adamas dec 2012
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1ADAMAS Dec 2012 Piotr Koczoń,GSI
Start Detector for TOF@CBM@FAIR
- observation- simulation- realisation P.Koczoń / DetLab
GSI Helmholtzzentrum für Schwerionenforschung GmbH
2ADAMAS Dec 2012 Piotr Koczoń,GSI
CBM@FAIR2018?
3
Compressed Baryonic Matter exp.
ADAMAS Dec 2012 Piotr Koczoń,GSI
TOFTarget
TARGET
Reaction products
MVD+STS
4ADAMAS Dec 2012 Piotr Koczoń,GSI
Beam pipe: 2.5°
TARGET
BEAM
Yoke: 25°
outside of acceptance
in acceptance
OBSERVATION:backward hemisphere is full of reaction products
R=30mm
5Piotr Koczoń,GSI
Details of the FAIR-Root simulations :
- event generators: FAIR–IonGun Au on Au (for δ-electrons)
Urqmd (2 – 10 AGeV AuAu, NiNi MB and Central events)- detector: two discs or a tube- like or sphere cutout (R=30 mm) ALLWAYS with an opening allowing for 25 deg acceptance cone
- sensor material: Si (just because available as activ mat.) - target Au, Ni, C- projectile Au, Ni, p
Simulations to investigate- time resolution of the first hit - suitable detector geometry- hit density
ADAMAS Dec 2012
6ADAMAS Dec 2012 Piotr Koczoń,GSI
UQMD version: 10035 1000 10002 output_file…transformation betas (NN,lab,pro) 0.0000000… impact_parameter_real/min/max(fm): 10.98 0.00 15.82…equation_of_state: 0 E_lab(GeV/u): 0.1271E+01 sqrt(s..event# 1 random seed: 67008028 (fixed)op 0 0 0 0 1 * 0 0 0 0 0 0 0 0 0 0 op 0 0 0 0 0 0 1 0 1 0 0 0 0 2 1 op 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0
peripheral events (MB) events with impact parameter Dlarger than 10 fm (selected fromthe mbias urqmd-files)
10 fm urqmd.auau.2gev.mbias.0021.ftn14
D = impact_parameter
x
y
central events D = 0 fm
Simulations:
empty events 99% HI produce only delta electrons
7ADAMAS Dec 2012 Piotr Koczoń,GSIPiotr Koczoń,GSI
Ideal spherical detector
28 mm
BEAM
8ADAMAS Dec 2012Piotr Koczoń,GSI
2AGeV Au @ Au δ + Urqmd 2AGeV Au on 0.25mm Au (centr+MBias)
ALL
FIRST particle RMS=4ps
curling δ’s
CentralMinBias
δ’s
HOTTEST areaopening circumference of 88 mm
25°
Θ [deg]
Φ[d
eg]
time [ps]
time [ps]Tot Eloss [keV]
Detector can distinguishbetween central, min bias
and empty events(δE<10keV, holds also for a ring ,
or 2 discs shape)
9ADAMAS Dec 2012 Piotr Koczoń,GSI
Sphere cutout (crown) geometries
8fold 1ringΘ=25-60 deg
16fold 2ringsΘ=25-90 deg
60fold 1ringΘ=25-35 deg
120fold 2ringsΘ=25-45 deg
240fold 4ringsΘ=25-55 deg
300fold 6ringsΘ=25-65 deg
10ADAMAS Dec 2012 Piotr Koczoń,GSI
Urqmd pC @ 30 GeV (central), 8-fold crown
Eff=50%
Timing: 18ps
Detector can deliverstart signal for TOF
with RMS ~ 20psand efficiency ~ 50 %
11ADAMAS Dec 2012 Piotr Koczoń,GSI
Realisation (possible sensors): price time res. rate cap. rad hard efficiency a) MCP discs of R=30mm + 70ps ++ + HI? >90% HI?b) Si detectors R=30mm + + + - >90%c) Diamond det. -- <5ps ++ + >90%?d) RPC barrel/discs ? <40ps 20kHz cm2 ++ >90 %e) DIRC barrel -- 50ps? ? +/- >90%?
(highly) segmented detectors!!!
12ADAMAS Dec 2012 Piotr Koczoń,GSI
Conclusions:
presented results let us hopethat it is possible to construct a detector - which can be used as START for TOF@CBM (with time res. ~ 20 ps and 50% efficiency for p+C) - at the same time it would be a reaction detector for AuAu, NiNi (distinguishing central and min-bias react’s from empty events) - could be used as reaction tag (data flow reduction est. by factor 2 – 3!)
13ADAMAS Dec 2012 Piotr Koczoń,GSI
Outlook:
Having a segmented detector in thevicinity of the target it should be possibleto measure the reaction plane as well(subject for further smulations)
14ADAMAS Dec 2012 Piotr Koczoń,GSI
15ADAMAS Dec 2012 Piotr Koczoń,GSI
16Piotr Koczoń,GSI
in the HOTTEST (red) area(in the cell of 5x10deg ->2.6x5.2 mm = 13.6 mm2 size)800 hits out of 1500 events -> 3.9 MHz/1 mm2 @ 1x109 s-1 Au on Au
Hit density
Φ[d
eg]
Θ [deg]
ADAMAS Dec 2012
17Piotr Koczoń,GSI
For completeness: 2 discs of R=30mm
Θ [deg]
Φ[d
eg]
Z[m
m]
X [mm]ADAMAS Dec 2012
18Piotr Koczoń,GSI
start detector properties
- size: R~30 mm- rate capability: several MHz / mm2 (worst case)- first particle arrival time: RMS=10 ps
- having energy resolution of ~ 10 keV it can be used for discrimination between empty events (only delta electrons) and nuclear reactions and for centrality selection
ADAMAS Dec 2012
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