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

Roychowdhury, P.; Kewlani, Hitesh; Mishra, L.; Gharat, Surendra; Rajawat, R. K.

doi:10.1016/j.nima.2015.05.043

Cited by 10 publications

(6 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results in Table II indicate lower emittance for higher gas pressure, as measured with similar ion sources (e.g., Roychowdhury et al 35 ). Pressure values were recorded with a vacuum gauge placed just past the beam extraction gap.…”

Section: Conclusion: Summary Of Experimental Performance and Future P...supporting

confidence: 68%

Development of a variable-energy, high-intensity, pulsed-mode ion source for low-energy nuclear astrophysics studies

Cooper

Kelly

Machado

et al. 2018

Review of Scientific Instruments

View full text Add to dashboard Cite

The primary challenge in directly measuring nuclear reaction rates near stellar energies is their small cross sections. The signal-to-background ratio in these complex experiments can be significantly improved by employing high-current (mA-range) beams and novel detection techniques. Therefore, the electron cyclotron resonance ion source at the Laboratory for Experimental Nuclear Astrophysics underwent a complete upgrade of its acceleration column and microwave system to obtain high-intensity, pulsed proton beams. The new column uses a compression design with O-ring seals for vacuum integrity. Its voltage gradient between electrode sections is produced by the parallel resistance of channels of chilled, deionized water. It also incorporates alternating, transverse magnetic fields for electron suppression and an axially adjustable beam extraction system. Following this upgrade, the operational bremsstrahlung radiation levels and high-voltage stability of the source were vastly improved, over 3.5 mA of target beam current was achieved, and an order-of-magnitude increase in normalized brightness was measured. Beam optics calculations, structural design, and further performance results for this source are presented.

show abstract

Section: Conclusion: Summary Of Experimental Performance and Future P...supporting

confidence: 68%

Development of a variable-energy, high-intensity, pulsed-mode ion source for low-energy nuclear astrophysics studies

Cooper

Kelly

Machado

et al. 2018

Review of Scientific Instruments

View full text Add to dashboard Cite

show abstract

“…The LEHIPA ECR-IS is a 50 keV, 15 mA proton source operating in pulsed as well as CW modes [10][11][12][13]. In proton ECR-ISs, apart from H + species, there is substantial contribution from molecular species like H 2 + and H 3 + [10,13].…”

Section: Introductionmentioning

confidence: 99%

Phase space reconstruction technique for beam optimization in the Low Energy High Intensity Proton Accelerator (LEHIPA)

Priyadarshini,

Mathew,

Mathad

et al. 2024

Phys. Scr.

View full text Add to dashboard Cite

The Low Energy High Intensity Proton Accelerator (LEHIPA) has been commissioned to the design energy of 20 MeV at BARC, India. The low energy beam transport (LEBT) channel of LEHIPA consists of two solenoids and drift spaces for matching the 50 keV proton beam from the ECR ion source (ECR-IS) to the RFQ. The ion beam extracted from the ECR-IS also contains molecular species like H2+ and H3+. Proton fraction in the beam is found to degrade slowly with time due to surface contamination of the plasma chamber and this reduction in proton beam current has implications for longitudinal and transverse beam dynamics. Hence, it becomes important to characterise the beam at different proton fraction levels to understand the end-to-end beam dynamics of LEHIPA. Computed Tomography (CT) technique has been used for the beam phase-space reconstruction in LEHIPA, using a Python program, incorporating the feature of filtering secondary species from the beam profiles measured using slit scanners in the LEBT. Simultaneous Algebraic Reconstruction Technique (SART) is used in the reconstruction since it is identified to be a better technique for a limited number of projections. The reconstruction program is benchmarked with the TraceWin beam dynamics code and implemented on the measured beam profiles to recreate the phase space distribution at the beginning of LEBT. Further, the tomographic reconstruction method is compared with the solenoid scan method and the rms emittance values are found to be in good agreement. The measured tomographic phase space distribution has then been used as TraceWin input for LEHIPA end-end beam dynamics simulations and the LEHIPA beam line parameters are re-optimized for minimum beam emittance growth. This paper presents the simulations of CT technique, benchmarking simulations with TraceWin, phase space reconstruction with measured beam profiles and beam dynamics studies of LEHIPA using the reconstructed beam distributions.

show abstract

“…Microwave based Electron Cyclotron Resonance Ion Source (ECR-IS) is widely used in high energy, high intensity accelerators for applications involving radioisotope production, spallation neutron sources, accelerator driven systems, high energy physics etc, since it can produce high intensity and high charge state ion beams with low beam emittance [1][2][3][4][5][6]. A high intensity ECR proton ion source has been developed for the Low Energy High Intensity Proton Accelerator (LEHIPA) at Bhabha Atomic Research Centre (BARC), India [4][5][6]. LEHIPA consists of H+ ion source at 50 keV which is accelerated to 3 MeV by Radio Frequency Quadrupole (RFQ) and thereafter to 20 MeV by an Alvarez type DTL consisting of 4 DTL tanks of 3 m each [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

“…Currently LEHIPA has been commissioned to 11 MeV by acceleration through the RFQ and two DTL tanks [7,8]. The LEHIPA ECR-IS has a two solenoid magnetic mirror field configuration with a conventional four-step ridge waveguide for microwave (MW) power coupling [4,5].…”

Section: Introductionmentioning

confidence: 99%

Tailoring of microwave power density in an ECR ion source using an optimized ridge coupler

Phogat,

Mathew

2023

Phys. Scr.

View full text Add to dashboard Cite

One of the interesting areas in the Electron Cyclotron Resonance Ion Source (ECR-IS) design which requires further exploration is the microwave power launching scheme and the power coupling optimization with the plasma chamber. The electron heating efficiency and thereby the plasma density highly depends on the electric field distribution inside the plasma chamber; therefore, it is important to optimize the coupling of microwave power to the plasma chamber, to maximize the electric fields in the plasma chamber for a given microwave power. For this, a single-step quarter wavelength ridge coupler design study has been carried out using CST MW Studio Suite along with the plasma chamber and ridge wave guide designs. The experimental measurements of electric and magnetic field profiles in the plasma chamber assembly with different coupling configurations have been done using an innovative bead pull technique and a magnetic field probe. The experimental results match well with the simulation results and the comparative studies of different coupling configurations reveal that the single step ridge coupler based scheme improves the electric field inside the plasma chamber to at least five times than the conventional ridge waveguide. To further improve the E-field amplitude in the plasma chamber by another 40 %, a novel tuning scheme for the coupler has been introduced. Preliminary plasma studies have been carried out with the optimized coupler on a multicusp ECR plasma source and the plasma density measurements performed using a microwave cut-off probe. The plasma measurements show that even at low input microwave powers (~ 300 W) the plasma density is comparable with standard ECR-IS. The present study thus, sheds light on the coupling configuration of microwave to plasma chamber with experimental measurements of cavity mode and fields in the cavity which will be useful for high intensity accelerator applications in understanding the plasma evolution, beam parameters and its dependence on different operating parameters.

show abstract

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

Cited by 10 publications

References 20 publications

Development of a variable-energy, high-intensity, pulsed-mode ion source for low-energy nuclear astrophysics studies

Development of a variable-energy, high-intensity, pulsed-mode ion source for low-energy nuclear astrophysics studies

Phase space reconstruction technique for beam optimization in the Low Energy High Intensity Proton Accelerator (LEHIPA)

Tailoring of microwave power density in an ECR ion source using an optimized ridge coupler

Contact Info

Product

Resources

About