High intensity electron cyclotron resonance proton source for low energy high intensity proton accelerator

Abstract

Electron cyclotron resonance (ECR) proton source at 50 keV, 50 mA has been designed, developed, and commissioned for the low energy high intensity proton accelerator (LEHIPA). Plasma characterization of this source has been performed. ECR plasma was generated with 400-1100 W of microwave power at 2.45 GHz, with hydrogen as working gas. Microwave was fed in the plasma chamber through quartz window. Plasma density and temperature was studied under various operating conditions, such as microwave power and gas pressure. Langmuir probe was used for plasma characterization using current voltage variation. The typical hydrogen plasma density and electron temperature measured were 7x10(11) cm(-3) and 6 eV, respectively. The total ion beam current of 42 mA was extracted, with three-electrode extraction geometry, at 40 keV of beam energy. The extracted ion current was studied as a function of microwave power and gas pressure. Depending on source pressure and discharge power, more than 30% total gas efficiency was achieved. The optimization of the source is under progress to meet the requirement of long time operation. The source will be used as an injector for continuous wave radio frequency quadrupole, a part of 20 MeV LEHIPA. The required rms normalized emittance of this source is less than 0.2 pi mm mrad. The simulated value of normalized emittance is well within this limit and will be measured shortly. This paper presents the study of plasma parameters, first beam results, and the status of ECR proton source.

Improvement of the characterization of the proton source for the European Spallation Source by means of optical emission spectroscopy

“…Electron temperature T e , in eV units, is shown in Fig. 5: it ranges between 5 and 15 eV, showing a slight decrease at microwave power larger than 300 W. A similar trend, obtained by means of Langmuir probe measurements, has been reported in [11].…”

Emittance and proton fraction measurement in High current electron cyclotron resonance proton ion source

“…The reflected power was minimized using a four stub auto-tuner. Once the plasma discharge was established, the ion beam was extracted by biasing the extraction electrodes [1,3]. An electron suppressed movable Faraday cup was used to measure the total ion beam current.…”

“…A high current Electron Cyclotron resonance (ECR) proton ion source has been designed and developed for Low Energy High Intensity Proton Accelerator (LEHIPA) at Bhabha Atomic Research Centre (BARC) [1][2][3]. LEHIPA consists of H þ ion source at 50 keV to be accelerated to 3 MeV by Radio Frequency Quadrupole (RFQ) and to 20 MeV by an Alvarez type DTL.…”

Optimization of solenoid based low energy beam transport line for high current H+beams

“…The ion source used in LEHIPA is an ECR based source with a five electrode system for beam extraction [20]. The LEBT was used to transport the phase space ellipse at the exit of the ion source and match it to the acceptance of the RFQ.…”