1. 60 GHz ECR Ion Source for RIB production
T. Lamy, L. Latrasse, T. Thuillier, C. Fourel, J. Giraud
Laboratoire de Physique Subatomique et de Cosmologie
CNRS/IN2P3, U. Joseph Fourier,
INP Grenoble, France
F. Debray, C. Trophime, P. Sala, J. Dumas
Laboratoire National des Champs Magnétiques Intenses
CNRS, INSA Toulouse, U. Paul Sabatier - Toulouse,
U. Joseph Fourier, Grenoble, France
I. Izotov, A. V. Sidorov, V. A. Skalyga, V. G. Zorin
Institute of Applied Physics
Russian Academy of Science
Nizhny Novgorod, Russia

2. Summary The initial idea : A dream ? Towards reality The reality
A possible future ?

3. 60 GHz ECR source for RIB production : where ?

4. The initial idea : A dream ?
Moriond meeting les Arcs 2003: Pascal Sortais LPSC-Grenoble
GHz « ECR Duoplasmatron » for pre-bunching of gaseous RIB
2.0 – 3.0 T
pulsed coils or SC coils
ECR: GHz
Very high density magnetized plasma
ne ~ 1014 cm-3
Very small plasma chamber
F ~ 20 mm / L ~ 50 mm
Target
1-3 mm 100 KV extraction
Rapid pulsed valve
100 µs
20 mA
1012 to 1013 ions per bunch
with high efficiency
60-90 GHz / KW
10 –200 µs /  = 6-3 mm
optical axial coupling

5. Magnetic field configuration
Towards reality
Plasma Density
Very high density magnetized plasma ne ~ 1014 cm-3
ECR Cut off density (nc)
c.e.(rad/s) = 2fc.e. (Hz) = p = (nce2/0 me)1/2 nc = (2fc.e)2 0 me /e2
2.45 GHz (Becr = 874 Gauss) ne = ni = cm-3
56 GHz (Becr = 2 T) ne = ni = cm-3
So 60 GHz (Becr = 2.14 T) ne = ni = cm-3
Magnetic field configuration
2.14 T
Pulsed coils or SC coils 2.0 – 3.0 T
Pulsed coils
Performed at Institute of Applied Physics Nyzhnyi Nogorod (Russia) – collaboration since 10 years
Restrictions for high frequency operation and exploration (1 Hz - 10 Hz – 25 Hz …)
Superconducting coils
Extremely expensive – not yet proven feasible – ‘definitive’ configuration (not R&D)
So static B and classical technologies (copper and water)

6. The 60 GHz Collaboration and
The reality (beginning).
The 60 GHz Collaboration and
LPSC , Grenoble
ECRIS development, low energy beam lines, beam analysis
LNCMI, Grenoble
Very High Magnetic Fields
Collaboration since 2 years
IAP, Nijni Novgorod, Russia
Plasma physics, gyrotrons and pulsed ECRIS
Collaboration since 10 years

7. The reality (Magnetic field) Courtesy of François Debray
3 Technologies for high field magnets
Bitter
Helix
Widely used in main high field labs
Developed at the LNCMI
Longitudinally cooled
Radially cooled
Continuous change of the current density
 allows a fine optimization of the current distribution
~ 1000 « high field » contacts variable pressure with B
~ 10 « low field » contacts independant of B
 Improved field stability

8. The reality, Beams and plasmas physics
WP4 : For beam bunching a high frequency ECR concept will be
studied as a continuation of work started in EURISOL DS
Pulsed ion beams afterglow and preglow effect studied
18 and 28 GHz
Theoretical 60 GHz extrapolation
higher intensity, shorter pulses
IAP theory and LPSC exp. results comparison

9. First 60 GHz ECR ion source prototype: dream ?
Magnetic structure expected:
2.1 Tesla closed ECR surface
4 Tesla radial confinement
6 Tesla at injection
3 Tesla at extraction
Compact source (100 mm long)
Structures using PolyHelix Technology
Fast and cheap design and construction First prototype to Master the technique and the environment: 60 GHz CUSP
4 T
3 T
6 T
Injection
Extraction
2.1 T
Field
line
60 mm
Peak to peak ~100 mm
ECR zone
Plasma chamber
shape with shoulder

10. The reality : magnetic structure for 60 GHz ECR
3D Simulation with Getdp
Exact geometry from CAD + mesher
Thermal study
2.1T
Injection
Extraction H1 H2 H3 H4
Magnetic field lines Br

11. The reality : validation of the simulation
B on axis (Gauss)
Experiment
Simulation
Aluminum model
of H1 coil (real size)
Tested at 140 A (low current)
Comparison with simulation : dB/B~3%
Identical magnetic center
Magnetic structure validated : OK to build Copper Coils
Delivery mid april

12. Multi electrode extraction
60 GHz ion source diagram
100 kV insulation
Gas
V= 100 kV
Ground
V=0
polyhelix
polyhelix
Multi electrode extraction
MW window
Ions extraction
60 GHz Microwaves
ECR
polyhelix
polyhelix
insulator
Water cooled plasma chamber

13. ECR Plasma 60 GHz ECR ion CAD Water cooling I– I+, 15000 A I–
600 mm
620 mm I–
I+, A
490 mm
ECR
Plasma I–
Size and cost reduction without changing
Internal characteristics unchanged
(B, cooling, plasma chamber)
I+, A
Water cooling

14. Technical specification :
60 GHz Gyrotron
IN2P3 funding
Technical specification :
100 kW max, 10 kW average
100 ms-15 ms pulses / 50 Hz
IAP Focusing Lens
Gycom Gyrotron
53 GHz
100 kW
Gycom Gyrotron frame

15. How to get a 60 GHz Gyrotron and perform experiments?
Use any external resources possible (collaborate!!)
ISTC project:
IAP Nizhny Novgorod (Plasma physics theory and experiments, gyrotron manufacturing)
LPSC in this programme will be responsible of the design and construction
of various ECR ion sources prototypes with specific magnetic field
configurations designed with the help of LNCMI.
Geert Rikken
Director of the LNCMI
LNCMI has committed itself to the magnetic characterization of the first prototype magnet, and is discussing the possibilities to reinforce our collaboration
(i.e. a permanent room for experiments + electrical Power!!)
Estimated total cost of the project (US $) 1 
Financial Sources:
Requested from the ISTC
Other financial source 1: LPSC

16. A place to perform experiments (1)
34 T /34 mm
19 T /160 mm ?
Hydraulic pumps
1000 m3/h deionized water
28 GHz A, 2.5 MW
60 GHz A 5 MW
Power supplies :
A, 24 MW

17. A place to perform experiments (2)
A new dedicated 60 GHz test bench has to be built (in a place)
Magnetic spectrometer developed in collaboration with M. Duval (GANIL)
150 mm GAP
Θ=90° , ρ=700 mm
350 mm horizontal aperture
2,5 Tons
Mass separation : 100
BρMAX=0.23 T.m
Delivered by SIGMAPHI (IN2P3 funding)
GAP 150 mm
Xbeam= 350 mm
Location of the test bench under discussion LNCMI
Need high level political support !

18. Political strategy for the 60 GHz ECR ion source development and tests
A part of the EUROnu deliverables list
Del. no.
Deliverable name
WP no.
Delivery date
(proj.
month) D2
Report on 1st year activities
All 12 D8
Collection device construction 4 18 D9
Interim report 24
D12
Report on the experimental validation of the collection device for Li-8 30
D13
Bunching performance evaluation 35
D14
Project review documentation 36
D22
Final report 48

19. Tentative planning including deliverables

20. If we believe in a dream, we may succeed… If dream gets into reality…
Conclusion
If we believe in a dream, we may succeed…
If dream gets into reality…
There is a possible future:
Beyond EURISOL and EURO-nu,
We may have 15 years to work on cw (not pulsed) high frequency
ECR Ion Sources !
Thank you for your attention !

21. Work characteristics :
Current :
30000A
Max density in 2 mm pitch helix part : J~650 A/mm2
Electrical Power : P~ 5 MW (6.5*)
Water cooling, deionized water :
Water cooling flow ~ 20 l/s
Pin = 27 bars ; Pout = 4 bars
Tinlet = 20 °C, Toutlet = 40 °C
Max Coil temperature
TMax loc. ~ 125°C (150*)
Tmean ~ 95°C (115*)
Mechanical characteristics
Max Hoop stress : ~ 280 MPa << Elastic limit of Copper Alloy (380 MPa)
Extraction and injection sides exerts each a force of 60 tons
* Pessimist calculus

22. Production of B and Li
B* and Li* are produced by irradiating a target. How is Boron or Lithium when it get out from the target?
Atoms – Ions – Molecules? What are the possibilities?
If we have molecules => they should be broken in the plasma
If we have ions => use the 1+/n+ method
Solutions:
Metallic vapor, efficiency ~ 1 – 10 %
Sputtering, efficiency ~ 1 % (energetic atoms)
Extract species using offline chemical separation techniques, efficiency ~ 10 % 7Be is produced by irradiating a lithium target (30 μA of 27 MeV protons) and is extracted by this way (Loiselet et al. Louvain-La-Neuve) …