1. Preliminary experimental results
Universidad de Córdoba
Preliminary experimental results
on the QL-lamp fed
by 2.45 GHz microwave power
Antonio Gamero
Department of Physics,
University of Cordoba,
Spain.

2. Contents - Studies of HF discharges at the University of Cordoba
UNIVERSIDAD DE
CÓRDOBA
Contents
- Studies of HF discharges at the University of Cordoba
- HF Discharges as Light Sources. Microwave-fed QL-lamp
Spectroscopic measurements
Radiometric measurements
Surface wave in coaxial structure
Conclusion / Future
Eindhoven University of Technology (Netherlands)
J.J.A.M. van der Mullen
University of Granada (Spain)
M. Rubiño, Y. Yebra and M.M. Pérez
LPGIP. Université Paris-Sud (Orsay, France)
C. Boisse-Laporte

3. Group of HF Discharges :
Departamento de Física
UNIVERSIDAD DE
CÓRDOBA
Group of HF Discharges :
Dr. Carlos Lao
Dr. M. Carmen Quintero
Dr. Antonio Rodero
Dr. Antonio Sola
Dr. Antonio Gamero
Ph. Students:
Olga Carabaño
Manuel Fernández
José Mª Palomares
Sebastián Rubio
Jesús Torres

4. Group of HF Discharges :
UNIVERSIDAD DE
CÓRDOBA
Departamento de Física
Group of HF Discharges :
Surface Wave Discharges (SWDs)
Plasma Torches
- Coaxial Discharges
Spectroscopic Diagnostics
Excitation Source for Spectrochemical Analysis
Destruction of Volatile Organic Compounds (VOCs)
- HF Discharges as Light Sources

5. Surface wave Discharges
POWER
GENERATOR
z = 0
Surfatron
dielectric tube
waveguide
ref P
Power
meter
inc
gas
manometer
pump
stubs
plasma
Microwave frequency: GHz
Microwave power: up to 200 W
(1500 W)
Gas: Ar, He
Pressure: mTorr – 1 atm

6. Microwave Plasma Produced by the Axial Injection Torch (TIA)
TIA (Torch á Injection Axiale)
noozle
tuneable
coaxial
plunger
gas
flame
WR-340
waveguide
z=10-12 mm
f= 2.45 GHz
Characteristics
Microwave power range: W
Length: mm
Diameter: mm
Gas flow rate range: L min-1

7. Spectroscopic Diagnostics
- Atomic Emission Spectroscopy
Molecular Emission Spectroscopy
Atomic State Distribution Function (ASDF)  Departure from LTE

8. Destruction of Volatile Organic Compounds (VOCs)
by using microwave plasma produced
by the Axial Injection Torch (TIA)
Reactor
Microwave Generator
Reactor
Gas Chromatograph
Computer
Plasma torch He
0,5% TCE
99,5% He
TCE = trichloroethylene
Destruction and Removal Efficiency (DRE ) > %

9. HF Discharges as Light Sources. Microwave-fed QL-lamp
(low-pressure argon, 2.45 GHz)
The QL-lamp from Philips, at 2.65 MHz
(commercialized since 1992)
Experimental version :
Argon filled pressure: 66, 133 Pa.
Amalgam: Bi/In/Hg in a mass ratio of 68/29/3
Acknowledgment to Dr Wim Hellebrekers (Philips Lighting)

10. QL-lamp at 2.45 GHZ Experimental Set-up Experimental version :
mercury amalgam
cavity
microwave antenna
auxiliary amalgam
Measure point:
4 mm from the inner tube
45 mm below the antenna end
Experimental version :
Argon filled pressure: 133 Pa.
Amalgam: Bi/In/Hg in a mass ratio of 68/29/3

11. Spectroscopic Experimental Set-up
Monochromator
Photomultiplier
CCD Camera
Entrance slit
Optic fibre
QL-lamp
Ribbon lamp
COMPONENTS
DESCRIPTION
Microwave generator
Microtron 200 Mark 3 (Electron Medical Supplies)
Monochromator
THR-1000 (Jobin-Ivon) 1200 grooves/mm grating
Fotomultiplier
Hamamatsu R636
QL-lamp
Experimental version. Argon filled pressure: 133 Pa Amalgam: Bi/In/Hg in a mass ratio of 68/29/3
Tungsten Ribbon Lamp
28/G/UV (Polaron Engineering Ltd.)

12. Atomic State Distribution FunctionAr Hg
effective
quantum
number

13. Atomic State Distribution FunctionAr Hg
Atomic State Distribution Function
- Excitation Saturation Balance (ESB)  x  5
ionisation processes neglected  x = 5

14. Radiometric Experimental Set-up
COMPONENTS
DESCRIPTION
Microwave generator
Microtron 200 Mark 3 (Electron Medical Supplies)
Spectroradiometer
QL-lamp
Comercial version. Argon filled pressure: 133 Pa Amalgam: Bi/In/Hg in a mass ratio of 68/29/3

15. Radiance (Wat/strd·m2)
Results
Lamp
Radiance (Wat/strd·m2)
Luminance
(Cd/m2)
x, y, z
Color Temperature
Dominant
Wavelength
Purity
Efficacy
(Lm/W)
Relative
Flux
RF 80 W
177,2
63.620
0.4138, ,
3336
583,0
46,04%
75.00
100%
µW 20 W
13,52
5.104
0.4463, ,
2973
582,0
62,78%
24.05
7,58%
µW 40 W
21,79
8.162
0.4415, ,
3017
582,1
60,25%
19.25
12,25%
µW 60 W
25,37
9.458
0.4402, ,
3030
582,2
59,59%
14.87
14,29%
µW 90 W
28,63
10.550
0.4387, ,
3037
582,4
58,24%
11.06
16,29%

16. Results
□ RF (80 W)
■ μW (90 W)
■ μW (60 W)
■ μW (40 W)
■ μW (20 W)

17. l (nm) Results Spectral radiance (watt/sr·m ) 20 W 40 W 60 W 90 W 400
500
600
700
800
200
1000
1200
1400
Spectral radiance (watt/sr·m ) 2 l
(nm)
20 W
40 W
60 W
90 W

18. m l (nm) Results ) Spectral radiance (watt/sr·m W (40 W) RF (80 W) 400
500
600
700
800 1 2 3 4 5 6 7
Spectral radiance (watt/sr·m ) l
(nm) m
W (40 W)
RF (80 W)

19. Radiance (Wat/strd·m2)
Results
Lamp
Radiance (Wat/strd·m2)
Luminance
(Cd/m2)
x, y, z
Color Temperature
Dominant
Wavelength
Purity
Efficacy
(Lm/W)
Relative
Flux
RF 80 W
177,2
63.620
0.4138, ,
3336
583,0
46,04%
75.00
100%
µW 20 W
13,52
5.104
0.4463, ,
2973
582,0
62,78%
24.05
7,58%
µW 40 W
21,79
8.162
0.4415, ,
3017
582,1
60,25%
19.25
12,25%
µW 60 W
25,37
9.458
0.4402, ,
3030
582,2
59,59%
14.87
14,29%
µW 90 W
28,63
10.550
0.4387, ,
3037
582,4
58,24%
11.06
16,29%

20. Coaxial Discharge
Discharge
Inner Conductor
Dielectric Tubes

21. Surface Wave Discharges
Coaxial structure
Plasma ep
Air
e = 1
Metallic
guide
Antenna
Dielectric tube
ev = 3.8
Antenna
R0 = 1.5 mm
Inner tube
R1 = mm
R2 = mm
Outer tube
R3 = mm
R4 = mm
Guide
R5 = mm

22. Surface Wave Propagation
mode I
mode II
_____
1/1 + v
- Radially uniform plasma
-   
Two solutions
Azimuthally symmetric modes
Er , Ez , H

23. Radial profile of the electric field Mode I
- Outside
Er > Ez
- Inside
Er < Ez
Minimum electric field exists
going to the internal tube with the ne
- Ein < Eext ne

24. Radial profile of the electric field Mode II
- Outside
Er > Ez
- Inside
Er < Ez
Minimum electric field exists
going to the external tube with the ne
- Ein ~ Eext ne

25. Conclusions / Future
It has been possible to produce a stable microwave QL-lamp at 2.45 GHz at the pressure of 1 Torr.
The microwave coupler must be improved in order to optimise the power absorbed by the plasma and so the efficiency of the lamp.
The relative importance of the both possible modes of the surface wave must be experimentally investigated under different experimental conditions.
The propagation of the surface wave in coaxial structure must be solved for different geometric dimension and for plasmas radially no uniform, looking for the best conditions of operation.
New experimental measurements must be made under these new conditions.

26. Thank you for your attention
Universidad de Córdoba
Thank you for your attention
Antonio Gamero
Department of Physics,
University of Cordoba,
Spain.

28. Lines measured Ar lines Hg lines l (nm) Ek (cm-1) gk Akj (108 s-1)
Transition
415.85
117184 5
0.0145
5p  4s
419.07
116999
419.83
117563 1
0.0276
420.06
116943 7
0.0103
425.93
118871
0.0415
427.21
117151 3
0.0084
430.01
433.35
118469
0.0060
696.54
107496
0.067
4p  4s
706.72
107290
0.0395
727.29
0.0200
738.39
0.087
750.38
108723
0.472
751.46
107054
0.430
763.51
106238
0.274
772.42
0.127
794.81
107132
0.196
800.61
0.0468
801.47
105617
0.096
810.36
106087
0.277
811.53
105463
0.366
826.45
0.168
840.82
0.244
842.46
0.233
852.14
0.147
Hg lines
l (nm)
Ek (cm-1) gk
Akj (108 s-1)
Transition
404,65
62350 3
0.21
7s  6p
407,78
63928 1
0.040
410,80
78404
0.030
9s  6p
433,92
77108 5
0.0288
7d  6p
435,83
0.557
491,60
74405
0.058
8s  6p
546,07
0.487
576,95
71396
0.236
6d  6p
690,75
76824
0.028
 8p  7s

29. Meeting in Granada (Spain), September 22-23, 2005
COST ACTION 529
“Efficient Lighting for the 21th century”
Workshop “Radiometric, photometric and color measurements of light sources and applications”
Meeting in Granada (Spain), September 22-23, 2005
“Radiometric (and spectroscopic) measurements on a low-pressure argon QL-lamp fed by
2.45 GHz microwaves” by
O. Carabaño, M. Fernández, A. Gamero and A. Sola, University of Cordoba (Spain)
M Rubiño, Y. Yebra and M.M. Pérez, University of Granada (Spain)
J.J.A.M. van der Mullen, University of Eindhoven (Netherlands)