High Resolution High Resolution Photon/Neutron Counting with - PowerPoint PPT Presentation

High Resolution High Resolution Photon/Neutron Counting with Photon/Neutron Counting with Microchannel Plate detectors Microchannel Plate detectors A.S. Tremsin 1 , J.V. Vallerga 1 , J.B. McPhate 1 , C. Ertley 1 O.H.W. Siegmund 1 , R.R. Raffanti 2 1 Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA 94720, USA 2 Techne Instruments, 4920 Telegraph Ave, Unit G, Oakland CA 94609, USA ULTIMA 2018 .

Outline Outline • MCP detector configurations • High spatial and timing resolution • Optimization of • spatial resolution • temporal resolution • counting rate capability • Applications of fast MCP detectors: • synchrotron soft X-ray instrumentation • neutron energy-resolved imaging • Near future improvements ULTIMA 2018 .

MCP detectors MCP detectors MCP detectors have a niche in applications where high resolution timing and position have to be registered for each particle. Resolution now is better than ~10  m and timing ~50 ps in imaging mode and <10 ps for non-imaging applications. Count rates now can be as high as GHz. Not all best parameters in one device. ULTIMA 2018 .

MCP detector configuration for photon/neutron applications  Photocathode converts Photocathode is used for photon to electron photon detection  MCP(s) amplify electron by 10 3 to 10 7  Rear field accelerates electrons to readout  Different readouts can be used, optimized for particular application No ideal detector fitting all applications. Compromises are always to be found. ULTIMA 2018 .

MCP detectors developed for low light applications MCP detectors developed for low light applications Applications are extended to high rate imaging with high spatial and time resolution. Single particle sensitivity . High dynamic range (>10 4 ). Multiple simultaneous particles (>10 3 -10 4 ). Intrinsically short response time. S. Mende, et al., Space Science Reviews, 91 (2000), pp.271-285. ULTIMA 2018 .

MCP/Timepix detector Phase imaging from Individual phases Regular digital camera individual photons imaged Phase 1 Phase 2 Spatial resolution is Phase 3 much better now. Photons timed and phased to a single period of 60Hz line frequency. Lightcurves of 3 different pixels shown at right. J.V. Vallerga, et al., Journal of Instrumentation JINST 9 C05055 (2014). ULTIMA 2018 .

Synchrotron applications of MCP detectors 2D Imaging + time for each detected photon Scattered photons Synchrotron generated photon pulses Thin film samples ~ 18 ps wide, 2 ns apart Elastically scattered photons Timing accuracy 55 ps RMS (130 ps FWHM) 300 8000 250 7000 Measured 6000 Gaussian fit 200 Photon counts 55 ps RMS 5000 Counts 150 4000 3000 100 2000 1000 50 0 0.7 0.8 0.9 1 1.1 1.2 1.3 0 Time (ns) 0 2 4 6 8 10 Time delay (ns) IEEE Trans. Nucl .Sci. 54 (2007) 706 ULTIMA 2018 .

ALS refill optimization: bunch diffusion ALS refill optimization: bunch diffusion Bunch population after Bunch population ~76 min injection later Diffusion of electrons between the adjacent bunches was optimized with MCP detection system W. E. Byrne, C.-W. Chiu, J. Guo, F. Sannibale, J.S. Hull, O.H.W. Siegmund, A. S. Tremsin , J.V. Vallerga Proceedings EPAC’06, Edinburgh, June 2006 ULTIMA 2018 .

LAPPD collaboration LAPPD collaboration ULTIMA 2018 . Slide from A. Elagin talk, U. Chicago, Nov. 2017

Towards ~ps timing resolution Towards ~ps timing resolution Rev. Sci. Instrum. 79 , 063108 2008 50  impedance matching anode Nucl. Instr. Meth. A 629 (2011) 123–132 Rev. Sci. Instrum. 67 (1996) 1790 ULTIMA 2018 .

Detector hardware implementations by Space Sciences Laboratory (UCB) Synchrotron beamline detectors: COS detector ARPES – angular resolved Installed on Hubble telescope photoelectron emission spectroscopy NASA Shuttle STS-125 Mission ALS RIXS detector LCLS, 2018 ULTIMA 2018 .

Readout types Readout types Medipix/Timepix Cross Delayline Cross Strip ASIC (XDL) (XS) 4 amps 2 x N amps N x N amps Gain ~ 10 7 Gain ~ 10 6 Gain ~ 10 4 -10 5 Rate < 1MHz Rate < 5MHz Rate > 500MHz  t ~ 50 ps rms  t ~ 50 ps rms  t ~ 1.6 ns (100 ps) ULTIMA 2018 .

Readout types Readout types Medipix/Timepix ASIC Multiple events Cross Delayline Cross Strip detected (XDL) (XS) (up to 25000) Single particle Single particle 1200 frames/s processed processed Timepix3 – Dead time 200-300 ns Dead time ~300ns 80 MHits per chip only for active fingers ULTIMA 2018 .

Spatial resolution of MCP detectors • XDL readout •Very linear images •Resolution ~20µm FWHM • XS readout and 50 ps rms •Very high resolution • CMOS readout •Large Formats (20cm x 20cm) ~10 µm FWHM •Resolution ~55µm FWHM and •Gain ~10 7 and ~100 ps rms ~10 µm FWHM with event •Global event rates <1 MHz •Gain ~10 6 centroiding •Event rates < 5 MHz •Very high event rates >1 GHz (no centroiding, no timing) •Gain <10 5 •Small active area 28x28 mm 2 ULTIMA 2018 .

Delay line readout Delay line readout Amplifier3 Timing signal Mesh TDC2 from MCP NC MCP NC Timing signal Timing XDL from Amplifier1 Stop anode Synchr. anode Trig NC TDC1 NC Ystart Ystop Xstart Xstop Amplifier2 Qy PC Qx ULTIMA 2018 .

Cross strip readout Cross strip readout 50 MHz ADC Anode strips 12 bit ADC 12 bit ADC FPGA board: 12 bit ADC X (Y) 12 bit ADC position Digital peak 12 bit ADC detection 12 bit ADC 12 bit ADC Centroiding 12 bit ADC +Correlated 12 bit ADC 12 bit ADC timing channel Charge cloud from MCP Bottom fingers Each finger has its preamplifier followed by an ADC, continuously digitizing the signal. Centroiding done on digitally calculated charge values. O. Siegmund, et al., Nucl. Instr. and Meth. A 610, pp.118-122 (2009) ULTIMA 2018 .

MCP/Timepix detector configuration: Gen. 2 A.S. Tremsin, et al., Nucl Instr Meth A 787 (2015) 20 ULTIMA 2018 .

MCP detector with Medipix/Timepix readout: Gen 2 • Up to 1200 frames/sec • Readout time ~310  s (0 us for new generation) • 3 acquisition modes. Each pixel provides either: • Event counts (image integrated on the chip) • Time of event (up to 10 ns accuracy) • Charge accumulated in a pixel (ToT mode) ULTIMA 2018 .

Timepix readout for MCP detectors: Timepix readout for MCP detectors: Gen 2, Gen 3, Gen. 4 Gen 2, Gen 3, Gen. 4  Simultaneous events can be detected (several thousands).  The same detector: event counting or frame-based imaging.  Operate at low gain (10 4 -10 5 ).  Can operate at very high counting rates exceeding 100 MHz/cm 2 (55  m resolution) or at rates of ~2-3 MHz (Gen. 2), >30 MHz (Gen. 3, 4) per 2x2 Timepix readout with resolution of <10 µm .  Analog amplification in pixels, only digital signals read out.  No readout noise.  Radiation hard. ULTIMA 2018 .

High input rates - frame-based High input rates - frame-based event counting mode (>1 GHz) event counting mode (>1 GHz) 3 mm 1 mm Group 2 Group 3 High count rates are possible. Up to 11800 counts per pixel before readout out. Resolution limited by ~55  m pixels ULTIMA 2018 .

Time of each event Time of each event UV penray lamp intensity fluctuations (60 Hz AC) 28 mm Timing of each event (currently with 10 ns resolution, Gen 2, 1.6 ns Gen.3 and <200ps Gen. 4) relative to external trigger is measured. Time histogram is accumulated in each pixel. Spatial resolution limited by ~55  m pixels (Gen. 2), ~7  m (Gen. 3, 4) ULTIMA 2018 .

Event centroiding Event centroiding 300 250 TOT counts 200 150 100 50 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Row number No readout noise! Each pixel measures charge accumulated in a frame 800 (Time Over Threshold method) 600 TOT counts 400 Only one event per pixel is allowed before the readout 200 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Row number ULTIMA 2018 .

High resolution mode: Event centroiding High resolution mode: Event centroiding High resolution imaging with resolution ~ MCP pore is possible 16 14 14 12 12 Counts/pix 10 10 Counts/pix 8 8 6 6 4 57 lpm 40.3 lpm 45.3 lpm 4 36 lpm 32 lpm 2 50.8 lpm 2 0 0 0 1 2 3 4 0 0.02 0.04 0.06 0.08 0.1 Position (mm) Subpixel position (mm) Readout resolution ~4  m FWHM Nucl, Instr. Meth. A 787 (2015) pp. 20-25. ULTIMA 2018 .

RIXS experiments at ALS RIXS experiments at ALS HOPG elastic peak vibronic coupling Courtesy of Xuefei Feng (ALS), Yi-De Chuang (ALS), Shawn Sallis (ALS), Wanli Yang (ALS), Jinghua Guo (ALS) ULTIMA 2018 .

Pump-probe experiments: FEL applications Pump-probe experiments: FEL applications M. Meyer, "Characterization of the FLASH XUV-FEL pulses by two-color photoionization experiments", UVX 2008 (2009) 113–118  T between X-ray pulse and Laser excitation is measured with sub-ps accuracy Pulse identification is needed for some experiments, where multiple photons are to be registered by the detector ULTIMA 2018 .

Pump-probe experiments: FEL applications Pump-probe experiments: FEL applications First experiment was conducted in April 2018. Results are being analyzed. Could easily identify each photon to FEL pulse. Should be easily doable for LCLS-II upgraded rates. ULTIMA 2018 .