| Accelerator terminal at 2.5 million Volt. This device
contains an "electron stripper" canal, a tube of about 0.5
inch diameter filled with a very small amount of argon gas. Up to
half of the ions passing through this canal encounter grazing collisions
with argon atoms that leave the ions "stripped" of four
of their valence electrons. These carbon ions now have only three
electrons left to counter their six protons and are therefore charged
positve (3+). This process also takes care of a potentially big problem:
compound ions of carbon and hydrogen (12CH, 12CH2,
13CH) which are always part of the negative ion beam coming
out of (a). These compounds become dissociated during stripping, leaving
the break-up products with incorrect kinetic energies for the final
stretch of the system. |
