EXCITATION FUNCTION MEASUREMENTS 07 PROTON INDUCED REACTIONS ON RHODIUM AND
INDIUM: YIELDS OF Ru-97, Tc-96, Cd-109, and Sn-113
T.H. Ku,* R.H. Hsieh,* L.G. Stang, Jr.,*
P. Richards,* P.P. Singh, and T.E. Ward
The o b j e c t i v e of t h i s experiment i s t o measure t h e
of In-113m i n c l u d e a s h o r t - h a l f - l i f e
of 1.658 h , a mono-
e x c i t a t i o n f u n c t i o n s of proton-induced n u c l e a r r e a c t i o n s
e n e r g e t i c gamma emission of 392 keV (65% abundant), and
f o r f o u r r a d i o n u c l i d e s of v a l u e i n n u c l e a r medicine.
no b e t a emissions t o c o n t r i b u t e t o t h e r a d i a t i o n dosage.
The Brookhaven Linac I s o t o p e Producer (BLIP) 5, ' 6,
Cross s e c t i o n s of Ru-97 and Tc-96 formed i n rhodium
t a r g e t s a s w e l l a s Cd-109 and Sn-113 formed i n indium
h a s been i n a c t i v e u s e f o r t h e p a s t few y e a r s f o r pre-
t a r g e t s w i l l b e determined f o r proton e n e r g i e s from 40
p a r i n g l a r g e q u a n t i t i e s of r a d i o n u c l i d e s of medical
t o 200 MeV.
interest.
These d a t a w i l l provide a b a s i s f o r se-
It u t i l i z e s t h e e x c e s s beam c a p a c i t y of a
l e c t i n g o p t i m a l i r r a d i a t i o n c o n d i t i o n s and c a l c u l a t i n g
200~MeVp r o t o n Linac t h a t i n j e c t s p r o t o n s i n t o t h e
thick-target yields for large-scale preparations a t the
A l t e r n a t e Gradient Synchrotron, a 33-GeV a c c e l e r a t o r
Brookhaven Linac I s o t o p e Producer (BLIP).
used i n high-energy p h y s i c s r e s e a r c h .
Ru-97,
Tc-96,
Cd-109, and Sn-113 a r e o f consider-
The Linac can
g e n e r a t e up t o 1 0 p u l s e s of 200-MeV per second, pro-
a b l e i n t e r e s t f o r biomedical and o t h e r a p p l i c a t i o n s .
v i d i n g beam c u r r e n t s of 70 t o 100 microamperes f o r
Ru-97 i s a p o t e n t i a l r a d i o n u c l i d e f o r n u c l e a r medicine
r a d i o n u c l i d e production.
a p p l i c a t i o n s t o n u c l e a r oncology because of i t s d e s i r -
u s e f u l q u a n t i t i e s of Ru-97 and Tc-96 from a rhodium
able physical c h a r a c t e r i s t i c s (t+
t a r g e t , and Cd-109 and Sn-113 from an indium t a r g e t a t
-
2.9 d, 86% 216 keV
P r e p a r a t i o n s of c l i n i c a l l y
gammas) and t h e high chemical r e a c t i v i t y of ruthenium.
t h e BLIP have been demonstrated t o b e f e a s i b l e .
I n a d d i t i o n , a number of ruthenium compounds have shown
p r i n c i p a l n u c l e a r r e a c t i o n s involved a r e Rh-103 (p, 2p5n)
promise a s u s e f u l a g e n t s i n cancer chemotherapy.')
Ru-97, Rh-103 (p, 3p5n)-Tc-96,
The
The
In-115 (p, 2p5e) Cd-109, and
convenient h a l f - l i f e of Tc-96 (4.3 d) makes i t a v a l u a b l e
In-115(p,3n)Sn-113.
t r a c e r f o r developing new r a d i o p h a r m a c e u t i c a l s of i t s
t h i n - t a r g e t c r o s s s e c t i o n s of t h e s e r e a c t i o n s w i l l
s h o r t - l i v e d i s o t o p e , Tc-99m (6.02 h ) , which h a s found
a l l o w t h e s e l e c t i o n of o p t i m a l bombardment c o n d i t i o n s
e x t e n s i v e a p p l i c a t i o n i n n u c l e a r medicine.
and a n e s t i m a t i o n of s p e c i f i c r a d i o n u c l i d e y i e l d s i n
Cd-109
( t k = 453 d) i s i n e q u i l i b r i u m w i t h i t s daughter, Ag-109m
thick targets.
( t g = 40 s ) , which emits a s i n g l e 88-keV gamma r a y
(3.92% abundant).
It i s u s e f u l a s a X-ray f l u o r e s c e n c e
o r radiography source.
The n u c l e a r p r o p e r t i e s of t h e
The experimental d e t e r m i n a t i o n of
A l l c r o s s s e c t i o n d e t e r m i n a t i o n s w i l l b e made by
a c t i v a t i o n o f t a r g e t s followed by measurement of t h e
a c t i v i t y o f t h e d e s i r e d product w i t h Ge(Li) d e t e c t o r
Cd-1091Ag-109m p a i r a l s o s a t i s f y t h e requirements f o r a
gamma-ray counting.
g e n e r a t o r system which would provide a continuous s o u r c e
necessary.
o f u l t r a s h o r t - l i v e d medical n u c l i d e for r e p e a t e d dynamic
e x t e r n a l beam of t h e I n d i a n a U n i v e r s i t y 200-MeV cyclo-
~ t u d i e s . ~ )Sn-113 ( t 4 = 114.9 d ) i s t h e p a r e n t n u c l i d e
tron.
f o r t h e important In-113m g e n e r a t o r system.
Faraday cup.
The In-113m
No chemical s e p a r a t i o n s a r e
I r r a d i a t i o n s w i l l be c a r r i e d out i n the
The p r o t o n f l u x w i l l b e monitored by means of a
High-purity m e t a l f o i l s of rhodium and
g e n e r a t o r h a s been shown t o b e of v a l u e i n many n u c l e a r
indium a r e used a s t a r g e t s .
imaging a p p l i c a t i o n s .
a l l r e a c t i o n s w i l l b e meaqured i n t h e proton energy
The d e s i r a b l e c h a r a c t e r i s t i c s
Excitation functions f o r
range of 40 t o 200 MeV (12 t a r g e t s each, a t
intervals).
'L
15 MeV
The i r r a d i a t e d t a r g e t s w i l l b e shipped t o
Brookhaven and t h e r a d i o a c t i v e p r o d u c t s i n t h e i n d i v i d u a l rhodium and indium f o i l s measured by gamma-ray
spectroscopy u s i n g a c a l i b r a t e d Ge(Li) d e t e c t o r .
To d a t e i r r a d i a t i o n s a t 60, 80, 96, 115, 149, 159,
174 and 200 MeV have been made.
A n a l y s i s of t h e y-ray
s p e c t r a taken o v e r a p e r i o d of a few months i s r e q u i r e d
b e f o r e experimental v a l u e s can b e quoted.
*Brookhaven N a t i o n a l Laboratory, Upton, L . I . ,
New York 11973.
1)
S.C. S r i v a s t a v a , P. Som, G. Meinken, A. Sewatkar,
and T.H. Ku, Ruthenium-97 l a b e l e d compounds--A new
c l a s s of r a d i o p h a r m a c e u t i c a l s , Second I n t e r n a t i o n a l
Congress of World F e d e r a t i o n o f Nuclear Medicine
and Biology, Washington, D.C., September 1978.
2)
P. Richards, e t a l . , i n Radiopharmaceuticals (ed.,
G. Subramanian, e t a l . , P a r t Two, S o c i e t y of
Nuclear Medicine, I n c . , New York (1975).
3)
P. Richards, D i v i s i o n of I s o t o p e s Development,
Research and Development P r o j e c t s , Atomic Energy
Commission, Washington, D.C., TID Report /I25372
4)
J. Alvarez, i n Radiopharmaceuticals (ed., G.
Subramanian, e t a l . ) , Chapter 1 0 , S o c i e t y of
Nuclear Medicine, I n c , New York (1975).
.
5)
P. Richards, E. Lebowitz, and L.G. Stang, Jr.,
i n Radiopharmaceuticals and Labeled Compounds,
Vol. I, 325-341, IAEA, Vienna (1973).
6)
L.G. Stang, Jr., The Brookhaven Linac I s o t o p e
Producer, Progr Nucl Med. 4, 34-36 (1978).
.
.