1. Development of a new compact 5.8 GHz ECR ion source at LPSC
J. Angot1, L. Bonny1, J. Jacob1, T. Lamy1, P. Sole1, P. Sortais2, T. Thuillier1, F. Villa1
1 CNRS/IN2P3/LPSC - 53, rue des Martyrs Grenoble Cedex, France
2 Polygon Physics - 53, rue des Martyrs Grenoble Cedex, France
WEPP09
Abstract
LPSC is developing a new 5.8 GHz compact ion source to produce low charge state ion beams and study their capture in the PHOENIX charge breeder. The source was designed to meet criteria like stability, compactness and low cost. It is mounted on a DN160 iso K flange and is fully under vacuum during operation. The technology brings modularity to ease the development. It can operate up to 60 kV. The plasma is heated by a 100 W solid state amplifier. The ECRIS produces 1 mA of H+ beam with 20 W of HF power and low charge state Argon ions. It was tested under several microwave and magnetic configurations on a test bench equipped with a mass spectrometer and diagnostics. Given its excellent performances, this source was installed to drive the accelerator-based neutron source, GENEPI 2, at LPSC.
The development of the source together and its performances are presented. Future plans for this ion source are discussed. This work was supported by the ERA-NET NuPNET in the framework of the EMILIE project.
Stability, modularity, compactness, low cost
Ion source design
Modular HF circuit
(circular waveguide here)
Modular magnetic structure (permanent magnets)
Water cooled Plasma chamber
Gas, cooling, HV and HF servitudes on the flange
NW 160
support flange
Extraction system
HF configurations (HFSS simulations)
Type
E field distribution (V/m)
Max E field on axis (kV/m for 1 W)
Coaxial, antenna with couplers
100
Coaxial , antenna 15
Circular waveguide TE11 mode
2.5
400 mm E1
ground
ground E2
Magnetic configurations
Type
Permanent magnets configuration
B field distribution (T)
Mathematica, radia simulations
Gradient
Min B
First application of the source on GENEPI 2
In June 2016, the 5.8 GHz ions source was installed on GENEPI2 at LPSC, the accelerator-based fast neutron source for multipurpose applications (nuclear physics experiments, irradiation platform, neutron detector calibration). The goal is to produce 1 mA of D+ beam at 220 kV.
In July 2016, a first D+ test beam was produced at 220 kV, with a total current limited to 47 µA by a reduced plasma electrode hole (Ø1 mm). Full characterization is underway.
250kV platform
Acceleration
gap
Optics
hexapole
Spectrometer
Results
Ion source ready for insertion in the vacuum chamber of the 250 kV platform
The GENEPI2 accelerator beam transport line
Extracted currents with a Ø4 mm plasma electrode hole
Magnetic / HF configs
Species
Current
(mA)
HF power (W)
Extraction voltage (kV)
Gradient /Coaxial antenna + couplers
Ar+ 1 25 40
MinB / coaxial antenna H+ 63 30
MinB / Waveguide
Ar+ / Ar2+ / Ar3+ / Ar4+
0.185 / / / 0.010 81 D+
1.15 17
1.45 45 35
Future plans
Test of new magnetic structures and HF couplings
Increase of the plasma electrode hole to increase the extracted currents
Design studies for HF frequency increase
Lower the source pressure to improve the achievable charge state
22nd International Workshop on ECR Ion Sources Busan, August 28th