Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Bianca KeilhauerTokyo, February 26th, 2004...

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/




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


• 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


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


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


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


Ekin (MeV) < 0.1 0.1 - 1 1 -10 10 - 100 100 -1000 > 1000

Contr. (%) 10 12 23 35 17 3




Nagano, Fukui Univ.


Gorodetzky, Paris


Fraga, LIP-Lisboa






Kemp, 2. ph.,


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


Ekin (MeV) < 0.1 0.1 - 1 1 -10 10 - 100 100 -1000 > 1000

Contr. (%) 10 12 23 35 17 3




Nagano, Fukui Univ.


Gorodetzky, Paris


Fraga, LIP-Lisboa






Kemp, 2. ph.,


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



• 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/

Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Bianca KeilhauerTokyo, February 26th, 2004...

Documents

Transcript of Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Bianca KeilhauerTokyo, February 26th, 2004...