Cavity Ring Down Spectroscopy (CRDS) is used to measure the D absolute density produced in the helicon plasma reactor RAID (Resonant Antenna Ion Device) at the Swiss Plasma Center. The birdcage geometry of the helicon antenna produces a homogeneous, high-density plasma column (ne ≅ 1.5 × 1018 m−3 in H2 and D2 at 0.3 Pa and 3 kW of input power) 1.4 m long. We present the CRDS experimental setup, its positioning on the RAID reactor, and how the mechanical and thermal effects of the plasma affect the measurement. First results in deuterium plasma confirm the production of negative ions (D) with a significant density: an average value of 3.0 × 1016 m−3 of D is obtained at 0.3 Pa and 5 kW of power input in Cs-free plasma. This result is in good agreement with calculations performed with the collisional radiative code YACORA.

1.
P.
Sonato
,
P.
Agostinetti
,
T.
Bolzonella
,
F.
Cismondi
,
U.
Fantz
,
A.
Fassina
,
T.
Franke
,
I.
Furno
,
C.
Hopf
, and
I.
Jenkins
,
Nucl. Fusion
57
,
056026
(
2017
).
2.
U.
Fantz
,
C.
Hopf
,
D.
Wünderlich
,
R.
Friedl
,
M.
Fröschle
,
B.
Heinemann
,
W.
Kraus
,
U.
Kurutz
,
R.
Nocentini
, and
L.
Schiesko
,
Nucl. Fusion
57
,
116007
(
2017
).
3.
A.
Simonin
,
R.
Agnello
,
S.
Bechu
,
J. M.
Bernard
,
C.
Blondel
,
J. P.
Boeuf
,
D.
Bresteau
,
G.
Cartry
,
W.
Chaibi
, and
C.
Drag
,
New J. Phys.
18
,
125005
(
2017
).
4.
S.
Briefi
and
U.
Fantz
,
AIP Conf. Proc.
1515
,
278
(
2013
).
5.
I.
Furno
,
R.
Agnello
,
U.
Fantz
,
A. A.
Howling
,
R.
Jacquier
,
C.
Marini
,
G.
Plyushchev
,
Ph.
Guittienne
, and
A.
Simonin
,
EPJ Web Conf.
157
,
03014
(
2017
).
6.
P.
Guittienne
and
E.
Chavalier
,
J. Appl. Phys.
98
,
083304
(
2005
).
7.
C.
Marini
,
R.
Agnello
,
B. P.
Duval
,
I.
Furno
,
A. A.
Howling
,
R.
Jacquier
,
A. N.
Karpushov
,
G.
Plyushchev
,
K.
Verhaegh
, and
Ph.
Guittienne
,
Nucl. Fusion
57
,
036024
(
2017
).
8.
D.
Wünderlich
,
S.
Dietrich
, and
U.
Fantz
,
J. Quant. Spectrosc. Radiat. Transfer
110
,
62
71
(
2009
).
9.
M.
Bacal
,
Rev. Sci. Instrum.
71
,
3981
(
2000
).
10.
F.
Grangeon
,
C.
Monard
,
J. L.
Dorier
,
A. A.
Howling
,
Ch.
Hollenstein
,
D.
Romanini
, and
N.
Sadeghi
,
Plasma Sources Sci. Technol.
8
,
448
(
1999
).
11.
J.
Santoso
,
R.
Manoharan
,
S.
O’Byrne
, and
C. S.
Corr
,
Phys. Plasmas
22
,
093513
(
2015
).
12.
H.
Nakano
,
K.
Tsumori
,
M.
Shibuya
,
S.
Geng
.
M.
Kisaki
,
K.
Ikeda
,
K.
Nagaoka
,
M.
Osakabe
,
Y.
Takeiri
, and
O.
Kaneko
, in
17th International Symposium on Laser-Aided Plasma Diagnostics
(
IOP Publishing
,
2015
), p.
3
.
13.
M.
Berger
,
U.
Fantz
,
S.
Christ-Koch
, and
NNBI Team
,
Plasma Sources Sci. Technol.
18
,
025004
(
2009
).
14.
S.
Cristofaro
,
R.
Friedl
, and
U.
Fantz
,
AIP Conf. Proc.
1869
,
030036
(
2017
).
15.
A.
O’Keefe
and
D. G.
Deacon
,
Rev. Sci. Instrum.
59
,
2544
(
1988
).
16.
R.
Pasqualotto
,
A.
Alfier
, and
L.
Lotto
,
Rev. Sci. Instrum.
81
,
10D710
(
2010
).
17.
See https://www.layertec.com for LAYERTEC GmbH website.
18.
B. E. A.
Saleh
and
M. C.
Teich
,
Fundamentals of Photonics
(
John Wiley and Sons, Inc.
,
1991
).
19.
R.
Pasqualotto
,
P.
Nielsen
, and
L.
Giudicotti
,
Rev. Sci. Instrum.
72
(
1
),
1134
(
2001
).
20.
A.
Spyridon
, “
Experimental study of H negative ion production by electron cyclotron resonance plasmas
,” Ph.D. thesis (
Université Grenoble Alpes
,
2016
).
You do not currently have access to this content.