DEVELOPMENT OF THE PHOENIX CHARGE BREEDER & LNL - …
Transcript of DEVELOPMENT OF THE PHOENIX CHARGE BREEDER & LNL - …
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
DEVELOPMENT OF THE PHOENIX CHARGE BREEDER& LNL - GANIL - LPSC COLLABORATION ON THE CONTAMINANTS REDUCTION
NACB Workshop, East Lansing, October 1st-2nd 20201
Julien ANGOT1, Alessio GALATA2, Laurent MAUNOURY3, Thomas THUILLIER1, Maud BAYLAC1, Myriam MIGLIORE1, and Patrick SOLE1
1Université Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, 38000 Grenoble, France
2INFN-Laboratori Nazionali di Legnaro, Viale dell’Università 2, 35020 Legnaro, Padova, Italy
3GANIL, bd Henri Becquerel, BP 55027, F-14076 Caen cedex 05, France
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
Outline
• Introduction
• Charge breeder R&D program
• Last results
• Future plans
• Conclusion
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LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA 3
LPSC - Grenoble –French AlpsCNRS – IN2P3
LPSC : About 200 peopleCyclotron accelerator stopped in 1998Groups still remain : Electronics, Detectors, Accelerators + Ion sources
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
Accelerators + ion sources group
➢ Head is Maud Baylac
➢ About 16 people
➢ 4 working for the ion sources development, mainly ECR ion sources
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XSCOMIC
Gradient2.45 GHz1+ ions
e-
SSUPERCOMIC
Min B5.8 GHz1+ ions
Low CS ions
LPHOENIX V3
Min B18 GHz
HCS ions
GENESIS(LPSC neutron
platform)
XLSEISM
Cusp Min B60 GHz
High intensity
Developped for SPIRAL 2 (GANIL)
Developped for R&D on ECR ion sources
6 cm 30 cm
•1+ source• Industry
100 cm
60 cm
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
Accelerators + ion sources group
➢ Head is Maud Baylac
➢ About 16 people
➢ 4 working for the ion sources development, mainly ECR ion sources
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XSCOMIC
Gradient2.45 GHz1+ ions
e-
SSUPERCOMIC
Min B5.8 GHz1+ ions
Low CS ions
LPHOENIX V3
Min B18 GHz
HCS ions
GENESIS(LPSC neutron
platform)
XLSEISM
Cusp Min B60 GHz
High intensity
Developped for SPIRAL 2 (GANIL)
Developped for R&D on ECR ion sources
6 cm 30 cm
•1+ source• Industry
100 cm
Charge breeder
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
CB : principle and features
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Hexapole : Br 0.8T at plasma chamber wallAxial field
14.5 GHz 600W
Injection optics
Total efficiency (low charge states excluded): 50 – 60%Efficiency / one charge state: 5 - 20%CB time : 5 – 20 ms/qOptimum charge state : A/q~3 up to A=50
A/q~5 up to A=150… contamination yield
Extraction optics
0.8 T
1.6 T
0.4 T+
+
+
PHOENIX Charge breeder
Operation at 20 kV
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
CB : principle and caracteristics
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➢ Signal to noise ratio is a key parameter for ECRIS CB at low RIB intensity
14 GHz ECR
Itotal~1 mA(~1015 − 1016 pps)
Buffer gas~1016 𝑝𝑝𝑠
Wall sputtering~109 − 1010 𝑝𝑝𝑠
Plasma intercepts the wall
1+ signal 𝒖𝒑 𝒕𝒐 𝟏𝟎𝟏𝟑 𝒑𝒑𝒔
N+ signal
contaminants
Gases contaminants~109 − 1013 𝑝𝑝𝑠Leaks, O-rings permeation,Buffer gas contaminantsWall outgassing
A/q
m/Δm =300
m/Δm =6000
Resolving power of downstream separator :
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
1+N+ Test bench
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Charge breeder
Ion gun
Comic
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA 9
LNL LPSC GANIL Collaboration
➢ LNL GANIL and LPSC use PHOENIX charge breeders with close configuration
➢ Contaminants reduction is a key point for SPES and SPIRAL1 regarding :
▪ Production yields (102 to 1010)
▪ Resolving power of downstream separators
▪ For the facility tuning (blind tuning)
➢ LNL LPSC and GANIL decided to collaborate on the contaminants reduction
▪ Starting point in 2018 : research collaboration agreement signed between LNL and LPSC
➢ Work on the reduction of all the contaminants sources
Taking advantage of the pionneering work done at ANL
▪ Vacuum
▪ Plasma chamber wall sputtering
▪ Gas contaminants
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
LPSC Charge breeder development plan
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✓ 1+N+ beamline upgrade
✓ Validation experiments
✓ Contaminants preliminaryexperiments
Charge Breeder5 coil config
1+n+ Performances
check
Contaminants reduction
experiments : liners
09/2018 10/2020 10/2022
Charge BreederEnlarged plasma chamber config
1+n+ Performances
check
Contaminants reduction
experiments
✓ Charge Breeder6 coil config
✓ 1+n+ Performances
check
✓ Configuration developped until now
• Improve axial field profile• Decrease coils cross talk• Improve beam injection
and extraction
• Improve high charge state production
• Reduce the contaminants proportion
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
LPSC Charge breeder development plan
11
✓ 1+N+ beamline upgrade
✓ Validation experiments
✓ Contaminants preliminaryexperiments
Charge Breeder5 coil config
1+n+ Performances
check
Contaminants reduction
experiments : liners
09/2018 10/2020 10/2022
Charge BreederEnlarged plasma chamber config
1+n+ Performances
check
Contaminants reduction
experiments
✓ Charge Breeder6 coil config
✓ 1+n+ Performances
check
✓ Configuration developped until now
• Improve axial field profile• Decrease coils cross talk• Improve beam injection
and extraction
• Improve high charge state production
• Reduce the contaminants proportion
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
LPSC Charge breeder development plan
12
✓ 1+N+ beamline upgrade
✓ Validation experiments
✓ Contaminants preliminaryexperiments
Charge Breeder5 coil config
1+n+ Performances
check
Contaminants reduction
experiments : liners
09/2018 10/2020 10/2022
Charge BreederEnlarged plasma chamber config
1+n+ Performances
check
Contaminants reduction
experiments
✓ Charge Breeder6 coil config
✓ 1+n+ Performances
check
✓ Configuration developped until now
• Improve axial field profile• Decrease coils cross talk• Improve beam injection
and extraction
• Improve high charge state production
• Reduce the contaminants proportion
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA 13
LPSC CB last developments➢ Modification of the injection optics
➢ Increase of injection axial B field
➢ Fine tuning of the soft iron rings position
➢ Extraction optics
400 200 0 200 400
0.0
0.5
1.0
1.5
Z mm
Bz T
X 0 mm , Y 0 mm
ICIS 2017 proceedings :“Recent improvements of the LPSC chargebreeder”, AIP Conference Proceedings 2011, 070005 (2018)
Bz (T)
z (mm)
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA 14
LPSC CB last developments
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
LPSC Charge breeder development plan
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✓ 1+N+ beamline upgrade
✓ Validation experiments
✓ Contaminants preliminaryexperiments
Charge Breeder5 coil config
1+n+ Performances
check
Contaminants reduction
experiments : liners
09/2018 10/2020 10/2022
Charge BreederEnlarged plasma chamber config
1+n+ Performances
check
Contaminants reduction
experiments
✓ Charge Breeder6 coil config
✓ 1+n+ Performances
check
✓ Configuration developped until now
• Improve axial field profile• Decrease coils cross talk• Improve beam injection
and extraction
• Improve high charge state production
• Reduce the contaminants proportion
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
1+N+ Beam line upgrade
➢ Goal : improve the vacuum and the devices alignment
➢ Starting situation : the 1+N+ beam line was assembled in 2002.
▪ Pollution with pumping oil vapors
▪ Aged pumping system (50 years turbo pumps)
▪ Most of sealing by O-rings
▪ Alignment was very difficult
➢ The whole beam line was dismounted
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LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
1+N+ Beam line upgrade
➢ All the vacuum chambers were modified or replaced to be UHV compatible
➢ Injection and extraction lenses replaced
➢ Diagnostics were replaced to be UHV
➢ 1+ and N+ spectrometers modified to grant alignment
➢ Cleaning
➢ Assembly
➢ Alignment
➢ Set under vacuum :
~5 10-7 mbar ➔ ~ 4 10-8 mbar dividing by 2 the number of turbo pumps
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LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
Validation experiments after upgrade
➢ Check of the performances with K charge breeding
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➢ Comparable distribution using He as support gas
lower capture and distribution slightly shifted on lower CS now
➔ incomplete conditioning ?
➢ High efficiency (17.9% K9+) obtained with H2
Bz 1.57/0.44/0.83T Br 0.8T
400W Pinj 4.4 10-7 mbar
O+ 4.8 µA N+ 1.65µA C+ 1.52 µA
Bz 1.57/0.45/0.85T Br 0.8T
500W Pinj 9.3 10-8 mbar
O+ 5.1 µA N+ 2.9µA C+ 1.15 µA
Bz 1.58/0.45/0.84T Br 0.8T
600W Pinj 1.4 10-7 mbar
N+ 0.3µA C+ 0.7 µA
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
Contaminants preliminary experiments➢ Technique to measure the contaminants spectrum
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Faraday cup
Allison type emittance scanner
Selection with 0.2 mm slits
➢ Provides higher resolution spectrum
… cutting the beams
➢ Relative measurements comparison
FC
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
Contaminants preliminary experiments
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➢ This technique was used to make comparative measurements :
▪ With several support gas (effect of the support gas mass) : H2 He N2 O2
▪ At several CB microwave power 100, 300, 450, 600W
➢ The CB was tuned (Axial B field and support gas dosing) to maximizethe 1+N+ K10+ efficiency, at 600W, with each support gas
➢ Record of the spectrums in the FC and in the emittance scanner at eachmicrowave power
With H2 in the emittance scanner
➢ Able to measure peaks down to 100 pA
➢ Dips in the spectrum
➢ A/q list of all the contaminant peaks
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
➢ Gas contaminants (CANgas® MESSER)
▪ H2 99.999% (H2O<5ppm, O2<1ppm, N2<5ppm, Hydrocarbon <0.1ppm,
CO +CO2<0.1ppm)
▪ He 99.999% (H2O<20ppm, O2< 1 ppm, N2 < 4 ppm, Hydrocarbon < 0.2 ppm)
▪ N2 99.999% (H2O<3ppm, O2<2ppm, Hydrocarbon <0.1ppm)
▪ O2 99.999% (H2O<2ppm, N2<20ppm, Hydrocarbon <0.2ppm, CO+CO2<0.4ppm)
Contaminants preliminary experiments➢ Present configuration of the plasma chamber
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➢ list of all the contaminants including isotopes
➢ Comparison with the spectrum peaks list
Plasma chamber : 304L SS (Fe, Cr, Ni, Mn, Si, N, P…)
Injection plug:Fe with Ni and Agplating
Waveguide : Brass (Cu, Zn, Pb, Sn ...)
Extraction electrode : 2017A (Al, Cu, Mg…)
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
Contaminants preliminary experiments
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contaminants A/q peak value List of most probable isotopes
➢ Metallic ions coming from the material sputtering (Mo, Sn, Fe, Cu, Mg, Ag)
➢ Gaseous elements (support gas contamination, vacuum, previous experiments)
➢ Some peaks corresponding to only one isotope
➢ The same was done with He, N2 and O2
➢ Support Gas : H2
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
Contaminants preliminary experiments
➢ Amplitude evolution of peaks
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40Ar7+ 96Mo15+
➢ H2 gives higher contamination (it is the best support gas for low mass species charge breeding…)
➢ This is true for most of other peaks
➢ Dependency with RF power : clear increase for 96Mo15+ and 12C5+, slight decrease for Ar7+ due to a shift to higher charge state ?
Very low signal / noise
12c5+
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
Contaminants preliminary experiments➢ Amplitude
▪ The lower measurable amplitude is ~ 100pA with the emittance scanner, corresponding to ~2 1010 pps in the N+ FC.
▪ As a comparison a 108 pps RIB flux at the CB entrance would give:
108 x 10% (CB efficiency) ~ 107 pps
▪ This technique doesn’t allow to measure low intensity contaminant beams
▪ Need of a different detector
▪ A lot of contaminants are identified, with very high flux
➢ A/q minimum step limitation :
▪ Resolution limitation of the data acquisition output, to be improved
➢ Dips present in the spectrum
▪ Due to secondary electrons emission
▪ Shielding of the emittance scanner will be tested
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LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
LPSC Charge breeder development plan
25
✓ 1+N+ beamline upgrade
✓ Validation experiments
✓ Contaminants preliminaryexperiments
Charge Breeder5 coil config
1+n+ Performances
check
Contaminants reduction
experiments : liners
09/2018 10/2020 10/2022
Charge BreederEnlarged plasma chamber config
1+n+ Performances
check
Contaminants reduction
experiments
✓ Charge Breeder6 coil config
✓ 1+n+ Performances
check
✓ Configuration developped until now
• Improve axial field profile• Decrease coils cross talk• Improve beam injection
and extraction
• Improve high charge state production
• Reduce the contaminants proportion
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
5 coil configuration
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• Improve axial field profile• Decrease coils cross talk• Improve beam injection and extraction
200 100 100 200z mm
0.5
1.0
1.5
Bz T
Bz (T)
z (mm)
1.7 T+
Maximum field at injection
Reproduce 6 coil config (check performances)
z (mm)
Bz (T)
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
Contaminants reduction : liners
➢ Comparative experiments using several material :
▪ Niobium
▪ Tantalum
▪ Al2O3 layer on pure Aluminum liner – collaboration with NIPNE
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➢ Design to cover all the surfaces in front of the plasma
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
Contaminants reduction : gas
➢ Follow ANL steps to get rid of gas contamination
➢ Use He or H2 as support gas
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Bakedgas
valve
4K Cryo PumpHe
H2
Condensed gascontaminantsfrom the gas bottle@ 4K
baked gascircuit injection
He,H2
He or H2 buffer plasma
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
Conclusion
➢ Upgrade of the 1+N+ beam line is finished, reduction of the residual pressure by a decade
➢ Preliminary contaminants reduction experiments showed limitations in the measurement technique, to be improved
➢ The R&D program on the charge breeder will go on to continue improving the performances…
➢ …with a great part dedicated to contaminants reduction
➢ Open for collaborations on ECR CB developments
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LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
➔ Following Tasha talk
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• 1+N+ beam line interface
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
➔ Following Tasha talk
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• 1+N+ beam line interface
LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
THANK YOU FOR YOUR ATTENTION
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LPSC Phoenix charge breeder
2020 North American Charge Breeding workshop, East Lansing, October 1st-2nd 2020, USA
Contaminants preliminary experiments
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➢ Resolution estimate in the emittance scanner with Xe plasma
132Xe19+131Xe19+
Resolution ~ 1:150 in the emittance scanner