• M.H. Jung, J.-K. Kil, K. R. Kim, S.J. Ra
  KAERI, Daejon

Proton therapy has features of minimal effect on tumor surrounding healthy tissue and huge damage on tumor volumes specifically. Due to these characteristics of proton therapy the number of patients with receiving proton therapy is increasing every year. Proton therapy is useful for tumor treatment but still not know mechanism of proton beam that how to kill the tumor cells. In korea, a lot of current research progressed at the cellular level by using a proton accelerator, the animal experiments was not held virtually because of the absence of the device. In this study, we installed a animal experiment device for proton beam irradiation in MC-50 cyclotron LEPT (Low Energy Proton Therapy) beam line. Bouls and collimator, we easily made to be installed and we used PMMA sheet in order to reduce the energy. In addition, we used ridge filter type modulator for making SOBP and depth-dose measurement system for a proton beam dosimetry.

• S.J. Ra, M.H. Jung, K. R. Kim
  KAERI, Daejon

During the beam irradiation experiments with more than a few MeV energetic protons, nuclear reactions are occurred in sample materials. Because of these nuclear reactions, the samples are activated so many kinds of additional problems for the post-processing of the samples are caused; such as time-loss, inconvenience of sample handling, personal radiation safety, etc. For in-vitro experiments, we observe death of tumor cells by proton irradiation. The use of large activated container material can cause erroneous results in this case. To solve these problems, we studied why the samples are activated and how the level of the activation can be reduced. In our proton beam irradiation experiments, the target materials can be defined as the container and sample itself. We could easily reduce activation of container material comparing to activation of sample itself. Therefore, we tried to find less activated container material by irradiating proton beam in PS (Polystyrene), PMP (Polymethypenten), and PMMA (Poly methacrylate). We used 45 MeV proton beams (MC-50 Cyclotron, KIRAM) with 10 nA.

• J.-K. Kil, M.H. Jung, K. R. Kim, S.J. Ra
  KAERI, Daejon

We made an experiment apparatus for the investigation of nano particle synthesis by proton inducing. It is composed of water tank, thin sample case with large area, ultrasonic oscillator, beam entrance window, monitoring camera, etc. Pt nano particles were fabricated. Nano particle characteristics are influenced by the condition of the solution, such as concentrations of H2PtCl6, CP and IPA. The experiment apparatus was designed that Pt nano particles were fabricated fore conditions. For a proton induced synthesis, some parameters, such as beam energy, beam current, flux, total dose, dose rate, etc. are also known as important process variables. To identify the effects of these irradiation parameters, we investigated the properties of nano particles according to the changes of these parameters. The energy was changed in the range of 10 ~ 40 MeV, beam current 1 uA. It could be examined by using an experiment apparatus developed for this purpose.

• K. R. Kim, M.H. Jung, J.-K. Kil, S.J. Ra
  KAERI, Daejon

Uniform irradiation is very important for many kinds of experiments of proton beam utilization. In general, scanning magnet have been used for the uniform irradiation of high energy proton beam in the type of wobbler scanning, raster scanning, spiral scanning, etc. In the case of using magnets, it is not easy and needs high cost to install and operate because the magnet size and power become bigger with increase of beam energy accordingly. In this paper, we proposed simpler method and apparatus for uniform irradiation using 2D motional stage. It is composed of two motion systems for X- and Y- direction motion and goniostage. The maximum area is 20cm x 20cm and the incident angle can be controlled from +15 to -15 degree. Maximum sample weight have to be less than 5kg. In this paper, preliminary results for simple wobbler scanning is shown when the proton energy and beam current are about 40MeV and 1~10 nA respectively. The uniform scanning area was checked by using GAF film, MD-55 or HD-810. The stage can be used for the beam alignment and beam profile measurement at any position of beam line.