| Popis: |
Particles in a linear accelerator obtain energy from the electric fields produced inside microwave cavities. In a conventional linac made of room-temperature copper, several megawatts of power are required to produce an energy gradient of a few MeV per foot. Since it is impossible to produce such high rf power from klystrons for more than a few microseconds, a conventional accelerator will typically have a duty cycle on the order of 10-3, with energy gradient of 2 or 3. MeV/ft. The low-duty cycle is highly undesirable in many nuclear experiments, due to the finite resolving time of the instruments. For instance, in coincidence experiments, the signal-to-noise ratio is roughly proportional to the duty cycle. |
