| Project/Area Number |
11680548
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
環境影響評価(含放射線生物学)
|
|---|
| Research Institution | Hiroshima University |
|---|
Principal Investigator |
ENDO Satoru Hiroshima University, School of Engineering, Associated Professor, 大学院・工学研究科, 助教授 (90243609)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
HOSHI Masaharu Hiroshima University, Research Institute for Radiation Biology and Medicine, Professor, 原爆放射能医学研究科, 教授 (50099090)
|
|---|
| Project Period (FY) |
1999 – 2001
|
| Project Status |
Completed (Fiscal Year 2001)
|
| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2001: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000)
|
|---|
| Keywords | Proton track code / Track simulation / W value / Neutron dosimetry / Recoil particle / Proton track code / Track simulation / Neutron dosimetry / Recoil particle / Newtron dosimetry / Recoil p**ticle |
|---|
| Research Abstract |
In general, neutron collisions with atomic nuclei lead to recoil atomic ions and nuclear reaction products in the form of secondary charged particles. The energies of these particles vary according to the energy of the incident neutrons. In hydrogen containing media such as water and tissue the most important interaction is elastic scattering with hydrogen nuclei (protons), which accounts for more than 90% of energy transfer. Protons are, therefore, considered to be the most important recoil particles for estimating neutron induced radiation effect. The recoil protons and other ions set in motion in the cell, in turn, interact with the bio-molecule leading to DNA damage and subsequent biological lesions. Most of these recoil protons are low energy particles below 1 MeV energy. Therefore, the motivation for this work arises for a need to simulate the tracks of low energy protons emitted in neutron interactions in tissue as needed for biophysical modeling. As the hydrogen atom has a diff
… More
erent ionization cross section from that of the proton, charge exchange processes (CEP) need to be considered in order to calculate the electronic stopping power for low energy protons. In this study, we have used the current state of the art in the Monte Carlo track simulation techniques and in conjunction with the published experimental and established theoretical data to develop a model for the extension of the proton track simulation in the low energy region. We want to understand the behaviors of the recoil proton, and establish the neutron dosimetric methods at the low energy region.
We developed a proton track code which can be used at the proton energy below several MeV. A publication related to this code is (in press) in the Nuclear Instruments and Methods section B (2002). Contribution of the neutralized proton is evaluated by a microdosimetric calculation. The effects for the 1 MeV neutrons are estimated to be 24%. This result was reported in the International congress on Medical Physics. The other results on this study are summarized in the reference. Less
|
