ivan procházka, jan kodet presented at : seminart aces – elt meeting, fundamental station...
TRANSCRIPT
Ivan Procházka, Jan Kodet
presented at :
seminartACES – ELT Meeting, Fundamental Station Wettzell, Technische Univ.Muenchen, Germany
May 8, 2009
Czech Technical University in Prague, Czech Republic
Actual status of SPAD detector development for ELT - ACES mission
I.Prochazka, Wettzell, May 8, 2009
Prague group activities fall 2008 May 2009
Detector package for WLRS # 1 (delivered) # 2 (reference)
Indoor tests # 2 (jitter, dark, background..)
Development of the ELT package Version 1.0 CMOS, low power OK 1.1 Bias voltage / temperature compensation OK 1.2. Temperature drift compensation in
progress
Detection absolute delay determination promissing
Contribution to WLRS experiment
Long term stability tests / SLR Graz / OK
I.Prochazka, Wettzell, May 8, 2009
Detector package for WLRS # 1
Delivered, operational since fall 2008
re-checked in Prague April 8, 2009
I.Prochazka, Wettzell, May 8, 2009
Detector package for WLRS # 2 - reference
Optimised Nov.-Dec. 2008 Prague indoor tests Wettzell comparison tests
April 8, 2009
I.Prochazka, Wettzell, May 8, 2009
Detector package for WLRS # 2 - reference
Operational up to 200 Mc /s of background photon flux
Timing jitter < 25 ps rms overall using 48 ps laser pulse
Detection delay stability +/- 4psover entire background dynamical range
I.Prochazka, Wettzell, May 8, 2009
Development of the ELT packageVersion 1.0 CMOS, low power
CMOS version, low power < 50 mW (detector) < 500 mW (power s.)
Ver. 1.1. Bias voltage / temperature compensation OKdetector bias controlled within the temp. range of -50… +50 C
I.Prochazka, Wettzell, May 8, 2009
Development of the ELT packageVersion 1.1. CMOS, low power
Detection delay dependence~ 60 ps / V at 2.5 V ab
= > +/- 3 ps delay stability using bias stabilizing circuit
Timing jitter < 30 ps overallfor > 1.5 V above48 ps laser pulse
I.Prochazka, Wettzell, May 8, 2009
Development of the ELT packageVersion 1.2. CMOS, temperature drift compensation
The new detector electronics is automatically compensating the temperature variations of the detector electronic circuit delayincluding the delay temperature drift of the (long) signal cables
The operation requires Gate ON pulses synchronously with the local time basec
I.Prochazka, Wettzell, May 8, 2009
Detection absolute delay determination
Analysis of the individual contributors Photon - > electron conversion ? << 1 ps Semiconductor propagation ? 1 ps Avalanche build up OK Electronic Detection mechanism OK
Avalanche build up 1.125 ns +/- ?? Electronic detection mech. 8 ps / 1 mV threshold det. Electronics propagation 5.300 ns +/- 7 ps
Independent comparison checks required
I.Prochazka, Wettzell, May 8, 2009
Contribution to the Wettzell experiment
Joint experiment , April 8-9, 2009 Optical alignment of SPAD #1 Routine calibration/SLR on #1 Reference SPAD #2 installation + calibration
Joint experiment Prague April 10, 2009 SPAD #1 gating circuit tuning SPAD #1 tests in Prague indoor cal.facilities
May 7-8, 2009 Laser pulse length monitoring
I.Prochazka, Wettzell, May 8, 2009
Wettzell laser pulse length
Joint
Instrumental constant determined in Prague using 50 ps laser pulse to be 140 ps
WLRS laser pulse length 184 +/- 10 ps
I.Prochazka, Wettzell, May 8, 2009
Satellite laser ranging chain stabilityincluding SPAD detector package
Ground target calibration runs
K.G.Kirchner, SLR Graz, private communication, May 2009
year
I.Prochazka, Wettzell, May 8, 2009
WLRS experiment status quo (as far as Prague involvement) All the specific HW is on site, The detector(s) and timer are operational on specs The resulting precision/accuracy goal was has not ben met yet due to
unexpected problems with Wettzell hardware (laser pulse) The individual test indicate the feasibility of the experiment
The development of the ELT detector package is in progress Version 1.0 CMOS, low power OK 1.1 Bias voltage / temperature compensation OK 1.2. Temperature drift compensation in
progress Long term detector stability tests / SLR Graz / OK
We are quite confident, that the ELT experiment is feasible
Actual status of SPAD detector development for ELT - ACES mission
CONCLUSION – May 8, 2009