SPS – DM Shadow Position Sensors – Demonstration Model Gerardo Capobianco INAF – Astrophysical Observatory of Turin Torino, 21 st January 2016ASPIICS/Proba-3 Meeting 1

Torino, 21 st January 2016ASPIICS/Proba-3 Meeting 2 STATUS The SPS-DM provided by SensL and delivered in October 2015 is actually in Florence where the functionality tests are in progress. -> Test a Firenze? -> Che tipo di calibrazioni sono di competenza SensL? Foto

Torino, 21 st January 2016ASPIICS/Proba-3 Meeting 3 Test-bed Objectives Validation of the SPS subsystem measuring the performances of the SiPMs, readout electronics and algorithms (test on SPS DM) Optimization of the SPS readout electronics(i.e., DAC offset) Provide a ground simulator for FF algorithms tests and in- flight data interpretation

Torino, 21 st January 2016ASPIICS/Proba-3 Meeting 4 Test-bed The test-bed will simulate the expected illumination of the 8 SPS SiPMs in the different FF configurations by using 8 indipendents calibrated light sources directly interfaced with the SiPMs.

Torino, 21 st January 2016ASPIICS/Proba-3 Meeting 5 Test-bed description Indipendent light sources Control PC SPS Flange Test-bedFlange Fiber optics

Torino, 21 st January 2016ASPIICS/Proba-3 Meeting 6 Test-bed flange - skatch

Torino, 21 st January 2016ASPIICS/Proba-3 Meeting 7 Test-bed flange - skatch

Torino, 21 st January 2016ASPIICS/Proba-3 Meeting 8 Test-bed Sources The selected light sources are LEDs. In order to achieve the requirements of dynamic range and accuracy, 3 (TBC) LEDs with independent forward current controllers will be merged in a single fiber. The requirements of dynamic range and accuracy could be matched also by a single high power LED by the combination of the forward current tuning and PWM. This option has been discharged cause the frequency of the PWM is < 100 kHz when the sampling of the SPS ADC is of 1 MHz.

Torino, 21 st January 2016ASPIICS/Proba-3 Meeting 9 LEDs Requirements Customized device by Prizmatix

Torino, 21 st January 2016ASPIICS/Proba-3 Meeting 10 LED Optical Specifications (single LED)

Torino, 21 st January 2016ASPIICS/Proba-3 Meeting 11 Test-bed reliability aspects The test-bed will be used for the SPS DM, EQM and PFM In case of schedule conflict between the full test-bed characterization and the SPS DM test results delivery, a single source of the test-bed will be used for the characterization of the SPS DM as a calibrated source Test-bed Status A demonstration model of a 3 LEDs source merged in a single fiber is under procurement for the concept validation tests and a measurement of the performances. This device should be used as calibrated source for the SPS DM tests. The delivery is expected for the beginning of March 2016.

Torino, 21 st January 2016ASPIICS/Proba-3 Meeting 12 Test-bed Calibration plan RADIOMETRIC Calibrations Spectral Calibrations The set-up for radiometric calibration will be also used for the time-stability characterization of the LEDs. If the already described action are not enough we plan to install an active stabilization system

Torino, 21 st January 2016ASPIICS/Proba-3 Meeting 13 SPS – DM Calibration Plan (single source) Radiometric calibration of the SPS DM SiPMs using the calibrated light source in the expected operational range (and higer) Evaluation of the contribution of the readout electronics to the error budget by measuring the current at the SiPMs pins and at the end of the acquisition pipeline (TBC) SPS – DM Calibration Plan with full test-bed a. Simulating different FF configurations, by illuminating each SiPM with the values of lookup tables derived from [RD 04] and corrected with the result obtained from the LEDs calibration tests and with the SiPM responsivity Running the SPS algorithms, we will reconstruct the FF configuration “as seen” by the SPS. This calibration will give the total accuracy of the SPS subsystem. b. If possible, reading the values of the output current of the SiPM and using the same procedure of a., we will be able to separate the contributions of the algorithms (that are based on a fits of the penumbra profiles) and the contributions of the SPS readout electronics from the total error budget by retrieving the FF configuration feedback before and after the readout electronics. c. If we will not be able to finalize the calibration described in b., because it will not be possible to connect the picoammeter on the SPS DM board, we’ll use the best estimation of the algorithms errors.

Torino, 21 st January 2016ASPIICS/Proba-3 Meeting 14 SPS – DM Calibration SCHEDULE 2016 March 14: Single LED source delivery; 2016 April 11: Complete LED characterization; 2016 April 22: Complete set-up integration and hw/sw debugging; 2016 May 14: Complete the SPS DM characterization