pascal sortais – isn/ssi - les arcs, march 17-22, 2003 1 cw input of ri a new prototype of super...
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Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 1
CW input of RI
A new prototype of super buncher for
RI~ 100 % efficiencyNo energy dispersion
Valve as rapid as possible
Beta- beam facility(not visible on the
picture)
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 2
ECR technique for RIB production
1 – « Slow ionization » Low density / long confinement / slow rising time /
1+ ionization / charge breeding / bunching / high efficiency
2 – « Rapid ionization »
Higher density / shorter confinement / faster rising time
High current / short pulsed development
3 – « Super bunching and ionization efficiency »
With very high density plasma,
is an « ECR-Duoplasmatron » possible ?
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 3
Ion production of gaseous elementor metallic ion inside a very high temperature cavity
To pumpi.e. defined by the
conductance of the extraction hole
Dominant if
ioni >> ext
To beami.e. defined by the « ionic pumping »
of the plasmaDominant if
ioni ext
1+
recycling
Target Ion source
plasma
Atoms diffusion in molecular regime
Ionization and diffusion in a magnetized plasma
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 4
Ionization time and mean free path of ionization
ext 1-3 mm
A°A+
ioni
ne , Te
some cm
ioni =vTi
nee< ioni ve
>Ti = 1/10 eV VTi = 7 104 cm/sTe = 50 eV VTe = 4 106 cm/s
ioni 2 10-16 cm-2 (from 0+ to Ar+)< ioni ve > 10-7 cm3/s
ioni = 0.7 cm at ne 1012 cm-3 10 GHz
7 cm at ne 1011 cm-3 2.45 GHz
0.07 cm at ne 1013 cm-3 28 GHz
ioni = 1 µs
10 µs
0.1 µs
100 % efficiency and rapid ionization only if ioni < ext so ne > 1013 e/cm-3
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 5
1+ ionization of ions with ECR ion sourceFrom Fredrik Wenander, Jacques Lettry, Nicolas Chritin, Ermanno Barbero, W. Pirkl, ISOLDE, CERN and G. Gaubert, P. Jardin, R. Leroy, et al., GANIL, Caen
GANIL / Picogan 10 GHz the smallest ECRIS : L, 3 cm
GANIL / ISOLDE MONOECRIS 1+
2.45 GHz
release (50%)
He ~ 20% 20 ms
Ne ~ 35 % 30 ms
Ar ~ 95% 40 ms
Kr ~ 95% 40 ms
( Ar ) ~ 70%
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 6
ECR Charge breeding for CW operation
n+ Faraday Cup
1+ Faraday Cup
1+ source
n+ spectrometer
1+ spectrometer
Vertical pulsation
Double Einzellens
PHOENIX Booster
Direct injection of atoms(gaseous ions only)simple confinement
Direct injection of 1+ beams(gaseous or metallic ions)sophisticated confinement
Ne1+ Ne6+ 10 %
release tens of ms
Ne1+ Ne6+ 10 %
release tens of ms
Release : i .e. recycling + magnetic trapping
PHOENIX – ISN/SSI
GANIL Nanogan /SPIRAL
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 7
ECRIT charge breeding and bunchingFrom : T. Lamy et al., Institut des Sciences Nucléaires UJF-IN2P3-CNRS, Grenoble, France
R.F. Power
Rb1+ Injection
Rbn+ Extracted
tH.F.
OFF
ON
t
tinj
OFF
ON
t H.F. 300 ms to 2 s
t inj 20 ms to t H.F.
t 0 to 1.5 s
Standard Values :
1+15+ = 2.2 % (Rb ions) i.e. half of the CW
1 - Efficiency measurement of afterglow process
2 - Promizing results for ms and more, bunches of metallic ions
3 - Afterglow time difficult to control
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 8
CERN duoplasmatron for H+ productionthe perfect time structure for the synchrotrons
Very good time structure
Very short confinement (some µs)
Very poor gas efficiency
µs
mA
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 9
PHOENIX 28 GHz : high current extraction (Xenon)From : T. Thuillier et al., Institut des Sciences Nucléaires UJF-IN2P3-CNRS, Grenoble, France
Xe17+ beam
Xe18+ beam
3D field map of thesolenoid
3D source extraction fieldand magnetic fringe field
of the source
15 emA (IHV)
12.5 emA (IFC1)
10.4 emA (Xe20+ 0.6 emA)
35 mm Faraday Cup
3D field map of the90° Bending magnet
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 10
PHOENIX 28 GHz : high current extraction (Lead)From : T. Thuillier et al., Institut des Sciences Nucléaires UJF-IN2P3-CNRS, Grenoble, France
10 emA total current(preliminary)
300 µs pulse
Shorter and higher afterglowthan with ECR4-14.5 GHz CERN
7 ( 10 ?)
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 11
28 GHz experiment at grenoble ISN/SSIFrom : T. Thuillier et al., Institut des Sciences Nucléaires UJF-IN2P3-CNRS, Grenoble, France
The new (and stable) 28 GHz /10 KW ISN gyrotron from GYCOM Inc. (Nizhny Novgorod , Russia)
1 – Proof of the high frequency / high density effect
2 – Emittance and efficiency to be measured
3 - Afterglow shorter but always difficult to control (0.3-1 ms)
28 GHz /10 KWPHOENIX 28 GHz
5 µs shutdown of the full power
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 12
SMIS 37.5 GHz with optical couplingfor very high intensity pulsed current
From : S.V. Golubev, D.A. Mansfeld, S.V. Razin, V.A. Skalyga, A.V. Vodopyanov, V.G. Zorin, Institute of Applied Physics, Russian Academy of Sciences, Nizhniy Novgorod, Russia, R. Geller, T. Lamy, P. Sortais, T. Thuillier Institut des Sciences Nucléaires UJF-IN2P3-CNRS, Grenoble, France
Optical coupling of the UHF power :
up to 100 KW / 1 ms each 20 s
Very simplemagnetic system
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 13
SMIS 37.5 GHz very high current density production
From : S.V. Golubev, D.A. Mansfeld, S.V. Razin, V.A. Skalyga, A.V. Vodopyanov, V.G. Zorin, Institute of Applied Physics, Russian Academy of Sciences, Nizhniy Novgorod, Russia, R. Geller, T. Lamy, P. Sortais, T. Thuillier Institut des Sciences Nucléaires UJF-IN2P3-CNRS, Grenoble, France30 emA / 3 mm total
current200-300 mAe/cm2
1013 part. during 100 µs with Multi Charged Ions
Rising time 100 µs
To be done : beam matching (100 KV duoplasmatron extractor) efficiency measurement with pulsed valve upgrade to 60 or 90 GHz with pulsed or SC coils possible
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 14
1 – To bunch the gas in short time
~ > 20 µs
2 – To ionize (>1+) with a time smaller than the effusion time
ne 1014 e/cm-3 60 GHz ECR discharge
+ strong axial magnetic field during the discharge ( 2T)
3 – To deliver a beam with a repetition rate compatible
with the lifetime of the ions
60-90 GHz « ECR Duoplasmatron » for gaseous RIB
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 15
60-90 GHz « ECR Duoplasmatron » for gaseous RIB
Very high densitymagnetized plasma
ne ~ 1014 cm-3
2.0 – 3.0 T pulsed coils or SC coils
60-90 GHz / 10-100 KW10 –200 µs / = 6-3 mm
optical axial coupling
optical radial coupling(if gas only)
1-3 mm100 KV
extractionUHF windowor « glass » chamber (?)
Target
Rapid pulsed valve
20 – 100 µs20 – 200 mA
1012 to 1013 ions per bunchwith high efficiency
Very small plasmachamber ~ 20 mm / L ~ 5 cm
Arbitrary distanceif gas
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 16
PHOENIX 28 GHz : afterglow control with Lead
a.u.
10 ms
0 ms
UHF pulse
Pb 25+,24+,23+,22+
O+O2+O3+O4+ C+ N+
Pb 16+ Pb 14+
“pre – glow” bunch correlated with presure dropIonic pumping during some hundreds of µs
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 17
New RFQ
LINAC 3
PSB
Simplification of the injection system
Pascal Sortais – ISN/SSI - Les Arcs, March 17-22, 2003 18
Rapid ionization of RIB : future prospects
1 – ECRIS can supply either efficiency or pulsed currents
ECRIS must supply efficiency AND pulsed currents
2 – 28 GHz / 10 KW preliminary tests could be done at ISN
3 – Possible extension to RIB of condensable elements and upgrade of the other metallic ion stable beams (Pb)
next step of PHOENIX development
4 – Never start an heavy ion project without a strong preliminary ion source development program !