電離輻射的劑量和單位

1、HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT電離輻射與物質(zhì)的相互作用HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT不帶電粒子（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總質(zhì)量阻止本領(lǐng)（total mass stopping power) HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT帶電粒子的射程 HBCH RADIOTHERAPY DEPAR

3、TMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT0.5mm R90 R50 RpDmaxD90DsD50 DxRqG=Rp/(Rp-Rq)電子束特性參數(shù)的定義HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT作用特征 HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT作用方式 光電子特征輻

4、射俄歇電子HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT反沖電子HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT負電子e-正電子e+HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT HBCH RADIOTHERAPY DEPARTMENT

5、HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT設(shè)定條件 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輻射量時間提出者輻射量演變單位演變照射量(X)1895 年1928 年1937 年1956 年1962 年1977 年物理學(xué)家國際放射學(xué)大會國際放射學(xué)大會ICRUICRUICRU紅 斑 量X線輻射國際單位X線劑量國際單位照射劑量照射量照射量(Dq/Dm)紅斑量倫琴(R)倫琴(R)倫琴(R)倫琴(R)CKg-1吸收劑量(D)1948 年1953 年1962 年1971 年1975 年帕 克ICRUICRUICRU國際計量大會物理倫琴當(dāng)量吸收劑量(D=/m)吸收劑量(D=/m)吸收劑量(D=/m

8、)吸收劑量(D=d/dm)Rep(=84爾格克-1)拉德(rad)拉德(rad)拉德(rad)戈瑞(Gy)劑量當(dāng)量(H)1948 年1955 年1962 年1979 年帕 克ICRUICRU國際計量大會人體劑量當(dāng)量劑 量劑量當(dāng)量(H=DQN)劑量當(dāng)量(H=DQN)雷姆(rem=1repRBE*)雷姆(rem)雷姆(rem)希沃特(Sv) 常用輻射量和單位歷史演變簡表常用輻射量和單位歷史演變簡表 *RBE-相對生物效應(yīng)HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT國際輻射單位

9、和測量委員會HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT法定計量單位HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT定義定義: : 意義：意義：表達式：表達式： 粒子注量率：粒子注量率：HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT定

10、義定義: : 意義：意義：表達式：表達式： 能量注量率：能量注量率：HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT定義：定義：意義：意義：HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT表達式：表達式： 與能量注量的關(guān)系與能量注量的關(guān)系： HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBC

11、H RADIOTHERAPY DEPARTMENT單單 位：位： 、HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT應(yīng)用范圍： 、HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT 單位時間內(nèi)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意義：是衡量在單位質(zhì)量物質(zhì)中轉(zhuǎn)移給次級帶電粒子初始動能總和的多少的物理量。n只適用于間接致電離輻射,但適用于任何物質(zhì)。n在帶電粒子平衡條件下,可表示為: HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RA

14、DIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT電子平衡：電子平衡： HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT帶電粒子平衡帶電粒子平衡VPdH

15、BCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT帶電粒子平衡帶電粒子平衡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 忽略衰減HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT劑量當(dāng)量 品質(zhì)因數(shù)與輻射類型的關(guān)系品質(zhì)因數(shù)與輻射

17、類型的關(guān)系照射類型 射線種類 品質(zhì)因數(shù) 、電子束 1 熱中子、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 重反沖核 20 、 +、e、 1 內(nèi)照射 10 裂變過程中的碎片、 反沖核 20HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT內(nèi)含活度內(nèi)含活度（Contained Activity） 即裸源活度。外觀活度外觀活度（Apparent Activity） 封裝后的源表面活度。照射

18、量率常數(shù)照射量率常數(shù)（ ） 用于描述不同核素，單位活度，距單 位距離處照射量率大小 的物理量。空氣比釋動能率常數(shù)空氣比釋動能率常數(shù)（ ） 用于描述不同活度，不同核素， 距單位距離處比釋動能率大小的物理量。 部分核素的照射量率和空氣比釋動能率常數(shù)部分核素的照射量率和空氣比釋動能率常數(shù) 核核 素素 (R m2hr-1 Ci-1) (Gy m2 hr-1 MBq-1) 鈷-60 1.308 0.310 銫-137 0.332 0.0781 銥-192 0.469 0.111 碘-125 0.145 0.034HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY

19、DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT內(nèi)含活度內(nèi)含活度（Contained Activity） 即裸源活度。外觀活度外觀活度（Apparent Activity） 封裝后的源表面活度。照射量率常數(shù)照射量率常數(shù)（ ） 用于描述不同核素，單位活度，距單 位距離處照射量率大小 的物理量?？諝獗柔寗幽苈食?shù)空氣比釋動能率常數(shù)（ ） 用于描述不同活度，不同核素， 距單位距離處比釋動能率大小的物理量。 部分核素的照射量率和空氣比釋動能率常數(shù)部分核素的照射量率和空氣比釋動能率常數(shù) 核核 素素 (R m2hr-1 Ci-1) (Gy m2 hr-1 MBq-1) 鈷-60

20、 1.308 0.310 銫-137 0.332 0.0781 銥-192 0.469 0.111 碘-125 0.145 0.034HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT電離輻射的測量HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT電離室的種類HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPART

21、MENTHBCH RADIOTHERAPY DEPARTMENT自由空氣電離室HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT柱形電離室HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT柱形電離

22、室的結(jié)構(gòu)HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT電離室的工作特性HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT電離室的工作特性HBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENTHBCH RADIOTHERAPY DEPARTMENT電離室的工作特性 +HBCH RADIOTHERAPY DEP