CODD system proposal

Creation of a beam synchronous reference frequency

To create a reference frequency, before injection the system follows the RF input, provided by the RF cavity control. A few tens of μs after beam injection, the phase discriminator changes over to a PU signal. To have exactly the same properties in all RF branches, three separate but indentical AD608 receiver chips are used.

In contrast to the old system, where one of the receivers was switched from PS RF to PU after injection, this scheme has dedicated receivers for all branches, and the switching is done at the receiver output. This circumvents the problem in the old system that had one of the receivers deal with an enormous swing in signal level at injection in some cases. This would cause momentary loss of lock.