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3 Nuclear Reaction
Astatine-211 can be synthesized by bombarding Bismuth-209 with accelerated
helium nuclei (32 MeV), from a 60 inch cyclotron.
209 Bi 83 +
4 He 2 →
211 At 85 + 2
1 n 0
A short description of this reaction is often given as
209 Bi(α, n)
211 At. The chemical
identity of the product may be established either by the separation of the constituent
from the target element or by studying the chemistry of the expected products (i.e.,
Astatine) by a suitable radiochemical procedure. In this nuclear reaction, Astatine211 from Bismuth-209 is separated by the volatilization process. Alternatively, the
product may be isolated from the target material by using a chemically similar element to Astatine (i.e., chemically similar to the product of the reaction). For example,
iodine which has a chemical property similar to Astatine can be used as a carrier.
The usefulness of carrier for such application will be dealt with later.
Another example of a nuclear reaction induced by accelerated doubly charged
helium ions is
239 Pu 94 +
4 He 2 →
242 Cm 96 +
1 n 0
The short description of this reaction can be written as
239 Pu(α, n)
242 Cm. The
product may be separated and its chemical identity recognized by its behavior on an
ion-exchange column. Details of the ion-exchange technique will be discussed later.
From these examples, it is observed that the products formed by nuclear reactions
involved with charged particles are usually chemically different from the target,
e.g., both Bismuth-209 and Pu-239 give products of different elements (
211 At 85 and
242 Cm 96 ). The chemical separation of products from the target material thus becomes
simpler for such type of nuclear reactions.
3.3 Reactions Initiated by Uncharged Particles
Neutron is the only uncharged particle that has a practical application in nuclear
reaction and has the advantage that it does not require to overcome the Coulombic
repulsive force of the nucleus. Broadly speaking, two types of nuclear reactions can
be initiated with uncharged particle:
(i) With energetic neutron energy of interacting neutron may be enough to eject
one or more than one nucleons from the nucleus (or)
(ii) With thermal neutron possessing energy in the vicinity of 0.03–0.1 eV (known
as thermal neutron).
In the latter type, γ -emission is associated with the nuclear reaction. The energy of
neutrons obtained from a neutron generator is in the range of a few MeV. Hence,
for the former type of nuclear reactions, neutrons from the neutron generator can be
3 Nuclear Reaction
Astatine-211 can be synthesized by bombarding Bismuth-209 with accelerated
helium nuclei (32 MeV), from a 60 inch cyclotron.
209 Bi 83 +
4 He 2 →
211 At 85 + 2
1 n 0
A short description of this reaction is often given as
209 Bi(α, n)
211 At. The chemical
identity of the product may be established either by the separation of the constituent
from the target element or by studying the chemistry of the expected products (i.e.,
Astatine) by a suitable radiochemical procedure. In this nuclear reaction, Astatine211 from Bismuth-209 is separated by the volatilization process. Alternatively, the
product may be isolated from the target material by using a chemically similar element to Astatine (i.e., chemically similar to the product of the reaction). For example,
iodine which has a chemical property similar to Astatine can be used as a carrier.
The usefulness of carrier for such application will be dealt with later.
Another example of a nuclear reaction induced by accelerated doubly charged
helium ions is
239 Pu 94 +
4 He 2 →
242 Cm 96 +
1 n 0
The short description of this reaction can be written as
239 Pu(α, n)
242 Cm. The
product may be separated and its chemical identity recognized by its behavior on an
ion-exchange column. Details of the ion-exchange technique will be discussed later.
From these examples, it is observed that the products formed by nuclear reactions
involved with charged particles are usually chemically different from the target,
e.g., both Bismuth-209 and Pu-239 give products of different elements (
211 At 85 and
242 Cm 96 ). The chemical separation of products from the target material thus becomes
simpler for such type of nuclear reactions.
3.3 Reactions Initiated by Uncharged Particles
Neutron is the only uncharged particle that has a practical application in nuclear
reaction and has the advantage that it does not require to overcome the Coulombic
repulsive force of the nucleus. Broadly speaking, two types of nuclear reactions can
be initiated with uncharged particle:
(i) With energetic neutron energy of interacting neutron may be enough to eject
one or more than one nucleons from the nucleus (or)
(ii) With thermal neutron possessing energy in the vicinity of 0.03–0.1 eV (known
as thermal neutron).
In the latter type, γ -emission is associated with the nuclear reaction. The energy of
neutrons obtained from a neutron generator is in the range of a few MeV. Hence,
for the former type of nuclear reactions, neutrons from the neutron generator can be