The advantage of a circular accelerator over a
linear accelerator is that the
particles in a circular accelerator (synchrotron) go around many times,
getting multiple kicks of
energy each time around. Therefore, synchrotrons can provide very
high-energy particles without having to be of tremendous length. Moreover,
the fact that the particles go around many times means that there are many
chances for collisions at those places
where particle beams are made to cross.
On the other hand, linear accelerators are
much easier to build than circular
accelerators because they don't need the large magnets required to coerce
particles into going in a circle. Circular accelerators also need an
enormous radii in order to get
particles to high enough energies, so they are expensive to build.
Another thing that physicists need to
consider is that when a charged particle
is accelerated, it radiates away energy.
At high energies the radiation loss is
larger for circular acceleration than for linear acceleration.
In addition, the
radiation loss is much worse for accelerating light
electrons than for heavier protons. Electrons and anti-electrons (positrons)
can be brought to high energies only in
linear accelerators or in circular ones
with large radii.
Question: Can an object accelerate while keeping the same speed?
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