bethe-bloch formula
DESCRIPTION
Bethe-Bloch formula. Cluster of electrons. Primary ionization. Total ionization. Cathode. The collection of these electrons on an appropriate electrode produces our signal. To drive the electrons towards the electrode an electric field is needed!. Anode. Drift and Diffusion. - PowerPoint PPT PresentationTRANSCRIPT
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Bethe-Bloch formula
Bethe-Bloch formula
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Cluster of electronsCluster of electrons
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Primary ionization
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Total ionization
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
The collection of these electrons on an appropriate electrode produces our signal. To drive the electrons towards the electrode an electric field is needed!
Anode
Cathode
Drift and Diffusion Drift and Diffusion
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Drift and Diffusion of electron in gases Drift and Diffusion of electron in gases
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Low electric field. Ionization regionNumber of electrons is independent on the applied field
Low electric field. Ionization regionNumber of electrons is independent on the applied field
If the electric field is too low, there is recombination between ions
If the electric field is too low, there is recombination between ions
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
R
d - q
cathode
anodesignal
-Vox
x
A charge q at a distance x from the anode has U=qV(x)
For a displacement of dx U=qV(x+dx)-qV(x)=qEdx
should be compensated from the power supply energy V0idt=V0dq
qEdx=V0idt
i=q(v/d) i is the current signal
A charge q at a distance x from the anode has U=qV(x)
For a displacement of dx U=qV(x+dx)-qV(x)=qEdx
should be compensated from the power supply energy V0idt=V0dq
qEdx=V0idt
i=q(v/d) i is the current signal
Constant electric filed E=V0/dConstant electric filed E=V0/d
Ionization chambersIonization chambers
ii
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
d-
--
+
++
t
i(t)
R1
R2
C2
C1
-HV
A
If R2C2 e R2C1 small in comparison to t = d/v
Current signal on R2
Q is the charge induced on the electrode
If R2C2 e R2C1 small in comparison to t = d/v
Current signal on R2
Q is the charge induced on the electrode
We neglect the signal due to positive ions because they arrive much laterWe neglect the signal due to positive ions because they arrive much later
If more clusters at different x, add all the contributions
Q(t)=q0
If more clusters at different x, add all the contributions
Q(t)=q0
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
E
Anode
Cathode1 cm of Argon produces about 100 electrons. Very small signal to detect. Amplification is needed!!!
1 cm of Argon produces about 100 electrons. Very small signal to detect. Amplification is needed!!!
Increase the electric field so that each primary electron is accelerated and gets enough energy to produce other ionizations
Increase the electric field so that each primary electron is accelerated and gets enough energy to produce other ionizations
= Townsend coefficient = Townsend coefficient
1
1 Average free pathxEenxn )(
0)( xEenxn )(0)(
d
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
• Limited proportional M < 108
• Streamer 108 < M <1010
• Geiger M >1010
• Limited proportional M < 108
• Streamer 108 < M <1010
• Geiger M >1010
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
GainGain
Korff relation Korff relation
ddxx
n
nM
00
)(exp
ddxx
n
nM
00
)(exp
E
Bp
Aep
E
Bp
Aep
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
a
b
r
E
1/r
a
cathode
anode
gas
Ethreshold
a
rCVrV
r
CVrE
ln2
)(
1
2
0
0
0
0
C = capacitance / unit length
Proportional regionCollected charge proportional to initial ionization
Proportional regionCollected charge proportional to initial ionization
6
0
10n
nM 6
0
10n
nM
The cylindrical geometry is suitable to easily achieve high electric fields a = 8 10-5 mb= 10-2 mHV =500 V
E = 5 104 V/m
The cylindrical geometry is suitable to easily achieve high electric fields a = 8 10-5 mb= 10-2 mHV =500 V
E = 5 104 V/m
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Avalanche
It develops close to central electrode at a radius of 4 10-4 m
Avalanche
It develops close to central electrode at a radius of 4 10-4 m
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Wire proportional chamberWire proportional chamber
a= 10 mm, b=10 mm r’=a +1 mm
The induced signal is due to positive ions
a= 10 mm, b=10 mm r’=a +1 mm
The induced signal is due to positive ions
2a
b
anode
cathode
R
+V0
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Cylindrical geometry is not the only one able to generate strong electric fieldCylindrical geometry is not the only one able to generate strong electric field
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Noble gases emits photons if excited (argon emits 11.6 eV photons).
Threshold energy for metal ionization is lower (e.g. Cu 7.7 eV)
Noble gases emits photons if excited (argon emits 11.6 eV photons).
Threshold energy for metal ionization is lower (e.g. Cu 7.7 eV)
QuenchersThe addition of polyatomic gases ( CH4,C4H10, ethane, CO2, BF3) is needed to absorb photons
QuenchersThe addition of polyatomic gases ( CH4,C4H10, ethane, CO2, BF3) is needed to absorb photons
Already important in the proportional regime.Already important in the proportional regime.
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
In 1968 Charpak proposed the first Multi Wire Proportional Chamber (MWPC)
In an array of anodic tightly spaced wires, each is like a proportional counter.
In 1968 Charpak proposed the first Multi Wire Proportional Chamber (MWPC)
In an array of anodic tightly spaced wires, each is like a proportional counter.
Typical parameters:L = 5 mm, d = 1÷2 mm, Rwire~ 20 m
Typical parameters:L = 5 mm, d = 1÷2 mm, Rwire~ 20 m
field lines and equipotentials around anode wires
The position of the particle can be definedThe position of the particle can be defined
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Anode Cathode
(V=0)
Cathode (V=0)
Far from the anode the field is uniform.Each wire work as a ”proportional chamber”
Far from the anode the field is uniform.Each wire work as a ”proportional chamber”
d
L
x
yC is the capacity per unit length C is the capacity per unit length
da
dL
C ln
2
da
dL
C ln
2
a = wire radiusa = wire radius
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
However for inclined tracks , more wires may be involvedHowever for inclined tracks , more wires may be involved
Ls
Different signal are generated but in different times. Our interest is for the first.
Therefore we can:• Set the gate of reading electronic system to
accept only the fast signals;• Introduce a percentage of electronegative gas to
stop the electrons generated far from anode.
Different signal are generated but in different times. Our interest is for the first.
Therefore we can:• Set the gate of reading electronic system to
accept only the fast signals;• Introduce a percentage of electronegative gas to
stop the electrons generated far from anode.
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
y
L
QBQA
track
%4.0 toup
L
y
Q
L
y
BA
B
Two coordinatesTwo coordinates
Double layer of wiresDouble layer of wiresCharge division Charge division
Time difference Time difference
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
The cathode is segmented in strips where a signal is induced. If each strip is at the coordinate zi , the center o gravity is:
The cathode is segmented in strips where a signal is induced. If each strip is at the coordinate zi , the center o gravity is:
i
ii
q
zqz
i
ii
q
zqz
The cathode strip chambersThe cathode strip chambers
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
The avalanche around an anode wire creates an induced charge distribution on the cathode, with a FWHM roughly 1.5 times the anode to cathode distance.
The CMS designThe CMS design
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
The CMS CSCThe CMS CSC
~ 70 m ~ 70 m
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Drift ChamberDrift Chamber
Measure arrival time of electrons at sense wire relative to a time t0.
anode
TDCStartStop
DELAYscintillator
drift
low field region drift
high field region gas amplification
dttvx D )(
x
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Advantage of drift chamber with respect to MWPCEasier mechanical construction (higher distance between wires)Lower number of wire less complex electronic (but more expansive)Higher precision (no more limited by the wire distance)
Advantage of drift chamber with respect to MWPCEasier mechanical construction (higher distance between wires)Lower number of wire less complex electronic (but more expansive)Higher precision (no more limited by the wire distance)
Fundamental parameters
Optimize geometry to have E constant
Gas which allow constant drift velocity Vd
(Vd ~ 50 mm/s in Argon-Isobutene 75%-25% and E~700-800V/cm)
Fundamental parameters
Optimize geometry to have E constant
Gas which allow constant drift velocity Vd
(Vd ~ 50 mm/s in Argon-Isobutene 75%-25% and E~700-800V/cm)
Introduce field wires Introduce field wires
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Resolution determined by• diffusion, • path fluctuations, • electronics • primary ionization
statistics
Resolution determined by• diffusion, • path fluctuations, • electronics • primary ionization
statistics
sense field
Resolution is better for tracks passing at larger distance from the sense wire… but at very large distance the diffusion enter in the game
Resolution is better for tracks passing at larger distance from the sense wire… but at very large distance the diffusion enter in the game
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Resolution determined by primary ionization statistics
Resolution determined by primary ionization statistics
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Transverse diffusion substantially reduced in some gases if E || BTransverse diffusion substantially reduced in some gases if E || B
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
The CMS drift chamberThe CMS drift chamber
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
TPC (Time Projection Chamber)TPC (Time Projection Chamber)
Small quantity of material (only gas). Multiple-scattering and photon conversion is minimized
Small quantity of material (only gas). Multiple-scattering and photon conversion is minimized
B
Central electrode (≈ -50kV)gas
Read out plane
Anode wires
Cathode padsz
y
x
Z coordinates measured by the drift time
X and Y measured on anode wires and cathode pads
Z coordinates measured by the drift time
X and Y measured on anode wires and cathode pads
MWPCMWPC
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
y
z
x
E
B drift
chargedtrack
wire chamber to detect projected tracks
gas volume with E & B fields
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
•The TPC allows to determine a point in the space ( x,y,z)
•The analog signal on the anode measures dE/dx
•E//B drift velocity parallel to E e B. Diffusion perpendicular to E is reduced. Electron move around B with a radius of about 1 mm (E ~ 50KV e B ~1.5 T )
Requirements:•To measure Z is necessary a good knowledge of Vd
•Laser Calibration and correction for pressure and temperature needed
•Very clean gas
Aleph TPC L = 4.4 m, Diameter = 3.6 m,
•The TPC allows to determine a point in the space ( x,y,z)
•The analog signal on the anode measures dE/dx
•E//B drift velocity parallel to E e B. Diffusion perpendicular to E is reduced. Electron move around B with a radius of about 1 mm (E ~ 50KV e B ~1.5 T )
Requirements:•To measure Z is necessary a good knowledge of Vd
•Laser Calibration and correction for pressure and temperature needed
•Very clean gas
Aleph TPC L = 4.4 m, Diameter = 3.6 m,
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Aleph TPCAleph TPC
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
MWPC limitationMWPC limitation
Rate (mm -1 s-1)
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
103 104 105 106 107 108
Rel
ativ
e ga
in
MWPC
MWPC Gain-Rate
Wire spacing: 1-2 mm
Rate capability: limited by space chargeRate capability: limited by space charge
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Thin metal-coated polymer foil chemically pierced by a high density of holes.On application of a voltage gradient, electrons released on the top side drift into the hole, multiply in avalanche and transfer the other side.Proportional gains above 103 are obtained in most common gases.
Thin metal-coated polymer foil chemically pierced by a high density of holes.On application of a voltage gradient, electrons released on the top side drift into the hole, multiply in avalanche and transfer the other side.Proportional gains above 103 are obtained in most common gases.
70 µm
Gas Electron Multiplier (GEM)Gas Electron Multiplier (GEM)
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Basic principlesBasic principles
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Basic GEM DetectorBasic GEM Detector
PATTERNEDREADOUT BOARD
1 mm
3 mm DRIFT
INDUCTION
MULTIPLICATION
-VD
-VTOP
-VBOT
VGEM
- Readout separated from multiplying electrodes- Multiple cascaded structures possible (large
gains, feedback suppression)- Cheap and reliable
- Readout separated from multiplying electrodes- Multiple cascaded structures possible (large
gains, feedback suppression)- Cheap and reliable
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
FAST ELECTRON SIGNAL
No positive ion tail: very good multi-track and time resolutionNo positive ion tail: very good multi-track and time resolution
S1 S2 S3 S4
Induction gap
e-
e-
I+Ar-CO2 70-30
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Single GEM + readout padsSingle GEM + readout pads
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Double GEM + readout pads
Same gain at lower voltage
Less discharges
Double GEM + readout pads
Same gain at lower voltage
Less discharges
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
SPACE RESOLUTION~ 40 µm rmsCLUSTER SIZE ~ 500 µm FWHM
SPACE RESOLUTION~ 40 µm rmsCLUSTER SIZE ~ 500 µm FWHM
A. Bressan et al, Nucl. Instr. And Meth. A425(1999)262
EFFICIENCY FOR MINIMUM IONIZING PARTICLES3 mm gap
EFFICIENCY FOR MINIMUM IONIZING PARTICLES3 mm gap
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Saturated avalanche
•Increase the gain up to 107
•Better signal •No need for amplification
But
•Only position measurement •dE/dx no possible
Saturated avalanche
•Increase the gain up to 107
•Better signal •No need for amplification
But
•Only position measurement •dE/dx no possible
A small quantity of electronegative gas (freon ) is needed to reduce the number of electrons in the avalanche
A small quantity of electronegative gas (freon ) is needed to reduce the number of electrons in the avalanche
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Streamer mode - Geiger mode
Gain > to 108
Streamer mode - Geiger mode
Gain > to 108
AvalancheAvalanchestreamerstreamer spar
kspark
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
StreamerWhen the gain is greater then 10 8 (Raether limit)
•The electron spatial charge produce a decrease of the electric field• Recombination e- -positive ions• Production of ultraviolet photons• Production of secondary avalanches from these photons
StreamerWhen the gain is greater then 10 8 (Raether limit)
•The electron spatial charge produce a decrease of the electric field• Recombination e- -positive ions• Production of ultraviolet photons• Production of secondary avalanches from these photons
E~0 , e-~108E~0 , e-~108
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
A modern deviceA modern device
Geiger –Muller counter in the Fermi laboratory
Geiger –Muller counter in the Fermi laboratory
A Geiger-Mueller (GM) tube is a gas-filled radiation detector. It commonly takes the form of a cylindrical outer shell (cathode) and the sealed gas-filled space with a thin central wire of about 30 m (the anode) held at ~ 1 KV positive voltage with respect to the cathode.
The fill gas is generally argon at a pressure of less than 0.l atm plus a small quantity of a quenching vapor.
A Geiger-Mueller (GM) tube is a gas-filled radiation detector. It commonly takes the form of a cylindrical outer shell (cathode) and the sealed gas-filled space with a thin central wire of about 30 m (the anode) held at ~ 1 KV positive voltage with respect to the cathode.
The fill gas is generally argon at a pressure of less than 0.l atm plus a small quantity of a quenching vapor.
The Geiger counter detects some or all of the four major types of ionizing radiation, namely Alpha, Beta, Gamma, and X-rays.
The Geiger counter detects some or all of the four major types of ionizing radiation, namely Alpha, Beta, Gamma, and X-rays.
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Collisions with the fill gas produce excited states (~11.6eV) that decay with the emission of a UV photon and electron-ion pairs (~26.4 eV for argon). The new electrons, plus the original, are accelerated to produce a cascade of ionization called "gas multiplication" or a Townsend avalanche. The multiplication factor for one avalanche is typically 106 to 108.
Collisions with the fill gas produce excited states (~11.6eV) that decay with the emission of a UV photon and electron-ion pairs (~26.4 eV for argon). The new electrons, plus the original, are accelerated to produce a cascade of ionization called "gas multiplication" or a Townsend avalanche. The multiplication factor for one avalanche is typically 106 to 108.
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
anode
cathode
R
+V0
The anode is supplied through a high R so that its voltage is under threshold for the Geiger mode during the discharge.
The RC constant should ensure that the detectotor is under threshold during the time the ions take to reach the cathode = milliseconds low rate
The anode is supplied through a high R so that its voltage is under threshold for the Geiger mode during the discharge.
The RC constant should ensure that the detectotor is under threshold during the time the ions take to reach the cathode = milliseconds low rate
Also: resistive quenchingAlso: resistive quenching
The full wire is interested in the discharge process Only “courting rate” is possible
The full wire is interested in the discharge process Only “courting rate” is possible
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
By adding a higher percentage of quencher, the discharge can be limited to only a small portion of the wire
Wire diameter: ~ 50÷100 mmGas mixture: ≤ 60% Argon , ≥ 40% Isobutene, few % Freon Wire voltage: ~5 KV
Wire diameter: ~ 50÷100 mmGas mixture: ≤ 60% Argon , ≥ 40% Isobutene, few % Freon Wire voltage: ~5 KV
Sense wireSense wire
Cathode (graphite coating)Cathode (graphite coating)
PVC cellPVC cell
External read-out stripExternal read-out strip
Streamer tubesStreamer tubes
Cathode must be resistiveCathode must be resistive
The internal graphite coating of the cathode has a resistivity of about .2-.5 M /cm This also ensure a self quenching mechanism in side the tube only a portion of the wire is interested by the discharge
The internal graphite coating of the cathode has a resistivity of about .2-.5 M /cm This also ensure a self quenching mechanism in side the tube only a portion of the wire is interested by the discharge
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
mm12
10 mm
12
10
Streamer tubesStreamer tubes
•Analog read out on the wire•Digital readout on the strip
If he strip is perpendicular to the wire, X–Y measurement is possible
•Analog read out on the wire•Digital readout on the strip
If he strip is perpendicular to the wire, X–Y measurement is possible
Time resolution 100 ns
spatial resolution 1 cm/sqrt12
Efficiency 90% , 10 % dear area
rate capability 100 Hz/cm2
Time resolution 100 ns
spatial resolution 1 cm/sqrt12
Efficiency 90% , 10 % dear area
rate capability 100 Hz/cm2
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
• 10 planes of streamer tubes (total of 50000 tubes)
• Gas mixture He (73%) and n-pentane (27%)
= 0.2°
• 10 planes of streamer tubes (total of 50000 tubes)
• Gas mixture He (73%) and n-pentane (27%)
= 0.2°
Macro Search for Up going muons,
A multiple event
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Used in many experiments:
calorimetry:
Charm II (CERN, SPS)
ALEPH (LEP, CERN)
DELPHI (LEP, CERN)
OPAL (LEP, CERN)
detection
UA1, (CERN)
ZEUS (HERA)
Used in many experiments:
calorimetry:
Charm II (CERN, SPS)
ALEPH (LEP, CERN)
DELPHI (LEP, CERN)
OPAL (LEP, CERN)
detection
UA1, (CERN)
ZEUS (HERA)Streamer tubes have been extensively used also for hadron calorimetric measurement
Streamer tubes have been extensively used also for hadron calorimetric measurement
Principle: numbers of hit proportional to the shower density
Principle: numbers of hit proportional to the shower density
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
HCAL:23 layer iron/streamer tube sandwich with total thickness of 120 cm of iron (the magnet return yoke)
HCAL:23 layer iron/streamer tube sandwich with total thickness of 120 cm of iron (the magnet return yoke)
The muon chambers are made of two layers (X-Y) of streamer tubesThe muon chambers are made of two layers (X-Y) of streamer tubes
ALEPH
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
Event with two muons Event with two muons Event with a muons and hadronic showers Event with a muons and hadronic showers
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
New challenge: improve time resolution with planar geometry
No wires, distance between electrode 1-2 mm. High electrical fied
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli
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Gaseous detectors Detector concepts for HEP
High Energy Physics school in Egypt , Cairo -November 2010 G. Iaselli