放射化学第九讲放射防护.ppt

放射化学
Radiochemistry
2017/12/24
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第九讲放射防护
放射防护中使用的量及单位
射线防护概念
放射防护标准
射线的防护
X、射线的防护;
中子的防护。
剂量监督
废物处理、处置
应用辐射管理
2017/12/24
NECPKU,
§9-1放射防护中使用的量及单位
吸收剂量;当量剂量
有效剂量
待积当量剂量;集体当量剂量
集体有效剂量
相对生物效应
确定性效应
随机效应
2017/12/24
NECPKU,
放射防护Radiological Protection
目标:
在不过分限制有益的、产生辐射的实践的前提下,为人们提供一个适宜的防护标准
To provide an appropriate standard of protection for man without unduly limiting the beneficial practices giving rise to radiation exposure
2017/12/24
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辐射, Radiation
Where does e from?
A large contribution of the radiation on earth is from the sun (solar) or from radioactive isotopes of the elements (terrestrial).
Radiation is going through you at this very moment!
2017/12/24
NECPKU,
日常照射
Radon is a highly radioactive element that can have serious adverse effects if it gathers in large quantities.
Your annual dose of radiation from natural sources is about Sv or 3 mSv
2017/12/24
NECPKU,
细胞的损伤及其对辐射的修复能力
All living cells have enzymes designed to repair radiation damage to DNA
In some cases, radiation-damaged DNA will produce cancer cells
Only estimates of the risk of low-level radiation exist
2017/12/24
NECPKU,
天然辐射与寿命损失
2017/12/24
NECPKU,
照射量(Radiation exposure)
一束X或射线穿过空气时与空气发生相互作用使空气电离而产生次级电子,这些次级电子继续使空气电离而产生带电粒子,最后全部损失了自身的能量。
dQ:在空气中所形成的一种符号的离子总电荷的绝对值。
2017/12/24
NECPKU,
照射量(Radiation exposure)
Exposure (X, 照射量) based on the ionizing effect in air of X- and g-radiation。
Unit: röntgen (R, 伦琴):
1R = x 10-4 C/kg
The unit “Roentgen”(R) is a measurement of the specific ionization of air molecules by photons. It only applies to gamma or x-ray radiation in air.
2017/12/24
NECPKU,