ikjadoon
Oct20-09, 01:36 PM
Hi! I hope I've posted this in the right section, but it definitely deals with the nucleus, so here goes.
I'm doing a presentation on Boron Neutron Capture Therapy, which, if you don't know, puts boron inside tumor cells, shines a neutron beam onto those cells, which causes the boron inside the cells to "fissle" (is this really fission?) into Lithium-7 and an alpha particle. This recoiling atom and alpha particle obliterate the cell, thus killing it.
So, there seems be a paucity of information on this topic (unlike my last project, fusion, which was made awesome by PF!). I have a few questions that I can't wrap my head around.
1. Has BNCT actually been done on humans? And how was that even possible if you need a reactor or a particle accelerator for the neutron beam? I've never heard of those in hospitals.
2. This "neutron beam": I can't seem to find information on this: all I understand is that it is a stream of neutrons and it comes either from a reactor or a particle accelerator. But, you would never find either of these in a hospital! So, how do you get the neutrons and how do you turn them into a so-called beam? I get how the collimator works to focus it, but how does the stream happen? Like, can you get a "bag" of neutrons from a reactor and then transport it over to hospital? Bad analogy, I know. :(
And then because of collisions, this beam becomes low-energy thermal neutrons which can be better absorbed by boron? But why?
I'm still researching the shell model of the nucleus (and I thought molecular orbital theory was rough!), but this plays a part in boron's unusually high cross-section, which is the surface area that is exposed. If anyone wants to link me a good site, that'd be great. I have one already,
http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/shell.html
But, it'd be safe to say that it's a bit over my head right now. Tell me if this is right:
Boron's neutron configuration is 1s2, 1p3. And it is just one neutron short of filling the 1p(3/2) subshell. The same goes for it's proton configuration. Or do they go together and it actually has a nucleon configuration 1s2, 1p4, 1d2? Because it's just ONE neutron short, it really wants to fill another neutron? So it's like the halogens, but with neutrons?
3. The main reaction when B10 gets hit by a neutron. It jumps to become B11 for like a femtosecond (I read it somewhere, but I don't remember the number). Why is this B11 unstable? It now is exactly the same as a B11 atom, which is stable (and accounts for 80% of all boron!). Why does this "decay" into lithium and an alpha particle?
Whew....thanks a ton already. :) If someone knows anything (like ANYTHING) that could help, that would awesome.
Thanks,
~Ibrahim~
I'm doing a presentation on Boron Neutron Capture Therapy, which, if you don't know, puts boron inside tumor cells, shines a neutron beam onto those cells, which causes the boron inside the cells to "fissle" (is this really fission?) into Lithium-7 and an alpha particle. This recoiling atom and alpha particle obliterate the cell, thus killing it.
So, there seems be a paucity of information on this topic (unlike my last project, fusion, which was made awesome by PF!). I have a few questions that I can't wrap my head around.
1. Has BNCT actually been done on humans? And how was that even possible if you need a reactor or a particle accelerator for the neutron beam? I've never heard of those in hospitals.
2. This "neutron beam": I can't seem to find information on this: all I understand is that it is a stream of neutrons and it comes either from a reactor or a particle accelerator. But, you would never find either of these in a hospital! So, how do you get the neutrons and how do you turn them into a so-called beam? I get how the collimator works to focus it, but how does the stream happen? Like, can you get a "bag" of neutrons from a reactor and then transport it over to hospital? Bad analogy, I know. :(
And then because of collisions, this beam becomes low-energy thermal neutrons which can be better absorbed by boron? But why?
I'm still researching the shell model of the nucleus (and I thought molecular orbital theory was rough!), but this plays a part in boron's unusually high cross-section, which is the surface area that is exposed. If anyone wants to link me a good site, that'd be great. I have one already,
http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/shell.html
But, it'd be safe to say that it's a bit over my head right now. Tell me if this is right:
Boron's neutron configuration is 1s2, 1p3. And it is just one neutron short of filling the 1p(3/2) subshell. The same goes for it's proton configuration. Or do they go together and it actually has a nucleon configuration 1s2, 1p4, 1d2? Because it's just ONE neutron short, it really wants to fill another neutron? So it's like the halogens, but with neutrons?
3. The main reaction when B10 gets hit by a neutron. It jumps to become B11 for like a femtosecond (I read it somewhere, but I don't remember the number). Why is this B11 unstable? It now is exactly the same as a B11 atom, which is stable (and accounts for 80% of all boron!). Why does this "decay" into lithium and an alpha particle?
Whew....thanks a ton already. :) If someone knows anything (like ANYTHING) that could help, that would awesome.
Thanks,
~Ibrahim~