New Readout Codification in Large-Area Multi-Gap Timing RPCs for Muon Scattering Tomography

Introduction Experimental Setup Method Results Applications Conclusion New Readout Codification in Large-Area Multi-Gap Timing RPCs for Muon Scattering Tomography Jo˜ao Pedro Saraiva Laboratory of Instrumentation and Experimental Particle Physics LIP Coimbra – Portugal Santiago de Compostela - September 9–13, 2024 [email protected] RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 1 / 46 Introduction Experimental Setup Method Results Applications Conclusion Outline Introduction Experimental Setup Method Results Applications Conclusion RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 2 / 46 Introduction Experimental Setup Method Results Applications Conclusion Background RPCs are well suited for large-area applications, since: •they can be built at relatively low cost •cover large surfaces with high efficiency, spatial and time resolutions RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 3 / 46 Introduction Experimental Setup Method Results Applications Conclusion Background RPCs are well suited for large-area applications, since: •they can be built at relatively low cost •cover large surfaces with high efficiency, spatial and time resolutions Driving cost of the detector: •Front-End Electronics and related electronics RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 3 / 46 Introduction Experimental Setup Method Results Applications Conclusion Background RPCs are well suited for large-area applications, since: •they can be built at relatively low cost •cover large surfaces with high efficiency, spatial and time resolutions Driving cost of the detector: •Front-End Electronics and related electronics For very large areas with submillimetric spatial resolution, the number of FEE channels can reach prohibitive values due to cost constraints RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 3 / 46 Introduction Experimental Setup Method Results Applications Conclusion Background For instance, the Muon Scattering Tomography (MST) of a shipping container requires a sensitive area ∼130 m2 RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 4 / 46 Introduction Experimental Setup Method Results Applications Conclusion Background For instance, the Muon Scattering Tomography (MST) of a shipping container requires a sensitive area ∼130 m2 with submillimetric spatial resolution ⇒25000+ FEE chs (assumed pitch: 2.54mm) RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 4 / 46 Introduction Experimental Setup Method Results Applications Conclusion Objective Develop a new readout technique with primary aim of: •decoupling number of FEE channels &RPC sensitive area. RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 5 / 46 Introduction Experimental Setup Method Results Applications Conclusion Objective Develop a new readout technique with primary aim of: •decoupling number of FEE channels &RPC sensitive area. Keeping: •high spatial resolution ⇝<1 mm σ •very good time resolution ⇝<100 ps σ RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 5 / 46 Introduction Experimental Setup Method Results Applications Conclusion Particle hit - I RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 9 / 46 Introduction Experimental Setup Method Results Applications Conclusion Particle hit - II RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 10 / 46 Introduction Experimental Setup Method Results Applications Conclusion Particle hit - III RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 11 / 46 Introduction Experimental Setup Method Results Applications Conclusion Wide-Strip Readout PCB The ambiguity raised by grouping together the thin strips must be disentangled in order to determine in which group the signal was in fact induced RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 12 / 46 Introduction Experimental Setup Method Results Applications Conclusion Particle hit - IV The wide-strip readout electrode provides an additional 2D raw position of each event, allowing the impinged group to be identified in both directions RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 13 / 46 Introduction Experimental Setup Method Results Applications Conclusion Wide-Strip Readout PCB - II 5 FEE channels =⇒ RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 14 / 46 Introduction Experimental Setup Method Results Applications Conclusion Layer Diagram & Full Setup Stack of 2 tRPCs with active area of 30×30 cm2 RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 15 / 46 Introduction Experimental Setup Method Results Applications Conclusion Detector operated during weeks with cosmic rays •Open gas flow, with R-134a (95.5%) and SF6 (4.5%) •Reduced field set to ∼380 Td (∼2.75 kV/gap, 92 kV/cm) Coincidence Trigger generated externally by plastic scintillators above and below the RPCs: •8×4×1cm3coupled to SiPMs •8×2×3cm3coupled to PMTs RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 16 / 46 Introduction Experimental Setup Method Results Applications Conclusion 2D fine position •Charge integrating FEE (custom-designed) ∗2×24 chs •Integration of the fast and slow components of the induced signals •Pulses digitally processed after digitization (trapezoidal filter) •Xfine,Yfine via charge interpolation RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 17 / 46 Introduction Experimental Setup Method Results Applications Conclusion 2D raw position + time •fast FEE (HADES @ GSI Darmstadt) ∗2×5 chs (both ends of 5 wide strips) •T= (Tf+Tb)/2(front (f) & back (b)) •Ycourse = (Tf−Tb)/2 •Qvia Time over Threshold method (fast component of the induced signals) •Xcourse via charge interpolation RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 18 / 46 Introduction Experimental Setup Method Results Applications Conclusion Muon Scattering Tomography (MST) Application requiring large sensitive area + high spatial resolution FLUKA 1st step sim.: extract muon flux at sea level •atmospheric model: 100 layers from 0 to 70 km above sea level with different densities •scoring between three cones for specific geomagnetic latitude •Primary spectra, Galactic C. Ray source: - Ion flux from Z = 1 to Z = 28 modulated for a minimum solar activity; - Energy: from 100MeV to 100TeV; - Geographic lat/long: 40.20ºN/8.42ºW; - Altitude: 105 m; - Vertical cutoff rigidity: 7.5 GeV; - Geomagnetic cut-off acceptance: 7 GeV. RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 25 / 46 Introduction Experimental Setup Method Results Applications Conclusion MST – Two step simulation Muon flux at sea leavel (1st step) afterwards used into a planar geometry with 4 RPCs and 10×10×10 cm3high-Z material blocks at the center of the detector (2nd step): FLUKA geometry Four 1.6×1.2 m2RPCs, 45 cm apart RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 26 / 46 Introduction Experimental Setup Method Results Applications Conclusion MST – Two step simulation Muon flux at sea leavel (1st step) afterwards used into a planar geometry with 4 RPCs and 10×10×10 cm3high-Z material blocks at the center of the detector (2nd step): FLUKA geometry Four 1.6×1.2 m2RPCs, 45 cm apart doi.org/10.1016/j.nima.2023.168183 RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 26 / 46 Introduction Experimental Setup Method Results Applications Conclusion MST – Lynch & Dahl formula θ0=13.6 MeV βcp zrx X01 + 0.038ln xz2 X0β2 rad (rms width of the projected angular distribution) •Angular distribution due to the multiple scatterings follows a gaussian distribution •4 GeV muons in 10 cm thick material, Fe: ∼0.5º, W: ∼1º High spatial resolution needed due to the precision needed to measure the small scattering angles 10 1100101102 P [GeV/c] 100 101 102 (mrad) Air H20 Al Fe Ag Pb W U 0.057 0.573 5.730 (°) vs. Momentum - 10 cm thick materials RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 27 / 46 Introduction Experimental Setup Method Results Applications Conclusion MST - Material Budget - I Angular distributions from FLUKA simulations of the scattered muons inside the fiducial region Comparing simulations: •full geometry: RPCs +Tungsten block (10×10×10 cm3) + air •’signal’: tungsten block only •’noise’: all except tungsten: RPCs + air 100 101 102 103 104 105 Occurrences RPCs + Tungsten block + Air Tungsten block only RPCs + Air 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Angle (º) of scattered muons 0 2 4 SNR SNR = Tungsten / RPCs+air (SNR = 1 -> =~12.71º) Muon scatterings from the tungsten block are dominant above ∼12◦ RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 28 / 46 Introduction Experimental Setup Method Results Applications Conclusion MST - Material Budget - II If only muon of high energy: above 500 MeV 100 101 102 103 104 105 Occurrences E>0.5GeV; RPCs + Tungsten block + Air E>0.5GeV; Tungsten block only E>0.5GeV; RPCs + Air 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Angle (º) of scattered muons 0 2 4 SNR SNR = Tungsten / RPCs+air (SNR = 1 -> =~0.89º) Muon scatterings from the tungsten block are dominant above ∼0.9◦ RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 29 / 46 Introduction Experimental Setup Method Results Applications Conclusion MST - Material Budget - III If only muon of low energy: below 500 MeV 100 101 102 103 104 105 Occurrences E<0.5GeV; RPCs + Tungsten block + Air E<0.5GeV; Tungsten block only E<0.5GeV; RPCs + Air 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Angle (º) of scattered muons 0 2 4 SNR SNR = Tungsten / RPCs+air (SNR = 1 -> =~30.44º) Muon scatterings from the tungsten block are dominant above ∼30◦ RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 30 / 46 Introduction Experimental Setup Method Results Applications Conclusion MST - Material Budget - 3D plot of PoCAs Point of Closest Approach (PoCA) between incident and exiting traj.; applied restrictions: scatters >1.5◦ x [cm] 60 40 20 020 40 60 y [cm] 80 60 40 20 0 20 40 60 80 z [cm] 0 20 40 60 80 100 120 140 Plotted POCAs: min: 1.50º -> max: 70.93º; Emin: 0.14 GeV -> Emax: 20.41 GeV Restrictions: ang: >01.5, energy: >0.0, position: [-60, 60, -80, 80, 48, 90] A) 629963 POCAs; B) 447293 inside inner RPCs (71.00% of A); C) 30759 plotted POCAs (6.88% of B); D) 3444 inside shielding (11.20% of C) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 E [GeV] Low energy muons highly affected by the material budget RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 31 / 46 Introduction Experimental Setup Method Results Applications Conclusion MST - Material Budget - 3D plot of PoCAs Point of Closest Approach (PoCA) between incident and exiting traj.; applied restrictions: scatters >1.5◦&E>500 MeV x [cm] 60 40 20 020 40 60 y [cm] 80 60 40 20 0 20 40 60 80 z [cm] 0 20 40 60 80 100 120 140 Plotted POCAs: min: 1.50º -> max: 51.37º; Emin: 0.50 GeV -> Emax: 20.41 GeV Restrictions: ang: >01.5, energy: >0.5, position: [-60, 60, -80, 80, 48, 90] A) 629963 POCAs; B) 447293 inside inner RPCs (71.00% of A); C) 10150 plotted POCAs (2.27% of B); D) 3288 inside shielding (32.39% of C) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 E [GeV] Low energy muons have high scatters even in air ⇒reject them! RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 32 / 46 Introduction Experimental Setup Method Results Applications Conclusion MST - Time of Flight (TOF) For ∼100 ps time resolution: 300 MeV/c muons can be rejected for a fiducial region of 0.45 m (1 GeV/c for 5 m) 10 1100101 P [GeV/c] 100 101 102 103 104 t (ps) t = t muon - t 45 cm 500 cm RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 33 / 46 Introduction Experimental Setup Method Results Applications Conclusion How long to identify the 10 cm tungsten block? with submillimetric spatial resolution ⇒less than 1 min Applied approach: •divide the fiducial region into 5×5×5 cm3voxels •populate voxels with POCAs (control run subtracted) •compute the average number of POCAs per voxel (µ) •search for outliers relative to the mean (µ) •plot the outliers with highest number of POCAs, inside (’good voxel’) and outside (’bad voxel’) the tungsten block region RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 34 / 46 Introduction Experimental Setup Method Results Applications Conclusion How long to identify the 10 cm tungsten block? with submillimetric spatial resolution ⇒less than 1 min Applied approach: •divide the fiducial region into 5×5×5 cm3voxels •populate voxels with POCAs (control run subtracted) •compute the average number of POCAs per voxel (µ) •search for outliers relative to the mean (µ) •plot the outliers with highest number of POCAs, inside (’good voxel’) and outside (’bad voxel’) the tungsten block region •repeat the procedure for different spatial resolutions (0.3 mm and ∼10 mm σx,y) RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 34 / 46 Introduction Experimental Setup Method Results Applications Conclusion How long to identify the 10 cm tungsten block? with submillimetric spatial resolution ⇒less than 1 min Applied approach: •divide the fiducial region into 5×5×5 cm3voxels •populate voxels with POCAs (control run subtracted) •compute the average number of POCAs per voxel (µ) •search for outliers relative to the mean (µ) •plot the outliers with highest number of POCAs, inside (’good voxel’) and outside (’bad voxel’) the tungsten block region •repeat the procedure for different spatial resolutions (0.3 mm and ∼10 mm σx,y) •decrease the exposure time and repeat all the above! RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 34 / 46 Introduction Experimental Setup Method Results Applications Conclusion How long to identify the 10 cm tungsten block? with submillimetric spatial resolution ⇒less than 1 min 0 10 20 30 40 50 time [min] 0 5 10 15 20 25 30 35 (POCAs_perVoxel - ) / 10 cm W, without digitizer - Good voxels 10 cm W, without digitizer - Bad voxels 10 cm W, 0.3 mm spatial res. - Good voxels 10 cm W, 0.3 mm spatial res. - Bad voxels 10 cm W, ~1 cm spatial res. - Good voxels 10 cm W, ~1 cm spatial res. - Bad voxels RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 35 / 46 Introduction Experimental Setup Method Results Applications Conclusion How long to identify the 10 cm tungsten block? 1-min exposure, no digitizer, all POCAs in the fid. reg. + voxels RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 36 / 46 Introduction Experimental Setup Method Results Applications Conclusion How long to identify the 10 cm tungsten block? 1-min, no digitizer, all POCAs in the fid. reg. RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 36 / 46 Introduction Experimental Setup Method Results Applications Conclusion How long to identify the 10 cm tungsten block? 1-min, no digitizer, POCAs 10σfrom µ(∼120 events) RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 36 / 46 Introduction Experimental Setup Method Results Applications Conclusion How long to identify the 10 cm tungsten block? 1-min, 0.3 mm spatial res., POCAs 10σfrom µ(∼70 events) RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 36 / 46 Introduction Experimental Setup Method Results Applications Conclusion How long to identify the 10 cm tungsten block? 10-mins, 10 mm spatial res., POCAs 6σfrom µ(∼33 events) RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 36 / 46 Introduction Experimental Setup Method Results Applications Conclusion Conclusions •A new readout PCB was developed to reduce the dependence between the detector area and the number of FEE channels RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 37 / 46 SMPCB + Thin & Wide-Strip Readout PCBs ... ... ... ... ... charge (Q) T, (X,Y)course Yfine time (T), charge (Q) Xfine charge (Q) ∫ ∫ ... RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 40 / 46 MST - Material Budget - 3D plot of PoCAs Point of Closest Approach (PoCA) algorithm; applied restrictions: scatters above 1.5◦&Emuons >1 GeV x [cm] 60 40 20 020 40 60 y [cm] 80 60 40 20 0 20 40 60 80 z [cm] 0 20 40 60 80 100 120 140 Plotted POCAs: min: 1.50º -> max: 42.55º; Emin: 1.00 GeV -> Emax: 20.41 GeV Restrictions: ang: >01.5, energy: >1.0, position: [-60, 60, -80, 80, 48, 90] A) 629963 POCAs; B) 447293 inside inner RPCs (71.00% of A); C) 4027 plotted POCAs (0.90% of B); D) 2633 inside shielding (65.38% of C) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 E [GeV] Low energy muons highly affected by the material budget RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 41 / 46 MST - Spatial Resolution - I Comparison of angular distributions from generated random numbers following gaussian distributions: •4 gaussian distributions, one on each plane, 45 cm apart; •distribitions vertically aligned; •two spatial resolutions tested: 1 cm vs. 1 mm (σx&σy); •plot angular distributions between incident and exit trajectories. RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 42 / 46 MST - Spatial Resolution - I Comparison of angular distributions from generated random numbers following gaussian distributions: •4 gaussian distributions, one on each plane, 45 cm apart; •distribitions vertically aligned; •two spatial resolutions tested: 1 cm vs. 1 mm (σx&σy); •plot angular distributions between incident and exit trajectories. RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 42 / 46 MST - Spatial Resolution - II σx=σy= 1 cm σx=σy= 1 mm Vertical trajectories with scattered angles up to 12ºin case of detectors with a spatial resolution of 1 cm (σ); significant improvement in case of detectors with millimetric resolution. RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 43 / 46 MST - Spatial Resolution - III These two geometries result in the same angular distribution: Fiducial region of 45 cm Fiducial region of 5 m The angular distribution improves increasing the distance between detectors above and below the fiducial region, but not increasing the fiducial region! (side effect: reduced detector acceptance) RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 44 / 46 MST – Detailed Detector geometry Stack of 2 MRPCs with 2 gas gaps each: Detailed view of one detector Layer diagram RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 45 / 46 Acknowledgment Work supported by: •Foundation for Science and Technology (Portugal) (CERN/FIS-INS/0006/2021) •European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement AIDAinnova n.◦101004761 RPC Group - LIP Coimbra XVII Conference on Resistive Plate Chambers September 13, 2024 46 / 46