n ÞV R Ë R { ES ‡ ˜ m0 n É ù p § T “ Ó Þ” X ¢ ’ ˜ m´ o  Û(Tantalum)8 ý ú n ÞV R Ë ƒ ºT ƒ † ‰ ˜ mì ÅX ì Ä • ¤X N Ë

ú

n ÞV R Ë  R  {  ES ‡ ˜ m0 n É ù p § T  “ Ó Þ” X ¢ ’ ˜ m´  o   Û(Tantalum)8 ý ú n ÞV R Ë  ƒ ºT ƒ † ‰ ˜ mì ÅX ì Ä • ¤X N Ë

T „ ‘ žŠ ~ x ^∗ · T „ ç ¡õ i ; · T + Ö <á — ¥ · T + ä * >

z

Œ ™Â Ò@ /† < Ɠ § ~ ½ Ó ‚  † < Æõ , F  g Å Ò 506-824

*

× <+ ä ¸ 6 Ò · * > * å M  · + ä ) Ö <Œ ‰ x · { ¡?   ™ ¸

1 l

x  @ /† < Ɠ § ’  ™ èF  Ó ü t o † < Æõ ,  Òí ß – 604-714

™

»Z ô[ Í

 â

· ¡ ¤ @ /† < Ɠ § Ó ü t o † < Æõ , @ /½ ¨ 702-701

Jun-ichi Hori · Shuji Yamamoto · Katsuhei Kobayashi

“

§ž Ð@ /† < Æ, š ¸  , { 9 ‘ : r 590-0494

(2004¸   3 Z 4 8{ 9  ~ à Î6 £ §, 2004¸   7 Z 4 18{ 9  þ j7 á x à º& ñ ‘ : r ~ à Î6 £ §)

{ 9

‘ : r “ §ž Ð@ /† < Æ " é ¶  – Ðz  ´+ « >™ è_  46-MeV „   ‚  + þ A5 Å q l \  ¦ s 6   x # Œ ×  æ$ í   q ' Ÿ  r ç ß –Z O (Time-of- Flight: TOF) ~ ½ ÓZ O Ü ¼– Ð, \  -t  % ò % i  0.003 ∼ 50 eV\  @ / # Œ ò ø Í» 1 ϵ ¢ §(Tantalum: Ta)_  ×  æ$ í   Ÿ í S \ ‰ é

ß

–€  & h `  ¦ 8 £ ¤& ñ % i  . ‘ : r ƒ  ½ ¨\ " f  6   x ) a Bi

Ge

O

(BGO) $ 3 F  g Ž Ø  ¦ l   H Ta_  ×  æ$ í  Ÿ í S \ ‰ì ø Í6 £ x Ü ¼

–

ÐÂ Ò' 
š ¸  H 7 £ ¤µ 1 ϟ í S \ ‰ y Œ ™ ‚   8 £ ¤& ñ \   6   x % i  . Ÿ í S \ ‰y Œ ™ ‚  8 £ ¤& ñ `  ¦ 0 AK " f ë ß –[ þ t # Q”    Ž Ø  ¦ © œu   H

×

 æ$ í  " é ¶ Ü ¼– РÒ'   o  12.7 ± 0.02 m 0 Au \  [ O u ÷ &# Q e ” Ü ¼ 9, 12> h_  BGO $ 3 F  g ^ ‰– Ð ½ ¨$ í ÷ &# Q e ” 



. r « Ñ\  { 9  ÷ &  H ×  æ$ í   5 Å q_  ] X @ /u \  ¦ ½ ¨ l  0 AK  Smõ 

B r « Ñ_  Sm(n, γ) x 9 

B(n, αγ) ì ø Í 6

£

x`  ¦ y Œ •y Œ • s 6   x % i “ ¦, ×  æ$ í   5 Å q_     o\  ¦ y Œ ™r  l  0 AK " f ×  æ$ í   5 Å q 5 Å q \  BF

 Ž Ø  ¦ l \  ¦ [ O u Ù þ ¡ .

%

3 # Q”   Ta\  @ /ô  Ç ×  æ$ í   Ÿ í S \ ‰ é ß –€  & h  8 £ ¤& ñ   õ   H s „  _  z  ´+ « >\  _ ô  Ç 8 £ ¤& ñ   õ [ þ t x 9  ENDF/B-VI, JENDL-3.2 x 9  JEF-2.2_  ¨ î   ) a ° ú כ[ þ t õ  q “ § x 9   Ž ž Ð\  ¦ % i  .

PACS numbers: 24

Keywords: ×  æ$ í  , Ù þ ˜ì ø Í6 £ x, ò ø Í» 1 ϵ ¢ §, q ' Ÿ r ç ß –Z O 

I. " e  ] Ø

œ

íl _  ×  æ$ í   Ÿ í S \ ‰ é ß –€  & h \  › ' aô  Ç ƒ  ½ ¨  H " é ¶  – Ð> h µ

1 Ï x 9  Ù þ ˜Á ºl > hµ 1 Ï`  ¦ 3 l q& h Ü ¼– Ð r  Œ •÷ &# Q M ® o Ü ¼
, Õ ª s  Ê

ê– Ð  H ’  + þ A" é ¶  – Ð> hµ 1 Ï ÷  r  m  , " é ¶  Ù þ ˜Ó ü t o † < Æ, Ä ºÅ Ò Ó

ü

t o † < Æ, Ä ºÅ ҂  _  ~ ½ Ó ‚   x ; Ÿ ¤~ ½ Ót  [ O >  x 9  _ « Ñ ~ ½ Ó ‚   ì

 r  \  B Ä º כ ¹|   >   6   x ÷ &# Qt “ ¦ e ”  . [" é ¶  Ù þ ˜Ó ü t o ]

ì

 r  \ " f # Œ Q t  Ù þ ˜— ¸+ þ A(\ V\  ¦ [ þ t€   y Œ •— ¸+ þ A, f ” ] X Ÿ í S \ ‰

—

¸+ þ A, 4 Ÿ ¤½ + ˗ ¸+ þ Aõ  : Ÿ x > — ¸+ þ A 1 p x)_   { © œ$ í  Ž ž Ð\  € 9 כ ¹ô  Ç

×

 æ כ ¹ô  Ç X <s ' \  ¦ ] j/ B N½ + É ÷  r  m   Ù þ ˜ ì ø Í6 £ x x 9  # Œl — ¸

×

¼\ " f_  Ù þ ˜ï  r0 A ƒ  ½ ¨\  e ” # Q" f• ¸ ×  æ כ ¹ô  Ç X <s ' – Ð æ ¼

#

Œt “ ¦ e ” “ ¦ [1], Õ ª ì ø Í6 £ x" é ¶ o \  ¦ s K  l  0 AK " f  H Ÿ í S \ ‰ é

ß –€  & h _  & ñ S X ‰ô  Ç 8 £ ¤& ñ “ É r € 9 à º Ô  ¦   ô  Ç  © œI s  . [’  + þ A

"

é

¶  – Ð > hµ 1 Ï]\  e ” # Q" f  H ‰ & ³F  ² D G ] j& h Ü ¼– Ð  Ö ¸µ 1 Ïy  ƒ  ½ ¨

∗

E-mail: [email protected]

 ”  ' Ÿ ÷ &“ ¦ e ”   H “ ¦5 Å q 7 £ xd ” – Ð(FBR: Fast Breeder Reac- tor) ü < 5 Å q l  ½ ¨1 l x – Ð(ADSR: Accelerator Driven System Reactor)_  ” ¸d ” [ O > , ` ‚[ O >  x 9  " é ¶  – Ð \ P Ø  ¦§ 4  > í ß – 1

p

x # Œ Q ì  r  _  l œ íX <s ' – Ð  6   x ÷ &# Q ”    [2–5]. [Ä º Å

ÒÓ ü t o † < Æ]\  e ” # Q" f  H Ä ºÅ Ò_  ”   o\  e ” # Q" f Ù þ ˜\  _ ô  Ç

×

 æ$ í   f  ¨ à ºü < Z …  Ô  æ õ _   â Ô q tÜ ¼– Ð Á º î  r " é ¶  Ù þ ˜s  + þ

A$ í ÷ &  H † ½ Ó$ í ? / Ò\ " f_  " é ¶ ™ è½ + Ë$ í õ & ñ \  e ” # Q" f s- x 9  r-process_  — ¸4 S q> í ß –\  ×  æ$ í   Ù þ ˜ì ø Í6 £ x X <s '   H ×  æ כ ¹ô  Ç כ

¹™ è– Ð+ ‹  6   x ÷ &# Q ”    [6–8]. [Ä ºÅ ҂  _  ~ ½ Ó ‚   x ; Ÿ ¤~ ½ Ó t

 [ O > ]ì  r  \ " f  H þ j  H Ä ºÅ Òõ † < Æ_  µ 1 τ  Ü ¼– Ð Ä ºÅ Ò\ 

"

f_   © œl ^ ‰À Ӗ Ð “  K  Ä ºÅ Ò\ " f 5 p x Á º" é ¶[ þ t_  ~ ½ Ó ‚  x ; Ÿ ¤ s

 ë  H ] jr  ÷ &“ ¦ e ” Ü ¼ 9, s \  @ /ô  Ç ¨ î  Œ •\ O s  ² D G ] j& h Ü ¼

–

Ð  Ö ¸µ 1 Ïy  ”  ' Ÿ ÷ &“ ¦ e ”   H Æ Ò[ js   [9]. [_ « Ñ ~ ½ Ó ‚  ]ì  r



\ " f  H

B_  ×  æ$ í  Ÿ í S \ ‰`  ¦ s 6   xô  Ç € Œ ™u « Ñ, Ô  æ ™ è×  æ$ í



Ÿ í S \ ‰ u « Ñכ ¹Z O (BNCT: Boron Neutron Capture Ther-

apy)  ² D G ] j& h Ü ¼– Ð  Ö ¸µ 1 Ïô  Ç ƒ  ½ ¨ é ß –> \  ü < e ” Ü ¼ 9 s \ 

-241-

Fig. 1. The evaluated data of ENDF/B-VI, JENDL- 3.2, JEF-2.2 and the previous measurement data for the Ta(n, γ) Reaction.

@

/ô  Ç “  ^ ‰_  p | ¾ Ó" é ¶ ™ è\  @ /ô  Ç ×  æ$ í   Ù þ ˜ì ø Í6 £ x X <s '   H

^

‰? /_   © œl ’ < H © œ\  @ /ô  Ç ×  æ כ ¹ô  Ç & ñ ˜ Ð\  ¦ ] j/ B Nô  Ç  [10].

0 Aü < ° ú  “ É r s Ä »\ " f & ñ S X ‰ô  Ç ×  æ$ í  Ÿ í S \ ‰ X <s ' \  ¦ 8 £ ¤

&

ñ   H  כ “ É r # Œ Q ì  r  \ " f B Ä º ×  æ כ ¹  . Õ ª Q
 y Œ • Ù þ

˜7 á x \  @ /ô  Ç ×  æ$ í  Ÿ í S \ ‰ X <s ' [ þ t“ É r \ P ×  æ$ í   % ò % i \ " f keV \  -t % ò % i \    5 g" f 8 £ ¤& ñ X <s ' _  € ª œõ  | 9 s  p  f

 ¨ “ ¦,  f ”  8 £ ¤& ñ ÷ &t  3 l wô  Ç Ù þ ˜7 á x • ¸ ´ ú §Ü ¼ 9,  8½ ¨
, 8 £ ¤

&

ñ _  & ñ x 9 • ¸• ¸ ë ß –7 á ¤ Û ¼X O t  3 l wô  Ç  כ s  ‰ & ³z  ´s  . Õ ª ×  æ \ 

"

f …  ;ƒ   Ta(ò ø Í» 1 ϵ ¢ §)Ù þ ˜7 á x“ É r F  gÙ þ ˜ì ø Í6 £ x`  ¦ : Ÿ xô  Ç ×  æ$ í  " é ¶ Ü ¼

–

Ð" f  6   x ÷ &“ ¦ e ” Ü ¼ 9 [11], : £ ¤ y  þ j  H \   H ADSR_  ×  æ

$ í

 " é ¶ Ü ¼– Ð Â Òy Œ •÷ &“ ¦ e ”   H ë ß –
p u V , “ É r \  -t  % ò % i \  @ / ô 

Ç Ta_  & ñ S X ‰ô  Ç ×  æ$ í  Ÿ í S \ ‰é ß –€  & h  8 £ ¤& ñ “ É r B Ä º ×  æ כ ¹ 



.

ò

ø Í» 1 ϓ É r \ P ×  æ$ í   Ÿ í S \ ‰é ß –€  & h s  20.67 barn [12]Ü ¼– Ð

"

f  © œ{ © œy 
p u \ • ¸ Ô  ¦ ½ ¨ “ ¦, · ú ¡\ " f " fÕ ü tô  Ç s Ä »\  _  K

" f Õ ª X <s ' _  € ª œõ  | 9 “ É r p f  ¨ô  Ç  כ s  ‰ & ³z  ´s  . Fig- ure 1 õ  Table 1\ " f
  · p  ü < ° ú  s  \ P ×  æ$ í  % ò % i  s 



© œ\ " f 100 eV s  _  8 £ ¤& ñ   õ   H p ì  r8 £ ¤& ñ   õ “   F.

Widder [13]_    õ ü < \ P ×  æ$ í  % ò % i _    õ “   H. Pomer- ance(21.3 ± 1.0 barn) [14], R. B. Tattersall(19.0 ± 0.2 barn) [15] ü < R. E. Schmunk(20.0 ± 0.9 barn) [16]_    õ 

\

 ¦ ] jü @ “ ¦  H \ O   H  כ s  ‰ & ³z  ´s  9, s [ þ t \ P ×  æ$ í  Ÿ í S \ ‰ é

ß –€  & h • ¸ š ¸ # 3 0 A î ß –\ " f { 9 › ' a$ í e ”   H ° ú כ[ þ t`  ¦ ] jr   t

 3 l w “ ¦ e ”  . s [ þ t ° ú כ[ þ t`  ¦ ] jü @ô  Ç
 Qt    õ [ þ t“ É r @ / Â

Òì  r s  100 eV s  © œ_  à º keV % ò % i  x 9  à º MeV_    õ [ þ t s

 @ / Òì  r s  . ô  Ǽ #  F. Widder_    õ   H " é ¶  – Ð_  “ ¦5 Å q

\

 -t ì  rZ > l ü < Moxon-Rae Ž Ø  ¦ l \  ¦  6   x # Œ % 3 “ É r    õ

– Ð" f Fig. 1\ " f ˜ Ѝ  H  ü < ° ú  s  / B N" î % ò % i \ " f_  ¨ î 

 

õ ü <  © œ{ © œô  Ç s \  ¦ ˜ Ðs “ ¦ e ”  . s  " é ¶ “  “ É r ×  æ$ í   \ 

-t  ì  r K 0 p x s 
 8 £ ¤& ñ \  -t  % ò % i \  e ” # Q" f• ¸ Ô  ¦S X ‰& ñ • ¸

\

 ¦ Ÿ í† < Êô  Ç   õ  “ ¦ Æ Ò& ñ ÷ &# Qt Ù ¼– Ð s  % ò % i \  @ /ô  Ç & ñ

Fig. 2. Experimental arrangement for the capture cross section measurement.

S X

‰ô  Ç 8 £ ¤& ñ s  כ ¹½ ¨÷ &“ ¦e ”  . ÷  rë ß –  m  , „   ‚  + þ A5 Å q l

\  _ ô  Ç F  gÙ þ ˜ì ø Í6 £ x \ " f µ 1 ÏÒ q t÷ &  H ×  æ$ í  \  ¦ s 6   xô  Ç ×  æ

$ í

 Ÿ í S \ ‰  õ   H \ O   H z  ´& ñ s  .   " f Ta\  @ /ô  Ç & ñ S X ‰ ô 

Ç ×  æ$ í  Ÿ í S \ ‰é ß –€  & h  X <s '   H # Œ Q t  s Ä »\ " f ] X  z 

´y  כ ¹½ ¨÷ &“ ¦ e ”   H  © œS ! s  .

0 Aü < ° ú  “ É r s Ä »\ " f ‘ : r ƒ  ½ ¨  H { 9 ‘ : r “ §ž Ð@ /† < Æ " é ¶  – Ð z 

´+ « >™ è_  y © œ§ 4 ô  Ç ` O Û ¼ + þ AI _  46-MeV „    ‚  + þ A 5 Å q l

– Ð 5 Å q ) a „   \  ¦ s 6   x # Œ Ta³ ð& h Ü ¼– РÒ' _  F  gÙ þ ˜ ì

ø Í6 £ x`  ¦ { 9 Ü ¼&  µ 1 ÏÒ q t ) a ×  æ$ í  \  ¦ s 6   x K , ×  æ$ í   q ' Ÿ  r

ç ß –(Time-of-flight) Z O  x 9  „  \  -t  f  ¨ à º+ þ A“   12> h_  BGO(Bi

Ge

O

) $ 3 F  g Ž Ø  ¦ l – Ð, \ P ×  æ$ í   \  -t  % ò % i 

\

" f à ºÑ þ ˜ eV % ò % i \  s Ø Ô  H ×  æ$ í  \  @ /ô  Ç Ta_  ×  æ$ í



Ÿ í S \ ‰é ß –€  & h `  ¦ 8 £ ¤& ñ % i  . r « Ñ\  { 9  ÷ &  H ×  æ$ í  5 Å q

`

 ¦ 8 £ ¤& ñ l  0 AK " f

B_ 

B(n, α) ì ø Í6 £ x`  ¦ s 6   x % i  .

8

£

¤& ñ   õ \ " f 100 eV s  _  % ò % i \  @ /K " f  H ‘ : r ƒ  ½ ¨

\

" f % ƒ6 £ § Ü ¼– Ð 8 £ ¤& ñ `  ¦ r • ¸   H % ò % i Ü ¼– Ð+ ‹, % 3 # Q”      õ   H l ” > r_  F. Widder_  8 £ ¤& ñ   õ ü < ¨ î ° ú כ[ þ t õ  q “ §

% i  . % 3 # Q”     õ   H 0 A\ " f ƒ  / å Lô  Ç # Œ Q ì  r  \ " f Ä » 6

x >   6   x ÷ &# Q| 9   כ Ü ¼– Ð l @ /÷ & 9 : £ ¤ y , ×  æ$ í  Ÿ í S \ ‰ é

ß –€  & h `  ¦ 8 £ ¤& ñ   H l Õ ü t õ  K $ 3 ~ ½ ÓZ O “ É r Ó ü t : r # Œ Q t 



 É r " é ¶ ™ è_  Ÿ í S \ ‰é ß –€  & h  8 £ ¤& ñ \  כ ¹|   >  s 6   x | ¨ c  כ Ü ¼

–

Ð l @ /  ) a  . ÷  rë ß –  m  , Ù þ ˜Ó ü t o † < Æõ  Ù þ ˜/ B N† < Æ_  l œ íì  r



– Ð" f ƒ  ½ ¨   õ   H Ù þ ˜ x 9  " é ¶  § 4 / B N† < Æ\  6 £ x6   x| ¨ c  כ Ü ¼– Ð l

@ /÷ & 9, 8 £ ¤& ñ ~ ½ ÓZ O õ  K $ 3 õ & ñ “ É r z  ´+ « > Ù þ ˜Ó ü t o † < Æ x 9  Ù þ ˜ /

B

N† < Æ_  ì  r  _  † < Æë  H s K \  ¦ 0 Aô  Ç ×  æ כ ¹ô  Ç l œ í8 £ ¤& ñ l Õ ü t s

 | ¨ c  כ Ü ¼– Ð l @ /  ) a  .

II. ÷ m Ç] M öX ê sV  õ m Í U ê s0 n É

1. 46-MeV  ¹ Å  Ò Å] k ù ’ Ò ×M Ñ ÷ ú n ÞV R Ë R  {  ES ‡ ˜ m0 n É ù

p § T  “ Ó Þ” X ¢ ÷ m Ç] M ö

‘

: r ƒ  ½ ¨  H “ §ž Ð@ /† < Æ" é ¶  – Ðz  ´+ « >™ è(KURRI: Kyoto

University Research Reactor Institute)_  46-MeV

Table 1. Experiments in the Previous Measurements for the Ta(n, γ) Reaction.

Quantity Energy Experimental Neutron flux Detector

Results range method determination

A. I. Leipunskij et al. 200 keV Linear Accelerator

I(n, γ) Scintillation Counter

(1958)

(Activation)

B. C. Diven et al. 175 keV ∼ -

U(n, f) Liquid Scintillator

(1960)

1 MeV Tank Detector

J. H. Gibbons et al. 7 ∼ 170 Van de Graaff In(n, γ) Liquid Scintillator

(1961)

keV (TOF) Tank Detector

R. C. Block et al. 205 eV ∼ Fast Chopper of - Liquid Scintillator

(1961)

7 keV Reactor (TOF) Tank Detector

R. L. Macklin et al. ∼ = 30 keV Van de Graaff Ag(n, γ) Moxon-Rae Detector

(1963)

(TOF)

I. Bergqvist et al. 35 ∼ 300 Van de Graaff Ag(n, γ) NaI(Tl)

(1963)

keV (TOF)

R. L. Macklin et al. 30 ∼ 314 Van de Graaff

U(n, f) Moxon-Rae Detector

(1966)

keV (TOF)

D. Kompe 13 ∼ 157 Van de Graaff

Au(n, γ) Liquid Scintillator

(1969)

keV (TOF) Tank Detector

M. P. Fricke et al. 0.96 keV ∼ Electron Linear

B(n, αγ) Large Liquid

(1970)

1.11 MeV Accelerator (TOF) Scintillator

D. Drake et al. Van de Graaff

H(n, tot) NaI(Tl) Anti-Compton

(1971)

14 MeV Spectrometer

J. Hellstroem 30 keV ∼ Van de Graaff

Au(n, γ) Liquid Scintillator

(1973)

1.5 MeV (TOF) Tank Detector

F. Widder 0.014 ∼ Fast Chopper of NE-912 Glass Moxon-Rae Detector (1975)

20 eV Reactor (TOF) Scintillator

C. Le Rigoleur et al. 13 ∼ 157 Van de Graaff

B(n, αγ) C

F

Detector

(1976)

keV (TOF)

Xia Yijun et al. 11 ∼ 100 Van de Graaff

Au(n, γ) Moxon-Rae Detector

(1988)

keV (TOF)

H. Pomerance Thermal Pile Oscillator of

Au(n, γ) -

(1951)

neutron Reactor

R. B. Tattersall et al. Thermal Pile Oscillator of

B(n, αγ) -

(1960)

neutron Reactor

R. E. Schmunk et al. Thermal Slow Chopper of

B(n, αγ) -

(1960)

neutron Reactor

„ 

  ‚  + þ A5 Å q l (Linac)ü < „  \  -t  f  ¨ à º Ž Ø  ¦ l “   BGO(B

G

O

) $ 3 F  g Ž Ø  ¦ l \  _ ô  Ç TOF(Time-of- Flight)~ ½ ÓZ O \  _ K " f r ' Ÿ ÷ &% 3 Ü ¼ 9, z  ´+ « >C u • ¸  H Figure 2 \ 
 ? /% 3  . z  ´+ « >\   6   x ÷ &# Q”   ×  æ$ í  q  '

Ÿ  ⠖ Ѝ  H KURRI „   ‚  + þ A5 Å q l _  „  c ” \  @ / # Œ 135

_  y Œ •• ¸– Ð [ O u ÷ &% 3  . Ta ×  æ$ í   " é ¶ Ü ¼– РÒ'  µ 1 ÏÒ q t

 )

a ×  æ$ í  5 Å q“ É r ×  æ$ í  " é ¶ Ü ¼– РÒ'  12.7 ± 0.02 m b  # Q”   0 Au \  [ O u ÷ &# Q e ”   H ×  æ$ í  Ÿ í S \ ‰ r « Ñ\  { 9   >   ) a



. ×  æ$ í   q ' Ÿ  ⠖ Ð 5 Å q \ " f_  ×  æ$ í  ü < y Œ ™ ‚  | 9 5 Å q“ É r

×

 æ$ í   c ” _  ”  ' Ÿ ~ ½ ӆ ¾ Ó\  @ / # Œ B

C, Li

CO

, Pb s    6  

x ÷ &% 3  . a % ~“ É r ×  æ$ í   c ” `  ¦ % 3 l  0 AK " f ×  æ$ í  q ' Ÿ  â

–

Ѝ  H ×  æ$ í  " é ¶_  f ”  ⠀  • 12 cm\ " f ×  æ$ í  Ÿ í S \ ‰ r « Ñ_ 

·

ú ¡ t _  1.8 × 1.8 cm

Ü ¼– Ð Z þ t # Qt >  ÷ &• ¸2 Ÿ ¤ ] j Œ •÷ &

%

3  . ×  æ$ í  Ÿ í S \ ‰ r « э  H BOG  Ž Ø  ¦ l _  ×  æd ” \  [ O u ÷ &

%

3 “ ¦, z  ´+ « >×  æ_  ×  æ$ í  c ” _    1 l x`  ¦ 8 £ ¤& ñ l  0 AK " f ×  æ

$ í

 c ”  ×  æç ß –\  BF

 Ž Ø  ¦ l \  ¦ [ O u Ù þ ¡ .

2.  ¹ Å  Ò Å] k ù ’ Ò ×M  õ m Í ú n ÞV R Ë  ®  ot  

5 Å q ) a „   \  ¦ Ta \  { 9  r & , „   _  ] j1 l x4 Ÿ ¤  \  _ 

Table 2. Details of the measuring conditions in the cur- rent experiment.

Linear Accelerator

Condition. TD of TOF › ¸| 

Energy - 30 MeV

Pulse width - 3 µsec

Repetition rate - 50 Hz

Peak current - 500 mA

- Time / channel 4 µs/ch - Full Channel number 4096 ch

Fig. 3. BGO assembly used in the current measurement.

ô 

Ç F  g Ù þ ˜ì ø Í6 £ x`  ¦ : Ÿ x K  ×  æ$ í  \  ¦ µ 1 ÏÒ q tr †    [11]. # Œl " f Ta  H f ”  â 5 cm\  ¿ ºa  6 cm_  Ti " é ¶: Ÿ x5 Å q \  12> h_  ó ø ÍÜ ¼

–

Ð ½ ¨$ í ÷ &# Qe ” “ ¦, F  gÙ þ ˜ì ø Í6 £ x \  _ K " f µ 1 ÏÒ q t÷ &  H \ P `  ¦ ´ ò Ö

 ¦& h Ü ¼– Ð Í ‰ ty Œ •r v l  0 AK " f ó ø Í[ þ t  s \   H Ó ü t – Ð G 0 >

4

R e ”  . s  ×  æ$ í  " é ¶“ É r “ ¦5 Å q×  æ$ í  \  ¦ y Œ ™5 Å q r v l  0 AK 

"

f ¿ ºa  0.8 cm, Z  } s  35 cm, f ”  â 30 cm_  Al 6   x l _  ×  æ

€

© œ\  [ O u ÷ &% 3  . TOF ×  æ$ í  c ” _  \  -t “ §& ñ “ É r ¸ ú ˜ · ú ˜

9”   Au_  4.92 eV, Co_  132 eV, Mn_  2.37 keV ×  æ$ í



Ÿ í S \ ‰/ B N" î `  ¦ s 6   x % i  . z  ´+ « >\   6   x ) a 5 Å q l _  › ¸

|

õ  TD(Time Digitizer)_  › ¸| `  ¦ Table 2 \ 
 ? /% 3 



.

3. • ¤X N ËS z » õ m Í ß e È û s ÚM 

×

 æ$ í  Ÿ í S \ ‰ z  ´+ « >\   6   x ÷ &# Q”   r « Ñ_  ] j" é ¶“ É r Table 3 \ 
 ? /% 3  . Tar « Ñ_  + þ AI   H · û ª“ É r F K5 Å q ó ø ÍÜ ¼– Ð ÷ &

#

Q e ” “ ¦ ¿ ºa   H 1 mm s  . r « Ñ_  ¿ ºa   H a % ~“ É r ’    ñ/¸ ú š 6

£

§ q \  ¦ % 3 “ ¦, r « Ñ ? /\ " f_  { 9  ×  æ$ í  _  \  -t \  _ 

”

> r   H ×  æ$ í    l  ` ‚´ òõ  x 9   ×  æí ß –ê ø Í´ òõ \  ¦ “ ¦ 9ô  Ç

 כ

s  . F K5 Å qì  r´ ú ˜ + þ AI _ 

B  H \  -t _ ” > r ×  æ$ í  5 Å q`  ¦ 8

£

¤& ñ l  0 AK " f  6   x ÷ &% 3 “ ¦, · û ª“ É r AlF K5 Å qó ø ÍÜ ¼– Ð ë ß –[ þ t

#

Q”    © œ  5 Å q \  V , # Q & ’  . s [ þ t r « Ñ[ þ t“ É r BGO$ 3 F  g Ž  Ø

 ¦ l _  ×  æd ”   Òì  r \  [ O u Ù þ ¡ .

×

 æ$ í  Ÿ í S \ ‰ \  _ K " f µ 1 ÏÒ q t ) a 7 £ ¤µ 1 Ï y Œ ™ ‚  “ É r „  \  -t  f

 ¨ à º+ þ A  Ž Ø  ¦ l “   BGO  Ž Ø  ¦ © œq \  _ K " f 8 £ ¤& ñ ÷ &% 3  .

BGO  Ž Ø  ¦ © œq   H Hitachi Chemical Industry  \  _ K " f ]

j Œ • ) a 5 × 5 × 7.5 cm

ß ¼l _  $ 3 F  g# 4 [  t 12 > h– Ð ½ ¨$ í ÷ &

#

Q e ”  . BGO  Ž Ø  ¦ © œq   H Figure 3 \ 
 ? /% 3  . 12> h BGO $ 3 F  g ^ ‰_  8 ú x  Òx   H 2.25 l – Ð" f s  כ “ É r @ /+ þ A Ó  o^ ‰ $ 3  F 

g ^ ‰  Òx _  1/1,000 à ºï  r s  . y Œ •y Œ •_  BGO $ 3 F  g ^ ‰  H f ” 

 â

3.8 cm_  F  g7 £ x C  › ' a(R580 Hamamatsu Photonics  )õ 

 

½ + Ë÷ &% 3  . Õ ªo “ ¦ 12> h_  $ 3 F  g ^ ‰[ þ t“ É r Figure 3 \  ˜ Ð# Œ

”

   כ õ  ° ú  s  ×  æ$ í  Ÿ í S \ ‰ r « і РÒ'  µ 1 ÏÒ q t÷ &  H 7 £ ¤µ 1 Ïy Œ ™



‚  `  ¦ — ¸¿ º f  ¨ à º½ + É Ã º e ”   H þ j& h Ü ¼– Ð › ¸| Ü ¼– Ð ½ ¨$ í ÷ &

%

3  . BGO  Ž Ø  ¦ © œq _  ×  æ€ © œ\   H ×  æ$ í  c ” s  : Ÿ x õ  • ¸ 2

Ÿ ¤ 1.8 × 1.8 cm

_  : Ÿ x – Ð e ” “ ¦, | 9 5 Å q ) a ×  æ$ í  c ” “ É r s  :

Ÿ

x – Ð\  ¦ : Ÿ x # Œ q ' Ÿ  >   ) a  .  8¹ ¡ ¤ s , s  BGO  Ž Ø  ¦ © œ q

  H  ƒ  ~ ½ Ó ‚  Ü ¼– Ð Â Ò' _  ’    ñ\  ¦ é ß – l  0 AK " f 5

× 10 cm

ß ¼l _  ± ú šÜ ¼– Ð ` ‚÷ &# Q e ”  . ÷  rë ß –  m   Figure 3 \ " f ˜ Ѝ  H  כ õ  ° ú  s  r « Ñ\  _ K  í ß –ê ø Í÷ &# Qt   H

×

 æ$ í  \  ¦ ` ‚ l  0 AK " f BGO  Ž Ø  ¦ © œu ? /_  r « Ñ

Z

 ~ # Œt   H ×  æ€ © œÂ Ò\  î ß –A á ¤ Ü ¼– Ð ¿ ºa  3 mm“  

LiF  { 9  s

 · ¡ ­ # Q e ”  .

4. • ¤ X N Ë X

<s ' à º| 9  © œu _  > h| Ä Ì• ¸\  ¦ Figure 4 \ 
 ? /% 3  .

×

 æ$ í  q ' Ÿ r ç ß –Z O “   TOFZ O `  ¦ 0 AK " f ¿ º 7 á x À Ó_  ’    ñ[ þ t s

 r ç ß –n t _ O   ¨ 8 Š © œu (TD: Time digitizer) 5 Å q Ü ¼– Ð { 9 

§

4 ÷ &% 3  . Ø  ¦µ 1 ϒ    ñ  H „   ‚  + þ A5 Å q l – РÒ'  µ 1 ÏÒ q t ) a ’    

ñ\  ¦ “ ¦5 Å q7 £ x; Ÿ ¤ l (FA: Fast amplifier)\  ¦  5 g" f TD– Ð { 9 

§

4 ÷ &% 3 “ ¦, & ñ t ’    ñ  H BGO Ž Ø  ¦ © œu _  y Œ ™ ‚  Ü ¼– Ð ë ß –[ þ t

#

Q”   % 3 # Q”   ’    ñü < ×  æ$ í  c ” _     o\  ¦ 8 £ ¤& ñ l  0 AK 

"

f [ O u   ) a BF

 Ž Ø  ¦ l \ " f % 3 # Q”   ’    ñ\  ¦  6   x % i  .

TD 5 Å q Ü ¼– Ð [ þ t # Qç ß – ’    ñ[ þ t“ É r FAST ComTec’s MPA/PC

\

 _ K " f $  © œ÷ &% 3  .

III. A 0 V Ä

1. ° ‚ Ç ú n ÞV R Ë  ’ Ò ×

Sm r « Ñ_  \ P ×  æ$ í  Ÿ í S \ ‰Ö  ¦, C

(E

)“ É r  6 £ § õ  ° ú  s  Å

Ò# Q| 9  à º e ”  .

C

(E

) = 

(E

)Y

(E

)φ(E

), (1)

#

Œl \ " f, ' ‘   “Sm”  H Samarium r « Ñ\  ¦ _ p  “ ¦,

E

  H \ P ×  æ$ í  \  -t ,   H BGO  Ž Ø  ¦ © œu _  y Œ ™ ‚   Ž 

Table 3. Physical parameters of the samples used in the current experiment.

Sample Ta Sm

B ∗

Physical form Metal plate Metal plate Metal powder

Chemical purity (%) 99.9 99.8 99.999

Isotopic composition (%) Natural Natural 96.98

Weight of sample (g) 2.72 1.25 2.92

Thickness of sample (cm) 0.1 0.05 0.8

(Atoms/kb) 2.82 1.81 52.42

Size of sample (cm

) 1.8 × 1.8 1.8 × 1.8 1.8 × 1.8

∗

B_  F K5 Å qì  r´ ú ˜“ É r 0.1 mm ¿ ºa _  Al F K5 Å qó ø ÍÜ ¼– Ð ë ß –[ þ t # Q”    © œ \  [ þ t # Qe ”  .

∗

B:96.98 %,

B:3.02 %.

Fig. 4. Block diagram for the current measurement using the BGO assembly.

Ø

 ¦ ´ òÖ  ¦, Y   H Ÿ í S \ ‰ à º, Õ ªo “ ¦ φ  H { 9   ×  æ$ í  5 Å q`  ¦ _ p  ô 

Ç . ô  Ǽ # , Sm r « э  H \ P ×  æ$ í  % ò % i \ " f 5,670 barn_  B

Ä º  H ×  æ$ í   Ÿ í S \ ‰é ß –€  & h `  ¦ t Ù ¼– Ð { 9     H \ P ×  æ

$ í

 \  ¦ — ¸¿ º Ÿ í S \ ‰½ + É Ã º e ”  .   " f Ÿ í S \ ‰ à º Y

(E

)  H

†

½ Ó © œ { 9  ×  æ$ í  à ºü < { 9 u  >   ) a  . Õ ªo “ ¦ “z  ´+ « > © œu  x 9

 ~ ½ ÓZ O ”\ " f " fÕ ü tô  Ç  כ % ƒ! 3  BGO  Ž Ø  ¦ © œu   H „  \  - t

 f  ¨ à º+ þ As Ù ¼– Ð y Œ ™ ‚  \  @ /ô  Ç  Ž Ø  ¦ ´ òÖ  ¦ 

(E

) • ¸ { 9 



×  æ$ í  € ª œõ  { 9 u  >   ) a   [30]. ô  Ǽ # , Smr « э  H ô  ǁ   _

 ×  æ$ í  Ÿ í S \ ‰ \  @ /K " f ¨ î ç  H 5.6 > h_  B Ä º  H y Œ ™ ‚  …  ; s

  ×  æ • ¸\  ¦ t “ ¦ e ”   [31]. s   z  ´“ É r Sm r « і РÒ' 

~

½ ÓØ  ¦ ) a y Œ ™ ‚  `  ¦ 8 £ ¤& ñ   H X < e ” # Q" f # Q‹ "  y Œ ™ ‚  • ¸ Z  ~ u

t  · ú §“ ¦ — ¸¿ º  Ž Ø  ¦ >  ô  Ç .   " f Smr « Ñ_   â Ä º

\ P

×  æ$ í  % ò % i \ " f_  ] X @ / ×  æ$ í  5 Å q`  ¦ 8 £ ¤& ñ 0 p x >  ô  Ç



.   " f ×  æ$ í  5 Å q õ  Smr « Ñ_  8 £ ¤& ñ Ö  ¦“ É r  6 £ § õ  ° ú  “ É r d ”

Ü ¼– Ð ³ ð‰ & ³½ + É Ã º e ”  .

C

(E

) = φ(E

). (2)

2. BGO ß e È û s ÚX ê sV 8 ý ƒ ºT ƒ †P c p  Ò Å ß e È û s ڄ Ç ù o Ú

ô 

Ǽ # 

B(n, αγ) ì ø Í6 £ x_  \ P ×  æ$ í  % ò % i \ " f_  ×  æ$ í  

Ÿ

í S \ ‰ é ß –€  & h “ É r 3837 ± 9 barns Ù ¼– Ð ƒ  ½ ¨\   6   x ÷ &# Q

”

 

B r « э  H \ P ×  æ$ í  % ò % i \ " f ×  æ$ í  \  ¦ — ¸¿ º f  ¨ à º\  ¦ ô 

Ç  [32]. 7 £ ¤ Y

(E

) = 1 s  $ í w n  ) a  . ÷  rë ß –  m  

10

B(n, αγ)/ {

B(n, αγ) +

B(n, α) } q Ö  ¦ • ¸ V , “ É r ×  æ$ í



\  -t  % ò % i \  @ /K " f { 9 & ñ   [33].   " f

B r « Ñ _  Ÿ í S \ ‰Ö  ¦“ É r  6 £ § õ  ° ú  s  ³ ðr ½ + É Ã º e ”  .

C

(E

) = 

(E

)Y

(E

)φ(E

) = 

(E

) · φ(E

), (3)

#

Œl \ " f ' ‘   “B”  H

B r « Ñ\  ¦ _ p ô  Ç . d ”  (2)ü <

(3) Ü ¼– РÒ'  \ P ×  æ$ í  % ò % i \  @ /ô  Ç BGO  Ž Ø  ¦ © œu _  y Œ ™



‚    Ž Ø  ¦ ´ òÖ  ¦“ É r 

(E

) Ü ¼– Ð ³ ðr ÷ & 9  6 £ § õ  ° ú  s  Ä »

•

¸÷ &# Q ”   .

C

(E

)/C

(E

) = 

(E

) (4)

10

B(n, αγ)ì ø Í6 £ x“ É r { 9   ×  æ$ í  _  \  -t \  _ ” > r t  · ú §

“

¦ 478 keV_  é ß –{ 9  y Œ ™ ‚  `  ¦ ~ ½ ÓØ  ¦ l  M :ë  H \  — ¸Ž  H ×  æ$ í



\  -t \  @ /K " f 

(E

)“ É r { 9 & ñ  “ ¦ ^  ¦ à º e ”  . Õ ª X O

l  M :ë  H \  \ P ×  æ$ í   % ò % i \ " f_  BGO  Ž Ø  ¦ © œu _   Ž  Ø

 ¦ ´ òÖ  ¦“ É r — ¸Ž  H ×  æ$ í   \  -t  % ò % i \ " f 

(E

) = 

 

“

¦ ^  ¦ à º e ”  . s  › ' a > – РÒ'  y Œ ™ ‚   Ž Ø  ¦ ´ òÖ  ¦`  ¦ 0.861 ±

0.003 – Ð ½ ¨ % i  .   " f y Œ ™ ‚    Ž Ø  ¦ ´ òÖ  ¦“ É r Y

(E

)

= Y

(E) = 1 s  ÷ & 9, e ” _ _  ×  æ$ í   \  -t \ " f_  { 9  

×

 æ$ í  5 Å q φ(E)“ É r  Ž Ø  ¦ ´ òÖ  ¦ 

\  ¦ s 6   x # Œ  6 £ § õ  ° ú  s 

³

ð‰ & ³½ + É Ã º e ”  .

φ(E) = C

(E)/

/Y

(E) = C

(E)/

(5)

3. ú n ÞV R Ë ƒ ºT ƒ †• ¤

BGO  Ž Ø  ¦ © œu \  ¦ s 6   x # Œ ] X @ / ×  æ$ í  Ÿ í S \ ‰é ß –€  & h `  ¦ 8

£

¤& ñ l  0 AK " f  H Ÿ í S \ ‰ r « Ñ B Ä º  H / B N" î `  ¦ t   H

 כ

“ É r € 9 à º& h s  “ ¦ ½ + É Ã º e ”  .  =
 €   Õ ª / B N" î \  - t

 % ò % i \ " f { 9  ×  æ$ í  5 Å q \  @ /K " f Ÿ í o ÷ &l  M :ë  H s

 . ô  Ǽ # , Ta  H 4.28 eV \ " f  H / B N" î `  ¦ t  9 Õ ª / B N" î

\

 -t  E

\ " f Ÿ í o { 9 # Q
>   ) a  .   " f / B N" î \  - t

\ " f_  Tar « Ñ_  ×  æ$ í  Ÿ í S \ ‰ à º Y

(E

)  H { 9  ×  æ$ í   5

Å

q õ  ° ú  >   ) a  . Õ ª QÙ ¼– Ð r « Ñ_  / B N" î \  -t \ " f_  ×  æ

$ í

 Ÿ í S \ ‰ à º  H  6 £ § õ  ° ú  s  ³ ð‰ & ³½ + É Ã º e ”  .

C

(E

) = 

(E

)Y

(E

)φ(E

) = 

(E

)φ(E

), (6)

#

Œl " f ' ‘   “S”  H Ta r « Ñ\  ¦ _ p  “ ¦, E

“ É r / B N" î \  - t

\  ¦, φ(E

)  H d ”  (5)– РÒ'  % 3 “ É r ×  æ$ í  5 Å q`  ¦ _ p ô  Ç



. d ”  (6)Ü ¼– РÒ'  Tar « Ñ_  ×  æ$ í  Ÿ í S \ ‰ \  @ /ô  Ç  Ž Ø  ¦

´

òÖ  ¦“ É r 0.891 ± 0.003– Ð % 3 # Q& ’  . ô  Ǽ # , BGO  Ž Ø  ¦ © œu 



 H „  \  -t + þ A  Ž Ø  ¦ l s Ù ¼– Ð Ÿ í S \ ‰ r « Ñ\  @ /ô  Ç  Ž Ø  ¦ ´ òÖ  ¦



(E

)`  ¦   É r % ò % i _  \  -t \  @ /K " f• ¸ ° ú   “ ¦ ^  ¦ à º e ”

 .   " f s   Ž Ø  ¦ ´ òÖ  ¦“ É r  6 £ § õ  ° ú  s  ³ ð‰ & ³½ + É Ã º e ” 



.



(E

) = 

. (7)



 " f \  -t  E\ " f_  ×  æ$ í  Ÿ í S \ ‰Ö  ¦“ É r  6 £ § õ  ° ú  s 
 

è ­ q à º e ”  .

C

(E) = 

Y

(E)φ(E) (8)



t } Œ •Ü ¼– Ð ×  æ$ í  Ÿ í S \ ‰ à º Y

(E)  H d ”  (5)ü < (8)`  ¦  6   x

# Œ  6 £ § õ  ° ú  s  ³ ð‰ & ³½ + É Ã º e ”  .

Y

(E) = C

(E)

Y

(E)/C

(E)/

, (9)

#

Œl " f C

(E) ü < C

(E)  H 8 £ ¤& ñ \  _ K " f % 3 # Q | 9  à º e ” 

“

¦, 

  H \ P ×  æ$ í  \  ¦ s 6   x # Œ Sm8 £ ¤& ñ Ü ¼– РÒ'  “ §& ñ | ¨ c Ã

º e ”  . 

  H Ÿ í S \ ‰ r « Ñ_  Ÿ í o‰ & ³ © œÜ ¼– РÒ'  “ §& ñ | ¨ c à º e ”

 .

B r « Ñ\  @ /K " f  H Ÿ í S \ ‰ à º Y

(E)  V , “ É r % ò % i \ 

 

5 g" f { 9 & ñ >   ) a  .

Fig. 5. The correction function for the neutron self- shielding and/or neutron scattering effects in the current cross section measurement.

4. ú n ÞV R Ë ƒ ºT ƒ †‰ ˜ mì ÅX ì Ä8 ý – ¥y ¢

×

 æ$ í  Ÿ í S \ ‰ à º  H r « Ñ? /\ " f { 9 # Q
  H Ÿ í S \ ‰ à º– Ð · ú ˜ à º e ”

Ü ¼ 9  6 £ § õ  ° ú  s 
 è ­ q à º e ”   [34].

Y

(E) = (1 − exp(−Nσ

(E)t))σ

(E)f

/σ

(E), (10)

#

Œl " f N“ É r r « Ñ_  " é ¶  x 9 • ¸(atomic density)s “ ¦, σ

(E)“ É r „  é ß –€  & h , t  H r « Ñ_  ¿ ºa , σ

(E)  H ×  æ$ í  Ÿ í S \

‰é ß –€  & h , f

  H r « Ñ ? /\ " f_  ×  æ$ í   ×  æí ß –ê ø Íõ   l 

` ‚´ òõ \  @ /ô  Ç ˜ Ð& ñ > à ºs  .

5. | ºX N ËÊ Ý ~ ¾ 

×

 æ$ í  Ÿ í S \ ‰é ß –€  & h  8 £ ¤& ñ \  e ” # Q" f, r « Ñ? /\ " f_  é ß –{ 9  í

ß –ê ø Í <  ʓ É r  ×  æí ß –ê ø Í´ òõ   H B Ä º ×  æ כ ¹  . s  ´ òõ   H r 

Fig. 6. Comparison of the previous experimental cross

sections and the evaluated cross sections for the Ta(n, γ)

reaction with the current measurement.

Table 4. The numerical data of the current measurement for the Ta(n, γ) reaction.

Capture Cross- Capture Cross-

Enerty (eV)

Section (barn) Error (barn) Energy (eV)

Capture Cross-Section (barn) Error (barn) 1 3.27E −03 5.64E+01 2.90E+00 51 1.85E −02 2.68E+01 2.93E −01 2 3.39E −03 5.79E+01 2.77E+00 52 1.91E −02 2.58E+01 2.75E −01 3 3.51E −03 5.89E+01 2.71E+00 53 1.98E −02 2.54E+01 2.68E −01 4 3.63E −03 5.11E+01 2.58E+00 54 2.05E −02 2.47E+01 2.55E −01 5 3.76E −03 5.47E+01 2.40E+00 55 2.12E −02 2.49E+01 2.53E −01 6 3.89E −03 5.37E+01 2.24E+00 56 2.19E −02 2.43E+01 2.40E −01 7 4.03E −03 5.54E+01 2.26E+00 57 2.27E −02 2.35E+01 2.31E −01 8 4.17E −03 5.39E+01 2.09E+00 58 2.35E −02 2.31E+01 2.22E −01 9 4.32E −03 5.25E+01 1.95E+00 59 2.43E −02 2.29E+01 2.15E −01 10 4.47E −03 5.36E+01 1.87E+00 60 2.50E −02 2.32E+01 2.72E −01 11 4.62E −03 5.28E+01 1.76E+00 61 2.59E −02 2.25E+01 1.77E −01 12 4.79E −03 5.20E+01 1.64E+00 62 2.70E −02 2.20E+01 1.97E −01 13 4.96E −03 4.96E+01 1.55E+00 63 2.80E −02 2.14E+01 1.88E −01 14 5.13E −03 4.63E+01 1.46E+00 64 2.89E −02 2.08E+01 1.78E −01 15 5.31E −03 4.82E+01 1.44E+00 65 3.00E −02 2.11E+01 1.80E −01 16 5.49E −03 4.69E+01 1.35E+00 66 3.10E −02 2.04E+01 1.75E −01 17 5.69E −03 4.86E+01 1.27E+00 67 3.21E −02 1.99E+01 1.68E −01 18 5.89E −03 4.78E+01 1.23E+00 68 3.32E −02 2.00E+01 1.64E −01 19 6.09E −03 4.52E+01 1.14E+00 69 3.44E −02 1.95E+01 1.61E −01 20 6.31E −03 4.48E+01 1.08E+00 70 3.56E −02 1.91E+01 1.56E −01 21 6.54E −03 4.34E+01 1.02E+00 71 3.69E −02 1.92E+01 1.51E −01 22 6.77E −03 4.37E+01 9.97E −01 72 3.82E −02 1.87E+01 1.46E −01 23 7.00E −03 4.44E+01 9.58E −01 73 3.95E −02 1.86E+01 1.45E −01 24 7.26E −03 4.43E+01 9.32E −01 74 4.09E −02 1.79E+01 1.43E −01 25 7.51E −03 4.36E+01 8.78E −01 75 4.24E −02 1.77E+01 1.35E −01 26 7.77E −03 4.30E+01 8.58E −01 76 4.38E −02 1.75E+01 1.38E −01 27 8.04E −03 4.07E+01 7.93E −01 77 4.54E −02 1.71E+01 1.31E −01 28 8.33E −03 3.88E+01 7.34E −01 78 4.70E −02 1.71E+01 1.32E −01 29 8.62E −03 3.96E+01 7.15E −01 79 4.86E −02 1.68E+01 1.28E −01 30 8.93E −03 3.83E+01 6.74E −01 80 5.03E −02 1.66E+01 1.25E −01 31 9.24E −03 3.64E+01 6.30E −01 81 5.21E −02 1.64E+01 1.22E −01 32 9.57E −03 3.66E+01 6.24E −01 82 5.40E −02 1.58E+01 1.22E −01 33 9.90E −03 3.46E+01 5.90E −01 83 5.58E −02 1.56E+01 1.23E −01 34 1.03E −02 3.37E+01 5.62E −01 84 5.78E −02 1.56E+01 1.18E −01 35 1.06E −02 3.35E+01 5.51E −01 85 5.99E −02 1.53E+01 1.19E −01 36 1.10E −02 3.29E+01 5.24E −01 86 6.20E −02 1.51E+01 1.17E −01 37 1.14E −02 3.39E+01 5.14E −01 87 6.41E −02 1.47E+01 1.15E −01 38 1.18E −02 3.24E+01 4.89E −01 88 6.64E −02 1.47E+01 1.18E −01 39 1.22E −02 3.05E+01 4.50E −01 89 6.87E −02 1.42E+01 1.15E −01 40 1.26E −02 3.11E+01 4.41E −01 90 7.12E −02 1.39E+01 1.13E −01 41 1.31E −02 3.04E+01 4.22E −01 91 7.37E −02 1.35E+01 1.11E −01 42 1.35E −02 2.99E+01 4.06E −01 92 7.63E −02 1.35E+01 1.16E −01 43 1.40E −02 2.97E+01 3.84E −01 93 7.89E −02 1.33E+01 1.15E −01 44 1.45E −02 2.99E+01 3.78E −01 94 8.17E −02 1.30E+01 1.14E −01

«

Ñ_  Ä »´ ò¿ ºa  7 £ x  ½ + Éà º2 Ÿ ¤ & t  9, { 9  ×  æ$ í  _  ~ ½ Ó † ¾ Óõ • ¸ › ' aº  $ í s  B Ä º Z  }  . ÷  rë ß –  m   r « Ñ_  Ä »´ ò

Capture Cross- Capture Cross- Enerty (eV)

Section (barn) Error (barn) Energy (eV)

Capture Cross-Section (barn) Error (barn) 45 1.50E −02 2.90E+01 3.65E −01 95 8.46E −02 1.27E+01 1.13E −01 46 1.55E −02 2.82E+01 3.45E −01 96 8.76E −02 1.23E+01 1.16E −01 47 1.61E −02 2.84E+01 3.38E −01 97 9.07E −02 1.23E+01 1.14E −01 48 1.66E −02 2.68E+01 3.15E −01 98 9.38E −02 1.22E+01 1.19E −01 49 1.72E −02 2.66E+01 3.10E −01 99 9.72E −02 1.19E+01 1.23E −01 50 1.78E −02 2.67E+01 2.97E −01 100 1.01E −01 1.15E+01 1.18E −01 101 1.04E −01 1.13E+01 1.24E −01 151 5.87E −01 6.29E+00 2.35E −01 102 1.08E −01 1.12E+01 1.26E −01 152 6.08E −01 5.51E+00 2.47E −01 103 1.12E −01 1.10E+01 1.28E −01 153 6.29E −01 4.83E+00 2.32E −01 104 1.16E −01 1.06E+01 1.27E −01 154 6.52E −01 5.10E+00 2.37E −01 105 1.20E −01 1.08E+01 1.38E −01 155 6.75E −01 5.41E+00 2.69E −01 106 1.24E −01 1.06E+01 1.34E −01 156 6.98E −01 4.98E+00 2.26E −01 107 1.28E −01 1.05E+01 1.44E −01 157 7.23E −01 5.27E+00 2.30E −01 108 1.33E −01 1.02E+01 1.46E −01 158 7.48E −01 5.47E+00 2.60E −01 109 1.37E −01 1.01E+01 1.57E −01 159 7.75E −01 4.74E+00 2.20E −01 110 1.42E −01 9.91E+00 1.53E −01 160 8.02E −01 5.22E+00 2.50E −01 111 1.47E −01 9.78E+00 1.64E −01 161 8.30E −01 5.12E+00 2.21E −01 112 1.52E −01 9.74E+00 1.70E −01 162 8.59E −01 5.37E+00 2.46E −01 113 1.58E −01 9.19E+00 1.71E −01 163 8.90E −01 5.09E+00 2.42E −01 114 1.63E −01 9.19E+00 1.78E −01 164 9.21E −01 5.14E+00 2.41E −01 115 1.69E −01 9.64E+00 1.89E −01 165 9.53E −01 5.17E+00 2.37E −01 116 1.75E −01 9.14E+00 2.01E −01 166 9.87E −01 5.10E+00 2.34E −01 117 1.81E −01 9.07E+00 1.99E −01 167 1.02E+00 4.86E+00 2.33E −01 118 1.87E −01 9.25E+00 2.18E −01 168 1.06E+00 5.07E+00 2.30E −01 119 1.94E −01 9.37E+00 2.25E −01 169 1.09E+00 4.91E+00 2.28E −01 120 2.01E −01 8.76E+00 2.26E −01 170 1.13E+00 5.30E+00 2.34E −01 121 2.08E −01 9.23E+00 2.49E −01 171 1.17E+00 4.99E+00 2.55E −01 122 2.15E −01 8.21E+00 2.34E −01 172 1.21E+00 4.72E+00 2.15E −01 123 2.23E −01 8.48E+00 2.54E −01 173 1.26E+00 5.07E+00 2.19E −01 124 2.31E −01 8.34E+00 2.44E −01 174 1.30E+00 5.30E+00 2.57E −01 125 2.39E −01 8.08E+00 2.61E −01 175 1.35E+00 5.19E+00 2.49E −01 126 2.47E −01 7.54E+00 2.57E −01 176 1.39E+00 5.18E+00 2.20E −01 127 2.56E −01 7.75E+00 2.66E −01 177 1.44E+00 5.12E+00 2.46E −01 128 2.65E −01 7.38E+00 2.73E −01 178 1.49E+00 4.56E+00 2.33E −01 129 2.74E −01 7.04E+00 2.49E −01 179 1.55E+00 5.65E+00 2.15E −01 130 2.84E −01 7.12E+00 2.75E −01 180 1.60E+00 5.74E+00 2.45E −01 131 2.94E −01 7.38E+00 2.59E −01 181 1.66E+00 5.61E+00 2.44E −01 132 3.04E −01 7.29E+00 2.68E −01 182 1.72E+00 5.55E+00 2.38E −01 133 3.15E −01 7.00E+00 2.68E −01 183 1.78E+00 5.63E+00 2.41E −01 134 3.26E −01 6.98E+00 2.61E −01 184 1.84E+00 6.03E+00 2.43E −01 135 3.38E −01 7.12E+00 2.61E −01 185 1.90E+00 5.98E+00 2.39E −01 136 3.50E −01 7.06E+00 2.61E −01 186 1.97E+00 6.21E+00 2.95E −01 137 3.62E −01 6.98E+00 2.78E −01 187 2.04E+00 7.50E+00 2.57E −01 138 3.75E −01 6.88E+00 2.51E −01 188 2.11E+00 7.47E+00 2.54E −01 139 3.88E −01 6.68E+00 2.65E −01 189 2.19E+00 7.14E+00 2.49E −01 140 4.01E −01 7.24E+00 2.73E −01 190 2.26E+00 7.29E+00 3.01E −01

¿

ºa  7 £ x  €   ×  æ$ í  _   l  ` ‚´ òõ \  _ K " f r  « Ñ_  ×  æ$ í  Ÿ í S \ ‰ à º  H ´ ú §“ É r   1 l x`  ¦ 4 R `  ¦ à º e ”  .  

Capture Cross- Capture Cross- Enerty (eV)

Section (barn) Error (barn) Energy (eV)

Capture Cross-Section (barn) Error (barn) 141 4.16E −01 7.10E+00 2.65E −01 191 2.34E+00 7.20E+00 2.43E −01 142 4.30E −01 7.80E+00 2.73E −01 192 2.43E+00 7.82E+00 3.03E −01 143 4.45E −01 8.18E+00 2.78E −01 193 2.51E+00 8.31E+00 2.55E −01 144 4.61E −01 7.91E+00 2.68E −01 194 2.60E+00 9.05E+00 3.20E −01 145 4.77E −01 6.99E+00 2.54E −01 195 2.69E+00 9.69E+00 2.70E −01 146 4.94E −01 6.59E+00 2.47E −01 196 2.79E+00 1.11E+01 3.45E −01 147 5.11E −01 6.43E+00 2.63E −01 197 2.88E+00 1.17E+01 2.88E −01 148 5.29E −01 5.54E+00 2.35E −01 198 2.99E+00 1.42E+01 3.80E −01 149 5.48E −01 5.83E+00 2.51E −01 199 3.09E+00 1.55E+01 3.90E −01 150 5.67E −01 6.13E+00 2.56E −01 200 3.20E+00 1.75E+01 4.11E −01 201 3.31E+00 2.07E+01 4.44E −01 233 1.00E+01 1.06E+02 8.40E −01 202 3.43E+00 2.68E+01 4.09E −01 234 1.04E+01 7.58E+02 4.58E+00 203 3.55E+00 3.57E+01 5.66E −01 235 1.07E+01 1.10E+02 1.11E+00 204 3.68E+00 4.83E+01 6.65E −01 236 1.11E+01 2.40E+01 4.87E −01 205 3.81E+00 7.43E+01 8.33E −01 237 1.15E+01 1.04E+01 3.25E −01 206 3.94E+00 1.33E+02 1.17E+00 238 1.19E+01 5.53E+00 1.78E −01 207 4.08E+00 3.16E+02 2.11E+00 239 1.23E+01 3.33E+00 2.10E −01 208 4.22E+00 2.08E+03 1.17E+01 240 1.28E+01 4.31E+00 2.25E −01 209 4.37E+00 1.27E+03 7.08E+00 241 1.32E+01 7.06E+00 2.64E −01 210 4.52E+00 3.48E+02 2.72E+00 242 1.37E+01 1.13E+02 1.09E+00 211 4.68E+00 1.58E+02 1.29E+00 243 1.42E+01 1.20E+02 1.14E+00 212 4.85E+00 7.06E+01 7.46E −01 244 1.47E+01 6.18E+00 2.45E −01 213 5.02E+00 3.78E+01 5.31E −01 245 1.52E+01 2.86E+00 1.89E −01 214 5.20E+00 2.32E+01 4.10E −01 246 1.57E+01 2.74E+00 1.82E −01 215 5.38E+00 1.67E+01 4.84E −01 247 1.63E+01 2.15E+00 1.66E −01 216 5.57E+00 1.24E+01 3.00E −01 248 1.68E+01 2.51E+00 1.72E −01 217 5.76E+00 9.16E+00 2.56E −01 249 1.74E+01 2.10E+00 1.63E −01 218 5.97E+00 8.94E+00 3.56E −01 250 1.81E+01 2.68E+00 1.77E −01 219 6.18E+00 6.17E+00 2.15E −01 251 1.87E+01 3.15E+00 1.83E −01 220 6.39E+00 6.10E+00 3.03E −01 252 1.93E+01 4.61E+00 2.10E −01 221 6.62E+00 5.07E+00 1.96E −01 253 2.00E+01 8.89E+01 8.71E −01 222 6.85E+00 4.56E+00 1.86E −01 254 2.07E+01 1.52E+01 3.44E −01 223 7.09E+00 4.02E+00 2.49E −01 255 2.30E+01 2.69E+01 4.46E −01 224 7.34E+00 3.69E+00 1.69E −01 256 2.38E+01 2.03E+02 1.46E+00 225 7.60E+00 3.39E+00 2.33E −01 257 2.47E+01 3.03E+01 4.62E −01 226 7.87E+00 4.18E+00 2.49E −01 258 2.73E+01 3.26E+00 1.75E −01 227 8.15E+00 4.02E+00 1.72E −01 259 2.83E+01 2.80E+00 1.69E −01 228 8.43E+00 4.90E+00 2.58E −01 260 3.14E+01 4.82E+00 1.94E −01 229 8.73E+00 4.94E+00 2.57E −01 261 3.25E+01 8.05E+00 2.36E −01 230 9.04E+00 6.80E+00 2.06E −01 262 3.61E+01 1.82E+02 1.28E+00 231 9.36E+00 1.02E+01 3.41E −01 263 4.00E+01 5.67E+01 5.87E −01 232 9.69E+00 1.62E+01 4.21E −01 264 4.76E+01 1.75E+01 3.04E −01



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3  . Ta_  ×  æ$ í  Ÿ í S \ ‰ì ø Í6 £ x \  @ /ô  Ç s „  _    õ [ þ t“ É r s 

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a # Œ   H / B N" î Ü ¼– Ð · ú ˜ 94 R e ”  .

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Ta_  / B N" î [ þ t s  9 s  / B N" î [ þ t \  › ' a K " f

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Measurement of the Neutron Capture Cross-Section of Tantalum by Using the Neutron Time-of-Flight Method

Samyol Lee,

Sangbock Lee, Junhaeng Lee and Jungmin Lee Department of Radiology, Nambu University, Gwangju 506-824

Jungran Yoon, Younggi Min, Soonchul Jung and Taeik Ro Department of New Material Physics, Dong-A University, Busan 604-714

Guinyun Kim

Department of Physics, The Center for High Energy Physics, Kyungbuk National University, Daegu 702-701

Jun-ichi Hori, Shuji Yamamoto and Katsuhei Kobayashi

Research Reactor Institute, Kumatori-cho, Kyoto University, Sennan-gun, Osaka 590-0494, Japan (Received 8 March 2004, in final form 18 July 2004)

The neutron capture cross-section of tantalum (Ta) has been measured by using the neutron time- of-flight (TOF) method with the 46-MeV electron linear accelerator (linac) of the Research Reactor Institute, Kyoto University (KURRI). An assembly of Bi

Ge

O

(BGO) scintillators, which was composed of 12 pieces of BGO, placed at a distance of 12.7 ± 0.02 m from the neutron source was employed as a total energy absorption detector to measure the prompt-capture γ-rays from the samples. A metal plate of Sm and a plug of

B powder were used in order to determine the absolute neutron flux impinging on the capture samples for the energy of a thermal neutron and for energies above that, respectively. The existing experimental data and evaluated capture cross-section in ENDF/B-VI, JENDL-3.2, and JEF-2.2 have been compared with the current result.

PACS numbers: 24

Keywords: Neutron, Nuclear reaction, Tantalum, Time-of-flight

∗

E-mail: [email protected]