Participation fran

1
MACFLY
Measurement At Cern of Fluorescence Light Yield
a measurement of the fluorescence light in UV
emitted by various gas (air, pure N2...) when
high-energy charged particles pass through it.
What ?
Where ?
CERN test beam ( PS and SPS line )
LAPP (Annecy France) P. Colin, J.P Mendiburu,
D. Naumov, P. Nedelec and J.P. Peigneux. Other
groups involved / interested ISN (France), APC
(France), LIP (Portugal), CERN. and who wants to
join us !
Who ?
2
MACFLY
The purpose
Measure air light yield as a function of

• Pressure ( 0 to 1 atm )
• Temperature
• Air composition (O2, Ar)
• Impurities (humidity, aerosol)
• Energy of particles (1.4MeV to 100GeV)
• Nature of high-energy particle (e-,?,p)
• Presence of Cerenkov light

Pressure and temperature profile of atmosphere
Simulate the UV light produced by an air shower
in the atmosphere.
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MACFLY
CERN

• Test beam facilities
• Particle beam of electron, pion or proton.
• Flux 10,000 particle/spill.

Line Energy Frequency
PS 5-15 GeV 1spill / 2s
SPS 25-100 GeV 1spill / 14s
Experimental area
UV laser
e-,p- beam
DAQ
CERN-SPS-X5 Test Beam line
Control room
4
MACFLY
beam
Setup
1m
mirrors
Quartz window
beam
PMT
Pressurised tank
PMT
PMT

• We control temperature,pressure and gas
  composition in the tank.
• Mirror system collects the light (geometric
  efficiency 57 ).
• several PMT detect the light ( with or without
  filters ).
• First simulation
• in dry air at atmospheric pressure
• 104 particles 3570 photoelectrons detected.

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MACFLY
Schedule
From Now to end of the year Setting up A device to measure fluorescence yield A simulation of this device
Beginning of 2003 First test with Radio active source (1.4MeV reference point). 337nm UV LASER.
Summer 2003 Measurement at CERN under test beam.
Summer 2004 Last measurement with test beam.
And first result at the next workshop
Contact us colin_at_lapp.in2p3.fr