Page contents:

1. Diagram of different frequency sources

2. Block diagram of the master oscillator

3. Photograph of the master oscillator

Paper on this subject:

C.C. Lo, B. Taylor and K. Baptiste, Advanced Light Source Master Oscillator, Proceedings of 1989 PAC, Vol. 1, pp.118-120,  LBL 29909

The master osillator singal is splitted into three parts. One part is divided by 4 to generate the 125MHz signal for the subharmonic bunching cavity, the master timing system and the gun electronics system.

The source of the oscillator signal could be from a VCXO, a TCXO or an external source. At the present time a HP8644B is used as the signal source due to its flexibility and very good noise performance. The one thing to watch out for with this signal source is one cannot change the operating frequency when ALS is running with beam; any change in frequency of this signal source will scrap the beam completely.

The photograph shows the master oscillator chassis. There are six distribution amplifiers, each provides 1 watt of 500MHz signal to various applications around the machine. The cable on the right side is connected to the HP8644B signal generator.