forschungszentrum karlsruhe in der helmholtz-gemeinschaft bianca keilhauertokyo, february 26th, 2004...
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Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
Bianca Keilhauer Tokyo, February 26th, 2004
Summary and Issues of
Workshop, Bad Liebenzell, Dec. 2003
• 4 interesting days in December 2003
• 39 participants
• 25 presentations
• 10 projects
⇒ improvements in understanding the aspects of molecular physics and in experimental measurements
http://www.auger.de/events/air-light-03/
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
Bianca Keilhauer Tokyo, February 26th, 2004
Bianca Keilhauer Tokyo, February 26th, 2004
Fluorescence Light -
starting theory -A. N. Bunner: Cosmic Ray Detection by Atmospheric Fluorescence, PhD thesis 1967
Franck-Condon-Principle for absorption and fluorescence
Fluorescence from Fluorescence from NitrogenNitrogen
N 2+
Data from Bunner (1964) : weighted averages of three experiments with an accuracy of not better than ±30%. Kakimoto et al (1996) : 1.4MeV-1000MeVare mainly used in UHECR experiments.
1st Negative band
2nd Positive band
N2
M. Nagano
Energy Spectrum M. Risse
Bianca Keilhauer Tokyo, February 26th, 2004
• conventional approach:
R. EngelE. Marques
Idea
The „classic“ method of determination of Ne (X) is subject to a purely geometrical correction due to the lateral spread of shower particles.
Discussion on Fluorescence Yield of an EAS
• ionization energy approach:
R. Engel
Bianca Keilhauer Tokyo, February 26th, 2004
E. Marques
Discussion on Fluorescence Yield of an EAS
Ionization energy deposit: problems
• Assumption
- No clear experimental evidence
- Precision of energy reconstruction will depend on fluorescence
yield data
• Angular spread and definition of track length dX
- Track length along shower axis
- Actual track length of particles
• Energy loss in fluorescence yield experiments
- Low energy ( E ≪ Ec): ionization loss
- High energy: ionization and radiative losses (small cascades)
- Detailed simulation of ionization energy deposit needed
• Calorimetric energy Ecal not equal to total shower energy
R. Engel
Air light 03
Dependencies
Process dependence parameters
Deposed Energy
By Ionisation
Incident particle
Air density
E, nature
P,T
Quenching Quencher density
N2 or N2+
T , PO2, PH2O ,(λ)
Process Decay Time
dependence parameters
Fluorescence τFBand width λ
Internal Quenching τIQTemperature T , (λ)
Collision Quenching τCMolecular
speed
Air density
P, T
Measured dependencies today : only E, P and λMacfly project : PO2, PH2O, (T, nature)
Exc
itatio
nD
esex
cita
tion
P. Colin
Excitation processes
• The C3u electronic state
is a forbidden state; it
cannot be directly excited
by fast charged particles.
Elim (C3u) = 11.03 eV
P.I. = 15.6 eV
W ~ 36 eV
M. Fraga
H. Brunet, PhD thesis, UPS,Toulouse,1973
Brunet PhD: http://www.auger.de/events/air-light-03/#phd_brunet
Fluorescence Light
EAS excites N2 molecules in air
18 transitions in 2P system between 300 and 400 nm
1 transition in 1N system between 300 and 400 nm
Calculation follows the principle way suggested by A. Bunner, 1967
⇒ quantum efficiency of fluorescence =
excitationperphotons
excitationdeofratetotal
radiationbyexcitationdeofrate
c
0
0
1
i
111
0
with
andNxn
m
Nxnc Tk
M
v
4
1
2
1
B. Keilhauer
Fluorescence Efficiency
depE
En
mediumobservedtheindepositenergy
photonscefluorescenofformtheinenergyradiated
Tpp
pTp
)('1
0,
with p/p‘ν for air (79% N2 and 21% O2):
OmNmNO
NmNN
A
OmNm
Aair
MMM
kTN
MM
NTp
p
p
,,,
,,
,,
,0
11221.02
179.04
21.079.0
),(
'
B. Keilhauer
sum in the region 300 – 400 nm
337,1 nm ≙ ①
357,7 nm ≙ ②
391,4 nm ≙ ③
flu
ore
scen
ce e
ffic
ien
cy (
ph
oto
ns/
MeV
)
height (km)
@ 0 km: ① + ② + ③ = 65,7%
@ 20 km:① + ② + ③ = 63,2%
31,8%
25,3%
8,6%
29,2%
23,3%
10,7%
Fluorescence Efficiency Profiles
B. Keilhauer
Electron impact cross sectionsfor N2 and O2
Pitchford and Phelps,
MagBoltz
Qd
rot
vibion
exc-S
exc-T
el.
att
vibion
Dashed curves - excitationsMagboltz -CERN
M. Fraga
Bianca Keilhauer Tokyo, February 26th, 2004
Ekin (MeV) < 0.1 0.1 - 1 1 -10 10 - 100 100 -1000 > 1000
Contr. (%) 10 12 23 35 17 3
source e-- gun e- from 90Sr beam from accelerator
experiment Arqueros, Madrid, < 30 keV
Ulrich, Munich, 12 keV
Nagano, Fukui Univ.
Waldenmaier, AirLight
Gorodetzky, Paris
Colin, MacFly 1. phase
Fraga, LIP-Lisboa
Kemp, Campinas 1. phase
2. phase: medical acc. 5-12 MeV
Privitera, AIRFLY, e±-beam at BTF, 50-750 MeV
Colin, MacFly 2. ph., e±/μ-beam at CERN 25-100 GeV
Reil, Flash, e--beam at SLAC 28 GeV
Kemp, 2. ph.,
e--beam at LNLS 1.37 GeV
Photon yields vs Bethe-Bloch
Nagano et al. Astroparticle Phys. (2003)
FY seems to be proportional to dE/dx for E > 0.8 FY seems to be proportional to dE/dx for E > 0.8 MeV.MeV.
dE/dx grows fast at low energies. Does this dE/dx grows fast at low energies. Does this relationship hold at very low energy?relationship hold at very low energy?
F. Arqueros
Preliminary set-up: the collision chamber
Nd:YAG
collision chambergas inlet
Faraday cup orscintillator
PMT
UV filter
photodiode/trigger
DigitalScope
HV (0 – 30 kV )
vacuum pump
Differential pumping (up to 100 mtorr) 1 PMT ORIEL 77348 (single counting) + UV filter Digital scope (1 ns)
F. Blanco and M. Ortiz
vacuum pump
Electron beam features
Energy up to 30 KeV. Pulse Rate = 1 – 20 Hz Time width = 20 ns (limited by the laser / plasma). Intensity up to 200 mA peak. Beam diameter 2 mm.
Some stability problems !!
F. Arqueros
Bianca Keilhauer Tokyo, February 26th, 2004
High-precision Measurements
of Experts for
„Particle beam induced light emission“
A. UlrichEnergy deposition in the gas (1 bar Ar)
Modelled using the „Casino“ Program
P. Drouin, A.R. Couture, R. Gauvin, P. Hovington, P. Horny, H. Demers, Univ. de Sherbrooke, Quebec, Canada (2002)
Parameters for low energy electron beam excitation:
Particle energy: typically 15 keV Foil: 300 nm silicon nitride Gas: typically 0.1 to 2 bar Beam current cw typ. 10 μA av. (0.15 W) or pulsed
Usage of the membranes: (principle) Diagnostics and gas system:
Time resolved optical spectroscopy
Grating monochromators (f=30cm, 0.03 nm resolution 1.order)
Wavelength range ~30 nm to 700 nm
Time resolution ~10ns beam pulses, ~1ns electronic res.
Detectors VUV-PMT,VUV MCP and diode array
Sensitivity measurements: two WI-17G Lamps (OSRAM) and D2 arc-lamps (Cathodeon)
Gas pressure 0 to ~ 2 bar (foil: 10 bar)
Gas mixing system with hot-metal gas purifiers (rare gases)
Capacitive manometers (MKS Baratron)
A. Ulrich
III. Preliminary results from air
Spectra:
Overview, 1 bar, ~12 keV electron beam excitation
Preliminary result. Needs to checked!
Assignment:
High resolution spectrum:
A. Ulrich
Bianca Keilhauer Tokyo, February 26th, 2004
Ekin (MeV) < 0.1 0.1 - 1 1 -10 10 - 100 100 -1000 > 1000
Contr. (%) 10 12 23 35 17 3
source e-- gun e- from 90Sr beam from accelerator
experiment Arqueros, Madrid, < 30 keV
Ulrich, Munich, 12 keV
Nagano, Fukui Univ.
Waldenmaier, AirLight
Gorodetzky, Paris
Colin, MacFly 1. phase
Fraga, LIP-Lisboa
Kemp, Campinas 1. phase
2. phase: medical acc. 5-12 MeV
Privitera, AIRFLY, e±-beam at BTF, 50-750 MeV
Colin, MacFly 2. ph., e±/μ-beam at CERN 25-100 GeV
Reil, Flash, e--beam at SLAC 28 GeV
Kemp, 2. ph.,
e--beam at LNLS 1.37 GeV
Electron beam Electron beam
90Sr ( 28.8y )
β 90Y ( 64.1h )
90Zr
β2.28MeV3.3MBq
average 0.85MeV
99.98% 0.02%
1.75MeV
M. Nagano
A and B of A and B of various various bands bands
TB
AY
i
ii
1
1
2
0
'
dd
1
p
TRB
h
ExE
A
where
TB
AY
Ni
i
i
i
i
ii
M. Nagano
⇒ For details: N. Sakaki --- right after this presentation
AirLight Experiment
Goals
precise measurement of the ...
→ pressure dependence
→ temperature dependence
→ effect of water vapor
→ effect of oxygen and argon
Filters [nm]: 317, 340, 360, 380, 394, 430, M-UG6
T. Waldenmaier
S. Klepser
Interference Filters Theory
→ CWL of filters should be 1-2 nm above the observed wavelength.
Effective Transmission Curves
→ „Effective Transmission Curve“ for every Filter can be averaged.
Rel. Error using 0°-Transmission > 20 %
Rel. Error using eff. Transmission < 7 %
Probes (T, P)
Gaz injection
“integral”PMT
(PMT #2)Plastic scintillator
Focusing lens Spectrometer
Source : 90Sr
Fluorescencezone
Scintillator PMT(PMT #1)
Spectrometer PMT(PMT #3)
Source holder
Bench Diagram
• PMT #1 below measures the 90Sr spectrum generates gates
• PMT #2 integral EUSO configuration [300- 400 nm] wavelength
• PMT #3 in spectrometer 1nm bandwidth
G. Lefeuvre
Air light 03
Macfly specificities
Key point:Real electromagnetic shower study
Shower = Σ component
electrons ??
Study of new dependencies :• Composition and contaminant (Macfly 1) Mainly : O2 Percentage and Humidity• Shower Age (Macfly 2)
Event by event measurement: Low electron density like in air shower.
P. Colin
Results : primary scintillation of N2
P = 105 Pa; T = 296 K; = 9 nm
280 300 320 340 360 380 400 420
0
20
40
60
80
100 Bunner 64
(nm)
0
20
40
60
80
100 present
Irel
h)''v,B(N)'v,C(N g3*
2A
u3*
2'v2nd pos. system
H. Brunet, PhD thesis, UPS, Toulouse, 1973; (2.8 MeV)
M. Fraga
Quenching by water vapor:
% H 2 O Y 0 0
0 10 . 5 0 . 9 7
1 0 . 9 42 0 . 8 83 0 . 8 3
0-0 band intensity decreases with increasing concentration of water vapor.
Atmospheric pressure was assumed.
M. Fraga
Plans for the future
• Measurement of band intensities of the 2nd positive system as a function of pressure and temperature;
• Study of the role of water vapor on the light yields and on the emission spectra.
• Participation in the tests at CERN in the SPS beam facility - proposal submitted by the Annecy group (Ref:MacFly-MEMO-01 of 11/24/2003)
Chamber Configurations
fo to m ultip lic a d o ra
fo to m ultip lic a d o ra
100 ,0 m m 75,0 m m
12,5 m m
10,0 m m 60,0 m m
fotomultiplicadora
fotomultiplicadora
fonteradioativa
e-
detector departículas
• Radioactive Source
• Particle Beam
e-
E. Kemp
Relative EfficiencyGas Filling: Dry Air → N2
Yi = NE / NP
•NE : coincidence excesses
•NP : particle detector counting
•i : gas type
Yair
YN2
YN2 / Yair= 5.1± 0.3
Kakimoto et al. , NIM 372A, 527 (1996)
~ 5.6
E. Kemp
Bianca Keilhauer Tokyo, February 26th, 2004
Ekin (MeV) < 0.1 0.1 - 1 1 -10 10 - 100 100 -1000 > 1000
Contr. (%) 10 12 23 35 17 3
source e-- gun e- from 90Sr beam from accelerator
experiment Arqueros, Madrid, < 30 keV
Ulrich, Munich, 12 keV
Nagano, Fukui Univ.
Waldenmaier, AirLight
Gorodetzky, Paris
Colin, MacFly 1. phase
Fraga, LIP-Lisboa
Kemp, Campinas 1. phase
2. phase: medical acc. 5-12 MeV
Privitera, AIRFLY, e±-beam at BTF, 50-750 MeV
Colin, MacFly 2. ph., e±/μ-beam at CERN 25-100 GeV
Reil, Flash, e--beam at SLAC 28 GeV
Kemp, 2. ph.,
e--beam at LNLS 1.37 GeV
Beam monitoring with the calorimeter
Calorimeter counts single electrons
1 e-
2 e-
3 e- 4 e-
pedest.
The calorimeter is used for absolute and relative beam intensity measurement (<1000 e-/bunch)
ADC counts
Time*24 (s)
P. Privitera
Energy dependence of fluorescence yield
Limited by multiple scattering on 1.5 mm thick exit Al window. The scan went down to 50 MeV.
PreliminaryNp.e.(fluor.)
ADCcal x E/442
UG6 filterThe scan was performed several times with consistent results.
Positrons (493 MeV) gave same yield within 3%
P. Privitera
Air light 03
CERN Beam simulation
CERN-SPS-X5 : 50 GeV electron beam
Macfly1 Macfly2
100 e- of 50 GeVOnly 1 e- of 50 GeV
ElectronsPositrons
P. Colin
⇒ For details: J.N. Matthews --- right after the coffee break
K. Reil
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
Bianca Keilhauer Tokyo, February 26th, 2004
• Exchange of already existing theoretical knowledge
• Exchange of practical solutions for experiment „everyday life“
• Fruitful discussion, even during night in the cellar
• Setup of an exchange platform on internet currently under construction
http://www.auger.de/events/air-light-03/