Radionuclide Generators Flashcards
When you have neutron excess, you have to go undergo what decay
beta decay
means that Sr-90 will decay into multiple particles. It will not only undergo beta-decay, but also positron, isomeric transition etc.
The Branching Ratio (BR)
Symbol: λ
decay factor
t 1/2
physical half life
Symbol: A
total activity
Symbol: A1
activity of the parent radionuclide
Symbol: A2
activity of the daughter radionuclide
The radioactivity of the daughter nuclides depends on two factors:
rate of its formation + rate of its decay
Symbol: A0/1
activity of the parent radionuclide at t=0
Symbol: A0/2
activity of the daughter radionuclide at t=0
λ2 / λ2 - λ1
constant with a value of 1.003 ~ 1
parent and daughter meet and simultaneously decay together
Equilibrium point
At equilibrium, the ratio of activities of daughter to that of parent (A2/A1) is approximately
constant
Generally, equilibrium is established approximately by
10T2
Occurs if the half-life of the parent is significantly greater than the half-life of the daughter
secular equilibrium
Occurs if the half-life of the parent is only a few times greater than the half-life of the daughter
transient equilibrium
What kind of equilibrium is the Decay of Strontium-90 vs Cumulative buildup of Yttrium-90
secular equilibrium
What kind of equilibrium is the Decay of Molybdenum-99 vs Cumulative buildup of Technetium-99m
transient equilibrium
what is the time when the activity of Tc99m is at maximum?
23 hours
Is it possible for daughter activity > parent activity?
No
What is the BR of Mo99m to Tc99m?
87.5% (experimentally determined)
term used to describe the probability that parent radionuclide would decay to form daughter radionuclide
Branching ratio
CH4 (g)
Pure Substance
Air
Mixture
Milk
Suspension
Tc-Sn
Colloid
NSS
Solution
NaCl in NSS
Solute
H2O in NSS
Solvent
Mo99/Tc99m
Solution
Field of chemistry that studies the separation between components of a mixture
Separation Chemistry
separation based on physical affinity towards something
Chromatography
2 Relevant chromatography methods in
radiochemistry
Partitioning
Adsorption
Based on relative solubility of the solutes between two fluids of different polarity
Partitioning
Based on relative adherence of solutes against active sites of a solid surface
Adsorption
Setups to separate repeatedly short-lived daughter nuclides from longer-lived mother nuclides by chemical methods
radionuclide generators
A resin (usually ion-exchange) -bound, longer- lived parent radionuclide decays to chemically different daughter nuclide which can be subsequently separated easily from the parent
radionuclide generators
This allows show lived radionuclides to be kept in ready supply at hospitals and research facilities, providing a consistent product for routine use
radionuclide generators
You cannot transport Tc-99m alone, you have to use another carrier which is the
longer half life parent Mo-99