H Ion Source Development Dan Faircloth ISIS Operational

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H- Ion Source Development Dan Faircloth

H- Ion Source Development Dan Faircloth

ISIS Operational Ion Source Penning H- ion source Surface Plasma Source (SPS) 35 m.

ISIS Operational Ion Source Penning H- ion source Surface Plasma Source (SPS) 35 m. A through 0. 6 10 mm aperture 200 -250 s, 50 Hz 1% duty cycle 20 ml/min H 2 3 g/month Cs 0. 17 mm mrad (665 ke. V, 35 m. A, rms) 20 -30 day average lifetime

H- Ion Beam Penning Pole Pieces Aperture Plate Anode Source Body Cathode Extract Electrode

H- Ion Beam Penning Pole Pieces Aperture Plate Anode Source Body Cathode Extract Electrode Discharge Region Ceramic Copper Spacer Mica Mounting Flange 10 mm

Platform DC Power Supply Platform Ground Pulsed 17 k. V Extract Power Supply Extraction

Platform DC Power Supply Platform Ground Pulsed 17 k. V Extract Power Supply Extraction Electrode, Coldbox and Analysing Magnet all Pulsed 35 k. V + Laboratory Ground 18 k. V - + 53. 7 mm Post Extraction Acceleration Gap 35 ke. V H- Beam

Development Goals • • Increase Pulse Length 200µs to 1. 5 ms Increase Output

Development Goals • • Increase Pulse Length 200µs to 1. 5 ms Increase Output Current 35 m. A to 70 m. A Reduce Emittance Maximise Lifetime

Thermal Modelling 3 D Finite Element Model of the Ion Source using ALGOR. Steady

Thermal Modelling 3 D Finite Element Model of the Ion Source using ALGOR. Steady State Solution 600 520 440 360 280 200 Computational Fluid Dynamic Cooling Calculation Transient Solution Cathode Surface Anode Surface 1000μs duty ΔT= 73 ºC ΔT= 39 ºC

Maximum Discharge Length Obtained 1. 8 ms @ 50 Hz

Maximum Discharge Length Obtained 1. 8 ms @ 50 Hz

Electromagnetic Modelling 3 D Finite Element Model of the Ion Source using MAFIA. Existing

Electromagnetic Modelling 3 D Finite Element Model of the Ion Source using MAFIA. Existing Extract Terminated Pierce Extract Potential in Extract Region Magnetic Field in Coldbox 17 ke. V normalised Hrms= 0. 04 mm mrad Vrms= 0. 16 mm mrad Correctly Terminated Analysing Field 0 T 0. 5 T 17 ke. V normalised Hrms= 0. 03 mm mrad Vrms= 0. 03 mm mrad

ISDR Infrastructure Changes Top Loading Ion Source Separate Penning Field Ion Source Assembly Pole

ISDR Infrastructure Changes Top Loading Ion Source Separate Penning Field Ion Source Assembly Pole tip extensions on the 90° Analysing Magnet Penning Field B Magnet Assembly

ISDR Infrastructure Changes Top Loading Ion Source Separate Penning Field Ion Source Assembly Penning

ISDR Infrastructure Changes Top Loading Ion Source Separate Penning Field Ion Source Assembly Penning Field B Magnet Assembly

Collaboration with IHEP, CAS Dr. Ouyang and Prof. Zhang Feb 2007: Dr. He Wei

Collaboration with IHEP, CAS Dr. Ouyang and Prof. Zhang Feb 2007: Dr. He Wei testing ion source components manufactured in China.

78 m. A 500 µs 50 Hz

78 m. A 500 µs 50 Hz

Development Goals • • Increase Pulse Length 200µs to 1. 5 ms Increase Output

Development Goals • • Increase Pulse Length 200µs to 1. 5 ms Increase Output Current 35 m. A to 70 m. A Reduce Emittance Maximise Lifetime

Improved Diagnostics

Improved Diagnostics

Transmission (%) δ(Transmission) / δ(−Vb) (%/V) Retarding Potential Energy Analyzer Bias Voltage (V) H-

Transmission (%) δ(Transmission) / δ(−Vb) (%/V) Retarding Potential Energy Analyzer Bias Voltage (V) H- Faraday Cup Beam Potential Hill Transmission (%) Discharge Current (A) Spectrum width σ (e. V) Bias Voltage (V) σ = 17. 6 e. V +/- 1. 5 e. V I Bias Voltage (V) Work done in collaboration with Oxford University Discharge Current (A)

Current Work

Current Work

17 k. V Extract Potential 62 m. A Beam Current 100 10 0 50

17 k. V Extract Potential 62 m. A Beam Current 100 10 0 50 y ‘(m. Rads) x ‘(m. Rads) 50 0 -50 -100 -60 -30 0 x (mm) 30 0. 84 norm πmm m. Rad -60 10 -60 0 -30 0 y (mm) 30 0. 92 norm πmm m. Rad -60

10 k. V Extract Potential 32 m. A Beam Current 50 50 y ‘(m.

10 k. V Extract Potential 32 m. A Beam Current 50 50 y ‘(m. Rads) 100 x ‘(m. Rads) 100 0 -50 100 -60 0 -50 -30 0 x (mm) 30 0. 48 norm πmm m. Rad -60 100 -60 -30 0 y (mm) 30 0. 55 norm πmm m. Rad -60

6. 5 k. V Extract Potential 100 50 50 y ‘(m. Rads) x ‘(m.

6. 5 k. V Extract Potential 100 50 50 y ‘(m. Rads) x ‘(m. Rads) 13 m. A Beam Current 0 0 -50 100 -60 -30 0 x (mm) 30 0. 16 norm πmm m. Rad -60 100 -60 -30 0 y (mm) 30 0. 32 norm πmm m. Rad -60

Scintillator Measurements 5 k. V Ext 5. 5 k. V Ext 6. 5 k.

Scintillator Measurements 5 k. V Ext 5. 5 k. V Ext 6. 5 k. V Ext 7 k. V Ext 8 k. V Ext 9 k. V Ext 11 k. V Ext

Ion Source Development Rig

Ion Source Development Rig

Pepper Pot Emittance Measurement • To help understand why the emittance is so large

Pepper Pot Emittance Measurement • To help understand why the emittance is so large • To allow optimised design of the LEBT for the Front End Test Stand • To develop diagnostic experience for the FETS collaboration Details in the next talk Mounting flange Window Support rods Moving rod Camera Scintillator and Pepperpot

Future Work • • Scanning Pepperpot and Scintillator studies Space charge studies with Krypton

Future Work • • Scanning Pepperpot and Scintillator studies Space charge studies with Krypton Different extraction geometries Different post acceleration gap Plasma meniscus modelling More detailed beam transport modelling Different materials for extended lifetime studies

Questions?

Questions?