This work was supported by the National Science Foundation Grant NSF PHY 81-14339 and by Indiana Universit

Austin, S.

Bahcall, J.N.

Foster, C.C.

Gaarde, C.

Goodman, C.D.

Horen, D.

Larsen, J.

Masterson, T.

Rapaport, J.

Sugarbaker, E.

Taddeucci, T.N.

English

IUScholarWorks

SOLAR NEUTRINO DETECTOR GT STRENGTH DISTRIBUTIONS VIA (p,n) REACTIONS 
J.N. Bahcall  
I n s t i t u t e  f o r  Advanced Study, Pr inceton Univers i ty ,  Pr inceton,  N J  08540 
J. Rapaport and T.N. Taddeucci 
Ohio Univers i ty ,  Athens, Ohio 47501 
E. Sugarbaker 
Ohio S t a t e  Univers i ty ,  Columbus, Ohio 43212 
C.D. Goodman and C.C. Fos te r  
Indiana Univers i ty  Cyclotron F a c i l i t y ,  Bloomington, Indiana 47405 
D. Horen 
Oak Ridge National Laboratory,  Oak Ridge, Tennessee 37830 
C. Gaarde and J. Larsen 
Nie l s  Bohr I n s t i t u t e ,  Copenhagen, Denmark 
T. Masterson 
Unive r s i ty  of Colorado, Boulder, CO 80309 
S. Austin 
Michigan S t a t e  Univers i ty ,  East Lansing, M I  48824 
The observed and predic ted  capture  r a t e s  f o r  t he  pas t  s e v e r a l  m i l l i o n  yea r s  by analyzing neu t r ino  
ch lo r ine  s o l a r  neu t r ino  experiment i n d i c a t e  a l a r g e  absorpt ion products i n  deeply buried molybdenum ore.  
discrepancy. This has s t imula t ed  new e f f o r t s  t o  I n  a l l  these  cases  the  c ross  s e c t i o n s  f o r  cap tu re  
e s t a b l i s h  empi r i ca l ly  whether t h i s  disagreement i s  of neu t r inos  by these  d e t e c t o r s  must be known accura t e ly  
caused by inadequate s o l a r  models o r  by a decrease  i n  i n  order  t o  i n t e r p r e t  t he  r e s u l t s  of t hese  expensive and 
t h e  de tec t ab le  neu t r ino  f l u x  i n  t r a n s i t  from the  sun. d i f f i c u l t  experiments. The technique t o  be used i n  
The most recent  experimental  r e s u l t s 1  f o r  t he  cap tu re  order  t o  g e t  t hese  c ross  s e c t i o n s  has been descr ibed i n  
r a t e ,  (2.1 + 0.3) SNU, a r e  very d i f f e r e n t  from the  a recent  paper. We have measured a t  IUCF (p,n) c ross  
model ~ r e d i c t i o n s , ~  ( 8  + 3.5) SNU. s e c t i o n s  a t  8 = 0" and 8 = 5O using 120 MeV protons  on 
Four d e t e c t o r s  a r e  p resen t ly  being considered a s  6 9 ~ a ,  7 1 ~ a ,  8 1 ~ r ,  98Mo and 1151n. We a l s o  obtained 
most l i k e l y  candidates  f o r  new s o l a r  neu t r ino  (p,n) s p e c t r a  a t  8=0° and 8=3" f o r  200 MeV protons on 
experiments. They a re :  7 1 ~ a ,  8 1 ~ r ,  9 8 ~ 0  and l151n. t he  same t a r g e t s .  We show some of the  120 MeV s p e c t r a  
The 7 1 ~ a  and li51n d e t e c t o r s  a r e  p r imar i ly  s e n s i t i v e  t o  i n  Figs. 1-3. Analys is  of t hese  d a t a  is i n  progress.  
t h e  f l u x  of proton-proton neu t r inos  whi le  the  8 1 ~ r  Both Ga t a r g e t s  were made a s  an a l l o y  wi th  2 4 ~ .  
d e t e c t o r  is most s e n s i t i v e  t o  the  neu t r ino  l i n e  from The l a t t e r  was used because of i ts  l a r g e  negat ive  (p,n) 
e l e c t r o n  capture  by 7 ~ e .  The r e a c t i o n  98Mo(v,e')98~c @value (Q  = -14.67 MeV). The 8 1 ~ r  t a r g e t  was 
w i l l  determine the  average 8~ neu t r ino  f l u x  over the  f a b r i c a t e d  from a compound wi th  n a t u r a l  Ca. Ca was 
chosen because of i ts  l a r g e  negat ive  Q-value. 
98 98 
I% (p,n)  Tc 
0 degrees 
Eo - 120 rccv 
I:. 
I ,  
la ~r loo N w T n d . t N E n ~ J * t * t v )  'I2 'Io 
115 115 
I n  ( p e n )  h 
0 degree* 
Figure 1. Neutron energy spectra  fo r  the 7 1 ~ a ( p , n )  and 
69ca(p,n) reactions at ezOO and Both Ga Figure 2. Neutron energy spec t ra  f o r  the 9 8 ~ o ( p , n )  and 
t a r g e t s  were made as  an a l loy  w i t (  24Mg. In  the 
7 1 ~ a ( p  ,n)  spectrum, the 2 4 ~ g ( p  ,n)  contr ibut ion has been 5 ~ n ( p  ,n)  react ions a t  0=0° and Ep=120 MeV. Background 
subtracted. and time-of-flight wrap-around contr ibut ions have been 
subtracted.  
81 na t  81 
B+ Ca (p,n)  Kr+Sc 
0 degrees 
1)  B.T. Cle,veland, R. Davis, Jr. and J.K. Rowley i n  
"Weak In te rac t ions  as  Probes of Unification", ed. by 
Coll ins ,  Chang and Ficenec (AIP Conf. Proc. #72 
1981), p. 322. 
2) J.N. Bahcall e t  a l . ,  Phys Rev. Lett.  45, 945 (1980). 
3) J. Rapaport e t  a l . ,  Phys. Rev. Lett.  47, 1518 
( 1981). 
F i  r e  3. Neutron energy spec t ra  obtained a t  0=0° and 
E p 2 2 0  MeV f o r  the (p,n) react ion on a ( 8 1 ~ r  + 
t a rge t .  


Solar Neutrino Detector GT Strength Distributions Via (p,n) Reactions

https://scholarworks.iu.edu/dspace/bitstream/2022/2668/1/iucf_1982_39-40.pdf

Solar Neutrino Detector GT Strength Distributions Via (p,n) Reactions

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