Fast Timing Workshop June 8 10 th 2015

Fast Timing Workshop June 8 -10 th 2015 FZU Prague Timing Methods with Fast Integrated Technologies Jean-François Genat 1

Fast Timing/Imaging Photo-detectors Multi-anodes PMTs Dynodes QE CE Rise-time TTS (1 PE) Pixel size Dark counts Dead time Magnetic field Radiation hardness Total Charge Silicon-PMTs Quenched Geiger 30% 90% 0. 5 -1 ns 150 ps 2 x 2 mm 2 1 -10 Hz 5 ns no 1 k. Rad (PC) 90% 70% 250 ps 100 ps 50 x 50 mm 2 1 -10 MHz/cm 2 100 -500 ns yes noise x 10 Micro Channel Plates Micro-Pores 20 -30% 60% 50 -200 ps 30 -50 ps 1. 5 x 1. 5 mm 2 1 -10 k. Hz/cm 2 1 ms 15 k. G 1 k. Rad (PC) 0. 5 -2 C/year Jean-François Genat, Fast Timing Workshop, June 8 -10 th 2015, FZU Prague 2

Example: GHz Bandwidth Micro-Channel Plate Signals - Detector + electronics noise >> quantization noise (LSB/√ 12) - Sampling frequency > 2 x Shannon-Nyquist=4 GHz Micro-Channel Plate Signal Spectrum Noise as small as possible 2 2 GHz 4 GHz 3 Jean-François Genat, Fast Timing Workshop, June 8 -10 th 2015, FZU Prague 3

Contributions to timing spreads: Timing spreads Detector: Transit Time Noisedetector Rise time Gain (Signal/noise) Electronics: Noiseelec Sample rate Analog bandwidth Stefan Ritt: sn = sn det + sn elec S = G Npe Jean-François Genat, Fast Timing Workshop, June 8 -10 th 2015, FZU Prague 4

Electronics: Fast Timing Techniques • Threshold techniques • • Single Threshold Double Threshold Multiple Thresholds Constant Fraction • Waveform sampling techniques • Waveform sampling using Flash ADCs (up to 8 -9 bit) or • Analog memories fast sampling + AD conversions with slow ADCs -bit) (12 and Digital Signal Processing Jean-François Genat, Fast Timing Workshop, June 8 -10 th 2015, FZU Prague 5

Fast Timing techniques Constant-fraction Multi-threshold Constant fraction Leading edge errors Extrapolated time Waveform sampling Jean-François Genat, Fast Timing Workshop, June 8 -10 th 2015, FZU Prague 6

Electronics: Timing Methods: Single threshold Multiple thresholds Constant fraction Waveform sampling Time resolution vs Number of photo-electrons zoom Jean-François Genat, Fast Timing Workshop, June 8 -10 th 2015, FZU Prague 7

Time Stretching Différential: Ramp goes up at rate Time is stretched by , down at rate , measured using a “slow” TDC d d Resolution: ps ? To Counter Jean-François Genat, Fast Timing Workshop, June 8 -10 th 2015, FZU Prague 8

Single Threshold Effects of Amplitude and Rise-time spreads Amplitude and/or Rise-time spectra translate into time spreads in case of single threshold Jean-François Genat, Fast Timing Workshop, June 8 -10 th 2015, FZU Prague 9

Effect of Noise using Single Threshold Methods Time spread proportional to rise-time Jean-François Genat, Fast Timing Workshop, June 8 -10 th 2015, FZU Prague 10

Discriminator walk effects Walk: Discriminator delay depends on the pulse slope across threshold Pulse slope: detector rise-time + amplifier Use appropriate gain x bandwidth technology to match the detector speed Jean-François Genat, Fast Timing Workshop, June 8 -10 th 2015, FZU Prague 11

Multi-threshold (simulation) Multi-threshold: sampling times instead of amplitudes : - Number of thresholds - Thresholds values - Order of the fit: 4 -8 equally spaced 2 d order optimum Extrapolated time Jean-François Genat, Fast Timing Workshop, June 8 -10 th 2015, FZU Prague 12

Multi-threshold performance Jean-François Genat, Fast Timing Workshop, June 8 -10 th 2015, FZU Prague 13

Waveform Sampling and Analysis Fit to waveform and derivative templates B. Cleland E. Stern Fast Timing Jean-François Genat, Fast Timing Workshop, June 8 -10 th 2015, FZU Prague 14

Timing Resolution using Waveform Sampling abw= analog bandwidth = rise time (10 -90%) = sampling period S Since = signal amplitude with and (Stefan Ritt, PSI) 15 Jean-François Genat, Fast Timing Workshop, June 8 -10 th 2015, FZU Prague 15

An Application of Waveform Sampling Two-dimension readout using delay lines Waveform sampling and analysis: • • • Picosecond timing with fast detectors Charge: centroids for 2 D readout Resolve double pulse Large area detectors read with delay lines in series Jean-François Jean-Francois Genat, March Fast 2009, Timing Argonne. Workshop, June 8 -10 th 2015, FZU Prague 19 th 16

Waveform Sampling and Analysis Two-dimension readout using delay lines B. Cleland E. Stern, BNL Signal Template Real MCP Laser data Extract precise time and amplitude from minimization of c 2 evaluated wrt a waveform template deduced from the measurements. Jean-François Jean-Francois Genat, March Fast 2009, Timing Argonne. Workshop, June 8 -10 th 2015, FZU Prague 19 th 17

Waveform Sampling Parameters - Sampling frequency: Set at twice the largest frequency in the signal spectrum f 0 - Digitization accuracy: 2 f 0 Evaluate what is needed from signals properties: Example (simulation) Micro-Channel Plate signals Jean-François Jean-Francois Genat, March Fast 2009, Timing Argonne. Workshop, June 8 -10 th 2015, FZU Prague 19 th 18

Waveform sampling: Measurements vs Simulation 50 Photo-electrons 18 Photoelectrons Jean-François Jean-Francois Genat, March rms=3. 82 ps vs 2. 5 ps (simulation) rms = 6. 05 ps vs 7 ps (simulation) Fast 2009, Timing Argonne. Workshop, June 8 -10 th 2015, FZU Prague 19 th 19

Waveform sampling: Switched Capacitors Arrays Sampling The input signal is sampled at the elementary delay period (ns-ps) Readout ADC can be very accurate (10 -14 bit), at the expense of the conversion time, external device Jean-François Genat, Fast Timing Workshop, June 8 -10 th 2015, FZU Prague 20

Today, 10 ps timing is available integrated 1 ps under work, looks promising from the 10 -100 GHz range VLSI technologies Hear during the Workshop …? The End Jean-François Genat, Fast Timing Workshop, June 8 -10 th March 8 th 2007, 2015, DAPNIA, FZU Prague Saclay 21