14—19.
BY DEUTERONS
“327
'
approximately 5 MeV, (2) a moderately homogeneous grouP near
3.85 Mev and (3) a continu0us distribution extending from 5 Mev
'
down to very low energies. The 5 Mev group is composed of the
alpha particles from
_
_
5B11 + 1H1 —> 4_Be8 + 2He4,
(14—23)
where the residual nucleus (4Be8) is; left in its ground state,with a
mass equal to that of two alpha particles.
Other of the boron—eleven nuclei in the target undergo a mul—
tiple reaction 25, as follows:
-
_
_
'
5311 + 1H1 -—> 5C12æ_ —>
2H64 _) 3 2He4,
_
in which the cross (x) has been used to indicate that the nucleus is“
in an excited state.
The rst helium nuclei appearing in this
three-particle reaction form the group whose energies are near 3.85
MeV…
The Be8‘”
was left with an excited Energy of 2.8 Mev
-
Which is greater than the dissociatibn eñergy required for a,separa—
tion into two alpha particles. Therefore, after approximately
‘
'
.
10*21 second, this nucleus breaks up; the alpha "particles having
,
the.continuous energy distribution of (3) aboVe.
Other multiple reactions are known.26
In general, these may
be written in the form
,
_
'.
,
_
Æ +
er + S+ Q,
.
(14—25)
where the notation ofequat10n14—4haSbêen
ànd D is the
_
nal nucleus. Oneorbothoftheejected par_ÜC1ÊS> Sand Q: may
_
be the samegàsthe madentpart1deP :
‘
_
.
1419T…uttnfPddbyDtn—Wth a
…g maghetic
heavy—
hydrogen nulmyb deœœd ont?
the
fd
TWO
,
the
"
]
otherapr®t®nwas€J€Cœdl‘îa‘mgahïhmmsevenresldual Ï
‘