Author: Forton, E.
Paper Title Page
TUP009 Cyclotron Cavity Pollution Recovery 169
 
  • J. Dabin, B. Adant, P. Cailliau, K. Ellis, E. Forton, J. Mandrillon, T.S. Ponter, P. Verbruggen
    IBA, Louvain-la-Neuve, Belgium
 
  In a cyclotron, RF cavities are usually among the most reliable subsystems, provided minimal care and maintenance. Nevertheless, several parameters may affect cavity performance after several years of operation. To name a few typical causes of degradation are: decreasing vacuum quality, various gas loads or gas qualities triggering adverse effects, deposition of highly emissive material on the cavity due to overheating of components like pass-through connectors, accidental use of chemicals or not-suitable greases. The cavity status can be monitored but, in the worst cases, the RF tuning may become difficult and it is important to apply methods in order to recover a better cavity Q-factor. In this paper, cases of cavity pollution will be shown, their potential root causes discussed and some recovery methods described.  
poster icon Poster TUP009 [0.398 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-TUP009  
About • paper received ※ 12 September 2019       paper accepted ※ 25 September 2019       issue date ※ 20 June 2020  
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THD02 Central Region Upgrade for the Jyväskylä K130 Cyclotron 326
 
  • T. Kalvas, P.M.T. Heikkinen, H.A. Koivisto
    JYFL, Jyväskylä, Finland
  • E. Forton, W.J.G.M. Kleeven, J. Mandrillon, V. Nuttens
    IBA, Louvain-la-Neuve, Belgium
 
  The Jyväskylä K130 cyclotron has been in operation for more than 25 years providing beams from H to Au with energies ranging from 1 to 80 MeV/u for nuclear physics research and applications. At the typical energies around 5 MeV/u used for the nuclear physics program the injection voltage used is about 10 kV. The low voltage limits the beam intensity especially from the 18 GHz ECRIS HIISI. To increase the beam intensities the central region of the K130 cyclotron is being upgraded by increasing the injection voltage by a factor of 2. The new central region with spiral inflectors for harmonics 1-3 has been designed. The new central region shows better transmission in simulations than the original one for all harmonics and especially for h=2 typically used for nuclear physics. The engineering design for the new central region is being done.  
slides icon Slides THD02 [12.967 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-THD02  
About • paper received ※ 15 September 2019       paper accepted ※ 27 September 2019       issue date ※ 20 June 2020  
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THD03 An Improved Concept for Self-Extraction Cyclotrons 330
 
  • W.J.G.M. Kleeven, E. Forton
    IBA, Louvain-la-Neuve, Belgium
 
  A study is made for an improved concept of self-extraction in low and medium energy cyclotrons to be used for production of medical isotopes. The prototype of the self-extracting cyclotron was realized around the year 2001*. From this machine, currents higher than 1 mA were extracted and transported to a Pd-103 production target. However, at the higher intensities, the extraction efficiency was dropping to about 70-75%, and the extracted emittance was rather poor, leading to additional losses in the beamline. Several improvements of the original concept are proposed: i) the beam coherent oscillation (as needed for good extraction) is no longer generated with harmonic coils, but is obtained from a significant off-centring of the ion source, ii) the cyclotron magnet has perfect 2-fold symmetry, allowing the placement of two internal sources and dual extraction on two opposite hill sectors, iii) a substantial improvement of the magnetic profile of the hill sectors. Simulations show an extraction efficiency up to almost 95% and emittances at least a factor 3 lower as compared to the original design. The new magnetic design is shown, and results of beam simulation are discussed.
* W. Kleeven et al., 16th Int. Conf. Cycl. Appl. 2001, East-Lansing.
 
slides icon Slides THD03 [4.060 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-THD03  
About • paper received ※ 19 September 2019       paper accepted ※ 27 September 2019       issue date ※ 20 June 2020  
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