Time of Flight (ToF): basics Start counterStop counter TOF – General consideration - early developments combining particle identifiers with TOF A) TOF

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  • Slide 1
  • Time of Flight (ToF): basics Start counterStop counter TOF General consideration - early developments combining particle identifiers with TOF A) TOF for Beam Detectors or mass identification - TOF Constituents - based on the use of SEE effect: - Thin Foils (SE generation) - SE transport - SE detection ( mainly MCP some basic set-up ) B) Fast electronics - Fast preamplifiers and discriminators LE; CFD; ARC-CFD - Time walk and jitter basic consideration C) Timing MCA-DAQ 2. Lecture 3. Lecture 1. Lecture D) Combining TOF with BPM technique
  • Slide 2
  • Timing MCA a) Classical approach TPHC (TAC) ADC b) TDC - direct Time-Digitizer (TDC) - Time - Expansion (Time-to-Charge) - direct Digital Interpolation TDC c) DAQ for Timing
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  • Principle of TPHC (TAC) ADC (13-14 bit) ( Dead Time 1-4 s) Performance Time resolution ----- FWHM ~ 5ps Differential DNL -----
  • K.Kosev et al, A high-resolution TOF-Tracking capabilities, NIM A 594 (2008) p.178 intrinsic timing resolution 240 ps (FWHM) position resolution 1.8 +/-0.3mm (FWHM) foil thickness 163 g/cm2 intend to be used at SIS-GSI, Darmstadt relative large MCP detectors ( with active area > 12 cm2 ) TOF-BPM at ELBE electron accelerator
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  • - from foil to mirror front side (field free drift) region - inside electrostatic mirror (~ homogeneous field ??) - electrostatic mirror out and MCP in (-out ?) d ~ 270 mm Foil 1-to-Foil 2 Apparent (intrinsic) MCP detectors resolution ~ 170 ps K. Kosev et al, FZ Dresden-Rosendorf NIM A 594 (2008) 178-183 Simulation SIMEON 3D ( http://www.simion.com )http://www.simion.com 40Cl ~ 40 MeV Alpha-particle ~ 5.8MeV Detection efficiency forward emitted SE
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  • Calculated position resolution as a function of the grid wires pitch. ----------- for particle deflected in the middle of the electrostatic mirror __________ for particle deflected at the edge of the electrostatic mirror
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  • - Angular resolution after reflection - ~ 1.5 - 2.5.10 sr - TOF time resolution - ~300 ps - Transparency/module - ~70 % - G. Pascovici, Institute of Nuclear Physics, Univ. of Cologne
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  • Michael Pfeiffer SIMION3D simulation for TOF, BPM for the HISPEC-DESPEC @ FAIR
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  • Sketch of the Hexanode X;Y;Z 2D O. Jagutzki et al, Multiple Hit Readout of a MCp with a three layer DL anode, IEEE Trans. NS, Vol. 49,(2002), p. 2477 The hexanode readout Expanding the application of delay-line anodes for experiments with serious multihit demands Maximize the multihit minimize the electronic dead-time With three layer arrangement one can build also a delay- line anode with central-hole, e.g. to allow the beam pass through
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  • Single Delay Line (SDL) configuration which consist of a planar zig-zag electrode etched into a copper layer on a substrate, that runs the entire length of the anode pattern. It is interleaved with two sets of wedge shaped electrodes that are half a period out of phase the determination of the X and Y event centroid coordinates are totally independent for the SDL anode configuration. The charge is divided between the delay line and the wedges in a ratio that may be chosen to suit the X and Y resolution requirements. Material: SiO2; Duroid ~10 & HF; 5mm thick; Cu~18 O.Siegmund et al, High resolution Delay Line readouts for MCPs, NIM A310 (1991)p311 X c = ( T + T d ).v/ 2 v - signal propagation T - the difference in signal arrival times Y c = fQ 1 /(Q 1 +Q 2 ) Q 1 ;Q 2 the charge signal detected at the two wedge electrodes R 0 ~ 43 ; v/2 ~ 0.53 mm/ns Td ~ 60 ns size: 53 x 53 mm Qi - CSP
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  • A. Prochazka, C. Nociforo et al.
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  • Timing Preamplifier - Ultra Fast current t r (intrinsic) ~ 600ps Position Preamplifiers Differential read-out (X 2 (active) - X 1 (passive) ) Pulser In T- Output Timing DDL differential read-out X1X1 X2X2 T1T1 (X 1- X 2 ) t r < 600ps (intrinsic)
  • Slide 41
  • DAQ G. Pascovici, Institute of Nuclear Physics, Univ. of Cologne
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