Development of a new approach to measure isotropic magnetic

Zeeman spectroscopy measurements for
aluminum ablated plasma in external
magnetic field
S. Tessarin, E. Stambulchik, D. Mikitchuk, R. Doron, E.
Kroupp, Y. Maron
Physics Department, Weizmann
Institute of Science, 76100
Rehovot
S. Tessarin
Weizamann Institute of Science
Zeeman spectroscopy measurements for aluminum ablated plasma in external magnetic field
Campi magnetici impulsati e diagnostica del plasma
Campi Magnetici & diagnostica del plasma
Determinazione del campo magnetico in un plasma
quando il pattern Zeeman e’ oscurato da altri effetti
(Stark, Doppler, instrumental).
Diagnostica di un plasma prodotto tramite un laser
impulsato caratterizzato da alte velocita’ ioniche.
Doppietto del Al III 4p-4s transizione 5696-5722 Å
in presenza di un intenso campo magnetico.
S. Tessarin
Weizamann Institute of Science
Zeeman spectroscopy measurements for aluminum ablated plasma in external magnetic field
Campi magnetici impulsati e diagnostica del plasma
Effetto Zeeman

B≠0
3/2
1/2
-1/2
-3/2
1/2
-1/2
π
σ+
σ−
±
π ,σ
0.12
±
B=17 T
0.10
0.08
0.06
0.04
1/2
-1/2
∆M = 0, ±1
σ

B = 17T
0.02
0.00
-60
-40
-20
0
20
∆ν cm-1
40
60
∆E = µ B ∆( Mg ) B
S. Tessarin
Weizamann Institute of Science
Zeeman spectroscopy measurements for aluminum ablated plasma in external magnetic field
Campi magnetici impulsati e diagnostica del plasma
Generatore induttivo + POS
I=160kA
Rise
Time=100ns
Line-of
sight=5mm
B=0.9 T
Ne=1016 cm-3
Te=5-10 eV
S. Tessarin
Weizamann Institute of Science
Zeeman spectroscopy measurements for aluminum ablated plasma in external magnetic field
Set-up sperimentale costruito nel 2007-2009
Generatore capacitivo CS
Linea di Trasmissione.
• Condensatori 4- µ F
• V=20-kV
• I di picco= 270 kA
@ 20kV
Periodo ad ¼ d’onda = 1.65 µs.
3x105
2x105
1
Current (A)
1x10
0
0
-1x105
dI/dt (A. U.)
5
-1
-2x105
-3x105
0.0
2.0x10-6
4.0x10-6
Time [s]
S. Tessarin
Weizamann Institute of Science
Zeeman spectroscopy measurements for aluminum ablated plasma in external magnetic field
Set-up sperimentale costruito nel 2007-2009
Linea di Trasmissione magneticamente isolata
Bersaglio di
Al
S. Tessarin
Weizamann Institute of Science
Zeeman spectroscopy measurements for aluminum ablated plasma in external magnetic field
Set-up sperimentale costruito nel 2007-2009
Nd-Yag II
Harmonic Continiuum
Surelite
PBS
WP
F=250mm
D=100mm
ICCD
1m Mono
chromator
BD
F=450mm
D=25mm
Current
I Monitor
PMT
B
I
Ground -Plate
HV -Plate
S. Tessarin
Weizamann Institute of Science
Zeeman spectroscopy measurements for aluminum ablated plasma in external magnetic field
Spettri di emissione
Distance form the target [mm]
Campo Magnetico vs t e distanza dal catodo
3.0
7.0
10.5
2.5
10.5
2.0
1.5
1.0
7.0
7.0
@ 1.5 mm
14.0
7.0
0.5
17.5
21.0
10.5
14.0
17.5
0.0
Current [A]
3x105
2x105
B=14.7 T
1x105
0
-1x105
-2x105
-3x105
0.00
1.50x10-6 3.00x10-6 4.50x10-6 6.00x10-6
1.60 µs
Time [s]
S. Tessarin
Weizamann Institute of Science
Zeeman spectroscopy measurements for aluminum ablated plasma in external magnetic field
Spettri di emissione
Fit dello spettro di emissione
S. Tessarin
Weizamann Institute of Science
Zeeman spectroscopy measurements for aluminum ablated plasma in external magnetic field
Spettri di emissione
Distance form the target [mm]
Campo Magnetico vs t e distanza dal catodo
3.0
7.0
10.5
2.5
10.5
2.0
1.5
1.0
7.0
7.0
14.0
7.0
0.5
17.5
21.0
@ 1 mm
10.5
14.0
17.5
0.0
Current [A]
3x105
B=17.4 T
2x105
1x105
0
-1x105
-2x105
-3x105
0.00
1.50x10-6 3.00x10-6 4.50x10-6 6.00x10-6
1.60 µs
Time [s]
S. Tessarin
Weizamann Institute of Science
Zeeman spectroscopy measurements for aluminum ablated plasma in external magnetic field
Spettri di emissione
@ 1 mm
S. Tessarin
Weizamann Institute of Science
Zeeman spectroscopy measurements for aluminum ablated plasma in external magnetic field
Spettri di emissione
@ 1 mm, Laser al valore di soglia
S. Tessarin
Weizamann Institute of Science
Zeeman spectroscopy measurements for aluminum ablated plasma in external magnetic field
TOF/ Conclusioni
TOF Al III 5696 Å
(V) Voltage PMT
(a)
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
Espansione Libera
1 mm
2 mm
3 mm
4 mm
5 mm
0.0
1.0x10-7
2.0x10-7
3.0x10-7
4.0x10-7
5.0x10-7
Time (s)
(b)
1mm (17 T)
2mm (13 T)
3mm (11 T)
4mm (9 T)
5mm (7 T)
(V) Voltage PMT
2.0
1.5
1.0
0.5
0.0
0.0
1.0x10-7
2.0x10-7
3.0x10-7
4.0x10-7
5.0x10-7
Espansione in
presenza
del campo
magnetico
Time [s]
S. Tessarin
Weizamann Institute of Science
Zeeman spectroscopy measurements for aluminum ablated plasma in external magnetic field
TOF/ Conclusioni
Separazione del Plasma
Plasma plume
I
PMT Signal 5969 Al III line
Current Monitor
Laser Monitor
Normalised Signal
Normalised Intesity
ΔL=2.65 µs
4.25 mm
0.7
0.0
-6
2.8x10
-6
3.0x10
-6
3.2x10
Time [s]
-6
3.4x10
-6
3.6x10
PMT signal from Al II 5593 A
Current Monitor
Laser Monitor
1.0
0.5
0.0
2.7x10-6 3.0x10-6 3.3x10-6 3.6x10-6 3.9x10-6
Time [s]
S. Tessarin
Weizamann Institute of Science
Zeeman spectroscopy measurements for aluminum ablated plasma in external magnetic field
TOF/ Conclusioni
Conclusioni
• La velocita’ degli ioni di Al III e’ ridotta sia nella fase
di espansione isotermica che in quella adiabatica.
• Il campo magnetico e’ stato misurato dalle righe
spettrali dell’Al III in un plasma con densita’
elettronica di circa 1018 cm-3.
• Insieme alla misura del campo magnetico si e’ ottenuto il
valore della densita’ elettronica.
• Separazione del plasma in due strutture durante
l’espansione adiabatica.
S. Tessarin
Weizamann Institute of Science
Zeeman spectroscopy measurements for aluminum ablated plasma in external magnetic field