[Databeers] 20150129 “Data Superpowers”. Marco Bressan (BBVA D&A)
6 June 2002Andrea Bressan University-INFN Trieste1 COMPASS RICH-1 on behalf of the COMPASS RICH...
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Transcript of 6 June 2002Andrea Bressan University-INFN Trieste1 COMPASS RICH-1 on behalf of the COMPASS RICH...
6 June 2002 Andrea Bressan University-INFN Trieste 1
COMPASSCOMPASSRICH-1RICH-1
on behalf of theon behalf of theCOMPASS RICH GroupCOMPASS RICH Group
6 June 2002 Andrea Bressan University-INFN Trieste 2
Plan of the talkPlan of the talk
• COMPASS for pedestrians• Rich-1 Parameters• Detector Components
• Radiator• Mirrors• Quartz Windows• Photon-Detectors• Front-End electronics
• Performances in 2001-Run• Conclusions and outlook
6 June 2002 Andrea Bressan University-INFN Trieste 3
COMPASS ProgramCOMPASS Program
Nucleon structure • Gluon polarization
G(x) • Flavour-dependent
helicity functions q(x)• Transverse-spin
distribution functions Tq(x)
• Spin-dependent fragmentation (D
q)
Spectroscopy• Primakov reactions
• Polarizability of and K
• Glueballs and hybrids• Charmed mesons and
baryons• Semileptonic decays• HQET• Observe double-charmed
baryons
6 June 2002 Andrea Bressan University-INFN Trieste 4
G MeasurementsG Measurements
• Single out g fusion graphs– Heavy quark lines (cc)– High transverse momentum
• Experimentally:– DIS + D0 (e.g. via ++K-)– DIS + D* (+D0)– DIS with high Pt hadrons
• Asymmetries measure G– A D AN ~ D Ag G/G
g
N(p)
hadrons
'' kμ
kμ
'kkq
c
c
6 June 2002 Andrea Bressan University-INFN Trieste 5
Polarized beams and polarized nucleon targets
hadron beams (up to 300 GeV energy)
Particle identification
Complex apparatus to allow a wide range of measurements
High-rate capabilities
Large dynamical range (angles and momenta)
COMPASS ExperimentCOMPASS Experiment
6 June 2002 Andrea Bressan University-INFN Trieste 6
2001 Apparatus2001 Apparatus
Spectrometer Magnet 1+tracking
Spectrometer Magnet 2
RICH1
Polarised Target
Calorimetry-1
Calorimetry
Muon Wall
Muon Wall
SPS 160 GeV beam
6 June 2002 Andrea Bressan University-INFN Trieste 7
RICH-1 ParametersRICH-1 Parameters
Main requests from the experiment:1. /K separation up to ~ 60 GeV/c2. Large angular acceptance: 250mrad 200mrad (V)
3. Minimize materials
Design:• Radiator: C4F10, length: ~ 3m• Mirrors:
• Spherical, focal length 3.3 m• Reflectance > 80% for > 165nm• Total surface
• Photon detectors: MWPC’s with CsI photocathodes,out of acceptance / total surface 5.3 m2
• Read-out electronics:• Analog read-out/ 83 K channels• average occupancy 5%• max data rate 2.5 Gb/sec in spill
Material Budget:• Total 22.5% of X0
• Mirrors 5.5%• Radiator 10.5%
6 June 2002 Andrea Bressan University-INFN Trieste 8
Measured ParametersMeasured Parameters
0.0
0.2
0.4
0.6
0.8
1.0
6.0 6.5 7.0 7.5 8.0Photon Energy (eV)
Quartz Transparency
C4F10 Transparency
Mirror Reflectivity
CsI Quantum Efficiency
Single Photon Efficiency
2002) exp. tionthermaliza (gas Deg0.2%1n
Δn FC of T
0.25%1n
ΔnWeight FC
)literature (from 1.2%1n
ΔnDispersion Chromatic
104
104
Contribution to n
6 June 2002 Andrea Bressan University-INFN Trieste 9
VESSELVESSEL
1
10
100
1000
28-Jul-2001 16-Sep-2001 5-Nov-2001 25-Dec-2001
Con
tam
inat
ion
(ppm
)
1
10
100
1000
28-Jul-2001 16-Sep-2001 5-Nov-2001 25-Dec-2001
Conta
min
atio
n (
ppm
)O2 H2O
Excellent Gas Tightness of the Vessel10 ppm Contamination of O2 at 4m3/h 0.2 l/hat 1 mbar overpressure
Flushing the vessel with N2
1
10
100
1000
10000
100000
0 2000 4000 6000 8000
Time (min)
Oxigen Content (ppm)
6 June 2002 Andrea Bressan University-INFN Trieste 10
2001 Mirror Mounting2001 Mirror Mounting
Dedicated talk: S. Costa, ”The mirror system of COMPASS RICH-1”
6 June 2002 Andrea Bressan University-INFN Trieste 11
Mirror Wall-ChecksMirror Wall-Checks
—reflectance of 2 test mirrors measured after 2 year in RICH-1 vessel:
—No degradation above 165 nm
mirror n. 2mirror n. 2
mirror n. 5mirror n. 5
wave lengthwave length
wave lengthwave length
refl
ecti
vity
refl
ecti
vity
refl
ecti
vity
refl
ecti
vity
20002000
20012001
20022002
2000 = immediately after coating2000 = immediately after coating
20020000
2002200220012001
6 June 2002 Andrea Bressan University-INFN Trieste 12
CC44FF1010 Gas RADIATOR Gas RADIATOR
Good Bottle
0.00
0.20
0.40
0.60
0.80
1.00
150 170 190 210 230
Wavelenght (nm)
Tran
smis
sion
(%
)
Starting value
100h cleaning
Bad Bottle
0.00
0.20
0.40
0.60
0.80
1.00
150 170 190 210 230Wavelenght (nm)
Tra
nsm
issi
on (%
)Starting Value
150 h Cleaning
pre-cleaning material loss: ~7%pre-cleaning material loss: ~7%
• C4F10 pre-cleaning (in liquid phase)
and on-line monitoring of VUV light transmission
• measured through 5 cm of liquid (~ 7 m of gas, 1 bar) scaled to 5 m of gas (mean photon path in vessel)
• In 2001 radiator gas was a mixture C4F10 : N2 = 50 : 50
pre-cleaning material loss: up to 50%pre-cleaning material loss: up to 50%
MC) (from0.87 19n
190.5)(N 8 0.5 )FC (design 30
16.5n
γ
2104
γ
Dedicated talk: P. Fauland, ”The radiator gas and the gas system of COMPASS RICH-1”
6 June 2002 Andrea Bressan University-INFN Trieste 13
RADIATOR GAS, 2002 RADIATOR GAS, 2002 MATERIALMATERIAL
• new C4F10 delivery, 570 Kg
• better quality, polluting contamination:
mainly water• new pre-cleaning
installation: cleaning in gas phase 0.00
0.20
0.40
0.60
0.80
1.00
150 170 190 210 230
WaveLength (nm)
tran
smis
sio
n (g
as, 5
m)
15.02.02
01.03.02
05.03.02
08.03.02
raw materialraw material
6 June 2002 Andrea Bressan University-INFN Trieste 14
Photon DetectorsPhoton Detectors
Basic Design from RD26
6 June 2002 Andrea Bressan University-INFN Trieste 15
Quartz WindowQuartz Window
Quartz n.14
0.0
0.2
0.4
0.6
0.8
1.0
160 170 180 190 200
Wavelenght (nm)
Tra
ns
pa
ren
cy
(%
)
6 June 2002 Andrea Bressan University-INFN Trieste 16
Problems with PDsProblems with PDsPDs electrical instability at high beam rate
(6 over 8 PDs operated at 100-150 V lower than the 2100 V nominal HV)
Actions taken:• hunting the technical problem: local wire defects• 4 refurbished wire planes• 2 new wire planes (wire LUMAMETALL OSRAM)
Status: PDs mounted again on RICH-1 vesselwire defect,wire defect,
diameter 20 diameter 20 mmSetup for anode wire Setup for anode wire
alignment and alignment and solderingsoldering
Detected SparkDetected Spark
6 June 2002 Andrea Bressan University-INFN Trieste 17
Photon Detector Photon Detector MountingMounting
CsI Deposit on PCBCsI Deposit on PCB
PCB Transport SystemPCB Transport System
PCB MountingPCB Mounting
Photon Detector MountingPhoton Detector Mounting
Final InstallationFinal Installation
6 June 2002 Andrea Bressan University-INFN Trieste 18
RICH-1 – READ-OUTRICH-1 – READ-OUT
• analogic read-out system, 84,000 channels with local intelligence (DSP, FPGA in FE BORA board) working
• dead time: limited to 500 ns / event up to trigger rates of 75 KHz
• average noise level: ~ 2000 e- , non homogeneous (2001)
• reinforced ground lines (2002), noise level: ~ 1100 e-
Front End BORA boards Front End BORA boards
mounted on photon detectormounted on photon detector
PC resident control PC resident control board DOLINAboard DOLINA
Dedicated talk: M.L. Crespo, ”The COMPASS RICH-1 Read-Out System”
6 June 2002 Andrea Bressan University-INFN Trieste 19
Noise ReductionNoise Reduction
Sigma
Run 2001=2100 e-
Run 2002=1100 e-
Noise sigma for each pad2001 RunThe shape of the PCB supportIs reproduced
Noise sigma for each pad2002 RunThe shape of the PCB supportAbsent
6 June 2002 Andrea Bressan University-INFN Trieste 20
2001 Data Analysis2001 Data Analysis
Abrided from the Dedicated Poster:P. Schiavon et al, ”RICHONE: a software package for the reduction of COMPASS RICH-1 data”
6 June 2002 Andrea Bressan University-INFN Trieste 21
Integrated EVENTSIntegrated EVENTS
Photon detector (Up)
Photon detector (Down)
Beam halo
6 June 2002 Andrea Bressan University-INFN Trieste 22
Reconstructed RINGReconstructed RING
“Ring event”
The cross indicates the track “image ”The blue dots are the padsThe black dots are the selected clusters
6 June 2002 Andrea Bressan University-INFN Trieste 23
Cherenkov ANGLECherenkov ANGLE(a) Cherenkov angle of photons of the Rich(b) Cherenkov angle of the ring for > 60 GeV particles
Superimposed (yellow) out of time signals
11
ringring
all all
photonsphotons
(b)(a)
6 June 2002 Andrea Bressan University-INFN Trieste 24
(a) Cherenkov angle of Reconstructed Ring(b) Number of Photons of the Reconstructed Ring Superimposed (yellow) out of time signals
Number of PhotonsNumber of Photons
photnsphotnsringring
11.7 photons 13.0 photons
all all all all (a) (b)
6 June 2002 Andrea Bressan University-INFN Trieste 25
Conclusions and OutlookConclusions and Outlook2001 Run:
– All important staffs on the floor – 50% of Radiator Gas in – Front End electronics working satisfactory – Noise figure higher than expected – Electrical Instabilities from PDs
2002 Run: New Staffs– Cooling system for the front-end electronics– Fast Radiator Gas mixing in the vessel– Improved noise– Refurbished and rewired PDs– Full radiator GAS
2002 Run: Still Missing Staffs– Vessel thermalisation