tailieunhanh - Báo cáo " Determination of the 15 MeV bremsstrahlung spectrum from thin W target on the microtron MT-17 accelerator "

Bremsstrahlung energy spectrum from thin W target produced by 15 MeV incident electrons was determined by a combination of measurements and theoretical calculation. The shape of spectrum was calculated by Monte-Carlo method using the code EGS4. The photon flux measurements were performed based on the activation technique using the high pure metallic foils. The radioactivities of the irradiated foils were measured by using a gamma spectrometer with a high energy resolution HPGe detector. | VNU Journal of Science Mathematics - Physics 24 2008 81-87 Determination of the 15 MeV bremsstrahlung spectrum from thin W target on the microtron MT-17 accelerator Pham Duc Khue1 Bui Van I .oat2 institute of Physics and Electronics Vietnam Academy of Science and Technology 18 Hoang Quoc Viet Hanoi Vietnam 2College of Sciences VNU 334 Nguyen Trai Thanh Xuan Hanoi Vietnam Received 23 March 2008 received in revised form 28 March 2008 Abstract. Bremsstrahlung energy spectrum from thin W target produced by 15 MeV incident electrons was determined by a combination of measurements and theoretical calculation. The shape of spectrum was calculated by Monte-Carlo method using the code EGS4. The photon flux measurements were performed based on the activation technique using the high pure metallic foils. The radioactivities of the irradiated foils were measured by using a gamma spectrometer with a high energy resolution HPGe detector. The experiments were carried out at the 15 MeV electron Microtron MT-17 accelerator located at Institute of Physics and Electronics Hanoi. 1. Introduction Electron accelerators with moderate energy are being used throughout the world for various scientific and technological fields 1-3 . The radiations used at electron accelerators are not only the primary electron beam but also the secondary beams such as bremsstrahlung photons and neutrons. Bremsstrahlung photons are produced from direct interaction of fast electrons with the nuclei of the target. Neutrons are generated mainly from photonuclear reactions induced by the bremsstrahlung photons. A high intensity gamma source is a good tool for investigating photonuclear reactions radiation affects mechanisms and photo activation analysis 1-3 . In order to analyze most experiments when bremmstrahlung radiation used it is necessary to know the absolute magnitude of the bremsstrahlung spectrum as a function of the photon energy and of the emission angle. Many methods are available for the .