Author: Peters, A.
Paper Title Page
TUPC066 Charged Particle Beam Profile Detector based on Yb-doped Optical Fibers 1150
 
  • C.S. Søndergaard
    Aarhus University Hospital, Aarhus, Denmark
  • A. Baurichter, B.R. Nielsen
    Danfysik A/S, Jyllinge, Denmark
  • G. Boudreault
    Rigshospitalet Copenhagen, PET and Cyclotron Unit, Copenhagen, Denmark
  • K. Hansen, D.V. Madsen, J. Rasmussen, B.F. Skipper
    Aarhus School of Engineering, Aarhus, Denmark
  • M. Kristensen
    Aarhus University, Aarhus, Denmark
  • S.P. Møller
    ISA, Aarhus, Denmark
  • A. Peters
    HIT, Heidelberg, Germany
 
  Funding: The Danish National Advanced Technology Foundation, contract # 002-2005-1
A radiation robust, high dynamic range beam profile detector based on scintillating fibers will be presented. The beam profile detector has been developed for particle therapy type ion beams of multiple hundreds MeV/n in the intensity range from 105 to 109 ions/s as a simple and less expensive replacement for MWPC based detectors. Scintillating fibers are typically based on doped polymers, which are sensitive to radiation damage. Here we report on the advantage of using silica optical fibers doped with rare-earth elements for the purpose of detecting ionizing radiation. Specifically, we find that ytterbium doped fibers generate a strong emission signal in the near-infrared from the Yb3+ state when penetrated by ionizing radiation, and that the emission has a high resistance against the accumulated dose in the fiber. We demonstrate the use of such fibers in a beam profile detector for charged particle beams in medical applications (radionuclide production and hadron therapy); more generally they are a promising alternative for prolonged used in ionizing radiation, such as accelerator diagnostics equipment or space applications.
 
 
WEPS044 Status of the Ion Source and RFQ Test Bench at the Heidelberg Ion Beam Therapy Centre 2586
 
  • R. Cee, E. Feldmeier, M. Galonska, Th. Haberer, J.M. Mosthaf, B. Naas, A. Peters, S. Scheloske, J. Schreiner, T. Winkelmann
    HIT, Heidelberg, Germany
 
  The possibility of cancer treatment with proton and carbon beams provides HIT (Heidelberg Ion Beam Therapy Centre) with an exceptional feature and gives it a unique position in Europe. In the future, the variety of available ions will be extended towards helium and oxygen. To allow fast switching between three of these ion species an additional ion-source / spectrometer combination will be installed in the LEBT. For comprehensive tests of the new components a dedicated test bench including a beam emittance analyzer has been set up at the HIT facility. It opens up the opportunity to perform detailed investigations of the improved ECR ion source with its enhanced extraction system and the redesigned RFQ of the HIT injector. Parallel to the measurements, the beam optical model of the assembly could be refined to better reproduce the beam diagnostic results. Since August 2010 the test bench has been in operation in different configurations. Behind the RFQ a beamline comprising a phase-probe-based time-of-flight system and beam current measurement devices is set up. The aim is to determine the RFQ working point and to validate the optimizations in terms of particle transmission.  
 
THOAA02 Implementation of an Intensity Feedback-loop for an Ion-therapy Synchrotron 2851
 
  • C. Schömers, E. Feldmeier, Th. Haberer, J. Naumann, R.E. Panse, A. Peters
    HIT, Heidelberg, Germany
 
  The Heidelberg Ion Therapy-Centre (HIT) started treatment of tumour patients in 2009. Its main acceleration stage is a synchrotron, where particles are extracted slowly, in the time frame of some seconds, to support the raster-scanning method. The slow extraction is driven by the transverse "RF-nockout-exciter". So far, this device has a variable but predefined amplitude curve. As the phase-space distribution of particles is not homogeneous and varies slightly from pulse to pulse, intensity-fluctuations of the extracted beam appear. Moreover, changing accelerator-settings requires a time-consuming re-adjustment of the exciter to achieve adequate beam-properties again. To keep the intensity on a predefined level, a feedback loop will be implemented. The actual-value of the intensity is provided by an ionization chamber in front of the patient. The feedback loop controls the amplitude of the Exciter, to adapt the number of extracted particles. Beside a rectangular spill with constant intensity, a dynamic intensity-adaptation during one spill with respect to the particular treatment-plan will be investigated. First tests for flat spill and variable intensity showed promising results.  
slides icon Slides THOAA02 [2.284 MB]  
 
THOAB03 Commissioning of the Ion Beam Gantry at HIT 2874
 
  • M. Galonska, R. Cee, Th. Haberer, K. Höppner, A. Peters, S. Scheloske, T. Winkelmann
    HIT, Heidelberg, Germany
 
  The Heidelberg Ion Beam Therapy Facility (HIT) is the first dedicated proton and carbon cancer therapy facility in Europe. It uses a full 3D intensity controlled raster scanning dose delivering method. The ion energy ranges from ca. 50 to 430 MeV/u corresponding to ion penetration depths of 20 to 300 mm in water. The HIT facility comprises the only heavy ion gantry worldwide designed for the beam transport of beams demanding a magnetic rigidity from 1 to 6.6 Tm. The gantry rotation of 360° enables beam scanning patient treatment from arbitrary directions. The libraries of carbon and proton pencil beams at the gantry are now offered with the whole variety of ion beam properties, i.e. 255 energy steps, 4 beam foci, 360°, and 10 intensities (106-1010/spill). The beam has to be adjusted only for a fraction of possible combinations of energy, focus, and gantry angle. These are taken as base points for a calculation of an overall number of about 37,000 different set values per ion type, and one intensity step according to the data supply model. This paper gives an outline on the practical concepts and results of adjusting the required beam properties independent of the gantry angle.  
slides icon Slides THOAB03 [4.526 MB]