Measurements of FLY with MACFLY

1
Measurements of FLY with MACFLY
2
Measurement of Air Cerenkov and Fluorescence
Light Yield
http//wwwlapp.in2p3.fr/MACFLY/
Collaboration

• LAPP (France) Pierre COLIN, Patrick NEDELEC
• LIP (Portugal) Antonio ONOFRE
• JINR (Russia) Leonid TKATCHEV, Artem CHUKANOV,
  Basar SABIROV,
• Yuri NEFEDOV, Sergei
  POROKHOVOI, Dmitry NAUMOV.

3
Original Goals
Reproduce and study in laboratory the light
emitted by an extensive air shower (EAS)
To Measure Air FLY variations as a function of
atmospheric conditions
4
MACFLY project 2 devices
Gas system
N2
Air
Vacuum pump
Gauge P,T,H2O
Ar
H2O
O3
shower

• Beam
• ß Source
• CERN
• JINR

Preshower
PMT
MACFLY 2 (for shower)
MACFLY 1 (for beam)
5
MF1 a reference device

• Single track events device
• Light, compact, movable (plane?),
• Used both
• _at_ Lab (quiet)
• on Test Beam (noisy)
• Measure
• Air/N2FLY
• Cherenkov contribution
• Used for comparison with
• Other experiments
• MF2

6
Macfly 1 _at_ Laboratory
Input/ouput of gas
Pompe à vide
Vacuum pump
PMT
Optic fibres
Radioactive source Sr90
Trigger PMT
PMT1
90Sr ß Source
Pressure sensor
Scintillator
Main tank
Temperature sensor
PM Trigger
Electrons beam
PMT2
7
Macfly 1 optical system
PMT EMI 9820QA Quartz Window
EMI 9820QA
EMI 9820QA
Filters
Quartz Lens
Light Guide
Electron beam
Mirror 98 (multi-layers)
15 cm
8
MF2 looking for real showers

• A From single track to showers device
• Heavy, Big, Fix ,
• Used
• Only on Test Beam Line
• Measure
• Air/N2 FLY induced by a e- shower (10-50 GeV)
• From 0 to Xmax radiation length
• Used to
• Perform original measurements
• for comparison with Monte Carlo prg (G4,)

9
Macfly 2 (MF2)
146 cm
Sensors (P,T)
PMT
Ø96 cm
CERN Beam
Cooper target (Preshower)
Input/Output of gas system
Volume 1m3
10
MF2 working process
PMT EMI 9820QA Quartz Window
Light guide
EMI
Black surface
Filters
Preshower
Preshower system
Electron beam
Electromagnetic Shower
Ø10 cm
Lead shield
EMI
Stack of copper disks (Thickness 1cm)
11
Measurement campaigns

• gt In Lab (MF1)
• Radioactive source (1.5 MeV electron)
• Pressure dependence ?
• gt At CERN (MF1MF2)
• SPS test Beam (5-100 GeV e-, µ-, p-)
• Pressure dependence ? Temp., H2O ?
• Shower age dependence (MF2)

• gt At JINR ? (MF1)
• Microtron(12 MeV) and Phasotron (170 MeV)
• Pressure and temperature dependencies

12
MACFLY set up overview at CERN
Pumping system
Macfly 2
MF1 in its thermal box
Delay chamber
Small Trigger
Large Trigger
13
Macfly Data
Event by event acquisition
106 triggers/run (1/2 data1/2 Bgd)
PMT signal read by a QADC (Gate100ns)
Very Low signal mean0.01photoelectron
Expected FLY 4 ph/m
14
Macfly Data selection
Centered events
15
MacFly Fluo. Signal extraction
Cherenkov Detected Light (Geant4 simulation)
Background (Vacuum measurement)
PMT Detected Light (fit method)
DL FLY x eMF CDL Bgd
Detector efficiency (Calibration)
Fluorescence Light Yield (in photons)
FLY/E FLY / Edep
Deposed Energy (Geant4 Simulation)
16
Macfly Data
DL FLY x eMF CDL Bgd
Detected Light PMT spectrum fit Method
2 photoelectrons
17
MacFly Geant4 Simulation
DL FLY x eMF CDL Bgd
Geometrical Acceptance (Optical Properties of
surfaces were previously measured)
eMF Accgeo x QEPMT
18
MacFly Geant4 Simulation
DL FLY x eMF CDL Bgd
Cherenkov Light compare simulation with data
Cherenkov light in MF1
19
MacFly data
DL FLY x eMF CDL Bgd
Background

• Well measured events
• Random triggers (_at_lab)
• Off-spill triggers (_at_beam)
• Vacuum On-spill triggers (_at_beam)

20
MacFly Geant4 Simulation
FLY/E FLY / Edep
Deposed Energy
Deposed Energy in MF2
7 disc
10 disc
5 disc
3 disc
1 disc
0 disc
Radiation length (X0)
21
Detected Light Composition
MF1 50 GeV e- in air
MF1 50 GeV e- in N2
DL
(Macfly data)
CDL
(Simulation)
Bgd
(Measurement)
FDL
MF2 50GeV Shower in air
MF1 1.5 MeV e- in air
Fluorescence detected light
22
Systematic errors of MF1
23
MF1 result Pressure dependence
We create a model of air FLY proportional to
deposed energy which fit all Macfly data. (Dry
air and pure Nitrogen)
24
MF1 result Energy dependence
dEdX Berger-Seltzer formula
All experiments are coherent
Reference point Dry air at 1atm. 23ºC FLY/E
18 ph/MeV
25
Absolute measurement
Errorlt 10 ?
dEdX Berger-Seltzer formula
All experiments are coherent
Reference point Dry air at 1atm. 23ºC FLY/E
18 ph/MeV
26
MF2 result Shower age dependence
500 hPa data
PDG model of shower development
100 hPa data
Air FLY follows the shower development !
27
MF2 Air FLY ? deposed Energy
FLY/Edep and pressure variations independent of
the excitation source
28
Conclusion

• Measurements done P. Colin thesis
• Dry air and pure Nitrogen fluorescence
• 1.5 MeV, 20 GeV and 50 GeV incident electron
• Lab. measurement of air Shower FLY
• Pressure and Shower age dependencies

• Fluorescence model
• Air FLY ? Edep
• Fitted on Macfly data
• Compatible with
• previous exp. (lt10)