ziad1985 said:
I do know that energy lost by radiation is more important as the particle is more heavy , but does have that much of an effect in the design of the accelerator?
I don't want to be sucked into having to explain the basic detail of an accelerating structure, but I'll give just one basic example.
When you design a series of an iris-loaded cavity, you are using an oscillating RF cavity at some frequency (the ILC parameter is in the L-band, so we'll pick 1.3 GHz, which is the RF that I use at my facility). Now, you have to design this in such a way that the particle you are accelerating are moving
in synch with the E-field that is increasing in the right direction as the particles are entering that cavity. As it is exiting that cavity and goes into the next cavity, the same thing has to happen again. All of these cavities are typically powered by a single RF source - a klystron - since a set of these cavities are what we call an accelerating structure. For the ILC, this will be a superconducting structure.
Now, that sounds simple, but it is not. The group velocity of the RF (even though it is really a standing wave structure), must MATCH the particle being accelerated, or else the field will outrun the particles and you have a very inefficient acceleration. This is where you have to design the geometry of the cavity to match the frequency of the RF being used. When you do this, you HAVE to consider the particle that you are accelerating. Electrons are WAY lighter than protons and heavy ions. The design, especially in the SIZE of the structure (such as the width of each of these cavities) are tailor-made for the type of particles. So it is hardwired into the design!
And this is just from the accelerating mechanism alone. We haven't talked about the type of detector that has to be designed for each of the different particle based on what is expected. Note that even when you have the same type of particles, you STILL need different detectors because no one detector can do everything. Tevatron has CDF and D0 that measures different things, but compliments each other. Now think, if one detector can't do everything even when all it looks at is the collision of one type of particles, consider how impossible it is to design a detector that can work with collision of other types of particles having such huge range scale!
We would LOVE to have a flexible accelerator facility that can accelerate everything. Wouldn't that be a terrific sell to build a really expensive facility and be done with? But it is close to a physical impossibility right now, and certainly an engineering impossibility.
Zz.
