2. Atomic number
Mass number
Isotopes
-stable isotopes
-unstable isotopes
Radio-active halflife
Units of Radio-activity
-Roentgen
-RAD
-REM
-Becquerel(bq)
3. METHODS OF PRODUCTION
PILE PRODUCED ISOTOPES (NUCLERA
REACTOR)
CYCLOTRON – PRODUCED ISOTOPES
RADIO ISOTOPES GENERATOR
4. Most of the R-A materials prepared in nuclear
pile
Uranium fission rxn produces large supply of
neutrons
Neutrons in rxn are a mixture of fast
neutrons and thermal
Thermal neutrons are obtained by fast
neutrons thru a moderator
n γ Rxn . Target nuclie captures thz thermal
neutron to yield a radioactive nucleus in an
excited state
Surplus energy emitted as γ-radiation
5. Eg. 2311Na +n 23 Na
14
23 Na +γ
14
1 neutron for each uranium atom undregoes
fission and other neutrons are used to produce
PLUTONIUM by interaction with 238U
These neutrons are either lost or used to
interact with specific target which have been
inserted into “neutron activation”
1. Radio-active material thru Fission process
2. Radio-active material thru Neutron activation
FISSION Reactions :
238
92 U+ 10n 131
50 Sn + 10642 Mo + 10n+ 1
0n
131
50 Sn and 10642 Mo are radio active nuclides
6. NEUTRON ACTIVATION
When simple neutron is captured or during
transmutation process neutron activation occurs
a radio-activated phosphorus, 32P can be
prepared from stable phosphorus , 31p by
neutron capture
7. Radio-activewhich are neutron deficient are
produced by cyclotron
Obtained by bombarding targer nuclie with
protons deuterons α particle
8.
9.
10.
11. During investigation , hazards to patients can
be reduced by using isotopes
Such isotope can be supplied in form of long
lived parent that decay to isotope required
Parent nuclide prepared in form of suitable
ion – absorbed to the ion exchange column
The whole assembly is known ass Radio-
isotope generator
This long lived parent results in production
short lived daughter
Whicj is “eluted” or “milked” from column
12. Eg. Technetium 99m
99m Tc generator sonsist of column containing
alumina on which Molybdenum 99 is absorbedin
form of ammonium molybdate
Radioactive decay of 99 Mo produces 99mTc
which is eluted from the column
This isotope is produced for brain , liver and in
thyroid scanning and is safer
It has short life and does not emit beta
radiations.