We have measured the nuclear fusion cross section for /sup 3/He(/sup 3/He, 2p)/sup 4/He near the solar Gamow peak with a compact accelerator facility OCEAN and with an assembly of counter telescopes with a detection efficiency of 10%. The data obtained at E/sub cm/ = 45.3 to 31.2 keV improved the existing astrophysical S-factors in statistical and systematic errors. A Monte Carlo simulation program exploiting GEANT3, SRIM and GENBOD computer codes has been developed to estimate the detection efficiency for two proton coincidences with /spl Delta/E-E telescopes. The precision of the developed program has been investigated by comparing the simulated results with the experimental values for the cross section of the D(/sup 3/He,p)/spl alpha/ reaction carried out by replacing the target with D gas. It turned out that the present study involves around 3% systematic errors for an estimation of the detection efficiency. The overall systematic errors for these data from 45.3 to 31.2 keV is 3.8%, that is as good as those of the previous experiments. The latest data obtained at 29.1 and 26.9 keV with large statistical and systematic errors show considerable larger S-factors than previous. An enhancement of the astrophysical S-factor might be expected by the existence of a certain resonance as well as by an atomic effect on the screening potential near the solar Gamow energy.
[1]
K. Takahisa,et al.
Versatile beam calorimeter with a heat flux sensor
,
2001
.
[2]
H. Toki,et al.
High brightness 3He ion source and plasma target for nuclear astrophysical applications
,
1998
.
[3]
E. Bellotti,et al.
Cross section of He-3(He-3,2p)He-4 measured at solar energies
,
1997,
nucl-ex/9707003.
[4]
Bochum,et al.
Energy loss, electron screening and the astrophysical 3He(d, p)4He cross section☆
,
1995,
nucl-th/9512015.
[5]
G. Fiorentini,et al.
Prospects for underground accelerator research
,
1995
.
[6]
M. Junker,et al.
Oppenheimer-Phillips effect and electron screening ind+ d fusion reactions
,
1995
.
[7]
H. Becker,et al.
Astrophysical S(E) factor of 3He(3He, 2p)4He at solar energies
,
1987
.