电离辐射的剂量和单位

1、HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT电离辐射与物质的相互作用HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT不带电粒子（光子、中子等）HBCH RADIOTHERAPY DEPAR

2、TMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT作用方式 HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT总质量阻止本领（total mass stopping power) HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT带电粒子的射程 HBCH RADIOTHERAPY DEPAR

3、TMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT0.5mm R90 R50 RpDmaxD90DsD50 DxRqG=Rp/(Rp-Rq)电子束特性参数的定义HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT作用特征 HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT作用方式 光电子特征辐

4、射俄歇电子HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT反冲电子HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT负电子e-正电子e+HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT HBCH RADIOTHERAPY DEPARTMENT

5、HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT设定条件 HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHER

6、APY DEPARTMENT HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH

7、 RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT辐射量时间提出者辐射量演变单位演变照射量(X)1895 年1928 年1937 年1956 年1962 年1977 年物理学家国际放射学大会国际放射学大会ICRUICRUICRU红 斑 量X线辐射国际单位X线剂量国际单位照射剂量照射量照射量(Dq/Dm)红斑量伦琴(R)伦琴(R)伦琴(R)伦琴(R)CKg-1吸收剂量(D)1948 年1953 年1962 年1971 年1975 年帕 克ICRUICRUICRU国际计量大会物理伦琴当量吸收剂量(D=/m)吸收剂量(D=/m)吸收剂量(D=/m

8、)吸收剂量(D=d/dm)Rep(=84尔格克-1)拉德(rad)拉德(rad)拉德(rad)戈瑞(Gy)剂量当量(H)1948 年1955 年1962 年1979 年帕 克ICRUICRU国际计量大会人体剂量当量剂 量剂量当量(H=DQN)剂量当量(H=DQN)雷姆(rem=1repRBE*)雷姆(rem)雷姆(rem)希沃特(Sv) 常用辐射量和单位历史演变简表常用辐射量和单位历史演变简表 *RBE-相对生物效应HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT国际辐射单位

9、和测量委员会HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT法定计量单位HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT定义定义: : 意义：意义：表达式：表达式： 粒子注量率：粒子注量率：HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT定

10、义定义: : 意义：意义：表达式：表达式： 能量注量率：能量注量率：HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT定义：定义：意义：意义：HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT表达式：表达式： 与能量注量的关系与能量注量的关系： HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBC

11、H RADIOTHERAPY DEPARTMENT单单 位：位： 、HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT应用范围： 、HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT 单位时间内照射量的增量 CKg-1S -1 RS -1 Rmin -1 m Rh -1HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY D

12、EPARTMENTHBCH RADIOTHERAPY DEPARTMENT HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIO

13、THERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTn意义：是衡量在单位质量物质中转移给次级带电粒子初始动能总和的多少的物理量。n只适用于间接致电离辐射,但适用于任何物质。n在带电粒子平衡条件下,可表示为: HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RA

14、DIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT电子平衡：电子平衡： HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT带电粒子平衡带电粒子平衡VPdH

15、BCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT带电粒子平衡带电粒子平衡VPdHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH

16、RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTD & KD & KD & KD & KDEPTHDEPTH平衡深度AB 忽略衰减HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT剂量当量 品质因数与辐射类型的关系品质因数与辐射

17、类型的关系照射类型 射线种类 品质因数 、电子束 1 热中子、中能中子（E0.005MeV） 3 外照射 中能中子（0.02MeV） 5 中能中子（0.1MeV） 8 快中子（0.510MeV) 10 重反冲核 20 、 +、e、 1 内照射 10 裂变过程中的碎片、 反冲核 20HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT内含活度内含活度（Contained Activity） 即裸源活度。外观活度外观活度（Apparent Activity） 封装后的源表面活度。照射

18、量率常数照射量率常数（ ） 用于描述不同核素，单位活度，距单 位距离处照射量率大小 的物理量。空气比释动能率常数空气比释动能率常数（ ） 用于描述不同活度，不同核素， 距单位距离处比释动能率大小的物理量。 部分核素的照射量率和空气比释动能率常数部分核素的照射量率和空气比释动能率常数 核核 素素 (R m2hr-1 Ci-1) (Gy m2 hr-1 MBq-1) 钴-60 1.308 0.310 铯-137 0.332 0.0781 铱-192 0.469 0.111 碘-125 0.145 0.034HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY

19、DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT内含活度内含活度（Contained Activity） 即裸源活度。外观活度外观活度（Apparent Activity） 封装后的源表面活度。照射量率常数照射量率常数（ ） 用于描述不同核素，单位活度，距单 位距离处照射量率大小 的物理量。空气比释动能率常数空气比释动能率常数（ ） 用于描述不同活度，不同核素， 距单位距离处比释动能率大小的物理量。 部分核素的照射量率和空气比释动能率常数部分核素的照射量率和空气比释动能率常数 核核 素素 (R m2hr-1 Ci-1) (Gy m2 hr-1 MBq-1) 钴-60

20、 1.308 0.310 铯-137 0.332 0.0781 铱-192 0.469 0.111 碘-125 0.145 0.034HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT电离辐射的测量HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT电离室的种类HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPART

21、MENTHBCH RADIOTHERAPY DEPARTMENT自由空气电离室HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT柱形电离室HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT柱形电离

22、室的结构HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT电离室的工作特性HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT电离室的工作特性HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT电离室的工作特性 +HBCH RADIOTHERAPY DEP