Transcript Slide 1
HADES
Upgrade for DIRAC-Phase-1
P. Salabura
Jagiellonian University Kraków, GSI Darmstadt
HADES detector @ GSI
20 institutions from 20
countries
1994 approved
2002 first production run
Physics runs conducted
November 2002: C+C 2 AGeV, commissioning and physics runs
–
two level trigger scheme (LVL1/LVL2)
–
full coverage with inner MDCI/II, 2 sectors complete tracking (MDCI-IV)
–
LH2 target
–
complete tracking in 4 sectors, 2 sectors with MDC(I-III)
400 Mevents
exclusive meson reconstruction
August 2004: C+C 1AGeV
–
inclusive e+,e- production ("DLS enhancement")
February 2004: p+p 2.2 GeV
220 Mevents
complete tracking in 4 sectors, 2 sectors with MDC(I-III)
inclusive e+,e- production ("DLS enhancement"
September 2005: Ar+KCl 1.75 AGeV
–
complete tracking in 4 sectors, 2 sectors with MDC(I-III)
inclusive e+,e- production: vector mesons in medium
650 Mevents
2200 Mevents
Dielectrons from C+C @ 2 AGeV
16k signal pairs @ S/B>1 for
M>140 MeV/c2
Corrected for Reconstruction
Efficiency
Inside HADES geometrical
within acceptance
acceptance, no extrapolation to
4!
Compared with a cocktail
based on known or mt-scaled
meson multiplicities and their
vacuum decay properties.
M/M()= 10%.
no outer tracking
Exclusive meson reconstruction in pp @ 2.2 GeV
Hadronic channels
pp→pp→pp+-0
Electromagnetic channels
• pp→pp→ppe+e-
• pp→pp0→ppe+e-
=14 MeV/c2
0
(pp/e+/e-) missing mass vs (pp)
missing mass distributions
future upgrades
Needed for :
(I) HI systems with at 1-2 AGeV Atot>80
(II) HADES @ FAIR (8AGeV)
(III) High intenisty pion beams
• RPC (inner time-of-flight) → essential for HI,
important for elementary
channels with strangeness production (/K separation)
(FP6 construction -> P. Fonte)
• Forward hodoscope → essential for p+d, important for HI
(FP6 construction-> H. Stroebele)
• Pion tracking → essential for +p, +HI
• DAQ → essential for HI (FP6 construction-> M. Traxler)
HADES1-TOFINO replacement by RPC
•TOFINO:(time-of-flight between 180 -45o)
– RPC:
4 paddles per sector only
– limited resolution (450 ps)
180 cells/sector (double hit<10%
– for
insufficient
granularity
1.0 AGeV
Au+Au)for HI
time resolution < 100 ps
TOFINO
target
Granularity:
1080 cells
RPC for HADES
operational parameter matched to HADES overall
performance
• granularity: double-hit probability below 10%
• resolution:
100 ps (s) or better
• rate capability: up to 600 Hz/cm2 (at forward)
efficiency: above 95% for single hits
concept of the design:
• shielded single cells
• 4 gaps with commercial glass 2mm thick
• common gas box sector-wise
• customized read-out: FEE (preamp,
discriminator, TimeOverThreshold) + TDC (128
channels) based on HPTDC & CPU with fast
ethernet
• All full-size components produced and
tested 10.05 @GSI
•30 months duration workplane
details in talk of P. Fonte
Gas mixture:
98.5% C2H2F4
+ 1% SF6
+ 0.5% i-C4H10
Potential = 3 kV
HADES2-Forward hodoscope
Acceptance for charge particles with < 80
• Collective observables for dilectron production in HI collisions (flow)
event plane determination
measurement of reaction centrality
• Spactator tagging for d+p reactions
direct comparison of dielectron production in pp and p+n reactions
Upgrade of old and well known KAOS FH:
• inspection of detectors (380 modules), new reflecting cover for light
guides, mainframe modifications
• new digital (TDC) electronic – same as used for the RPC
• new HV and slow control system
•Total project duration 12 months → see talk of H.
Stroebele for workplan details
HADES3 – DAQ upgrade
(1) Exchange of CPUs for event building for more efficient transport of
large events.
•
•
x86 CPUs running under LINUX and featuring GIGAbit Ethernet
successfully tested in the last Ar+KCl beam time
(2) New Image Processing Unit for Time of Flight and RPC detector
•
essential for heavy systems (Atot >80) with large multiplicities
(3) New Matching Unit for faster processing of second level trigger in large
multiplicity environment
•
essential for heavy systems (Atot>80 ) with large multiplicities
• Final goal is to reach 20 KHz LVL1 trigger rate (presently 7kHz)
Total duration 26 months → see talk of M. Traxler for workplan details
time line
DIRAC
AA collisions
2008
2005
2006
p, on p, d
2007
on p, A
Allocated man power and investment
• 5 institutions: GSI Darmstadt, Institute fuer Kernphysik Frankfurt (IKF), Jagiellonian
University (JU) Kraków, University Santiago de Compostella (USC), Laboratório de
Instrumentação e Física Experimental de Partículas (LIP) Coimbra, Nuclear Physics
Institute (INR) Rez, Institute for Nuclear Reasearch Moscow
•3 tasks: HADES1-RPC (P.Fonte), HADES2-FH (H.Stroebele), HADES3-DAQ (M.
Traxler)
Man power : DIRAC
Investment (k€): DIRAC
All
321
72
132
132
60
96
129
Total
570
130
100
HADES collaboration
1)Institute of Physics, Slovak Academy of Sciences, 84228 Bratislava, Slovakia
2)Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, 95125 Catania, Italy
3)Dipartimento di Fisica e Astronomia, Università di Catania, 95125, Catania, Italy
4)LIP-Laboratório de Instrumentação e Física Experimental de Partículas, Departamento de Física da
Universidade de Coimbra, 3004-516 Coimbra, Portugal
5)Smoluchowski Institute of Physics, Jagiellonian University of Cracow, 30059 Cracow, Poland
6)Gesellschaft für Schwerionenforschung mbH, 64291 Darmstadt, Germany
7)Joint Institute of Nuclear Research, 141980 Dubna, Russia
8)Institut für Kernphysik, Johann Wolfgang Goethe-Universität, 60486 Frankfurt, Germany
9)II.Physikalisches Institut, Justus Liebig Universität Giessen, 35392 Giessen, Germany
10)Istituto Nazionale di Fisica Nucleare, Sezione di Milano, 20133 Milano, Italy
11)Dipartimento di Fisica, Università di Milano, 20133 Milano, Italy
12)Institute for Nuclear Research, Russian Academy of Science, 117312 Moscow, Russia
13)Institute of Theoretical and Experimental Physics, 117218 Moscow, Russia
14)Physik Department E12, Technische Universität München, 85748 Garching, Germany
15)Department of Physics, University of Cyprus, 1678 Nicosia, Cyprus
16)Institut de Physique Nucléaire d'Orsay, CNRS/IN2P3, 91406 Orsay, France
17)Nuclear Physics Institute, Academy of Sciences of Czech Republic, 25068 Rez, Czech Republic
18)Institut für Kern- und Hadronenphysik, Forschungszentrum Rossendorf, PF 510119, 01314 Dresden,
Germany
19)Departamento de Física de Partículas. University of Santiago de Compostela. 15782 Santiago de
Compostela, Spain
20)Instituto de Física Corpuscular, Universidad de Valencia-CSIC,46971-Valencia, Spain
Comparison with transport theory
RQMD calculation: D. Cozma, C. Fuchs and A. Faessler, Tübingen
vacuum calculation
Filtered with HADES
acceptance
resolution smeared
in-medium calculation
collisional broadening
extended VDM + decoherence
Brown-Rho scaling of VMs
See Phys. Rev. C68 (2003) 014904 for details.