[ RadSafe ] New cancer weapon: nuclear nanocapsules

[Geo>K0FF]

By definition, "Radioactive Decay" is the spontaneous transformation of a nuclide into one or more nuclides. ( "Electronics and Nucleonics Dictionary", McGraw Hill.)
The commonly recognized decay modes are Alpha, Beta ( both B+ and B- plus several others), Electron Capture, Proton, Double Proton,  Neutron, Cluster Decay  and Spontaneous Fission (S.F.)

Gamma Ray emission, IT, IB, PA, and Internal Conversion are *NOT* a decay mode ( they do not change the nuclide), they are artifacts of a real decay mode. More on this if needed.

Alphas and Betas are of course particles and fall perfectly under the definition of "ionizing radiation". Neutrons do not directly ionize and so are called "indirectly ionizing radiation". High energy Photons, UV and above, are also considered ionizing radiation, although as mentioned, not a decay mode per se.

Induced fission, S.F. spontaneous fission and cluster decay all eject massive nucleon clusters ( nuclides) from a parent nucleus, but I personally would not describe them as "radiation" and more than Radon from Radium is radiation. 


Cluster Decay:
http://en.wikipedia.org/wiki/Cluster_decay

"Boron neutron capture therapy (BNCT) bring together two components that when kept separate have only minor effects on normal cells.^The first component is a stable isotope of boron (boron 10) that can be concentrated in tumor cells.^The second is a beam of low-energy neutrons that produces short-range radiation when absorbed, or captured, by the boron.^The combination of these two conditions at the site of a tumor releases intense radiation that can destroy malignant tissues.^BNCT is based on the nuclear reaction that occurs when boron 10 is irradiated with an absorbs neutrons.^The neutrons that it takes up are called thermal, or slow, neutrons.^They are of such low energy that they cause little tissue damage as compared with other forms of radiation such as protons, gamma rays and fast neutrons.^When an atom of boron 10 captures a neutron, an unstable isotope, boron 11, forms.^The boron 11 instantly fissions, yielding lithium 7 nuclei and energetic alpha particles.^These heavy particles, which carry 2.79 million electron volts of energy, are a highly lethal form of radiation.^If the treatment proceeds as intended, the destructive effects of the capture reaction would occur primarily in those cancer cells that have accumulated boron 10.^Normal cells with low concentrations of boron would be spared." REF: OSTI

see:
http://web.mit.edu/nrl/www/bnct/info/description/description.html

In BNCT, both Alpha particles and ionized Li7 are definitely part of the energy transfer to the target. Under traditional parlance, perhaps we have here an ionizing nuclear radiation ( Alpha) and a high energy ion. Strictly defining any high energy ion (or light, radio, heat etc.) as "radiation" is OK, for that does not imply "nuclear radiation". When we specifically speak of "nuclear radiation", it should be in the traditional terms, in my opinion.
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Semantics aside, BNCT is indeed fascinating technology.


George Dowell

----- Original Message ----- 
From: "Jaro" <jaro-10kbq at sympatico.ca>
To: <radsafe at radlab.nl>
Sent: Friday, August 24, 2007 6:50 AM
Subject: RE: [ RadSafe ] New cancer weapon: nuclear nanocapsules


> Thanks very much for posting the link to the article.
> Very interesting research.
> 
> But I notice an obvious error in the article :
> <quote>
> Astatine, like radium and uranium, emits alpha particles via radioactive
> decay. Alpha particles, which contain two protons and two neutrons, are the
> most massive particles emitted as radiation.
> <end quote>
> 
> In Boron-Neutron Capture Therapy (BNCT), the radiation emitted in the
> induced Boron fission is an alpha particle (He4 nucleus) and a Lithium ion
> (Li7).
> Since Li7 is nearly double the mass of He4, it is *untrue* that "Alpha
> particles... are the most massive particles emitted as radiation."
> 
> > Jaro
> ^^^^^^^^^^^^^^^^^^^^^
> 
>