Development of Liquid Nitrogen Time Projection Chambers A. Ereditato, M. Hess, S. Janoŝ, I. Kreslo, S. Lehmann, M. Messina, U. Moser, B. Rossi, H. -U. Schütz, M. Zeller Presented by Igor E. Kreslo, Ph. D. LHEP, University of Bern I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 1
Multi-energy X-ray cargo radiography – can still something be hidden? Sensitive to: Metal objects High density objects Characteristic shapes Not very sensitive to: Specific chemical composition 2 D shaped objects (sheet explosives) I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 2
Gamma Nuclear Resonant Absorption method of Nitrogen detection (Soreq NRC, 1985) 9. 17 Me. V I. Kreslo γ 14 N 13 C p CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. ~1. 5 Me. V 3
Gamma Nuclear Resonant Absorption method of Nitrogen detection (Proposed by Soreq NRC* to US FAA in 1985) Detector Non-Resonant γ ee- γ 14 N Intensity 13 C e- p ee- N content * Sorec National Research Center, Yavne, 81800, Israel I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 4
Detector for GRNA radiography High spatial resolution (order of 1 mm or better) Large active volume TPC on liquid Noble gases (LAr, LXe) High density High Nitrogen content I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. LNitrogen ? 5
Ionisation signals in Liquid Argon - Nitrogen Plans and Perspectives I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 6
Charge transport in Liquid Argon - Nitrogen I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 7
Electron mobility in Liquid Argon - Nitrogen Detector scheme I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 8
LAR TPC prototype Mixture LAr-LN is prepared directly in the cryostat. The content of Nitrogen is monitored by density sensor. ρLAr = 1. 4 g/cm 3 ρLN = 0. 8 g/cm 3 Density sensor: Floater C = f(ρ) I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 9
LAR TPC prototype Wire pitch 2 mm 100 x 100 mm HV power supply 0 -30 k. V To preamp 8 mm I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 10
LAr TPC prototype Argon used: Carbagas 1, Commercial grade “ 48” ( < 2*10 -7 impurities concentration) Nitrogen used: Carbagas, Commercial grade “ 50” ( < 10 -7 impurities concentration) No additional purification is done for the first tests. 1 Carbagas, I. Kreslo Hofgut, 3073 Gumligen , Switzerland CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 11
LAR TPC prototype and performance Detector readout, amplifier, DAQ CAEN V 1724 VME 8 x. ADC Shaping Q-integrating preamplifier, ~ 25 m. V/f. C Wire chamber I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 12
LAR TPC prototype and performance Muon 0 -30 k. V I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 13
LAR TPC prototype and performance Cosmic Muon Tracks recorded ~ 5 mm drift I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 14
LAr TPC prototype and performance TPC response to a primary ionization Primary ionisation Q 0 Particle Recombination losses q 0=A*Q 0 Attachment losses q=q 0 e -(D/λ) coll E ecti on wire s IAr+ e. I- Ar+ I- e- e. D, drift distance I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 15
LAR TPC prototype and performance TPC response to a Compton electrons - simulation Losses during the charge drift affect the shape of the spectrum, but not the end point ! End point can be used to measure recombination. I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 16
LAR TPC prototype and performance TPC response to Compton electrons from 60 Co (1. 17 and 1. 33 Me. V gammas) (measured data) I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 17
LAR TPC prototype and performance 60 Co (1. 17 and 1. 33 Me. V gammas) “Box model” : I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 18
LAR+N TPC prototype and performance 60 Co (1. 17 and 1. 33 Me. V gammas) Recombination vs Nitrogen content (vol. %) A=1 I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 19
LAR+N TPC prototype and performance Recombination vs Nitrogen content, (vol. %) A~0. 5 A=1 I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 20
LAR+N TPC prototype and performance Recombination vs Nitrogen content, (vol. %) A~0. 5 A=1 I. Kreslo Similar effect was observed by D. W. Swan in 1963, with about 0. 6 vol. % of LN ( for reference see slide 7) but not explained ! CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 21
LAR+N TPC prototype and performance Betha A Box model parameters evolution with LN content (vol. %) I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 22
LAR+N TPC first test conclusions 1. First prototype TPC with Liquid Argon-Nitrogen mixture operates well in Bern. 2. Collected charge at 8 mm drift and 6 vol. % of Nitrogen is sufficient to see MIPs and 1 Me. V electrons (signal / noise >10). 3. At 6% of Nitrogen such TPC is already more efficient for GRNA, than liquid scintillator detectors. 4. Further study on recombination mechanisms in LAr-N is needed. 5. The technology is very promising for security applications ! I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 23
LAR+N TPC Plans and Perspectives 1. More detailed study on recombination vs Nitrogen content with non-resonant gammas. 2. Study of charge attachment cross-section vs Nitrogen content. 3. Proton - electron separation study (simulation) 4. Tests with resonant gammas on a proton accelerator. 5. Optimization of the detector geometry for GRNA scenario. 6. Contacts with industry - building a cargo screener prototype I. Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11 -12 June 2008. 24
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