development of liquid nitrogen time projection chambers
DESCRIPTION
Development of Liquid Nitrogen Time Projection Chambers A. Ereditato, M. Hess, S. Jano ŝ , I. Kreslo, S. Lehmann, M. Messina, U. Moser, B. Rossi, H.-U. Sch ü tz, M. Zeller Presented by Igor E. Kreslo, Ph.D. LHEP, University of Bern. Multi-energy X-ray cargo radiography – - PowerPoint PPT PresentationTRANSCRIPT
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.1
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 2008.2
Multi-energy X-ray cargo radiography – can still something be hidden?
Sensitive to:
Metal objectsHigh density objectsCharacteristic shapes
Not very sensitive to:
Specific chemical composition2D shaped objects (sheet explosives)
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.3
Gamma Nuclear Resonant Absorption method of Nitrogen detection(Soreq NRC, 1985)
14N9.17 MeV γ
13C p ~1.5 MeV
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.4
Gamma Nuclear Resonant Absorption method of Nitrogen detection(Proposed by Soreq NRC* to US FAA in 1985)
14N
Resonant γ
Detector
14N 13C p
e-
e-
e-
Intensity
N content
e-
e-
e-
Non-Resonant γe-
* Sorec National Research Center, Yavne, 81800, Israel
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.5
Detector for GRNA radiography
High spatial resolution (order of 1 mm or better)
Large active volume
High density
High Nitrogen content
TPC on liquidNoble gases(LAr, LXe)
LNitrogen ?
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.6
Plans and Perspectives
Ionisation signals in Liquid Argon - Nitrogen
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.7
Charge transport in Liquid Argon - Nitrogen
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.8
Detector scheme
Electron mobility in Liquid Argon - Nitrogen
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.9
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/cm3
ρLN = 0.8 g/cm3
Density sensor:
Floater
C = f(ρ)
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.10
LAR TPC prototype
8mm
100 x 100 mm
Wire pitch2 mm
To preamp
HV power supply0-30kV
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.11
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, Hofgut, 3073 Gumligen , Switzerland
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.12
LAR TPC prototype and performance
Detector readout, amplifier, DAQ
CAEN V1724 VME 8xADC
Shaping Q-integrating preamplifier, ~ 25 mV/fC
Wire chamber
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.13
LAR TPC prototype and performance
Muon
0-30 kV
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.14
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 2008.15
I-
LAr TPC prototype and performance
TPC response to a primary ionization
Particle
Ar+ e-
Ar+ e-
E
Recombination losses q0=A*Q0
Primary ionisation Q0
e-
Attachment
losses q=q0e -(D/λ)
collection wires
D, drift distance
I-
I-
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.16
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 2008.17
LAR TPC prototype and performance
TPC response to Compton electrons from 60Co (1.17 and 1.33 MeV gammas)(measured data)
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.18
LAR TPC prototype and performance60Co (1.17 and 1.33 MeV gammas)
“Box model” :
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.19
LAR+N TPC prototype and performance
A=1
Recombination vs Nitrogen content (vol. %)
60Co (1.17 and 1.33 MeV gammas)
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.20
LAR+N TPC prototype and performance
A=1
A~0.5
Recombination vs Nitrogen content, (vol. %)
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.21
LAR+N TPC prototype and performance
A=1
A~0.5
Recombination vs Nitrogen content, (vol. %)
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 !
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.22
LAR+N TPC prototype and performance
Box model parameters evolution with LN content (vol. %)
Bet
ha
A
I.Kreslo CHIPP workshop on Detector R&D, University of Geneva, 11-12 June 2008.23
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 MeV 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 2008.24
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