Author: Bhaskar, B.S.
Paper Title Page
TUWZO04
 Influences of Magnetic Field Parameters to ECRIS Plasma Characteristics  
 
  • J.B. Li, J.W. Guo, D. Hitz, L.B. Li, L.X. Li, W. Lu, L.T. Sun, X.Z. Zhang, H.W. Zhao, H. Zhao
    IMP/CAS, Lanzhou, People’s Republic of China
  • B.S. Bhaskar, T. Thuillier
    LPSC, Grenoble Cedex, France
  • B.S. Bhaskar, H.A. Koivisto, O.A. Tarvainen, V. Toivanen
    JYFL, Jyväskylä, Finland
  • O.A. Tarvainen
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  
  To investigate the hot electron population and the appearance of kinetic instabilities in ECRIS plasma, the axially emitted bremsstrahlung spectra and microwave bursts emitted from ECRIS plasma were synchronously measured on SECRAL-II ion source with various magnetic field configurations. The experimental results show that when Bmin/Becr is less than ~0.8, the spectral temperature Ts increases linearly with the Bmin/Becr-ratio when the injection, extraction and radial mirror fields are kept constant. Above this threshold Ts saturates and the electron cyclotron instability appears simultaneously. This study has also demonstrated that Ts decreases linearly with the increase of the average gradient over the ECR surface when the on-axis gradient and hexapole field strengths are constant. In addition, it is found that Ts decreases with the increase of the gradient at the resonance zone at relatively low mirror ratio and is insensitive to the gradient at high mirror ratio when Bmin is constant. Compared to a recent study taken on a fully superconducting ECRIS, this study shows different results discussing the mechanisms behind the correlation of magnetic field parameters to Ts.  
slides icon Slides TUWZO04 [4.062 MB]  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUZZO02 Electron Cyclotron Resonance Ion Source Related Research and Development Work at the Department of Physics, University of Jyväskylä (JYFL) 98
 
  • H.A. Koivisto, B.S. Bhaskar, A. Ikonen, T. Kalvas, S.T. Kosonen, R.J. Kronholm, M.S.P. Marttinen, O.P.I. Timonen, V. Toivanen
    JYFL, Jyväskylä, Finland
  • J. Angot, B.S. Bhaskar, T. Thuillier
    LPSC, Grenoble Cedex, France
  • I. Izotov, V. Skalyga
    IAP/RAS, Nizhny Novgorod, Russia
  • L. Maunoury
    GANIL, Caen, France
  • O.A. Tarvainen
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  
  Funding: The work has received funding from the Academy of Finland under the Academy of Finland Project funding (No. 315855) and from University Grenoble Alps under EMERGENCE-project.
Recent research work of the JYFL ion source team covers multi-diagnostic studies of plasma instabilities, high-resolution plasma optical emission spectroscopy, ion current transient measurements to define the total life-time of a particle in the highly charged plasma. The JYFL team also elaborates the magnetic and technical design of the unconventional ion source named CUBE. The R&D work includes, in addition, the commissioning and operation of the high-performance 18 GHz ECRIS, HIISI. The instability measurements have revealed new information about the parameters affecting the onset of the plasma instabilities and shown that different instability modes exist. The ion-beam transient studies have given information about the cumulative life-time of highly-charged ions convergent with the ion temperatures deduced from the Doppler broadening of emission lines. The CUBE prototype has a minimum-B quadrupole magnetic field topology, similar to ARC-ECRIS, and its all-permanent magnet structure has been optimized for 10 GHz frequency. The CUBE design will be presented along with its commissioning status. The status and operational experience with HIISI will be reported as well. 		 
slides icon Slides TUZZO02 [9.553 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUZZO02  
About • Received ※ 28 September 2020 — Revised ※ 09 November 2020 — Accepted ※ 03 December 2020 — Issue date ※ 05 May 2021
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUZZO03
 Study on the Correlation between Energy Distribution of Electrons Lost from the Confinement and Plasma Bremsstrahlung on a min-B ECR Plasmas  
 
  • B.S. Bhaskar, T. Thuillier
    LPSC, Grenoble Cedex, France
  • B.S. Bhaskar, T. Kalvas, H.A. Koivisto, R.J. Kronholm, M.S.P. Marttinen, O.A. Tarvainen, V. Toivanen
    JYFL, Jyväskylä, Finland
  • I. Izotov, V. Skalyga
    IAP/RAS, Nizhny Novgorod, Russia
  • O.A. Tarvainen
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  
  Funding: The work has received funding from the Academy of Finland under the Academy of Finland Project funding (No. 315855) and from University Grenoble Alps under EMERGENCE-project.
The study of plasma bremsstrahlung has been used as a diagnostic tool for understanding the behavior of confined plasma in Electron Cyclotron Resonance Ion Sources (ECRIS). In order to understand the relation connecting the confined plasma and the electrons escaping the confinement, a series of measurements have been made to measure the bremsstrahlung produced in the axial and radial direction along with the Lost Electron Energy Distribution (LEED) axially on JYFL 14 GHz ECR. We present here the effect of various source parameters on the axial and radial bremsstrahlung along with the LEED on a min-B confined ECR plasma. The measured LEED has been found to show a correlation with bremsstrahlung measurement and also have observed as a potential diagnostic method for instability. The explanation for observed LEED and bremsstrahlung trends is provided. 		 
slides icon Slides TUZZO03 [1.520 MB]  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)