• 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.