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LIU LNG BC X&TC DNG CA BC X ION HO LN VT CHT SNG
-
Questions Phng x l g ? Phng x ion ho l g ? Phng x n t u ? nh hng
ca phng x nh th no ? Phng x c li hay c hi ?
-
Phng x l g ?
-
Ph bc x in tf = c/
-
Cc ht phng
x++/-+/-NeutronsProtonsPionsMuonsNeutrinosElectrons+/-and many
othersAlphas
-
Bc x ion ho--RadiationElectronIon
-
IonizingNon ionizing
-
Phng x n t u ?Ngun t nhin:Tia t v trPhn r t nhinNgun nhn to:Tia
X - quangY hc ht nhnTro bi phng xNng lng ht nhn
-
NGUN T NHINProtonPionsMuons1 muon per minute
-
NGUN T NHIN
-
Phn r t nhin60CoBeta ray(electron)226RaAlpha ray (helium
nucleus)7BeGamma ray7Be 7Li + 11C 11B + +60Co 60Ni + 226Ra 222Rn +
11CPositronAntoine Henri Becquerel(18521908)Discovered
radioactivity of uranium
-
Alpha, Beta, GammaSradiumNamed by Ernest
Rutherford(18711937)filmleadN
-
Kh nng m xuyn ca bc x
-
Ngun nhn to
-
XraysWilhelm Roentgen(18451923)Xray tube
-
Xrays
-
Cancer Therapy60Co
-
Nng lng ht nhnEnergy generated by fission of uranium
-
Accelerator ON
-
Hiroshima70,000 people died by the end of the year because of
the bombing
-
Chernobyl
-
ChernobylNumber of cases of thyroid cancers in children under 15
years oldThree of the 1036 children have died (2002)
Chart2
386811
41712
688814
5891116
3112658
6212285
62349114
87144132
77644127
82747136
67256125
73536114
39984492
Belarus
Russian Federation
Ukraine
Total
Year
Number of thyroid cancers
Sheet1
BelarusRussian FederationUkraineTotal
8630.280.211
8740.310.370.112
8860.480.114
8950.3110.216
90311.910.3260.258
91623.910.3220.285
92623.930.9490.5114
93875.510.3440.4132
94775.162.8440.4127
95825.672.5470.5136
96674.820.6560.6125
97735.652.2360.4114
98393.9440.592
Sheet1
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
Belarus
Russian Federation
Ukraine
Total
Year
Number of thyroid cancers
Sheet2
Sheet3
-
LIU LNG BC X
-
Ch p dng cho cc bc x sng in t (tia X v gamma), cho bit s in tch
cng du ca cc ion c to ra trong mt n v khi lng khng kh kh di tc dng
ca tia X hay tia gamma.LIU CHIUQ: tng s in tch cng du sinh ra trong
khi lng m
-
LIU CHIUTrong h SI, n v o liu chiu l C/kg. n v thng dng l
Roentgen (R). Gia C/kg v R c mi lin h nh sau: 1R = 2,58x10-4 C/kg
hay 1C/kg = 3876R.
-
LIU HP THLiu hp th l nng lng b hp th trn n v khi lng ca i tng b
chiu x.Trong , E(J) l nng lng ca bc x mt i do s ion ho trong i tng
b chiu x, m(Kg) l khi lng ca i tng b chiu x.
-
LIU HP THGi tr liu hp th bc x ph thuc vo tnh cht ca bc x v mi
trng hp th
-
TRNG S PHNG X
-
LIU TNG NG
-
LIU HIU DNG
-
BNG TRNG S M
-
LIU HIU DNG
-
MT S LIU KHC.v.v.
-
i vi mt ngun phng x pht tia gamma, c trng cho kh nng ion ha vt
cht ca chm gamma , ngi ta dng h s ion ha gamma (k hiu l I). I l sut
liu lng chiu Pc ca mt ngun im c hot phng x C = 1Ci ti im cch ngun
mt khng r = 1m v khi mi phn r phng x pht ra 1 tia gamma; n v I l
Rm2/Ci.h. Nh vy, sut liu lng Pc ca mt ngun phng x gamma c hot phng
x C (Ci) cho trc ti im cch ngun r (m) l:Trong Pc tnh bng R/h. Xc nh
liu lng bc x
-
1. a) Tnh liu hp th mt ngi phi nhn trong 2 gi, khi lm vic vi
ngun phng x gamma Na22 c phng x 100Ci v ng cch ngun 50cm. Bit chu k
bn r ca ng v Na22 rt di, hng s gamma ca ng v K=12(R.cm2/h.mCi), v i
vi m 1R tng ng vi 0,95rad b) TnhLiu tng ng ? Nu cng liu hp th nh cu
a nhng do bc x neutron nng lng 2,5MeV to ra th liu tng ng l bao
nhiu ? c) Nu ngun gamma Na22 cu a v neutron cu b chiu vo c quan
(phi). Tnh liu hiu dng ngi phi nhn trong thi gian trn d) Nu ngun
gamma Na22 cu a chiu vo gang v neutron cu b chiu vo c quan (phi).
Tnh liu hiu dng ngi phi nhn trong thi gian trn
-
4.5.a) Mt nhn vin b chiu khp c th nhn liu hp th ca gamma l 8mGy
v 180mGy t neutron nng lng 80 keV (Wr=6). Tnh liu hiu dng b) Mt nhn
vin b chiu trong bi bc x alpha ln phi l 8mGy; 180mGy ln tuyn gip v
ngoi ton thn bi gamma l 14mGy .Tnh liu hiu dng ngi ny nhn
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