Cyclotrons2013 - List of Authors (Kim, Y.-S.)

Paper	Title	Page
TUPSH005	Investigation of Cyclotron Carbon Foil Lifetime in Relation to its Thickness	227
	J.-W. Kim, S. Hong, J.H. Kim IBS, Daejeon, Republic of Korea Y. Choi Dongguk University, Gyeongju, Republic of Korea Y.-S. Kim Energy & Environmental System, Gyeongju, Republic of Korea
	For extracting positive hydrogen atoms from accelerated negative ones, a thin carbon foil is usually used to stripe two electrons from negative atoms, which consists of one proton and two electrons traveling together up to 70MeV proton. The kinetic energy of electron is 38.13keV at the moment of stripping. The energy loss of protons and electrons in carbon foil could be estimated by the multiplication of stopping power (dE/dz) and the foil thickness where passing through. The stopping powers were estimated with 8.5 and 7.25 MeV/(g/cm²) for the proton and electron, respectively. In cyclotron the stripper is located in a strong magnetic field of ~Tesla, which makes electrons circular motion around the foil depositing all their kinetic energies into it. In this study, three different carbon foil thicknesses (200, 400, and 800 ug/cm²) were employed to investigate the correlation of foil temperature and their lifetime for the case of 1mA proton extraction. We are aiming the lifetime of a stripper foil to be as long as 2 weeks for irradiating protons onto an ISOL target. An effective lifetime of foils will be discussed as a function of a foil peak temperature.

Paper

Title

Page

Investigation of Cyclotron Carbon Foil Lifetime in Relation to its Thickness

227

J.-W. Kim, S. Hong, J.H. Kim
IBS, Daejeon, Republic of Korea
Y. Choi
Dongguk University, Gyeongju, Republic of Korea
Y.-S. Kim
Energy & Environmental System, Gyeongju, Republic of Korea

For extracting positive hydrogen atoms from accelerated negative ones, a thin carbon foil is usually used to stripe two electrons from negative atoms, which consists of one proton and two electrons traveling together up to 70MeV proton. The kinetic energy of electron is 38.13keV at the moment of stripping. The energy loss of protons and electrons in carbon foil could be estimated by the multiplication of stopping power (dE/dz) and the foil thickness where passing through. The stopping powers were estimated with 8.5 and 7.25 MeV/(g/cm²) for the proton and electron, respectively. In cyclotron the stripper is located in a strong magnetic field of ~Tesla, which makes electrons circular motion around the foil depositing all their kinetic energies into it. In this study, three different carbon foil thicknesses (200, 400, and 800 ug/cm²) were employed to investigate the correlation of foil temperature and their lifetime for the case of 1mA proton extraction. We are aiming the lifetime of a stripper foil to be as long as 2 weeks for irradiating protons onto an ISOL target. An effective lifetime of foils will be discussed as a function of a foil peak temperature.