$
[; c .U P c p Ò Å ¤X N Ë ù p § ü X ¢ PIN º º T ~ ¾© Ñ ÷ ¹ Å Ü Ã ÅP c p] k ù ¹ ÅV Ö « ×M 8 ý Þ
Ã Å Æ õ m Í ± q Ö ¨ ¤V R Ë
» ¢ 9g ` @ · »* å ¬ £ ∗
¸ @ / < Æ § u õ @ / < Æ, F g Å Ò 501-759 (2007¸ 3 Z 4 28{ 9 ~ Ã Î6 £ §)
:
r ½ ¨\ " f H CsI(Tl) $ 3 F g ^ , PIN í Ð s ¸× ¼, y + þ A u 7 £ x; ¤ l Ð ½ ¨$ í ) a y Ø ¦ r
Û ¼% 7 s Tc-99 mÜ ¼ ÐÂ Ò' µ 1 ÏÒ q t H 140 keV _ $ \ -t y ` ¦ 8 £ ¤& ñ H è+ þ A y B j \ s 6
x| ¨ c à º e 6 £ §` ¦ ] jr % i . $ \ -t y Ø ¦` ¦ 0 A # ª ô Ç 7 á x À Ó_ PIN í Ð s ¸× ¼ü <
y + þ A u 7 £ x; ¤ l \ @ /ô Ç ñü < ¸ ú 6 £ §` ¦ 8 £ ¤& ñ ¦, Õ ª : £ ¤$ í ` ¦ ì r$ 3 % i Ü ¼ 9, s \ ¦ : x # þ j è _
¸ ú 6 £ §` ¦ t H è \ ¦ y y × þ % i . × þ ô Ç í Ð s ¸× ¼ü < y + þ A u 7 £ x; ¤ l \ ¦ s 6 x
# $ \ -t y \ @ /ô Ç 8 £ ¤& ñ ` ¦ à º' # , í Ð s ¸× ¼_ À Ó Ð H & J r Û ¼ r Û ¼
% 7
¸ ú 6 £ § \ ß ¼> % ò ¾ Ó` ¦ p u H כ ` ¦ · ú Ã º e % 3 . ¢ ¸ô Ç & ñ + þ A o r ç ß (shaping time) x 9 % i s # QÛ ¼
· ú õ ° ú É r 1 l x ¸| \ " f ¸ r Û ¼% 7 ¸ ú 6 £ § s o H כ ` ¦ · ú Ã º e % 3 .
PACS numbers: 29.40.Wk
Keywords: y Ø ¦, Ä »~ ½ Ó w Õ ª x , y B j , í Ð s ¸× ¼, y + þ A u 7 £ x; ¤ l , $ 3 F g ^
I. " e  ] Ø
Ä
»~ ½ Ó é ß ` ¦ 0 A # Tc-99 m MIBI\ ¦ 6 x ô Ç Ä »~ ½ ÓÛ ¼
± p (scintimammography)` ¦ z ´r < Ê\ e # Q" f, Tc-99 m\
"
f ~ ½ ÓØ ¦ H 140 keV _ $ \ -t y ` ¦ 8 £ ¤& ñ l 0 A
# Z } É r ñ ß ¼l ü < ± ú É r ¸ ú 6 £ § ß ¼l \ ¦ t H 9 uØ þ à
Ôô Ç y Ø ¦ r Û ¼% 7 ` ¦ > hµ 1 Ï H כ s 9 כ ¹ [1, 2]. s Qô Ç r Û ¼% 7 ` ¦ ½ ¨ & ³ l 0 A # ~ ½ Ó ` ¦ r F g
Ü ¼ Ð ¨ 8 K Å Ò H CsI(Tl) ß ¼o Û ¼_ O ` ¦ í Ð s ¸× ¼ _
F g { 9 \ ½ + Ë % i Ü ¼ 9, s M : í Ð s ¸× ¼\ { 9
) a r F g É r ñ Ð+ -& ñ / B N © ` ¦ Ò q t$ í ô Ç . y
Ø ¦ \ s 6 x ÷ & H s Qô Ç í Ð s ¸× ¼ H 9 uØ þ à Ô
¦, $ í 0 p x @ /q ´ òÖ ¦ s Z } H © & h ` ¦ t ¦ e t ë
ß , $ \ -t y Ø ¦ r Û ¼% 7 ` ¦ ½ ¨$ í H PIN í
Ð s ¸× ¼ü < y + þ A u 7 £ x; ¤ l (charge sensitive preamplifier) _ ½ + Ë : £ ¤$ í Ü ¼ Ð # Ø ¦ r Û ¼% 7 _ $ í 0
p
x : £ ¤$ í ` ¦ \ V8 £ ¤ l j Ë µ[ þ t # Q ¿ º è \ ¦ ½ + Ë H X < # Q 9
¹
¡
§` ¦ î ß ¦ e . ¢ ¸ô Ç, í Ð s ¸× ¼\ " f µ 1 ÏÒ q t÷ & H ñ
H Õ ª ß ¼l F g7 £ x C ' a \ q # B Ä º ± ú Ü ¼Ù ¼ Ð, Ø ¦ r Û
¼% 7 _ ¸ ú 6 £ § É r $ \ -t y _ 8 £ ¤& ñ # Â Ò\ ¦ & ñ
H B Ä º × æ כ ¹ô Ç כ ¹ è ½ + É Ã º e . Õ ª Q , í Ð s ¸
×
¼ü < ñ% o è ½ + Ë ) a Ø ¦ r Û ¼% 7 _ : £ ¤$ í ` ¦
∗
E-mail: [email protected]
&
ñ H כ ¹ è\ @ / # " î S X y · ú 9 \ O Ü ¼ 9, : £ ¤ y
$
\ -t y Ø ¦ r Û ¼% 7 \ " f H 8¹ ¡ ¤ Õ ª Q .
" f, ñü < ¸ ú 6 £ § _ à ºï r` ¦ \ V8 £ ¤ ¦, s \ ¦ 8 £ ¤& ñ ) a õ ü
< q §, ì r$ 3 # : r Ø ¦ r Û ¼% 7 _ : £ ¤$ í \ % ò ¾ Ó` ¦ Å Ò
H כ ¹ è\ ¦ ¸Ø ¦ H כ s 9 כ ¹½ + É כ s . s \ ¦ 0 A # ,
ÐÄ » ¦ e H í Ð s ¸× ¼ü < y + þ A u 7 £ x; ¤ l
×
æ \ & h ] X ô Ç כ ` ¦ Y > t × þ ¦, s \ ¦ " f Ð ½ + Ë
#
Y > t y " é ¶ \ @ /ô Ç 8 £ ¤& ñ x 9 ì r$ 3 ` ¦ Ã º' % i
.
II. Þ Ã Å Æ ¹ Å
í Ð s ¸× ¼_ Ø ¦§ 4 é ß \ " f_ ñ H ç ß é ß ô Ç s
: r d ` ¦ : x # ¸Ø ¦ ½ + É Ã º e Ü ¼ 9, > í ß s 6 x s ¸2 ¤ PIN í Ð s ¸× ¼_ I % ò % i \ ¸² ú ô Ç F g H < Hz ´ \ O s
-& ñ / B N © ` ¦ Ò q t$ í ô Ç ¦ & ñ % i . í Ð s ¸
×
¼_ F g { 9 \ ½ + Ë ) a CsI(Tl) ß ¼o Û ¼_ O _ $ 3 F g s 1
p q (light yield)` ¦ L y , F g È Òõ ´ òÖ ¦ (transmission effi- ciency)` ¦ ε, í Ð s ¸× ¼_ ª ´ òÖ ¦ (quantum effi- ciency)` ¦ η(λ) ¦ ½ + É M :, í Ð s ¸× ¼ ? /\ " f Ò q t$ í
)
a ñ _ Ã º Q S H 6 £ § õ ° ú s & ñ _ ½ + É Ã º e .
Q S = L y · ε · η(λ) (1)
-378-
#
l " f 140 keV\ @ /ô Ç CsI(Tl)_ L y H 9100 [3], DE- TECT97 r Ó ý t Y Us Ü ¼ РÒ' ¸Ø ¦ ) a ε H 0.69, d (2) Ð Â
Ò' ½ ¨ô Ç í Ð s ¸× ¼_ η(λ) H 0.87 s . DETECT97 r
Ó ý t Y Us É r Ï ã J] X Ò ¦ (refractive index) s 1.79s ¦ ß ¼l
2.4 mm × 2.4 mm × 6 mm CsI(Tl) ß ¼o Û ¼_ O , Ï ã J] X Ò
¦ s 1.56s ¦ ¿ ºa 1 µm F g ] X Ã Ì] j (optical grease), Ï
ã J] X Ò ¦ s 1.46s ¦ à º F g  Ò_ ¿ ºa 1 µm í Ð s
¸× ¼ ½ + Ë÷ &% 3 ` ¦ M :\ ¦ & ñ # à º' ÷ &% 3 .
η(λ) = S × 1240
λ × 100[%] (2) F
g y ¸ (photosensitivity) S 0.38 í Ð s ¸
×
¼ü < 540 nm © _ y n C` ¦ ~ ½ ÓØ ¦ H ß ¼o Û ¼_ O \ @ / # [3], í Ð s ¸× ¼ ? /\ " f Ò q t$ í ) a 8 ú x ñ _ à º H 5479 > h Ð \ V8 £ ¤ ÷ &% 3 Ü ¼ 9, s H ë H ³\ " f ] jr ¦ e H Ã
ºu \ ¸ ú Â Ò½ + Ë < Ê` ¦ · ú Ã º e [4]. s Qô Ç ñ_ ß ¼l
\
¦ F G @ / o l 0 AK " f H $ 3 F g ^ \ " f µ 1 ÏÒ q t ) a y n C` ¦ í Ð
s ¸× ¼\ " f ´ òÖ ¦& h Ü ¼ Ð Ã º| 9 H כ s Á º% Á Ð × æ כ ¹
. { 9 ì ø Í& h Ü ¼ Ð $ 3 F g ^ _ $ 3 F g s 1 p q õ í Ð s ¸× ¼_
ª ´ òÖ ¦ É r 6 x e _ Ð & ñ ½ + É Ã º e H ½ Ós m
Ù ¼ Ð, 7 £ ¤ Ò q tí ß \ _ K " f & ñ ÷ &Ù ¼ Ð, ß ¼o Û ¼_ O õ í
Ð s ¸× ¼ s _ Ï ã J] X Ò ¦` ¦ ¸ ú ¸½ + Ë # F g È Òõ ´ òÖ ¦
`
¦ Z }e Ü ¼ Ð+ ñ_ ß ¼l \ ¦ F G @ / o ½ + É Ã º e .
III. ± q Ö ¨ ¤V R Ë
1. º º T ~ ¾© ± q Ö ¨
í Ð s ¸× ¼\ " f F g _ Ø ¦ ô Ç> H ¸ ú 6 £ § : £ ¤$ í \ _
K & ñ ) a . í Ð s ¸× ¼_ ¸ ú 6 £ § i P D H ° ú A $
½ Ó (shunt resistance) R SH \ _ K " f µ 1 ÏÒ q t÷ & H \ P ¸ ú 6 £ § (thermal noise) i T , À Ó (dark current) I d ü < F g À
Ó (photocurrent) I L \ _ K " f µ 1 ÏÒ q t÷ & H í ß ò ø ͸ ú 6 £ § (shot noise) i S _ ½ + Ës 9, 6 £ § õ ° ú s ³ ð & ³ ) a .
i P D = q
i 2 T + i 2 S (3)
i S i T s Ù ¼ Ð, í Ð s ¸× ¼ Ð { 9 ÷ & H y n Cs > r F t
· ú
§` ¦ â Ä º\ À Ó Å Ò Ð í Ð s ¸× ¼_ ¸ ú 6 £ § \ l
#
9, d (3) É r 6 £ § õ ° ú s ³ ð & ³½ + É Ã º e .
i P D = i S = p
2qI d B (4)
#
l " f q H _ | ¾ Ós 9, B H ¸ ú 6 £ § @ /% i ; ¤ (noise bandwidth) s .
2. º º T ~ ¾© - Ö « ×M S y ð ± q Ö ¨
í Ð s ¸× ¼, y + þ A u 7 £ x; ¤ l , & ñ + þ A o 7 £ x; ¤ l
(shaping amplifier) ½ + Ë ) a r Û ¼% 7 \ " f & ñ + þ A o 7 £ x
;
¤ l _ & ñ + þ A o (shaping) ~ ½ Ód s CR-(RC) 4 { 9 â Ä º,
^
r Û ¼% 7 _ ¸ ú 6 £ § É r [ j t _ Å Òכ ¹ô Ç ¸ ú 6 £ §" é ¶ \ l ô Ç
[5].
a) Ø ¦ l _ í ß ò ø ͸ ú 6 £ § 0.9 I q
Rτ , b) 7 £ x; ¤ l _ \ P ¸ ú 6 £ § A τ 1 , c) 7 £ x; ¤ l _ 1/f¸ ú 6 £ §. " f, 8 ú x ¸ ú 6 £ § É r
E T OT = 0.9 I R
q τ + A 1
τ + B (5)
#
l " f I R É r Ø ¦ l _ % i ~ ½ Ó ¾ Ó À Ó, q H _ | ¾ Ó, τ H 7 £ x; ¤ l _ & ñ + þ A o r ç ß (shaping time), Aü < B H 8 £ ¤
&
ñ \ ' a ) a © Ã ºs . { 9 ì ø Í& h Ü ¼ Ð E T OT H s : r& h ] X H
Ð H z ´+ « >& h ] X H` ¦ : x K " f \ V8 £ ¤ ½ + É Ã º e .
IV. ÷ m Ç] M ö õ m Í + s ÇÊ Ý
1. ¹ Å Ü Ã ÅP c p] k ù ¹ ÅV Ö « ×M
#
Q t _ y + þ A u 7 £ x; ¤ l × æ E T OT ± ú É r 7
£
x; ¤ l \ ¦ Y > t & ñ # ¸ ú 6 £ § 8 £ ¤& ñ ` ¦ Ã º' % i . eV Product _ eV 5091õ eV 5093, Amptek _ A250õ A250F\ ¦ : r z ´+ « >\ s 6 x % i Ü ¼ 9, s H © 6 x o ) a
y + þ A u 7 £ x; ¤ l × æ ¸ ú 6 £ § à ºï r s ± ú ¦ · ú 94 R e .
` O
Û ¼ µ 1 ÏÒ q tl \ ¦ s 6 x ô Ç §& ñ (charge calibration)` ¦ :
x # y + þ A u 7 £ x; ¤ l _ ¸ ú 6 £ §` ¦ 8 £ ¤& ñ ½ + É Ã º e
%
3 Ü ¼ 9, d (6)õ d (7)\ " f × æ G V , ì r$ 3 l (Multi Channel Analyzer, MCA) ü < u 7 £ x; ¤ l _ { 9 § 4 é ß \ > r F
H §& ñ & J r ' (calibration capacitor) C c \ ¦ s 6 x
# G V , { © ¨ î ç H · ú ` ¦ ¸ ú 6 £ § 1 p x (Noise Equiv- alent Charge, NEC) Ð ¨ 8 H [ jô Ç ~ ½ ÓZ O ` ¦ Ð# ï r
.
Avg.V /Ch. = 1
2 × (F W HM @H.V + F W HM @L.V ) × (H.V − L.V ) (P [email protected] − P [email protected] )
N EC(F W HM ) = C c × (Avg.V Ch.)
q = Q N
1.602 × 10 −19 (6)
Fig. 1. NEC measurements of eV 5091 charge sensitive preamplifier with various capacitances.
d
(7)\ " f Q N É r ¸ ú 6 £ § | ¾ Ó` ¦ · p . & ñ + þ A o r ç
ß õ Ø ¦ l & J r Û ¼_ o\ É r u 7 £ x; ¤ l _ NEC o\ ¦ 8 £ ¤& ñ % i Ü ¼ 9, Fig. 1, Fig. 2, Fig. 3, Fig.
4 \ " f y u 7 £ x; ¤ l \ @ /ô Ç õ \ ¦ Ð# ï r .
8
£ ¤& ñ õ ÐÂ Ò' , & ñ + þ A o r ç ß \ " f ç ß _ s
e t ë ß , eV 5091` ¦ ] jü @ ¦ eV 5093, A250, A250F
H s : r& h ¸4 S q\ Â Ò½ + Ë % i [6]. eV 5093\ " f NEC
É r u 7 £ x; ¤ l \ q # © ± ú ¤Ü ¼ 9, : £ ¤ y ± ú É r ° ú כ _
Ø ¦ l & J r Û ¼\ " f © ± ú É r NEC ° ú כ` ¦ Ð% i .
2. º º T ~ ¾©
í Ð s ¸× ¼_ & J r Û ¼ü < À Ó\ É r l & h :
£ ¤$ í ` ¦ ¦ 9 l 0 A # , ¿ º t ¸4 S q_ í Ð s ¸× ¼
\
@ /ô Ç À Ó\ ¦ 8 £ ¤& ñ % i . Detection Technology _
í Ð s ¸× ¼ PDC 24s-MUü < PDC 100s-CR\ ¦ s 6 x
% i Ü ¼ 9, y y 5 pFõ 54 pF_ & J r Û ¼ ° ú כ` ¦ .
: r z ´+ « >\ " f H ª ô Ç s # QÛ ¼ · ú \ É r CsI(Tl) ü <
í Ð s ¸× ¼_ ½ + Ë % ò ¾ Ó ¸ ¦ 9 % i Ü ¼ 9, Fig. 5ü <
Fig. 6 \ " f Õ ª õ \ ¦ Ð# ï r .
Fig. 2. NEC measurements of eV 5093 charge sensitive preamplifier with various capacitances.
Fig. 3. NEC measurements of A250 charge sensitive preamplifier with various capacitances.
Fig. 5 \ " f í Ð s ¸× ¼ a1, b1, c1 É r CsI(Tl) õ
½
+ Ë t · ú § É r â Ä ºs 9, a2, b2, c2 H a1, b1, c1 y y \ CsI(Tl)\ ¦ ½ + Ëô Ç â Ä º\ ¦ · p . í Ð s ¸× ¼ a1, b1, c1 É r Ä »´ ò & h s 2.4 mm × 2.4 mms ¦, & J r
Û ¼ 5 pF PDC 24s-MUs .
Fig. 5 \ " f Ð , CsI(Tl)\ ¦ ½ + ËÙ þ ¡` ¦ â Ä ºü < ½ + Ë t
· ú § ¤` ¦ â Ä º\ s e 6 £ §` ¦ · ú Ã º e . CsI(Tl)s
Fig. 4. NEC measurements of A250F charge sensitive preamplifier with various capacitances.
Fig. 5. Dark current measurements of PDC 24s-MU con- sidering coupling effects with CsI(Tl).
½ + Ë÷ &# Q e ` ¦ â Ä º 15V\ " f ½ Ó4 ¤ (breakdown) s µ 1 Ï Ò q
t 9, a1õ a2\ ¦ q §Ù þ ¡` ¦ â Ä º 2C & ñ ¸_ À Ó ß
¼l _ s \ ¦ Ð% i .
Fig. 6 \ " f, í Ð s ¸× ¼ gü < h H 10 mm × 10 mm _ Ä
»´ ò & h õ 54 pF_ & J r Û ¼\ ¦ t H PDC 100s- CR s . CsI(Tl)\ ¦ ½ + Ë t · ú § ¤` ¦ â Ä º\ ë ß À Ó 8 £ ¤
&
ñ ` ¦ % i Ü ¼ 9, PDC 100s-CRs PDC 24s-MU\ q # a
% ~ É r À Ó : £ ¤$ í ` ¦ Ð% i .
Fig. 7 \ " f H í Ð s ¸× ¼ PDC 24s-MUü < PDC 100s-CR` ¦ y + þ A u 7 £ x; ¤ l eV 5093õ ½ + Ë
#
NEC\ ¦ 8 £ ¤& ñ ô Ç õ \ ¦ Ð# ï r . Õ ªa Ë >\ " f · ú Ã º e 1
p
w s ± ú É r ° ú כ_ & J r Û ¼ ° ú כ` ¦ t H í Ð s ¸× ¼
\
" f ± ú É r NEC ° ú כ` ¦ Ð% i . s â Ä º\ í Ð s ¸× ¼_
¸ ú
6 £ § \ % ò ¾ Ó` ¦ Å Ò H Å Òכ ¹ô Ç כ ¹ è H À Ó Ø ¦ l
_ & J r Û ¼ H כ ` ¦ · ú Ã º e .
Fig. 6. Dark current measurements of PDC 100s-CR without coupling of CsI(Tl).
Fig. 7. NEC measurements of PDC 24s-MU and PDC 100s-CR.
s
© _ õ ÐÂ Ò' , PDC 24s-MU\ ¦ $ ¸ ú 6 £ § í Ð s
¸× ¼ Ð × þ % i Ü ¼ 9, s ] j H & ñ + þ A o 7 £ x; ¤ l _ & ñ + þ A o r
ç ß õ s # QÛ ¼ · ú õ ° ú É r Ø ¦ r Û ¼% 7 _ 1 l x ¸|
`
¦ ¦ 9 # ô Ç . Fig. 8, Fig. 9, Fig. 10\ " f ª ô
Ç & ñ + þ A o r ç ß õ s # QÛ ¼ · ú \ É r Y > t PDC 24s-MU _ NEC 8 £ ¤& ñ õ \ ¦ Ð# ï r .
Fig. 8 õ Fig. 9\ " f, NEC ° ú כ É r í Ð s ¸× ¼_
À Ó_ ß ¼l \ % ò ¾ Ó` ¦ ~ Ã Ît ë ß , & ñ + þ A o r ç ß õ s # QÛ ¼
· ú _ < Êà º H כ ¸ Ð# ï r . í Ð s ¸× ¼ a1` ¦ ] j ü
@ ¦ H 15V_ ½ Ó4 ¤ · ú (breakdown voltage) s ©
\
" f NEC\ ¦ 8 £ ¤& ñ ½ + É Ã º \ O % 3 H X <, a1_ â Ä º CsI(Tl)ü <
½ + Ë÷ &# Q e t · ú §l M :ë H \ ½ Ó4 ¤ s µ 1 ÏÒ q t t · ú § H כ ` ¦ Fig. 5 \ " f S X ½ + É Ã º e . Fig. 10\ " f H  ú ª É r & ñ + þ A o r
ç ß õ H % i s # QÛ ¼ · ú \ " f NEC ° ú כs ± ú 6 £ §` ¦ Ð# ï
r .
Fig. 8. NEC measurements of PDC 24s-MU for reverse bias @ 0.5 µsec shaping time.
Fig. 9. NEC measurements of PDC 24s-MU for reverse bias @ 1.0 µsec shaping time.
Fig. 10. NEC measurements of PDC 24s-MU and eV 5093 charge sensitive preamplifier.
Fig. 11. Counts per channel in MCA with Ba-133 source.
Fig. 12. Counts per channel in MCA without any source.
3. ß e È û s Ú S y ð 8 ý ± q Ö ¨ ¤X N Ë
Fig. 8, Fig. 9, Fig. 10 Ü ¼ ÐÂ Ò' 5 pF_ & J r Û ¼\ ¦
t H í Ð s ¸× ¼ PDC 24s-MUü < CsI(Tl) ½ + Ë ) a c2 ü < eV 5093_ ¸½ + Ës © a % ~ É r ¸ ú 6 £ § : £ ¤$ í ` ¦ f ` ¦
· ú
à º e . ¢ ¸ô Ç © l _ ¸½ + Ë\ @ / # 0.5 µsec_ & ñ + þ A
o r ç ß õ 15V_ s # QÛ ¼ · ú s þ j © _ 1 l x ¸| e
`
¦ · ú Ã º e % 3 Ü ¼ 9, s M :_ NEC ° ú כ É r 700 & ñ ¸\ ¦ Ð
%
i . s â Ä º\ é ß í H y Ø ¦ r Û ¼% 7 _ ¸ ú 6 £ § ë ß ` ¦ ¦ 9
% i
` ¦ M :, Tc-99 mõ Co-57_ ñ@ / ¸ ú 6 £ § q H y y 7.8 õ 6.8s Ù ¼ Ð, $ \ -t y Ø ¦ s 0 p x ½ + É כ Ü ¼ Ð l
@ /½ + É Ã º e .
4. $ [; c .U P c p Ò Å ß e È û s Ú
t } Ü ¼ Ð × æ G V , ì r$ 3 l \ ¦ s 6 x # $ \ -t y
\ @ /ô Ç Û ¼& 7 à Ô! 3 ` ¦ 8 £ ¤& ñ % i . Fig. 11\ " f Ð#
Fig. 13. Counts per channel in MCA with Co-57 source.
Å
Ò1 p w s : r Ø ¦ r Û ¼% 7 ` ¦ s 6 x # Ba-133_ Û ¼& 7 à Ô! 3 8
£ ¤& ñ s 0 p x Ù ¼ Ð, 356 keV_ \ -t \ ¦ t H Ba-133
" é ¶` ¦ r Û ¼% 7 _ §& ñ ` ¦ 0 A # 6 x % i . { 9 ) a y
\ -t \ É r photopeak _ G V , ` ¦ > í ß l 0 A
#
° ú כ` ¦ · ú ¦ e H ¿ º > h_ ` O Û ¼\ ¦ ¦ G V , { ©
_ Ã º\ ¦ 8 £ ¤& ñ % i .
§& ñ õ & ñ Ê ê\ , ~ ½ Ó " é ¶ s > r F t · ú § H ¨ 8 â \ " f
¿
º r ç ß 1 l x î ß Û ¼& 7 à Ô! 3 ` ¦ 8 £ ¤& ñ % i Ü ¼ 9, s \ ¦ Fig. 12 \
"
f Ð# ï r . Tc-99 m É r ì ø Íy l B Ä º Â ú ª 6 x l
\
# Q 9¹ ¡ § s e Ü ¼Ù ¼ Ð, © H ô Ç \ -t \ ¦ t H 122 keV _ Co-57` ¦ 6 x # ¿ º r ç ß 1 l x î ß Û ¼& 7 à Ô! 3 ` ¦ 8 £ ¤& ñ
% i Ü ¼ 9, Fig. 13\ Í Ç x . Ô ¦' > ¸ photopeak_ { 9
Â Ò ë ß s 8 £ ¤& ñ ÷ &% 3 Ü ¼ 9, @ / Òì r ¸ ú 6 £ § % ò % i \ > r F #
¢ -
a# 4 ô Ç photopeak H 8 £ ¤& ñ ½ + É Ã º \ O % 3 . Õ ª Q , s © _
õ Ð p À Ò# Q Ð : r Ø ¦ r Û ¼% 7 ` ¦ s 6 x # Co-57 Ð
H \ -t \ ¦ t H Tc-99m _ 8 £ ¤& ñ s 0 p x ½ + É כ Ü ¼ Ð
\ V8 £ ¤ ) a .
V. + s Ç Â ] Ø
“3. Ø ¦ r Û ¼% 7 _ ¸ ú 6 £ § 8 £ ¤& ñ ”\ " f / å LÙ þ ¡~ כ % ! 3 ,
\
V8 £ ¤ ô Ç ñ ß ¼l ü < r Û ¼% 7 _ ¸ ú 6 £ § ë ß ` ¦ ¦ 9ô Ç , Tc- 99 m õ Co-57_ ñ@ / ¸ ú 6 £ § q H y y 7.8õ 6.8s Ù ¼ Ð,
: r Ø ¦ r Û ¼% 7 ` ¦ s 6 x # $ \ -t y ` ¦ 8 £ ¤& ñ
H X < ë H ] j \ O ` ¦ כ s . Õ ª Q , Ø æì r ô Ç ñ@ / ¸ ú 6 £ § q
\
¦ f \ ¸ Ô ¦ ½ ¨ ¦ Co-57 " é ¶ \ @ /ô Ç photopeak
\
-t Û ¼& 7 à Ô! 3 © \ " f ¸ ú 6 £ § % ò % i \ > r F % i Ü ¼ 9, s
H Ba-133 " é ¶ \ @ /ô Ç photopeak_ > í ß ` ¦ : x # Co- 57 _ photopeak 200 G V , H % , 7 £ ¤ ¸ ú 6 £ § % ò % i \ ± ú
כ
` ¦ \ V8 £ ¤ ½ + É Ã º e . Õ ª Q , ° ú É r ~ ½ ÓZ O ` ¦ s 6 x ½ + É â Ä º,
Fig. 14. With and without Co-57 source in MCA.
Tc-99m _ photopeak H 240 G V , \ ± ú כ Ü ¼ Ð \ V8 £ ¤
÷
&# Q \ -t Û ¼& 7 à Ô! 3 8 £ ¤& ñ s 0 p x ½ + É כ Ü ¼ Ð : r .
: r ½ ¨\ " f H © 6 x o ) a í Ð s ¸× ¼ x 9 y + þ
A u 7 £ x; ¤ l _ ¸½ + Ë` ¦ : x # $ \ -t y 8 £ ¤& ñ
\
@ /ô Ç 0 p x$ í ` ¦ ] jr % i . í Ð s ¸× ¼_ & J r
Û ¼ü < y + þ A u 7 £ x; ¤ l r Û ¼% 7 ¸ ú 6 £ §` ¦ þ j è
o ½ + É Ã º e H Å Òכ ¹ô Ç כ ¹ èe ` ¦ Ð# Å Ò% 3 Ü ¼ 9, ¢ ¸ô Ç s
# QÛ ¼ · ú x 9 & ñ + þ A o r ç ß õ ° ú É r 1 l x ¸| ` ¦ þ j& h o
# r Û ¼% 7 ¸ ú 6 £ §` ¦ % 3 ] j½ + É Ã º e 6 £ §` ¦ · ú Ã º e % 3 .
Y
c p w à U Ø ô
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tors and Semimetals (Academic Press, San Diego, 1995), p. 531.
Signal and Noise Performance of a PIN Photodiode and
Charge-sensitive Preamplifier for Low-energy Gamma-ray Detection
Kwang Hyun Kim and Young Soo Kim ∗
College of Dentistry, Chosun University, Gwangju 501-759 (Received 28 March 2007)
Through a simple analytical approach, a combination of a scintillator, a PIN-type photodiode, and a CSA (charge-sensitive preamplifier) can be used as a small gamma-ray camera for detecting low-energy gamma-rays such as the 140-keV gamma-ray from Tc-99 m. We performed experiments with a PIN-type photodiode and a CSA to detect low-energy gammas and analyzed the results, concentrating on the characteristics of the signal and noise. From each noise measurement for both the photodiode and the CSAs, the lowest-noise photodiode and CSA were selected. Detection tests for low-energy gamma-rays were performed for a combination of the selected components. We showed that the existing devices could be used to detect 140 keV gamma-ray from Tc-99m and that the dominant factors to minimize system noise was the capacitance than the dark current of the photodiode. Concerning the operating conditions of the system, it is necessary to lower the shaping time and the reverse bias voltage in order to minimize the noise for the system.
PACS numbers: 29.40.Wk
Keywords: Gamma-ray detection, Scintimammography, Gamma camera, Photodiode, Charge-sensitive preamplifier, Scintillator
∗
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