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Track annealing studies in muscovite mica
0191-278X/89 $3.00 + .00 © 1989 Pergamon Press pie
Nucl. Tracks Radiat. Meas., Vol. 15, Nos. 1--4, pp. 241-244, 1988 Int. J. Radiat. Appl. lnstrum., Part D Printed in Great Britain
TRACK ANNEALING STUDIES IN MUSCOVITE MICA A.S. SANDHU, SURINDER SINGH and H.S. VIRK SSNTD Laboratory, Department o f Physics, Guru Nanak Dev University, Amritsar-143 005, India.
A b s t r a c t - The e f f e c t o f c r y s t a l l o g r a p h i c s t r u c t u r e on t h e a n n e a l i n g b e h a v i o u r o f heavy i o n s r a d i a t i o n damage i n m u s c o v i t e is r e p o r t e d . I t has been found t h a t t h e t r a c k s l y i n g p a r a l l e l t o t h e c l e a v a g e p l a n e s a r e much more r e s i s t a n t to t h e r m a l a n n e a l i n g t h a n t h o s e l y i n g . p e r p e n d i c u l a r to the cleavage planes. The a c t i v a t i o n e n e r g y (E a ) i s f o u n d to vary with the incident angle. However, f o r a g i v e n d i p a n g l e t h e v a l u e o f Ea seems t o be i n d e p e n d e n t o f t h e n a t u r e and energy of i n c i d e n t i o n . 1. INTRODUCTION I t has been shown e a r l i e r 1 t h a t t h e a n n e a l i n g of f i s s i o n fragment tracks normal t o t h e s u r f a c e o f m u s c o v i t e p r o c e e d s more r a p i d l y t h a n t h o s e w h i c h are nearly parallel to cleaved surface. B u l l and D u r r a n i 2 a t t r i b u t e d this effect to the directional differences in the diffusion coefficients of the atomic d e f e c t s a s s o c i a t e d w i t h t h e damage t r a i l . Crystalline m i n e r a l s have a r e g u l a r atomic s t r u c t u r a l a r r a n g e m e n t and t h e a t o m i c s p a c i n g i s q u i t e variable along different crystallographic directions. I t has been shown earlier3-4 that the value of activation e n e r g y i n a p a t i t e and q u a r t z v a r i e s considerably with crystallographic orientation t n t h e same c r y s t a l . The present study investigates the track annealing kinetics in muscovite d e t e c t o r i n o r d e r t o see t h e i n f l u e n c e o f c r y s t a l l o g r a p h i c s t r u c t u r e on activation energy of t r a c k a n n e a l i n g . 2. EXPERIMENTAL PROCEDURE D i f f e r e n t s e t s o f samples p r e p a r e d f r o m m u s c o v i t e w e r e exposed t o 238U (10 M e V / n ) , 93Nb (18 MeV/n) and 208pb (17 MeV/n) t o n beams from t h e UNILAC accelerator at GSI Darmstadt, West Germany, at 15 ° and 75 ° angles of incidence w.r.t, the detector surface. Another set of samples from muscovite was irradiated with collimated beam of fission fragments from 252Cf source in vacuum chamber. The irradiated samples were heated at various temperatures ranging from 350 to 700°C, for lO mln intervals. The unannea[ed samples were etched in 48 ~ HF to reveal full residual track lengths. The track lengths were measured at each t e m p e r a t u r e w l t h an Olympus binocular microscope and the results are shown in Fig.l(a-d). The following empirical relationS: V
a
= At -n e -Ea/kT
(i)
is used to determine the activation energy (Ea) for different ions. track annealing rate (Va) is calculated from the relation:
Va = d L / d t
The
(2)
assuming that Va remains constant over the first I0 mln of heating. Plot of InVa vs I/T for different ions are shown in Fig.2(a-d). The values of Ea are given in Table i. 3. RESULTS AND DISCUSSION The experimental data on annealing of heavy ion tracks in ~uscovite fully satisfies the empirical relation proposed by ~k)dgll and Virk D. A comparison of Ea for different dip angles (Table I) shows that the minimum energy
241
242
A . S . S A N D H U et al.
N USCOVITE [ 4 8 % HF, 2S°C. 140rain ] 120
MUSCOV[ TE { 4 I~%HF, 25"C, 120 rain | 160
93Nb { I0.0 MoVn'I],ANNEALING TIME, ! 0 min 110
150 I00
H.O 90
13C 80
• ,¢
120
\
o
\
75 °
[ 7o
~ 110
•~ c
~ I00
6O ,
o
go
4C
,
i
z,
Cont.
I
]SO
.
I
.
400
,
450
.
J
,
S00
J
I
SSO
[
600
I
650
.
0
J
,
,
,,
i
,
i
,
i
,
i
,
,
,
Cont." 350 400 450 SO0 S50 AnneaLing temperature ( °C|
700
Annealing temperature ( °C }
(o)
i
,
600
,
,
J
650 100
(b) M U S C O V I T E [ 4 8 % HF, 2 5 ° C , 6 0 r a i n ]
MUSCOVITE
238U (10.0
[4S% M
HF',
2S°C, EO rain |
FISSION FRAGMENTS [ZSZCf ]
*V t;1) 14
OIP &NGL[
ANNEALING TIME ,10 rain
80
,iS ° 12
70
10
60
5O
£
~,° w
u o
!.
30
2O
2 * ,, i i I , I , I i I i | , i , I Cont." 350 &00 450 S00 SS0 600 &50 700 Annoaling
ternperoture ( °C )
(c) Fig.l.
|
ii
I
Cont." 300
|
,
|
350
Annealing
I
400
i
|
'
4S0
ternpereture(°C)
(d)
The variation of mean length of (a) 93Nb (b) 208pb (c) 238U and (d) fission fragment tracks with annealing temperature for different dip angles in muscovite.
1
SO0
,
i
SSO
TRACK ANNEALING IN MUSCOVITE MICA
243
MUSCOVITE
+3.0 • 3.0
MUSCOVITE 93NbllB.0
* 2.0
20t~pb(
17.0 MeV
~1)
+2.0
MEV ~1)
D i P ANGLE DiP ANGLE • ISe
* 1.0
oiS"
+1.0
0-0
0-0
- 1.0
-2.0
::~ o 2.0
_c
-l.O -L.O
-&.O
°S~
a -
LO
1,1
1,~
1.$
1.4
1.1
!.1
5.0
11.1e
i 1 ,o
10'I/T(oK)
i 1.1
i
| 1.2
i 1.3
Id/T
,
i 1.L
.
i 1.ll
,
i 1.1
.
i i.y
(°K)
(b)
(a)
MUSCOVITE
MUSCOVITE +2.0
•
2S2cf
2 3 8 U ( I O M eV r~1) ~ .
+1.0 OlP•15OANGLE
OIP ANGLE
\"k
idli
.,s"
0"0 -1.G -1.0
-t,4D
-44} i 1.o
i 1.1
,
i , 1.2
i 1.)
.
103/T ( ° K )
(c)
Fig.2.
i 14
,
I 15
'
i ~l
,
1 I.?
-MI 1.o
i
i
1
i
1.1
1.a
i.*
1.4
t~/T(GK)
(d)
Plot of lnVa vs I/T for (a) g ~ b (b) 208pb (c)238U and (d) fission fragment tracks in muscovite,
,
s |.I
i 14
,
i 1.7
,
J 1,l
244
A . S . S A N D H U et al.
Table I.
The value of activation energy in muscovite using different ion beams.
Incident
ion
Activation
Ea(eV)
energy
15 °
75 °
93Nb (18 MeV/n)
0.98
0.78
208pb (17 MeV/n)
0.97
0.78
238U
0.97
0.79
0.96
0.78
(i0 MeV/n)
Fission fragments (252Cf)
required to start the annealing process in muscovite is strongly controlled by the crystallographic orientation. However, it is interesting to note that even using three different beams of ions, identical values of Ha=are observed for a given dip angle. This further supports the hypothesls u that activation energy is independent of the nature and energy of the track forming ion a n d is a characteristic property of the detector material. ACKNOWLEDGEMENTS
The authors are grateful to Dr. R. Spohr, GSI, Darmstadt, for providing heavy ion irradiation facilities at UNILAC accelerator. One of them (A.S. Sandhu) is grateful to CSIR, New Delhi, for the award of SRF(9/254/86-EMR-I). REFERENCES
I. 2. 3.
4. 5.
Ya. E. Geguzin t I.V. Vorebeva and I.G. Berjlna, Soviet Phys. Solid State i0, 1431(1968)o R.K. Bull and S.A. Durranl, Proc. 6th Lunar Sci. Conf., 3619(1975). A.S. Sandhu, Surinder Singh and H.S. Virk, Mineral. 3. 13, 307(1987). A.S. Sandhu, Surind@r Singh and H.S. Virk, Mineral. 3. 14, I(1988). S.K. Modgil and H.S. Virk, Nucl. Instrum. Meth. 812, 212(1985).
Nucl. Tracks Radiat. Meas., Vol. 15, Nos. 1--4, pp. 241-244, 1988 Int. J. Radiat. Appl. lnstrum., Part D Printed in Great Britain
TRACK ANNEALING STUDIES IN MUSCOVITE MICA A.S. SANDHU, SURINDER SINGH and H.S. VIRK SSNTD Laboratory, Department o f Physics, Guru Nanak Dev University, Amritsar-143 005, India.
A b s t r a c t - The e f f e c t o f c r y s t a l l o g r a p h i c s t r u c t u r e on t h e a n n e a l i n g b e h a v i o u r o f heavy i o n s r a d i a t i o n damage i n m u s c o v i t e is r e p o r t e d . I t has been found t h a t t h e t r a c k s l y i n g p a r a l l e l t o t h e c l e a v a g e p l a n e s a r e much more r e s i s t a n t to t h e r m a l a n n e a l i n g t h a n t h o s e l y i n g . p e r p e n d i c u l a r to the cleavage planes. The a c t i v a t i o n e n e r g y (E a ) i s f o u n d to vary with the incident angle. However, f o r a g i v e n d i p a n g l e t h e v a l u e o f Ea seems t o be i n d e p e n d e n t o f t h e n a t u r e and energy of i n c i d e n t i o n . 1. INTRODUCTION I t has been shown e a r l i e r 1 t h a t t h e a n n e a l i n g of f i s s i o n fragment tracks normal t o t h e s u r f a c e o f m u s c o v i t e p r o c e e d s more r a p i d l y t h a n t h o s e w h i c h are nearly parallel to cleaved surface. B u l l and D u r r a n i 2 a t t r i b u t e d this effect to the directional differences in the diffusion coefficients of the atomic d e f e c t s a s s o c i a t e d w i t h t h e damage t r a i l . Crystalline m i n e r a l s have a r e g u l a r atomic s t r u c t u r a l a r r a n g e m e n t and t h e a t o m i c s p a c i n g i s q u i t e variable along different crystallographic directions. I t has been shown earlier3-4 that the value of activation e n e r g y i n a p a t i t e and q u a r t z v a r i e s considerably with crystallographic orientation t n t h e same c r y s t a l . The present study investigates the track annealing kinetics in muscovite d e t e c t o r i n o r d e r t o see t h e i n f l u e n c e o f c r y s t a l l o g r a p h i c s t r u c t u r e on activation energy of t r a c k a n n e a l i n g . 2. EXPERIMENTAL PROCEDURE D i f f e r e n t s e t s o f samples p r e p a r e d f r o m m u s c o v i t e w e r e exposed t o 238U (10 M e V / n ) , 93Nb (18 MeV/n) and 208pb (17 MeV/n) t o n beams from t h e UNILAC accelerator at GSI Darmstadt, West Germany, at 15 ° and 75 ° angles of incidence w.r.t, the detector surface. Another set of samples from muscovite was irradiated with collimated beam of fission fragments from 252Cf source in vacuum chamber. The irradiated samples were heated at various temperatures ranging from 350 to 700°C, for lO mln intervals. The unannea[ed samples were etched in 48 ~ HF to reveal full residual track lengths. The track lengths were measured at each t e m p e r a t u r e w l t h an Olympus binocular microscope and the results are shown in Fig.l(a-d). The following empirical relationS: V
a
= At -n e -Ea/kT
(i)
is used to determine the activation energy (Ea) for different ions. track annealing rate (Va) is calculated from the relation:
Va = d L / d t
The
(2)
assuming that Va remains constant over the first I0 mln of heating. Plot of InVa vs I/T for different ions are shown in Fig.2(a-d). The values of Ea are given in Table i. 3. RESULTS AND DISCUSSION The experimental data on annealing of heavy ion tracks in ~uscovite fully satisfies the empirical relation proposed by ~k)dgll and Virk D. A comparison of Ea for different dip angles (Table I) shows that the minimum energy
241
242
A . S . S A N D H U et al.
N USCOVITE [ 4 8 % HF, 2S°C. 140rain ] 120
MUSCOV[ TE { 4 I~%HF, 25"C, 120 rain | 160
93Nb { I0.0 MoVn'I],ANNEALING TIME, ! 0 min 110
150 I00
H.O 90
13C 80
• ,¢
120
\
o
\
75 °
[ 7o
~ 110
•~ c
~ I00
6O ,
o
go
4C
,
i
z,
Cont.
I
]SO
.
I
.
400
,
450
.
J
,
S00
J
I
SSO
[
600
I
650
.
0
J
,
,
,,
i
,
i
,
i
,
i
,
,
,
Cont." 350 400 450 SO0 S50 AnneaLing temperature ( °C|
700
Annealing temperature ( °C }
(o)
i
,
600
,
,
J
650 100
(b) M U S C O V I T E [ 4 8 % HF, 2 5 ° C , 6 0 r a i n ]
MUSCOVITE
238U (10.0
[4S% M
HF',
2S°C, EO rain |
FISSION FRAGMENTS [ZSZCf ]
*V t;1) 14
OIP &NGL[
ANNEALING TIME ,10 rain
80
,iS ° 12
70
10
60
5O
£
~,° w
u o
!.
30
2O
2 * ,, i i I , I , I i I i | , i , I Cont." 350 &00 450 S00 SS0 600 &50 700 Annoaling
ternperoture ( °C )
(c) Fig.l.
|
ii
I
Cont." 300
|
,
|
350
Annealing
I
400
i
|
'
4S0
ternpereture(°C)
(d)
The variation of mean length of (a) 93Nb (b) 208pb (c) 238U and (d) fission fragment tracks with annealing temperature for different dip angles in muscovite.
1
SO0
,
i
SSO
TRACK ANNEALING IN MUSCOVITE MICA
243
MUSCOVITE
+3.0 • 3.0
MUSCOVITE 93NbllB.0
* 2.0
20t~pb(
17.0 MeV
~1)
+2.0
MEV ~1)
D i P ANGLE DiP ANGLE • ISe
* 1.0
oiS"
+1.0
0-0
0-0
- 1.0
-2.0
::~ o 2.0
_c
-l.O -L.O
-&.O
°S~
a -
LO
1,1
1,~
1.$
1.4
1.1
!.1
5.0
11.1e
i 1 ,o
10'I/T(oK)
i 1.1
i
| 1.2
i 1.3
Id/T
,
i 1.L
.
i 1.ll
,
i 1.1
.
i i.y
(°K)
(b)
(a)
MUSCOVITE
MUSCOVITE +2.0
•
2S2cf
2 3 8 U ( I O M eV r~1) ~ .
+1.0 OlP•15OANGLE
OIP ANGLE
\"k
idli
.,s"
0"0 -1.G -1.0
-t,4D
-44} i 1.o
i 1.1
,
i , 1.2
i 1.)
.
103/T ( ° K )
(c)
Fig.2.
i 14
,
I 15
'
i ~l
,
1 I.?
-MI 1.o
i
i
1
i
1.1
1.a
i.*
1.4
t~/T(GK)
(d)
Plot of lnVa vs I/T for (a) g ~ b (b) 208pb (c)238U and (d) fission fragment tracks in muscovite,
,
s |.I
i 14
,
i 1.7
,
J 1,l
244
A . S . S A N D H U et al.
Table I.
The value of activation energy in muscovite using different ion beams.
Incident
ion
Activation
Ea(eV)
energy
15 °
75 °
93Nb (18 MeV/n)
0.98
0.78
208pb (17 MeV/n)
0.97
0.78
238U
0.97
0.79
0.96
0.78
(i0 MeV/n)
Fission fragments (252Cf)
required to start the annealing process in muscovite is strongly controlled by the crystallographic orientation. However, it is interesting to note that even using three different beams of ions, identical values of Ha=are observed for a given dip angle. This further supports the hypothesls u that activation energy is independent of the nature and energy of the track forming ion a n d is a characteristic property of the detector material. ACKNOWLEDGEMENTS
The authors are grateful to Dr. R. Spohr, GSI, Darmstadt, for providing heavy ion irradiation facilities at UNILAC accelerator. One of them (A.S. Sandhu) is grateful to CSIR, New Delhi, for the award of SRF(9/254/86-EMR-I). REFERENCES
I. 2. 3.
4. 5.
Ya. E. Geguzin t I.V. Vorebeva and I.G. Berjlna, Soviet Phys. Solid State i0, 1431(1968)o R.K. Bull and S.A. Durranl, Proc. 6th Lunar Sci. Conf., 3619(1975). A.S. Sandhu, Surinder Singh and H.S. Virk, Mineral. 3. 13, 307(1987). A.S. Sandhu, Surind@r Singh and H.S. Virk, Mineral. 3. 14, I(1988). S.K. Modgil and H.S. Virk, Nucl. Instrum. Meth. 812, 212(1985).