground calibration info stored on DB and updated with on-flight info EUSO General Meeting, Munchen 17-20 November 2003

20. Calibration DB: Info for on-board config Information to be uplinked (on-board configuration files): • HV map • Analog Threshold map for the digital FE • Analog FE Threshold map • 1 digital comparator levels per macrocell • Pixel mask map • LV for UV LEDs, LV/HV to monitoring detectors EUSO General Meeting, Munchen 17-20 November 2003

21. EUSO General Meeting, Munchen 17-20 November 2003

22. Contributions to the global efficiency • Transmissivity and uniformity changes of Fresnel lenses • Variation of the UV filter characteristics • Transmissivity or reflectivity reduction of optical adapter • Efficiency variation of the adapter+detector system due to vibrations, possible damage, misalignments, increased scattering power, etc. • Variations of the detector gain and photocathode QE • Failure of some photo-detectors • Increase of the scattered light level • Electronics performance EUSO General Meeting, Munchen 17-20 November 2003