Upload
mira
View
56
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Aerogel Cherenkov counters for CBM. S.V.Afanasiev VBLHE JINR Dubna. GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna. The envisaged CBM physics program. - PowerPoint PPT Presentation
Citation preview
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
Aerogel Cherenkov counters for CBM
S.V.Afanasiev
VBLHE JINR
Dubna
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
The envisaged CBM physics program
• Signatures of chiral symmetry restoration. Probes: Dilepton pairs, D mesons.
• The deconfinement phase transition. Probes: charmonium, strangeness, collective flow.
• The critical point. Probes: event-by-event fluctuations (K/pi ratio)
• Exotic states of matter. Probes: strange and multistrange particles, K/ ratio
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
AEROGEL PROPERTIES
• Silica aerogels are a colloidal form of glass. They are solid, very light, transparent and refraction index can be in range 1.1 - 1.002.
Ya.Wang and W.L.Wolf, J.Opt.Soc.Am., Vol.73, No.11 (1983)
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
Silica aerogels of low refractive index (n=1.012-1.028) arefound to be radiation-hard at least up to 9.8 Mrad of gamma
ray radiation.
S.K.Sahu et al. NIM A382(1996)
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
KEDR aerogel system
• 160 counters• 800 liters of aerogel • refractive index
n=1.05• p and K separation in
the momentum range 0.6 - 1.5 GeV/c.
M.Yu.Barnykov et al., NIM. A 453(2000)
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
BELLE ACC
• 1188 counters• 2000 litters of aerogel • refractive index
n=1.03-1.01• p and separation in
the momentum range up to 3.5 GeV/c.
T.Sumiyoshi et al. J.Non-Crys. Sol. 225(1998)369
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
PHENIX ACC
• 160 counters• 420 liters of aerogel • refractive index
n=1.012 • K and separation in
the momentum range 0.2 - 2.0 GeV/c.
M.Yu.Barnykov et al., NIM. A 453(2000)
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
5 - 91 - 5 n=1.012Aerogel
17 -5 - 17 n=1.00044RICH
- 50 - 2.5 ~100 psTOF
K-p separation-K separation
0 4 8
0 4 8
0 4 8
0 4 8
0 4 8
0 4 8
The PHENIX ACCtogether with TOF can extend the PID capability upto 10 GeV/c
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
JINR ACC test
Secondary particles p of the nuclotron beam
Large TOF base for particle separation
V.F.Peresedov et al. Proc. Of the RNP Int. Workshop,Slovak Rep. Stara Lesna, 2003
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
• Clear separation of protons and pions observed.PID by TOF successful
Pions
Protons
+2 GeV/c
Proton
Pion
d
K
Aerogel Signal for protons and pions
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
Potentialities of ACC
To see the threshold momenta for the different indices of AEROGEL, the expected number of emitted photon arecalculated through empirical equation
N p.e. = 55 L {1-(1/n2)}
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
Particle densityN/100 cm2 along the horizontalaxis (black line) and along thevertical axis (red line) within 10cm wide windows which cross thecenter of the detector
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
Qlab. N/cm2 area [m2] cell size [cm2] No. of cells
1o – 5o 510-2 – 210-2 1.2 - - 5o – 10o 210-2 – 610-3 2.6 100 26010o – 15o 610-3 – 210-3 4.8 200 24015o – 25o 210-3 – 510-4 21.5 400 540
Emission angle, charged particle density, detector surface, pad size and number of cells per aerogel layer. The numbers refer to a central Au+Au collision at 25 GeV/u and an occupancy below 5%.
Segmentation of Aerogel
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
Aerogel RICH
GSI meeting 20-21 November 2003 Afanasiev S.V. JINR Dubna
CONCLUSIONS
• refractive index 1.1 - 1.005
• radiation-hard• stable• compact size
• refractive index <1.01• physical and chemical
properties
The Aerogel Threshold Cherenkov detector can be used as bridge between TOF and gas RICH detectors
For study