مقرر 236كيم
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G M/N W
( Roentgen ) Becquerel
Debierne ( Mund ) ( Fricke ) ( Lind )
( TNT )
600
131
(Atom)
(Empedocles) ( Leucipus ) ( Democritus )
( constant motion) ( indivisible ) (a tomos )
( element )
( compound ) ( H2O )
(
(X
rays )
( Moseley ) Roentgen )
The contents of the atom
(Atomic mass unit, a.m.u )
10-13
( nucleus ) 10-8 ( neutrons) ( protons )
The Contents of the Nucleus The Proton
( atomic mass units ) ( 1 amu ) (A) ( nucleon )
1.67 x 10- 24
(A
Z)
The Electron
1/1840
9.11 x 10-28
The Neutron ( ( Be ) (1/10 Chadwick )
1837 12
( orbits )
L N M
(K
shell ) K
K
Mass and Atomic Numbers
A
Z1 1H 238
Z = 92
92U
A=1 92238 92U
Z=1 238
146
94Pu
12
Isotopes
(A=1,Z=1)3 1H
1
1H
(A=2,Z=1) (A=3,Z=1)
2
1H
( radioactive )
Z 64
(Radiochemistry)
( Nuclear Chemistry )
( photochemistry ) h ( Ultraviolet ) h
200 340 C =C/ 700 nm
(Visible) 340 nm
( Excited state ) ( Energy of
( Electron transition ) ( Excitation ) excitation )
(Bond Dissociation Energy)
( Monochromatic light )
( Radioactive isotopes ) 137 60 90 ( Van de Graaff )
( Radioactive isotopes )
)
( ( 42 He +2 ) ( Excitation ) ( Ionization )
)
( 1.4 x 109
2.2 x 109 cm sec-1 )
(4
10 M eV )
n
p+ + e-
( Maximum Value )
Antineutrions
40 ( Monoenergetic ) 60
0.03 0.0003 nm 4 Mev ( Discrete energies ) 173.1 1.332 kev
0.5 cm 137 60
X
Rays
Linear Electron Accelerator
630 500
Cyclotron
40
20
0.1kev
nm
peaks
( Bremsstrahlung )
( Characteristic X-rays )
Van de Graaffaccelerator ( Insulating column) ( Moving belt) ( High voltage terminal ) ( Accelerating tube )
(Mercury diffusion pump ) ( coils )
300 1500
( Betatron ) ( Synchrotron )
0.025
Radioactivity and Radiation
( Radioactivity) decay
Decay
A
90
234 90 Th
146
92 144
238
92U
238 92U
-----
234 90
Th
+ 42He (
)
( daughter parent nucleus nucleus )
Decay ( particles) ( positron )
Types of
decay
Electron decay
1
0n
--------
1
1p
+
-
positron decay
1
1p
--------
1
0n+
+
Electron capture
L
k
1
1p
+ 0-1e --------
1
0n
(
+
)
(
-
)
( neutrino ) m =01 0n
--------
1
1p
+
-
+ +
1
1p
--------
1
0n+
+
1
1p
+ 0-1e --------
1
0n
+
( anti
neutrino )
Natural Radioactive Series: 82
64
32
60
.
32
24
51
1.2 Mev
Induced Radioactivity:
6059
Co60
59 Co
59
27Co
+ 10 n
60 27
Co +
31
15P
+d
32
15P
+P
32
31
Interaction of Ionizing Radiation With Matter
Interaction of Heavey Charged Particles with Matter
k 103
Interaction of Electron with Matter :
1/2
Interaction of Gamma
Radiation with Matter
photoelectric effect :
Compton effect
pair production
1.022
I = I 0 e-
x
=
E
+
C
+
P
( photoelectric effect ) ( Compton scattering ) ( pair production) I0 ex
E C P
Absorbed energy = Ia = I0 I a = I 0 ( 1 - e- x )
I = I0
I0 I
0.1 10 0.1 10
Nuclear reasonance scattering and the Mossbauer effect:
Interaction of Neutrons with Matter:
0
n
P+ +
-
+
-
12 min
0.025
( -rays )
( Clusters or spurs ) ( Blobs ) (Short tracks) (Branched tracks)
100
2nm
( Spur ) nm
( Blobs )
A
A+ , e- , A* A+ eA*
h = quantum A*
A+h
( Homolysis )
A*
X. + Y.
( Heterolytic scission ) A* X+ + Y-
( Molecular elimination )
A*
B+C
( Ion-molecule reaction ) A.+ + A A.+ + A AD+ + E. A 2. +
( Ion
fragmentation )
A.+
X+ + Y .
X . + e-
X
X. + A
XH + R .
X. + X.
X2
X. + A
AX .
X.
M.+N ( Disproportionation )
X. + X.
I+J
( Blobs )
( Blobs ) ( primary species )
( Scavangers ) A. + S AS .
( e solv ) e- + solvent e-solv + S e-solv S .S .10-4 M 0.1 M ( Blobs ) 10-4 M AS .
10-18 10-15 10-14 10-13 10-12 10-11 10-10 ( Diffuson controlled reactions ) ( single state ) 10-5 ( Triplet state ) 10-3 1.0 ( Postirradiation ) 10-8
Units and Experimental Techniques :
( Radiation dosimetry)
Hz
3.7 x 1010 ( Roentgen ) 0.000258 ( Dose rate )
Ci
( Absorbed dose ) 10 100
0.03 nm
E = h = hc/ E =( 6.6x10-34 x 3x1010) / ( 0.03x10-7) =6.61 x 10-15J
1.0 ev = 0.16021 x 10-18J ( 1.0 x 6.61 x10-15)/ 0.16021x10-18 = 41300 ev kev = 0.16021 x 10-15 J ( 1.0 x 6.61 x 10-15) / 0.16021 x10-15 = 41.3 kev
Rad = 100 erg / gm = 10-5 J/gm = 6.24 x 1013 ev/gm = 2.4 x 10-6 cal / gm = 1.83 x 1012 ion-pair / gm air = 10-5 watt.sec / gm
ev / molecule = 23.06 kcal / mol
= 96.49 kJ / mol
(Ion-
( Radiation Chemical Yaild ) pair yield)
G M/N
G G 100 ev G
G = ((n A)/D) x 100 ev
D
A
n
M/ N W 100 No. of ion pair = 100/W
W
100 / 30 = 3.3 W G 100 ev
W = 30 ev
G = ( 100/W ) x ( M/N)
M N
( M/N)
( Radiation Dosimetry )
( Steady-state radioloysis ) ( Pulse-radiolysis )
Fricke-Dosimeter
( Ceric sulphate dosimeter )
( Nitrous oxide dosimeter )
K6Fe(CN)6
HO2
Nuclear Radiation Detectors :
Radiation detectors
Radiation Chemistry of Gases
G
G
( ( Initiator )
75% Platinum black )
700
1100
( Initiation ) H2+ + e+ H 2*
H2
H2 H2* H2+ + H2* H3+ + e-
2H H 3+
3H
H2+ + e-
2H
( Chain propagation )
H + para-H2
ortho-H2
( Termination ) H 1/2 H2
M 2H + M H2 + M
253.7 nm
Radiation Chemistry of Liquid Organic Compounds:
(Fused ring )
Ge
3 Ge 0.1 Ge 1
RH C6H5Br + e-
RH+ + eC6H5 + Br
C6H5 + RH
R + C6H6
M H + RH R + H2 RH2 R + R-R2 H+H H+R M+N H2 RH
H2 + M RH+ + eRH+ + RH RH** H2 + R2+
RI ( Isotopic dilution analysis )
I2
85%
C6H12
C6H11 . + H .
15%
C6H12
C6H10 + H2
H + C6H12 2C6H11 .
C6H11 . + H2
C12H22
2C6H11 .
C6H12 + C6H10
C
C
Cyclohexanone
Cyclohexanol
Cyclohexyl hydroperoxide C6H11OOH
H + C6H12
C6H11 + H2
C6H11 + O2
C6H11OO
2 C6H11OO
C6H11OH + C6H10O + O2
HO2
e- + N2O
N2 + O-
Radiation Chemistry of Polar Liquids:
5.17
H-OH 500
H2O
e- , H2O+ , H2O*
eaq- , H , H2 , H2O2 , OH , H3O+
Primary Radical Species
Hydrated electrons
eaq- + eaqeaq- + H2O
H2 + 2OH-
H + OH
H+ + eaq-
H
O2-
200
240 nm
HO2. O2-
H. + RH.
H2 + R.
230nm
H2O+ + H2O H2O*
OH + H3O+ OH + H
OH.
O- + H+
OH- + OH.
H2O + OO-
O-
S- + OH.
S + OHS-
HO2 OH. + H2O2
H2O + HO2
O2-
HO2.
O2 + H. O2 + eaqO2230 nm
HO2. O2-. HO2.
International Commission on Radiological Protection ( ICRP) ( ICRP )
5 0.5 5
50
60
2
20
8
Handbook of Radiation Chemistry , by Yoneho Tabata ; Yasuo Ito ;
Seiichi Tagawa , 1991 by CRC press , Inc .USA
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