Observations of the frequency tuning effect in the 14GHz CAPRICE ion source

Celona, L.; Ciavola, G.; Consoli, F.; Gammino, S.; Maimone, F.; Mascali, D.; Spädtke, P.; Tinschert, K.; Lang, R.; Mäder, Jan; Roßbach, J.; Barbarino, S.; Catalano, Roberto

doi:10.1063/1.2841694

Cited by 66 publications

(37 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The percentage of power that is reflected versus the frequency, Figure 2, is obtained without changing the optimized parameters. As can be seen, sudden variations of plasma coupling can be obtained with small variations of frequency, similar to results observed in [12 ].…”

Section: Interlocksupporting

confidence: 76%

Integrating a Traveling-Wave Tube into an AECR-U Ion Source

Covo

Benitez

Ratti

et al. 2011

IEEE Trans. Plasma Sci.

View full text Add to dashboard Cite

Abstract-An RF system of 500W -10.75 to 12.75 GHz was designed and integrated into the Advanced Electron Cyclotron Resonance -Upgrade (AECR-U) ion source of the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. The AECR-U produces ion beams for the Cyclotron giving large flexibility of ion species and charge states. The broadband frequency of a Traveling Wave Tube (TWT) allows modifying the volume that couples and heats the plasma. The TWT system design and integration with the AECR-U ion source and results from commissioning are presented.

show abstract

Section: Interlocksupporting

confidence: 76%

Integrating a Traveling-Wave Tube into an AECR-U Ion Source

Covo

Benitez

Ratti

et al. 2011

IEEE Trans. Plasma Sci.

View full text Add to dashboard Cite

show abstract

“…However, despite the effect of the magnetic field was expected, a so deep influence of the pumping wave frequency on the structural properties of the plasma is something new. It was indirectly observed at GSI-Darmstadt [17], predicted by theoretical papers [18], but never observed so clearly (and directly into the plasma chamber) up to now. The two points above open wide two interesting issues.…”

Section: Discussion and Comparison With Simulationsmentioning

confidence: 98%

“…Due to the moderate curvature of the magnetic field lines in the near axis region, ions are taken from the near axis regions as well, hence delivered to the extraction hole. Therefore, hollow plasmas will produce lower ion beam currents, and, sometimes, hollow beams as well [17].…”

Section: Discussion and Comparison With Simulationsmentioning

confidence: 99%

Electron cyclotron resonance ion source plasma characterization by energy dispersive x-ray imaging

Rácz

Biri

Caliri

et al. 2017

Plasma Sources Sci. Technol.

View full text Add to dashboard Cite

Pinhole and CCD based quasi-optical X-ray imaging technique was applied to investigate the plasma of an Electron Cyclotron Resonance Ion Source. Spectrally integrated and energy resolved images were taken from an axial perspective. The comparison of integrated images taken of argon plasma highlights the structural changes affected by some ECRIS setting parameters, like strength of the axial magnetic confinement, RF frequency and microwave power. Photon counting analysis gives precise intensity distribution of the X-ray emitted by the argon plasma and by the plasma chamber walls. This advanced technique points out that the spatial positions of the electron losses are strongly determined by the kinetic energy of the electrons themselves to be lost and also shows evidences how strongly the plasma distribution is affected by slight changes in the RF frequency.

show abstract

“…8,9 A promising newcomer in this "collection of techniques" is the so-called frequency tuning effect (FTE). 10 Experiments with some 2nd generation ECR ion sources have demonstrated that the extracted beam currents are sensitive to microwave frequency variations on the order of 10 MHz. 10,11 It has been argued 12 that the beam current variations associated with the minute frequency shifts are due to the excitation of electromagnetic eigenmodes of the plasma chamber acting as a resonator cavity, and subsequent differences between the electron heating properties that presumably affect the ionization rate and plasma confinement, as well as ion dynamics.…”

Section: Introductionmentioning

confidence: 99%

The effect of cavity tuning on oxygen beam currents of an A-ECR type 14 GHz electron cyclotron resonance ion source

Tarvainen

Orpana

Kronholm

et al. 2016

Review of Scientific Instruments

View full text Add to dashboard Cite

The effect of cavity tuning on oxygen beam currents of an A-ECR type 14 GHz electron cyclotron resonance ion source Tarvainen, Olli; Orpana, J.; Kronholm, Risto; Kalvas, Taneli; Laulainen, Janne; Koivisto, Hannu; Izotov, I.; Skalyga, V.; Toivanen, V.Tarvainen, O., Orpana, J., Kronholm, R., Kalvas, T., Laulainen, J., Koivisto, H., . . . Toivanen, V. (2016) The direct injection of intense ion beams from a high field electron cyclotron resonance ion source into a radio frequency quadrupolea) Rev. Sci. Instrum. 85, 02A740 (2014) The efficiency of the microwave-plasma coupling plays a significant role in the production of highly charged ion beams with electron cyclotron resonance ion sources (ECRISs). The coupling properties are affected by the mechanical design of the ion source plasma chamber and microwave launching system, as well as damping of the microwave electric field by the plasma. Several experiments attempting to optimize the microwave-plasma coupling characteristics by fine-tuning the frequency of the injected microwaves have been conducted with varying degrees of success. The inherent difficulty in interpretation of the frequency tuning results is that the effects of microwave coupling system and the cavity behavior of the plasma chamber cannot be separated. A preferable approach to study the effect of the cavity properties of the plasma chamber on extracted beam currents is to adjust the cavity dimensions. were recorded at various tuner positions and frequencies in the range of 14.00-14.15 GHz. It was observed that the tuner position affects the beam currents of high charge state ions up to several tens of percent. In particular, it was found that at some tuner position / frequency combinations the plasma exhibited "mode-hopping" between two operating regimes. The results improve the understanding of the role of plasma chamber cavity properties on ECRIS performances. Published by AIP Publishing.[http://dx

show abstract

Observations of the frequency tuning effect in the 14GHz CAPRICE ion source

Cited by 66 publications

References 13 publications

Integrating a Traveling-Wave Tube into an AECR-U Ion Source

Integrating a Traveling-Wave Tube into an AECR-U Ion Source

Electron cyclotron resonance ion source plasma characterization by energy dispersive x-ray imaging

The effect of cavity tuning on oxygen beam currents of an A-ECR type 14 GHz electron cyclotron resonance ion source

Contact Info

Product

Resources

About