± ô m Ç; c" e8 ý = k Ö Â³ × Ñ ÷ V È° Ë Ñ ÇÊ Ý; c 6 X ¢ ì Å

(1)

± ô m Ç; c" e8 ý = k Ö Â³ × Ñ ÷ V È° Ë Ñ ÇÊ Ý; c 6 X ¢ ì Å

»+ ä Â 6 Ò ^∗ · A j* å · ¤ - > - ! H · T + Ö <¦ · . > * > + ä · L |# Ü a @

Â

Òí ß @ / < Æ § Ó ü t o < Æõ , Â Òí ß 609-735 (2006¸ 3 Z 4 30{ 9 ~ Ã Î6 £ §)

90

Sr Z " é ¶ s ß ¼w n =` ¦ : x õ 9 µ 1 ÏÒ q tr v H F g \ ¦ F g 7 £ x C ' a` ¦ s 6 x # 8 £ ¤& ñ % i . s M

: µ 1 ÏÒ q tô Ç F g ^ E $ ïá Ô4 ¤ \ " f l ô Ç כ t , ß ¼w n =s ° ú H $ 3 F g ´ òõ \ _ ô Ç כ t \ ¦ S X

l 0 AK ß ¼w n = 4 ¤ ^ ü < F g 7 £ x C ' a _ l < Æ& h ½ ¨ ¸\ ¦ or & $ 3 F g ´ òõ ü < ^ E $ ïá Ô 4 ¤

\ _ K µ 1 ÏÒ q tô Ç y y _ ñ\ ¦ ì r o 8 £ ¤& ñ % i . s 8 £ ¤& ñ X <s ' \ ¦ ì r$ 3 # ß ¼w n =\ " f µ 1 ÏÒ q t H

^

E $ ïá Ô 4 ¤ $ 3 F g ´ òõ _ 10.227 ± 1.000(stat.) ± 7.855(sys.)C \ s Ø Ô H õ \ ¦ % 3 % 3 .

PACS numbers: 41.60.Bq

Keywords: ^ E $ ïá Ô 4 ¤ , $ 3 F g ´ òõ , ß ¼w n = 4 ¤ ^

I. " e Â ] Ø

) a { 9 Ï ã J] X Ò ¦ n B | 9 ` ¦ t ± ú M : µ 1 ÏÒ q tr v

H l _ 5 Å q ¸ (

_n^c

) , s B | 9 ` ¦ : x õ H { 9 _ 5

Å

q ¸ (v = βc) Ð ` ¦ M :, ^ E $ ïá Ô 4 ¤ µ 1 ÏÒ q t H X

<, s M : µ 1 ÏÒ q t H ^ E $ ïá Ô 4 ¤ { 9 _ ' ~ ½ Ó ¾ Ó õ

s À Ò H y (θ

c

) õ { 9 _ ' 5 Å q ¸ (β)ü < s À Ò H ' a >

H d 1õ ° ú . [1,2]

cosθ

c

= 1

βn (1)

s

M :, cosθ

^c

< 1 s # Q Ù ¼ Ð, B | 9 _ Ï ã J] X Ò ¦ \

^ E $ ïá Ô 4 ¤ \ ¦ µ 1 ÏÒ q tr ~ ´ Ã º e H { 9 _ 5 Å q ¸ (β >

_cn¹

) & ñ K t H X <, # Q B | 9 (n)\ " f_ ^ E $ ïá Ô y

(θ

^c

) õ { 9 _ 5 Å q ¸ (β) ° ú H ' a > H Fig. 1 õ ° ú .

Fig. 1 \ " f Ð1 p w s , { 9 & ñ ô Ç B | 9 \ " f ^ E $ ïá Ô 4 ¤

(

4 R H y θ

c

\ ¦ 8 £ ¤& ñ < ÊÜ ¼ Ð+ { 9 _ 5 Å q ¸ 8 £ ¤& ñ s

0 p x ô ÇX <, z ´] j& h Ü ¼ Ð H { 9 ' " f µ 1 ÏÒ q tr v H

5 Å q& h ^ E $ ïá Ô 4 ¤ M :ë H \ θ

c

_ 8 £ ¤& ñ s 6 x s t

· ú

§ . : £ ¤& ñ y θ

c

\ ¦ s À Ò 9 " é ¶ Æ Ò+ þ AÜ ¼ Ð ( 4 R H ^ E $

ïá Ô 4 ¤ \ ¦, & h ] X ô Ç / B GÒ ¦ ì ø Í â _ ì ø Í ^ \ ¦ s 6 x # ì ø Í

r v , ¨ î ' > [ þ t # Q ¸ H 4 ¤ / B GÒ ¦ ì ø Í â _ 1/2

÷

& H t & h \ ¸# " f ¨ 8 © (Ring Image)` ¦ ë ß [ þ t > ÷ & H X <, s

" é ¶ o \ ¦ s 6 x ô Ç כ s RICH (Ring Image CHerenkov)

Ø ¦ l s [3,5].

: r z ´+ « >z ´\ " f H ß ¼w n = (Plexiglass, CH

₂

= C(CH

₃

)COOCH

₃

, [6]) ` ¦ Â Ò Ã Ìô Ç F g 7 £ x C ' a \ ©

∗

E-mail: [email protected]

Fig. 1. The relation between Cherenkov radiation angle(θ

c

) and the velocity(β) of particle in various ra- diators.

{

© | ¾ Ó_ ñ Ø ¦ ÷ & H כ ` ¦ µ 1 Ï| < ÊÜ ¼ Ð" f, ß ¼w n = ^ E $

ïá Ô Ø ¦ l \ ¦ > hµ 1 Ï l r % i H X <, s H ß ¼w n = _

8 A# Qè ß / B N$ í õ $ § 4 ô Ç ` ¦ ¦ 9½ + É M :, ^ E $ ïá Ô 4

¤ | ¾ Óë ß Ø æì r y ´ ú § , Õ ª l < Æ& h ´ òõ \ ¦ F G @ / o

½

+ É Ã º e ` ¦ כ Ü ¼ Ð l @ / l M :ë H s . ß ¼w n =` ¦ F g 7

£

x C ' a \ Â Ò Ã ÌÙ þ ¡` ¦ M :ü < s ß ¼w n =s \ O ` ¦ M :_ C â 4 ¤

_ s H Fig. 2 õ ° ú [7–10]. Õ ª Q ß ¼w n = É r

¸$ í © (CH

²

= C(CH

3

)COOCH

3

) e ¦ Û ¼w $ 3 F g ^ (CH

2

= C

6

H

5

CH) ü < Ä » l M :ë H \ , Ô ¦í HÓ ü t \ _ ô Ç

$ 3

F g ´ òõ ¸ ° ú ¦ e . " f ß ¼w n =\ " f µ 1 ÏÒ q t H $ 3 F

g ´ òõ \ _ ô Ç 4 ¤ ü < ^ E $ ïá Ô ´ òõ \ _ ô Ç 4 ¤ × æ # Q Ö

¼ ´ òõ 8¹ ¡ ¤ ¿ º× ¼ Qt H t ¸ K ^ ¦ 9 כ ¹ e .

-210-

(2)

Fig. 2. Comparison between the results measured the photomultiplier with and without acryl radiator [7–10].

Table 1. The properties of the used acryl (Plexiglass).

Property Plexiglass

^a

(MMA, CH

2

= C(CH

3

)COOCH

3

) Density ρ[g/cm

³

] 1.19

Transmittance τ [%] 92.72 ± 0.79 ± 0.67 Reflex Index n 1.50 ± 0.0033 ± 0.0067

a

with statistical and systematical errors, respectively

II. ÷ m Ç ] M ö U ê s 0 n É

4 ¤ ^ Ð" f ß ¼w n =` ¦ : x õ H { 9 µ 1 ÏÒ q tr v H

ñ $ 3 F g ´ òõ \ _ ô Ç כ t , ^ E $ ïá Ô 4 ¤ ´ òõ \ _ ô

Ç כ t \ ¦ q § l 0 AK r × æ \ " f ½ ¨{ 9 ô Ç ß ¼w n =_

$ í

| 9 ` ¦ Table 1 \ & ñ o % i .

Table 1 _ Ï ã J] X Ò ¦ õ È Òõ Ò ¦ É r F g7 £ x 7 £ x C ' a _ y ¸

80%s © © % ò % i (405 nm ≤ λ ≤ 459 nm)\

@

/K f ] X 8 £ ¤& ñ ) a ° ú כ[ þ t s . כ Ü ¼ Ð" f, s \ ¦ 0 A # ì rF g

" é ¶ K $ 3 l (WexTech Systems. Ins, WVASE32) s 6 x

÷

&% 3 . 8 ú x 12 _ 8 £ ¤& ñ Ü ¼ ÐÂ Ò' : x > & h ¸ (stat.)\ ¦, 8

£ ¤& ñ [ þ t` ¦ 0 Aô Ç ß ¼w n = / B N õ [ O u 1 p x \ " f l | ¨ c Ã º e

H l l ¸ (sys.)\ ¦ % 3 % 3 .

: r z ´+ « > É r, s ß ¼w n = 4 ¤ ^ \ Z " é ¶ (

⁹⁰

Sr)` ¦ { 9 r

& , { 9 µ 1 ÏÒ q tr v H $ 3 F g ´ òõ \ _ ô Ç F g ü <,

^

E $ ïá Ô4 ¤ \ _ ô Ç F g \ ¦ y l É r l < Æ& h ½ ¨ ¸\

"

f F g 7 £ x C ' a (Hamamatsu, H6410) Ü ¼ Ð 8 £ ¤& ñ < Ê` ¦ : x K

s À Ò# Q& . Z " é ¶

⁹⁰

Sr É r β Ô æ õ \ ¦ : x K þ j@ / 2.28 MeV \ s Ø Ô H \ -t (E

e,max

= 2.28M eV, β = 0.98)

Fig. 3. The setting of the geometry to detect (a)only the Scintillation effect.

(b)the Cherenkov radiation and the Scintillation effect.

_

\ ¦ ß ¼w n = 4 ¤ ^ \ ~ ½ Ó > ÷ & H X <, ^ E $ ïá Ô 4

¤ _ þ j@ /y (θ

c

= cos

⁻¹

(

_βn¹

) = 46.5

^◦

)` ¦ l < Æ& h Ü

¼ Ð s 6 x l 0 AK , U ´s 12 mm, f â 1 mm_ · ú À Òp ³ o u c

+ t o B js ' \ ¦ 6 x % i . Ø æì r ô Ç ¿ ºa _ ß ¼w n =` ¦ : x õ

H H Õ ª î r1 l x \ -t \ ¦ { 9 # Q (

^dE_dx

∼ 2.242M eV /cm for p

e

∼ 2.22M eV ) [11, 12] β = 0.67 s | ¨ c M : t ë

ß ^ E $ ïá Ô 4 ¤ \ ¦ µ 1 ÏÒ q tr H כ õ , $ \ -t _

ß ¼w n = ? /_ { 9 [ þ t õ Ø æ[ t # , t Õ ªF Õ ª î r1 l x` ¦ { 9

Ü ¼ H & h t ¸¿ º ¦ 9 # , Fig. 3(a),(b)ü < ° ú

É r z ´+ « > © u \ ¦ ¦î ß % i . 7 £ ¤, l < Æ& h Ü ¼ Ð f ¹ ¢ ¤ ^ (H × W × T = 45 × 45 × 22mm

³

) _ ß ¼w n =_ ¸

H ` ¦ F g < Æ& h Ü ¼ Ð / B N ¦, f â 2 u _ F g 7 £ x C

'

a (Hamamatsu, H6410)` ¦ ½ + Ër v H X < e # Q" f, Fig.

3(a) _ â Ä º, Z s t H " f ^ E $ ïá Ô 4 ¤

(

4 R H É r q 0 >¿ º ¦, ^ E $ ïá Ô 4 ¤ ¸² ú t

· ú § H A Â Òì r 7 £ ¤, ^ E $ ïá Ô 4 ¤ _ þ j@ /y 46.5 ¸ s

© _ \ P \ F g 7 £ x C ' a` ¦ ¿ º# Q 1 p x ~ ½ Ó& h Ü ¼ Ð ( 4 R

H $ 3 F g ´ òõ \ " f µ 1 ÏÒ q t H F g ñ\ ¦ ~ Ã Î H ½ ¨ ¸s .

Fig. 3(b) H 3(a) ü < ° ú É r ½ ¨ ¸\ " f F g 7 £ x C ' a _ 0 A u

\ ¦ Z \ " f µ 1 ÏÒ q t H ^ E $ ïá Ô4 ¤ _ ' ~ ½ Ó ¾ Ó_

&

ñ \ ¿ º# Q ^ E $ ïá Ô 4 ¤ ü < $ 3 F g ´ òõ \ _ ô Ç F g

ñ\ ¦ ¸¿ º ~ Ã Î ¸2 ¤ % i . s ü < ° ú s Fig. 3(a) ($ 3 F g ´ ò õ

\ _ ô Ç F g ñ)ü < 3(b) (^ E $ ïá Ô 4 ¤ ü < $ 3 F g ´ ò õ

Ñ ü t \ _ ô Ç F g ñ) \ ¦ q § ì r$ 3 < ÊÜ ¼ Ð+ # QÖ ¼ ´ ò õ

8 H t \ ¦ · ú è q Ã º e .

(3)

Fig. 4. The circuit diagram

F

g 7 £ x C ' a \ " f É r l & h r Õ ªV , (t

r

∼ 4 ns, t

f

∼ 10 ns, FWHM ∼ 8 ns) Ð ÷ ¶ ñ H, Fig. 4 õ ° ú

É

r r Ð ¸\ _ K , ¸s Ý ¼\ ¦ ] j ô Ç © I Ð n t _ O Ð 7

# Q PCI-CAMAC ! QÛ ¼\ ¦ : x K o ³ n q Û ¼ PC Ð l 2 ¤Ù þ ¡ .

III. ÷ m Ç ] M ö + s Ç Ê Ý

¿

º z ´+ « > É r 1 l qw n & h s l M :ë H \ ¿ º z ´+ « > X <s \ " f ¿ º

´

òõ , 7 £ ¤ $ 3 F g ´ òõ ü < ^ E $ ïá Ô 4 ¤ _ ´ òõ \ ¦ ½ ¨Z > H

כ

É r # Q§ > . Ä º y y _ z ´+ « >` ¦ ì r$ 3 ¦ ¿ º z ´+ « >Ü ¼ Ð Â

Ò' ¿ º ´ òõ \ ¦ q §K Ð ¤ .

1. ÷ m Ç] M ö 1 : 9 0ß O Ë Þ Ã Å ÆÑ ÷ V È° Ë Ñ Þ Ã Å Æ8 ý R w

z

´+ « >1 (Fig.3 (a)) É r Z s þ j@ /\ -t (E

^e,max

= 2.28 MeV){ 9 M : µ 1 ÏÒ q t H ^ E $ ïá Ô 4 ¤ þ j@ /y _ ¾ ú A

á

¤ \ F g 7 £ x C ' a` ¦ 0 Au r & , F g 7 £ x C ' a Ü ¼ Ð [ þ t

#

Q ¸ H ^ E $ ïá Ô 4 ¤ _ ´ òõ \ ¦ ] j % i . s M : F g

7 £ x C ' a \ 8 £ ¤& ñ ) a ñ H, Z " é ¶` ¦ ] j Ù þ ¡` ¦ M :\

¸ > r F H C â ñ (bg1)ü < Z { 9 _ $ 3 F g ´ òõ \ _

ô Ç $ 3 F g ñ (sc1)_ ½ + Ë$ í Ü ¼ Ð Ò q ty ½ + É Ã º e . Fig. 5

É r, z ´] j Ð Z " é ¶` ¦ ] j Ù þ ¡` ¦ M : 8 £ ¤& ñ ) a ñ (bg1)ü <

Z

" é ¶` ¦ ¿ º ¦ 8 £ ¤& ñ Ù þ ¡` ¦ M :_ ñ (bg1+sc1)\ ¦ q § ô

Ç Õ ªa Ë >s .

s

[ þ t ¿ º 8 £ ¤& ñ X <s ' H QDC G V , 30Â Ò' 100 t _ ¸ ú 6

£ § (Noise) \ @ / # & ñ ½ © o % i H X <, s M : ¸ ú 6 £ § s ì r í

H QDC G V , % ò % i @ / " î S X t · ú §Ü ¼Ù ¼ Ð, 30ç ß Ü ¼

Ð 25Â Ò' 35 t or & 9 & ñ ½ © o\ ¦ Ã º' # , 8 £ ¤

&

ñ _ r Û ¼% 7 ¸ \ ¦ > í ß % i . õ & h Ü ¼ Ð Fig. 5 É r Z

" é ¶ Ü ¼ ÐÂ Ò' ¸ H $ 3 F g ñ (sc1)\ ¦ í < Êô Ç X <s '

(bg1+sc1) H, C â ñ (bg1) ë ß _ X <s ' ü < q §Ù þ ¡

`

¦ M :, 8 £ ¤& ñ ° ú כ_ : x > & h ¸ ? /\ e 6 £ §` ¦ Ð# ï r .

Fig. 5. PMT signal distribution measured by the setting 3(a) with (red) and without (black) a beta source (

⁹⁰

Sr).

Fig. 6. PMT signal distribution measured by the setting 3(b) with (red) and without (black) a beta source (

⁹⁰

Sr).

2. ÷ m Ç] M ö 2 : 9 0ß O ËÞ Ã Å ÆÑ ÷ (V È° Ë ÑÞ Ã Å Æ + = k Ö Â³ Þ Ã Å

Æ)8 ý R w

z

´+ « >2 (Fig. 3(b)) H ^ E $ ïá Ô 4 ¤ s ¸¿ º F g

7 £ x C ' a \ [ þ t # Q° ú Ã º e ¸2 ¤ F g 7 £ x C ' a` ¦ Z

"

é

¶ & ñ \ 0 Au r ( . " f, F g 7 £ x C ' a Ü ¼ Ð [ þ t # Q

¸ H ñ H C â ñ (bg2)ü < $ 3 F g ñ (sc2) Õ ªo ¦ ^ E $

ïá Ô 4 ¤ \ _ ô Ç ^ E $ ïá Ô ñ (CH) ¸¿ º í < Ê ) a

. z ´+ « >1õ ð ø Ít Ð Z " é ¶` ¦ ] j < ÊÜ ¼ Ð+ C â 4

¤ \ _ ô Ç ñ\ ¦ Ð 8 £ ¤& ñ % i . s z ´+ « > õ ü < ¸ ú 6

£

§ Â Òì r (QDC G V , 30Â Ò' 100 t ) ` ¦ & ñ ½ © o # q

§ Fig. 6õ ° ú .

õ & h Ü ¼ Ð Fig. 6 É r ^ E $ ïá Ô 4 ¤ \ _ ô Ç ^ E $ ïá Ô

ñ (CH)ü < $ 3 F g ñ (sc2)\ ¦ í < Êô Ç ñ (CH+sc2+

bg2) C â ñ (bg2)ü < ì r" î ô Ç s \ ¦ ? / ¦ e 6 £ §

`

¦ Ð# ï r . t ë ß , s M : F g 7 £ x C ' a s ] X ô Ç ß ¼ w n

=_ & h s z ´+ « >1\ " fü < Ø Ôl M :ë H \ , z ´+ « >2\ " f 8 £ ¤

&

ñ ) a $ 3 F g ñ (sc2) H z ´+ « >1\ " f_ $ 3 F g ñ (sc1)ü <

(4)

Table 2. Summary table of the Exp. 1 and 2.

Exp.1 Exp2 counts

^a

with a

⁹⁰

Sr-source bg1+sc1 bg2+sc2+CH

with no source bg1 bg2

a

integrated over the QDC channel [30, 100]

s

\ ¦ Ðs H כ { 9 Ã º e . " f, z ´+ « >1õ z ´+ « >2_ q

§ì r$ 3 ` ¦ III 3 \ " f [ O " î H ü < ° ú s Ã º' % i .

3. ÷ m Ç] M ö1Ê Ý ÷ m Ç] M ö28 ý R w Ä Z ØV Ä : V È° Ë ÑÞ Ã Å Æ vs. = k

Ö

Â³ Þ Ã Å Æ

0 A_ ¿ º z ´+ « >` ¦ q § l 0 A # , s \ ¦ ³ ð Ð & ñ o Table 2 ü < ° ú . ¿ º z ´+ « > õ \ " f, Sr-90 Z " é ¶` ¦ ] j

¦ 8 £ ¤& ñ ô Ç bg1õ bg2 Ð# Å Ò H s H, í H Ã º > z

´+ « >1õ z ´+ « >2_ " f Ð É r z ´+ « > ¸| (F g 7 £ x C ' a s

ß ¼w n =\ ] X H & h s Ø Ô H ¸| )\ " fë ß l ô Ç

כ

s Ù ¼ Ð, s ¿ º C â ñ_ q bg2/bg1 \ ¦ ¿ º z ´+ « > õ _

Ð& ñ ° ú כÜ ¼ Ð 2 [ % i . s ÐÂ Ò' z ´+ « >2\ " f 8 £ ¤& ñ ) a í H Ã

ºô Ç ^ E $ ïá Ô ñ (CH)_ Â Òì r` ¦ 6 £ § _ ' a > d õ ° ú s

> í ß ½ + É Ã º e .

CH = (bg2 + sc2 + CH) − bg2

bg1 (bg1 + sc1) (2)

¢

¸ô Ç d 2\ " f % 3 # Q ^ E $ ïá Ô ñ (CH) ü < s p 8 £ ¤& ñ

)

a bg2\ ¦ s 6 x # , z ´+ « >2\ " f 8 £ ¤& ñ ) a í H Ã ºô Ç $ 3 F g ñ (sc2)\ ¦ % 3 > ) a .

s

Qô Ç q §ì r$ 3 ` ¦ : x K , z ´+ « >2\ " f 8 £ ¤& ñ ) a í H Ã ºô Ç ^ E $

ïá Ô ñ (CH)ü < $ 3 F g ñ (sc2) \ ¦ 1 l x r \ y Û ¼ ÐÕ ª Ï þ

Ü ¼ Ð ? / Fig. 7 õ ° ú .

IV. + s Ç Â ] Ø

õ & h Ü ¼ Ð Fig. 7_ 8 £ ¤& ñ õ ÐÂ Ò' % 3 # Q í H Ã ºô Ç

Ö ¦ É r 6 £ § õ ° ú .

CH/sc2 = 10.227 ± 1.000(stat.) ± 7.855(sys.) (3) s

õ ° ú כ_ : x > & h ¸ (stat.) H Fig. 6,7 \ " f y G V , {

count)\ ¦ r & % 3

#

° ú H QDC G V , ` ¦ ^ > & h Ü ¼ Ð or & 9 % 3 # Q

³

ðï r¼ # s .

Fig. 7. pure Cherenkov radiation signals (black) and scintillation signals(red) extracted from Fig.6 according to Eq.2.

: r& h Ü ¼ Ð, : r ½ ¨ s 6 x ô Ç 45 × 45 × 22 mm

³

_ ß ¼w n =\ " f Sr-90Ü ¼ ÐÂ Ò' ~ ½ ÓØ ¦ ) a (E

_e,max

= 2.28MeV) µ 1 ÏÒ q tr v H ^ E $ ïá Ô ñ

H, ß ¼w n = ? /\ " f µ 1 ÏÒ q tr v H $ 3 F g ñ\ q K

, > H 2.3C , ß ¼> H 18C \ ² ú H כ ( = 10.227 ± p

stat.

²

+ sys.

²

)` ¦ · ú Ã º e . s õ

ß ¼w n =s ^ E $ ïá Ô 4 ¤ ^ Ð" f Ø æì r ô Ç ´ ò6 x u \ ¦ ° ú

H H z ´` ¦ Ð# Å Ò 9, # Q t l < Æ& h n

`

Ø ¦ l _ ] j 0 p x$ í ` ¦ r ô Ç [13].

P

c p 8 ý ò k >

s

7 Hë H É r Â Òí ß @ / < Æ § Ä »õ ] j < ÆÕ ü t ½ ¨q (2¸ )\ _

# ½ ¨÷ &% 3 6 £ §.

Y

c p w Ã U Ø ô

[1] W. R. Leo, Techniques for Nuclear and Particle Physics Experiment (Springer-Verlg Berlin Heidel- berg, Germany, 1987), Chap. 2, pp. 33-34.

[2] J. D. Jackson, Classical Electrodynamics, 3rd ed.

(Hamilton Printing Company, United States of America, 1998), Chap. 13.

[3] K. Kleinknecht, Detectors for Particle Radiation, 2nd ed. (Cambridge University Press, 1998), Chap.

5, pp. 148.

(5)

[4] J. D´ıaz, G. Mart´ınez and Y. Schutz, Gamma Ray and Particle Production in Heavy Ion Reactions, (World Scientific Publishing Co. Pte. Ltd., 1998), pp. 521-558.

[5] J. D. Jackson, Classical Electrodynamics (Hamilton Printing Company, 1998), Chap. 13.

[6] http://esales.lgmma.com:2104/pro_info/p_i_h_02.htm [7] J. -H. Kim et al., Development of an Acryl

Cherenkov Detector and Test Using Cosmic Ray, Bulletin of The Korean Physics Society (Seoul, Ko- rea, April 21-23, 2005), Vol. 1, pp. 303-304.

[8] http://nuri.pusan.ac.kr/ ∼ hipex/bluekjh/Lab/data/

2005_KPS_poster.ppt

[9] K. -U. Choi et al., Development of a mini-RICH De- tector using Acryl, Bulletin of The Korean Physics Society(Deajun, Korea, October 20-22, 2005), Vol.

2, pp. 400.

[10] http://nuri.pusan.ac.kr/ ∼ hipex/bluekjh/Lab/data/

2005_KPS_talk.ppt

[11] R. M. Sternheimer, Phys. Rev. 88, 851 (1952).

[12] D. Marinelli, Ann. Rev. Nucl. Sci. 3, 249 (1953).

[13] I. -K, Yoo, Development of a mini-RICH Detector using Acryl, Project Final Report, MOST (Ministry of Science and Technology) (2006).

Study on the Cherenkov Radiation and Scintillation Effect in an Acryl Radiator

Jung-han Kim,

^∗

Hye-Young Park, In-Kwon Yoo, Jun-Kyu Yi, Minjeong Jean and Kyung Eon Choi Department of Physics, Pusan National University, Pusan 609-735

(Received 30 March 2006)

Using a beta-source,

⁹⁰

Sr, photon signals produced in an acryl-radiator were measured. We measured the scintillation effect and the Cherenkov radiation effect by varying the geometrical setting of the experiments. From a comparison of the two effects, we obtained a Cherenkov radiation signals that was 10.227±1.000(stat.)±7.855(sys.) times higher than the scintillation signals.

PACS numbers: 41.60.Bq

Keywords: Chrenkov radiation, Scintillation, Acryl radiator

∗

E-mail: [email protected]

± ô m Ç; c" e8 ý = k Ö  Â³   × Ñ ÷ V È° Ë Ñ  ÇÊ Ý; c 6  X ¢  ì Å 



± ô m Ç; c" e8 ý = k Ö  Â³    × Ñ ÷ V È° Ë Ñ  ÇÊ Ý; c 6  X ¢  ì Å 

 »+ ä Â 6 Ò ∗ ·   A j* å  · ­ ¤ - > - ! H · T + Ö <¦  · . > * > + ä  · L |# Ü a  @

Â

Òí ß @ / < Æ § Ó ü t o  < Æõ , Â Òí ß  609-735 (2006¸  3 Z 4 30{ 9  ~ Ã Î6 £ §)

Sr Z   " é ¶ s   ß ¼w n =`  ¦ :  x õ   9 µ 1 ÏÒ q tr v   H F g  \  ¦ F g    7 £ x C   ' a`  ¦ s 6 x #  8 £ ¤& ñ % i  . s  M

: µ 1 ÏÒ q tô  Ç F g   ^ E $  ïá Ô4  ¤  \ " f l   ô  Ç  כ   t ,  ß ¼w n =s  ° ú   H $ 3 F g ´ òõ \  _ ô  Ç  כ   t \  ¦ S X   

l  0 AK   ß ¼w n = 4  ¤  ^ ü < F g    7 £ x C   ' a _  l   < Æ& h   ½ ¨ ¸\  ¦   or &  $ 3 F g ´ òõ ü < ^ E $  ïá Ô 4  ¤



\  _ K  µ 1 ÏÒ q tô  Ç y  y  _    ñ\  ¦ ì  r o  8 £ ¤& ñ % i  . s  8 £ ¤& ñ X <s ' \  ¦ ì  r$ 3 #   ß ¼w n =\ " f µ 1 ÏÒ q t   H

^

E $  ïá Ô 4  ¤   $ 3 F g ´ òõ _     10.227 ± 1.000(stat.) ± 7.855(sys.)C \  s Ø Ô  H   õ \  ¦ % 3 % 3  .

PACS numbers: 41.60.Bq

Keywords: ^ E $  ïá Ô 4  ¤  , $ 3 F g ´ òõ ,  ß ¼w n = 4  ¤  ^ 

I. " e Â ] Ø

   ) a { 9   Ï ã J] X Ò  ¦ n  B | 9 `  ¦ t ± ú  M : µ 1 ÏÒ q tr v 



 H    l  _  5 Å q  ¸ (

) , s  B | 9 `  ¦ :  x õ    H { 9  _  5

Å

q  ¸ (v = βc) Ð    `  ¦ M :, ^ E $  ïá Ô 4  ¤   µ 1 ÏÒ q t   H X

<, s  M : µ 1 ÏÒ q t   H ^ E $  ïá Ô 4  ¤    { 9  _    '  ~ ½ Ó ¾ Ó õ

 s À Ò  H y   (θ

) õ  { 9  _    '  5 Å q  ¸ (β)ü < s À Ò  H  ' a > 



 H d  1õ  ° ú . [1,2]

cosθ

= 1

βn (1)

s

 M :, cosθ

< 1 s # Q  Ù ¼ Ð, B | 9 _  Ï ã J] X Ò  ¦ \ 



  ^ E $  ïá Ô 4  ¤  \  ¦ µ 1 ÏÒ q tr ~ ´ Ã º e    H { 9  _  5 Å q  ¸ (β >

)  & ñ K t   H X <, #  Q B | 9 (n)\ " f_  ^ E $  ïá Ô y



 (θ

) õ  { 9  _  5 Å q  ¸ (β) ° ú   H  ' a >   H Fig. 1 õ  ° ú .

Fig. 1 \ " f  Ð1 p w s , { 9 & ñ ô  Ç B | 9 \ " f ^ E $  ïá Ô 4  ¤  

(

4 R   H y   θ

\  ¦ 8 £ ¤& ñ  < ÊÜ ¼ Ð+  { 9  _  5 Å q  ¸ 8 £ ¤& ñ s 

0 p x ô  ÇX <, z ´] j& h Ü ¼ Ð  H { 9     '     " f µ 1 ÏÒ q tr v   H



 5 Å q& h   ^ E $  ïá Ô 4  ¤   M :ë  H \  θ

_  8 £ ¤& ñ s  6 x s  t 

· ú

§ . : £ ¤& ñ y   θ

\  ¦ s À Ò 9 " é ¶ Æ Ò+ þ AÜ ¼ Ð ( 4 R   H ^ E $ 



ïá Ô 4  ¤  \  ¦, & h ] X ô  Ç / B GÒ  ¦ ì ø Í â _  ì ø Í ^ \  ¦ s 6 x #  ì ø Í



r v   , ¨ î '   >  [ þ t # Q ¸  H 4  ¤    / B GÒ  ¦ ì ø Í â _  1/2

÷

&  H t & h \   ¸# " f ¨ 8   ©  (Ring Image)`  ¦ ë ß [ þ t >  ÷ &  H X <, s

 " é ¶ o \  ¦ s 6 x ô  Ç  כ s  RICH (Ring Image CHerenkov)

 

Ø  ¦ l s   [3,5].



: r z ´+ « >z ´\ " f  H  ß ¼w n = (Plexiglass, CH

= C(CH

)COOCH

, [6]) `  ¦ Â Ò Ã Ìô  Ç F g    7 £ x C   ' a \   © 

E-mail: [email protected]

Fig. 1. The relation between Cherenkov radiation angle(θ

) and the velocity(β) of particle in various ra- diators.

{

© | ¾ Ó_    ñ   Ø  ¦ ÷ &  H  כ `  ¦ µ 1 Ï|  < ÊÜ ¼ Ð" f,  ß ¼w n = ^  E $

 ïá Ô   Ø  ¦ l \  ¦ > hµ 1 Ï l  r    % i   H X <, s   H  ß ¼w n = _

 8 A# Qè ß  / B N$ í õ  $ § 4 ô  Ç   `  ¦  ¦ 9½ + É M :, ^ E $  ïá Ô 4



¤  | ¾ Óë ß  Ø  æì  r y  ´ ú §   , Õ ª l   < Æ& h   ´ òõ \  ¦ F G @ / o

½

+ É Ã º e  `  ¦  כ Ü ¼ Ð l @ / l  M :ë  H s  .  ß ¼w n =`  ¦ F g    7

£

x C   ' a \  Â Ò Ã ÌÙ þ ¡`  ¦ M :ü < s   ß ¼w n =s  \ O `  ¦ M :_  C  â 4  ¤



_  s   H Fig. 2 õ  ° ú  [7–10]. Õ ª Q   ß ¼w n = É r



± ô m Ç; c" e8 ý = k Ö Â³ × Ñ ÷ V È° Ë Ñ ÇÊ Ý; c 6 X ¢ ì Å

± ô m Ç; c" e8 ý = k Ö Â³ × Ñ ÷ V È° Ë Ñ ÇÊ Ý; c 6 X ¢ ì Å

»+ ä Â 6 Ò ^∗ · A j* å · ¤ - > - ! H · T + Ö <¦ · . > * > + ä · L |# Ü a @

Òí ß @ / < Æ § Ó ü t o < Æõ , Â Òí ß 609-735 (2006¸ 3 Z 4 30{ 9 ~ Ã Î6 £ §)

Sr Z " é ¶ s ß ¼w n =` ¦ : x õ 9 µ 1 ÏÒ q tr v H F g \ ¦ F g 7 £ x C ' a` ¦ s 6 x # 8 £ ¤& ñ % i . s M

: µ 1 ÏÒ q tô Ç F g ^ E $ ïá Ô4 ¤ \ " f l ô Ç כ t , ß ¼w n =s ° ú H $ 3 F g ´ òõ \ _ ô Ç כ t \ ¦ S X

l 0 AK ß ¼w n = 4 ¤ ^ ü < F g 7 £ x C ' a _ l < Æ& h ½ ¨ ¸\ ¦ or & $ 3 F g ´ òõ ü < ^ E $ ïá Ô 4 ¤

\ _ K µ 1 ÏÒ q tô Ç y y _ ñ\ ¦ ì r o 8 £ ¤& ñ % i . s 8 £ ¤& ñ X <s ' \ ¦ ì r$ 3 # ß ¼w n =\ " f µ 1 ÏÒ q t H

E $ ïá Ô 4 ¤ $ 3 F g ´ òõ _ 10.227 ± 1.000(stat.) ± 7.855(sys.)C \ s Ø Ô H õ \ ¦ % 3 % 3 .

Keywords: ^ E $ ïá Ô 4 ¤ , $ 3 F g ´ òõ , ß ¼w n = 4 ¤ ^

) a { 9 Ï ã J] X Ò ¦ n B | 9 ` ¦ t ± ú M : µ 1 ÏÒ q tr v

H l _ 5 Å q ¸ (

) , s B | 9 ` ¦ : x õ H { 9 _ 5

q ¸ (v = βc) Ð ` ¦ M :, ^ E $ ïá Ô 4 ¤ µ 1 ÏÒ q t H X

<, s M : µ 1 ÏÒ q t H ^ E $ ïá Ô 4 ¤ { 9 _ ' ~ ½ Ó ¾ Ó õ

s À Ò H y (θ

) õ { 9 _ ' 5 Å q ¸ (β)ü < s À Ò H ' a >

H d 1õ ° ú . [1,2]

M :, cosθ

< 1 s # Q Ù ¼ Ð, B | 9 _ Ï ã J] X Ò ¦ \

^ E $ ïá Ô 4 ¤ \ ¦ µ 1 ÏÒ q tr ~ ´ Ã º e H { 9 _ 5 Å q ¸ (β >

) & ñ K t H X <, # Q B | 9 (n)\ " f_ ^ E $ ïá Ô y

(θ

) õ { 9 _ 5 Å q ¸ (β) ° ú H ' a > H Fig. 1 õ ° ú .

Fig. 1 \ " f Ð1 p w s , { 9 & ñ ô Ç B | 9 \ " f ^ E $ ïá Ô 4 ¤

4 R H y θ

\ ¦ 8 £ ¤& ñ < ÊÜ ¼ Ð+ { 9 _ 5 Å q ¸ 8 £ ¤& ñ s

0 p x ô ÇX <, z ´] j& h Ü ¼ Ð H { 9 ' " f µ 1 ÏÒ q tr v H

5 Å q& h ^ E $ ïá Ô 4 ¤ M :ë H \ θ

_ 8 £ ¤& ñ s 6 x s t

§ . : £ ¤& ñ y θ

\ ¦ s À Ò 9 " é ¶ Æ Ò+ þ AÜ ¼ Ð ( 4 R H ^ E $

ïá Ô 4 ¤ \ ¦, & h ] X ô Ç / B GÒ ¦ ì ø Í â _ ì ø Í ^ \ ¦ s 6 x # ì ø Í

r v , ¨ î ' > [ þ t # Q ¸ H 4 ¤ / B GÒ ¦ ì ø Í â _ 1/2

& H t & h \ ¸# " f ¨ 8 © (Ring Image)` ¦ ë ß [ þ t > ÷ & H X <, s

" é ¶ o \ ¦ s 6 x ô Ç כ s RICH (Ring Image CHerenkov)

Ø ¦ l s [3,5].

: r z ´+ « >z ´\ " f H ß ¼w n = (Plexiglass, CH

, [6]) ` ¦ Â Ò Ã Ìô Ç F g 7 £ x C ' a \ ©

© | ¾ Ó_ ñ Ø ¦ ÷ & H כ ` ¦ µ 1 Ï| < ÊÜ ¼ Ð" f, ß ¼w n = ^ E $

ïá Ô Ø ¦ l \ ¦ > hµ 1 Ï l r % i H X <, s H ß ¼w n = _

8 A# Qè ß / B N$ í õ $ § 4 ô Ç ` ¦ ¦ 9½ + É M :, ^ E $ ïá Ô 4

¤ | ¾ Óë ß Ø æì r y ´ ú § , Õ ª l < Æ& h ´ òõ \ ¦ F G @ / o

+ É Ã º e ` ¦ כ Ü ¼ Ð l @ / l M :ë H s . ß ¼w n =` ¦ F g 7

x C ' a \ Â Ò Ã ÌÙ þ ¡` ¦ M :ü < s ß ¼w n =s \ O ` ¦ M :_ C â 4 ¤

_ s H Fig. 2 õ ° ú [7–10]. Õ ª Q ß ¼w n = É r

¸$ í © (CH

) e ¦ Û ¼w $ 3 F g ^ (CH

CH) ü < Ä » l M :ë H \ , Ô ¦í HÓ ü t \ _ ô Ç

F g ´ òõ ¸ ° ú ¦ e . " f ß ¼w n =\ " f µ 1 ÏÒ q t H $ 3 F

g ´ òõ \ _ ô Ç 4 ¤ ü < ^ E $ ïá Ô ´ òõ \ _ ô Ç 4 ¤ × æ # Q Ö

¼ ´ òõ 8¹ ¡ ¤ ¿ º× ¼ Qt H t ¸ K ^ ¦ 9 כ ¹ e .

¤ ^ Ð" f ß ¼w n =` ¦ : x õ H { 9 µ 1 ÏÒ q tr v H

ñ $ 3 F g ´ òõ \ _ ô Ç כ t , ^ E $ ïá Ô 4 ¤ ´ òõ \ _ ô

Ç כ t \ ¦ q § l 0 AK r × æ \ " f ½ ¨{ 9 ô Ç ß ¼w n =_

| 9 ` ¦ Table 1 \ & ñ o % i .

Table 1 _ Ï ã J] X Ò ¦ õ È Òõ Ò ¦ É r F g7 £ x 7 £ x C ' a _ y ¸

80%s © © % ò % i (405 nm ≤ λ ≤ 459 nm)\

/K f ] X 8 £ ¤& ñ ) a ° ú כ[ þ t s . כ Ü ¼ Ð" f, s \ ¦ 0 A # ì rF g

" é ¶ K $ 3 l (WexTech Systems. Ins, WVASE32) s 6 x

&% 3 . 8 ú x 12 _ 8 £ ¤& ñ Ü ¼ ÐÂ Ò' : x > & h ¸ (stat.)\ ¦, 8

£ ¤& ñ [ þ t` ¦ 0 Aô Ç ß ¼w n = / B N õ [ O u 1 p x \ " f l | ¨ c Ã º e

H l l ¸ (sys.)\ ¦ % 3 % 3 .

: r z ´+ « > É r, s ß ¼w n = 4 ¤ ^ \ Z " é ¶ (

Sr)` ¦ { 9 r

& , { 9 µ 1 ÏÒ q tr v H $ 3 F g ´ òõ \ _ ô Ç F g ü <,

E $ ïá Ô4 ¤ \ _ ô Ç F g \ ¦ y l É r l < Æ& h ½ ¨ ¸\

f F g 7 £ x C ' a (Hamamatsu, H6410) Ü ¼ Ð 8 £ ¤& ñ < Ê` ¦ : x K

s À Ò# Q& . Z " é ¶

Sr É r β Ô æ õ \ ¦ : x K þ j@ / 2.28 MeV \ s Ø Ô H \ -t (E

\ ¦ ß ¼w n = 4 ¤ ^ \ ~ ½ Ó > ÷ & H X <, ^ E $ ïá Ô 4

¤ _ þ j@ /y (θ

)` ¦ l < Æ& h Ü

¼ Ð s 6 x l 0 AK , U ´s 12 mm, f â 1 mm_ · ú À Òp ³ o u c

+ t o B js ' \ ¦ 6 x % i . Ø æì r ô Ç ¿ ºa _ ß ¼w n =` ¦ : x õ

H H Õ ª î r1 l x \ -t \ ¦ { 9 # Q (

∼ 2.22M eV ) [11, 12] β = 0.67 s | ¨ c M : t ë

ß ^ E $ ïá Ô 4 ¤ \ ¦ µ 1 ÏÒ q tr H כ õ , $ \ -t _