possible at the PET cyclotrons.
External beam lines, known from classical isotope production at cyclotrons, will take this function over.
The new generation of multi-purpose
99Mo–99mTc Generator:-
The 99Mo radionuclide has a half-life of 66 hr and decays by β emission.
The radionuclide 99mTc has a half-life of 6 hr and decays to 99Tc by isomeric transition of 140 keV.
The irradiation of solid materials
requires much better beam quality
parameters than gas targets. Consequently, beam homogenisation and beam manipulation is needed, ussually not
Have different penetrating ability with materials of different thickness and densities
Kill cells
Cause cell mutation
Ionise molecules
Have the same chemical properties as non-radioactive isotopes of the same element
The extreme usefulness of this generator is due to the excellent radiation characteristics of 99mTc, namely its 6hr half-life, very little electron emission, and a high yield of 140-keV γ rays (90%), which are nearly ideal for the current generation of imaging devices in nuclear medicine
Isotope 45Ti 55Co 64Cu 67Cu 66Ga 76Br
81Rb/81mKr 86Y 89Zr 90Nb 94Tc 110In 120I 123I 124I 165Er 186Re
T 1/2 3.08 h 17.54 h 12.7 h 61.9 h 9.4 h 16 h 4.58 h 14.7 h 78.4 h 14.6 h 4.9 h 69.1 m 1.35 h 13.2 h 4.15 d 10.3 h 90.6 h
Reaction nat.Sc (p,n) 45Ti natFe (p,2n) 55Co 64Ni (p,n) 64Cu 70Zn (p,) 67Cu 66Zn (p,n) 66Ga 76Se (p,n) 76Br 82Kr (p,2n) 81Rb 86Sr (p,n) 86Y 89Y (p,n) 89Zr 90Zr (p,n) 90Nb 94Mo (p,n) 94Tc 110Cd (p,n) 110In 120Te (p,n) 120I 123Te (p,n) 123I 124Te (p,n) 124I natHo (p,n) 165Er 186W (p,n) 186Re
the consumption of isotopes in a country depends on the level of its economic development and industrialization
1.2 Stable and Radioactive nuclides
Z = # of protons
Three Component Decay Chains
Daughter Decays Faster than the Parent λI < λ2,
daughter's decay rate is limited by the decay rate of the parent.
Important Radionuclide Generators
cyclotrons will be equipped with hightech diagnostic tools and provide higher beam current s of a Generator
The use of short-lived radionuclides has grown considerably, because larger dosages of these radionuclides can be administered to the patient with only minimal radiation dose and produce excellent image quality. A generator is constructed on the principle of the decay-growth relationship between a long-lived parent radionuclide and its short-lived daughter radionuclide
Nuclear reactor
accelerator
generator
2.1 Nuclear Reactor Irradiation Neutron flux: 1010~1013cm-2·s-1，
(n,α), (n,p), (n,f), (n,γ)
(n,α)、(n,p): En High, σ Small，Light nuclides 32S(n,p)32P, 6Li(n,α)3H 。 Parent and daughter is different Chemical separation
Application PET: bioconjugates PET, encymes, vitamines PET & therapy, therapy, bioconjugates
PET PET Generator, SPECT PET, bioconjugates PET, bioconjugates PET, bioconjugates PET PET PET SPECT PET Auger Therapy Therapy
Batch size 10-2100GGBBqq 0.5-150GGBBqq
4100GGBBqq 10-250 GBq
150GGBBqq 210GGBBqq 0.5-120GGBBqq 5-150 GBq 120 GBq 120 GBq 120 GBq 5-120 GBq 10 GBq 120 GBq 12 GBq 240 GBq 520GGBBqq
Its activity decreases with time
2. Production of Radioisotopes
27 13
Al

24He
1350
P

01n
30 15
P
1340Si
10e


Produce
Select suitable nuclides
Radioactive nuclei
chemical extraction techniques possible Low yields
(n,γ): （14C：5730a），（19O：26.9s）
Accelerator: 25Mg(p,α)22Na ，11C、13N…
Nevertheless, is less popular than reactor method Only in the cases:
High ratio radioactivity chemical extraction possible suitable half lifetime
Production of other useful isotopes with < 20wMitheVthperoPtEoTn cinydculocterodnreactions
The chemical property of the daughter nuclide must be distinctly deferent from that of the parent nuclide so that the former can be readily separated.
230Th 226Ra
234U 234Pa 234Th
238U
218At
210Po
214Po
218Po
210Bi
214Bi
206Pb
210Pb
214Pb
206Tl
210Tl
206Hg
222Rn
decay Major route Minor route
decay
Radioactive Series in Nature
Radioactive Nuclides: 2800
Natural: 238U、232Th、 226Ra…
Man-made: 239Pu、 239Np、131I
N = # of neutrons
Radioactivity - 238U radioactive decay series
The Decay Path of 4n + 2 or 238U Family
In a generator, basically a long-lived parent nuclide is allowed to decay to its short-lived daughter nuclide and the latter is then chemically separated.