Multi-Photon Time Resolution and Applications

Transcription

1 FAST Action WG3 meeting Multi-Photon Time Resolution and Applications. 1 E. POPOVA, 1,2 S. VINOGRADOV, 1 D. PHILIPPOV, 1 P. BUZHAN, 1 A. STIFUTKIN, 13th June 2018 Schwetzingen, Germany 1 National Research Nuclear University «MEPhI» 2 Lebedev Physical Institute RAS ICASIPM the International Conference on the Advancement of Silicon Photomultipliers

2 Motivation There are many applications demanding for a photon-number-resolving detection of light pulses, some of them also require an extreme timing resolution at the multi-photon level (TOF PET, LIDAR, 4D calorimetry) Why we are interested in SPTR? We exct that good SPTR provides good timing resolution One group of ople wants to select the best detectors for their application Another group of ople wants to develop SiPMs most suitable for these applications Goals of presentation: 1. How to extract SPTR if it hardly measurable due significant electronic noise contribution 2. What is influence of SPTR and another parameters of SiPM and light pulse sha on multi-photon time resolution TR

3 Timing measurements with KETEK SiPM+amplifiers assembly Exrimental setup: picosecond laser (405 nm, FWHM 40 ps) advanced timing optimized 3x3 mm 2 KETEK SiPM chip and scially designed (by S. Ageev) and produced monolithic trans-imdance amplifier(s) (BW 1.5GHz) on PCB assembly External KETEK evaluation kit amplifier thermal chamber with light protection T=-30 C digital oscillosco LeCroy WaveRunner 620Zi (2GHz, 20GS/s ) PMT-monitor for calibration light intensity into N SiPM + Amplifiers PCB New timing optimized SiPM 3

4 SPTR measurements Temrature = -30 С FWHM 1 ns 3x3 mm 2 SiPM, SPTR = 112 ps 1_phe pulse sha, Uov = 4.5 V SPTR Uov = 9.5 V 4

5 Multi-photon time resolution Analytical model Amplitude noise for timing resolution (S.Vinogradov) S.Vinogradov. Evaluation of rformance of silicon photomultipliers in LIDAR application. Proceedings of the SPIE, Volume 10229, id L 10 pp. (2017) S.Vinogradov. Approximations of coincidence time resolution models of scintillator detectors with leading edge discriminator. NIM A

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7 ρ ρ

8 Analytical model (short laser light & no noise) Gaussian sha of laser pulse and SPTR allows to get TR dendence on SPTR: - in case if SER is a Heaviside step response it has an analytical form: σ sptr 1 σ sptr σ t ( N ) = π e 1 erf N 2 N - in case if SER is a bi-exponential with rise Tr and fall Tf times it has an analytical form: For typical SiPM pulses (Tr = ns, Tf = ns) dendence of CTR on Tr and Tf is rather weak, so it can be approximated as: σ sptr σ t ( N ) ( ) N

9 TR vs Light intensity for short laser pulse (T = -30 C, Uov = 4.5V, SPTR (true SPTR without noise contribution)= 147 ps Pct=0.13, ENFct=1.16, no Dark rate) Time resolution (FWHM), ps SPTR Light source laser, FWHM = 40 ps Uov = 4.5 V, T = -30 C Laser trigger electronic jitter? (not include in model) Exriment Model Exrimental fit FWHM (N t ) SPTR 1.5 N Analytical model: Tr = 0.5 ns, Tf = 1 ns FWHM (N t ) 210 ps N Exrimental Fit Number of photoelectrons r pulse 210 1,5 =140 SPTR corr Extracted SPTR 9

10 LIDAR SER with τ rise and τ dec

11 TOF PET, scintillator readout we are interested to estimate a coincidence time resolution CTR on the basis of known photodetector and scintillator parameters. Choosing of the best photodetector Choosing of the best scintillator Choosing of the best photodetector and scintillator * Photodetector analogue SiPM SiPM LIGHT single photon time resolution SPTR pulse sha SER,t rise, t dec PDE crosstalk Dark rate Electronic noise T r rise time T d decay time photon numbers

12 Common understanding of the CTR dendence for scintillator light CTR dends on Number of photons slightly on τr and σ sptr Too small for analysis

13 Monte-Carlo simulations of the Time Resolution the Time Resolution (TR) of SiPMs is extensively studied in exriments and Monte-Carlo simulations, Analytical extraction of parametric dendences from Monte-Carlo simulations But after obtaining of MC-simulation results is quite difficult to analyse them S.E. Derenzo, W.-S. Choong, W.W. Moses, Fundamental limits of timing resolution for scintillation detectors, Phys. Med. Biol. 59 (2014)

14 TOF PET bi-expanentional light pulse Analytical Approximation of model for CTR : ) signal: where tr rise time, td decay time for scint If Tr<<Td noise: Scint rise time SPTR&OTTS Almost equal contributions!!! full (combined):

15 MEPHI MPTR measurements (T = -30 C, Uov = 4.5V, SPTR = 147 ps, ENFct=1.16): Light source laser + WLS-fiber, Tr 80 ps, Td 1.8ns, scintillator-simulated exriment 15

16 Exriment MPTR with laser+wls-fiber MPTR histograms (Tr 80ps, Td 1.9ns) : top N 0.2 bottom N 52.3 Exrimental Fit MPTR FWHM, ps (CTR with scintillator simulation) vs Light intensity Uov = 4.5 V, T = -30 Exriment Model Exrimental fit FWHM, ps FWHM (N t 1007 ps ) N Number of photoelectrons r pulse 16

17 Analytical model calculations: MPTR as function of SPTR for scintillator-simulated pulse Time resolution (FWHM), ps N = 1 N = 10 N = Time resolution (FWHM), ps 100 N = 100, Td = 18 ns N = 100, Td = 1.8 ns decay=1.8 ns decay=18 ns SPTR FWHM, ps SPTR FWHM, ps MPTR has regions with different dendence on SPTR Kind of plateau for smaller SPTR value is connected with WLS rise time (80 ps) 17

18 Summary The multi-photon timing measurements with different pulse shas were carried out to show how coincidence timing resolution dends on SPTR. Analytical model of Amplitude noise has a good agreement with exriment results for light intensity N > 1. MPTR for short light pulse may allow to extract true SPTRdetector (not affected by noise) should be checked Analytical model shows how MPTR dends on SPTR for long scintillator-like pulses, but it should be checked with more exrimental data. Supported by Russian grants # /4.6 and /9.10 And FAST COST (Euroan Cooration in Science and Technology) action TD

19 BACKUP 19

20 Timing measurements with new PCB multi-photon TR results Timing resolution vs Light intensity (in fired pixels), Uov = 4.5 V N, pixel SPTR, ps , , , ,1 20

21 Timing measurements with new PCB CTR simulation exriment results Simulated coincidence timing resolution vs Light intensity (in fired pixels), Uov = 4.5 V N, pixel CTR, ps

22 Analytical model: CTR as function of SPTR and other parameters Modern analytical approaches: n Monte Carlo simulations, n Detection event statistics, n Order statistics of photoelectron detection time, n Cramer-Rao lower bound estimation. 22

23 Timing resolution - analytical model (S.Vinogradov) σ ( N t ) = Var[ V out dvout ( t) dt ( t)] V out ( t Discrim ) = Discrim = N ENF N SiPM d 2 [ ρ ph ρsptr hser ] [ ρ ρ h ]( t ph sptr dt ser V ( t) + V ) 2 noise 2 ser Filtered marked point process Analytical model Amplitude noise for timing resolution N ENF SiPM ρ ph ρ sptr h ser - Number of photoelectrons - Excess noise factor of SiPM (include DCR, XT, AP) - Probability density function of light - Probability density function of SiPM SPTR - Single-electron response function (SER) Constant threshold at the first photon- no CT, no AP, no dark rate ENF 1 23

24 Exrimental data with lidar prototy laser 40 ps FWHM 405nm 0,1 Light background 100 MHz 0,0 Scanning lidar Amplitude, V -0,1-0,2-0,3 A M Antonova and V A Kaplin 2018 J. Phys.: Conf. Ser SiPM timing characteristics under conditions of a large background for lidars ,4-0, Time, ns Time resolution (FWHM), ps fired cell E-6 1E-5 1E-4 SiPM current, A 1µA=4.2MHz

25 Exriment TR dendence (T = -30 C, Uov = 4.5V, SPTR (true SPTR without noise contribution)= 147 ps, ENFct= Pct=0.13, ENFct=1.16, no Dark rate) Light source laser, FWHM = 40 ps FWHM (N t ) SPTR 1.5 N Analytical model: Tr = 0.5 ns, Tf = 1 ns FWHM (N t ) 210 ps N Exrimental Fit 210 1,5 =140 SPTR corr 25 LED threshold