can a cyclotron be used for nuclear fusion

[RADboy]

essentailly cyclotrons are used to smash one atom into another. can it be done to fuse atoms?

oh and i read that cyclotrons are used to treat canncer. they shoot ionizing particles at the cancer while, avoiding non cancer tissue. if anyone knows the best way to cure cancer in terms of radiation please let me know.

[chrisbaird]

Yes, cyclotrons are a type of particle accelerator and fusing atoms is mostly an act of banging them together hard enough that they overcome the potential barrier, so it can be done. Although, this would not be a very efficient method alone to generate sustained power as a nuclear fusion reactor, if that's what you had in mind. The tokamak (http://en.wikipedia.org/wiki/Tokamak) is much more promising as a nuclear fusion reactor, and it is related in principle to a cyclotron in that they both used magnetic confinement.

[daveb]

To answer your question about the best way to treat cancer, it depends on the type of cancer, where it's located, how advanced it is, etc. For exampl,e most thyroid cancers are easily treatable with I-131 to ablate the thyroid. Certain gliomas use I-131 bound to scorpion venom, others use a gamma knife, others use linacs, etc.

[RADboy]

whoa please define a gamma knife!

[Bob S]

I have seen a 300 kilovolt electrostatic accelerator (Cockroft-Walton) used for D-T fusion neutron generation. Using a cyclotron would be overkill for D-T fusion. "Gamma knife" I think is a trade-mark name for a Varian brand electron accelerator (linac), about 6 MeV, used for cancer treatment with high energy collimated x-rays (actually bremsstrahlung).

Compact cyclotrons (about 250 MeV) are being used to do proton beam cancer treatment. The facilities are much more complex than electron beam accelerators, and do provide a better beam for some (all?) cancers.

Bob S

[RADboy]

@BobS
yes i rad that the gamma knife is used for brain surgery. using colbalt-60 as the radioactive element. they surgically attach the operating table onto the patients head. the laser is attached to the operating tabel and as the gamma knife's name implys it's as accurate as a blade

[Astronuc]

@BobS
yes i rad that the gamma knife is used for brain surgery. using colbalt-60 as the radioactive element. they surgically attach the operating table onto the patients head. the laser is attached to the operating tabel and as the gamma knife's name implys it's as accurate as a blade GE has developed such a system. The trick is to use several separate and collimated gamma sources, such anyone is a reduced dose, but the beams are directed at a common point or focus, so that the target recieves a much higher dose than the surrounding tissue.

The cobalt sources are irradiated in a commerical reactor in a special assembly.

[Bob S]

GE has developed such a system. The trick is to use several separate and collimated gamma sources, such any one is a reduced dose, but the beams are directed at a common point or focus, so that the target recieves a much higher dose than the surrounding tissue.
The electron linac radiation sources are very small and typically rotate through a complete 360 degree arc around the patient during a single IMRT (intensity modulated radiation treatment) radiation treatment. The intensity modulation includes active control of the beam collimation aperture (tungsten shims). Each treatment lasts less than 5 minutes.

For proton beams, the roughly 240-MeV proton beam requires an accelerator (cyclotron, synchrotron) which is much too large to move around the patient, so a very large gantry of bending and focusing magnets rotates around the patient during treatment. (It would be easier to spin the patient, but internal organs tend to move around during the treatment).

Bob S

[RADboy]

yes i remember. what's special about the assembly. i know cobalt-60's half-life is around 5 years. does that have anything to do with it?

[Joseph Chikva]

Yes, cyclotrons are a type of particle accelerator and fusing atoms is mostly an act of banging them together hard enough that they overcome the potential barrier, so it can be done. Although, this would not be a very efficient method alone to generate sustained power as a nuclear fusion reactor, if that's what you had in mind. The tokamak (http://en.wikipedia.org/wiki/Tokamak) is much more promising as a nuclear fusion reactor, and it is related in principle to a cyclotron in that they both used magnetic confinement.
By the method of generation of circular electric field TOKAMAK is very similar to betatron.
As in both those devices plasma torus in one case and the circulating beam in the second are considered as secondary winding of transformer.
Betatrons have space charge current limitation as their purpose is to generation of beams of charged particles charged uniformly - or in the other words beams in betatrons are non-neutralized.
Currents in TOKAMAKs where quasineutral plasma is used reach to megaamperes orders and limited with instabilities creation conditions e.g. Kruskal-Shafranov limitation.
There are some projects to build high currents betatrons: FFAG betatrons, betatron with additional Stellarator windings (Stellatron) http://cdsweb.cern.ch/record/1108024/files/p79.pdf , etc.

I proposed to inject into the common equilibrium betatron orbit two types of reacting ions moving with different velocities at one direction and relativistic electrons oppositely.
That should work as we can avoid betatron's space charge current limitation, unidirectional currents attract each other making pinch and different velocities can provide enough collision energy in center-of-mass frame.