PIP - 200 MHz Modulator - WG2
Attendees: J. Walters, D. Wolff, H. Pfeffer, T. Butler, F.G. Garcia
Date: 07/20/2011
Location: Loft 1:30 PM
Type | Cathode-Driven Triode |
Designed | 1960 |
Filament | Thoriated Tungsten |
Filament V | 4 V |
Filament I | 6800 A |
Plate Dissipation | 300 kW |
Plate Voltage Max | 40 kV |
One of the discussion evolved around the current length of the flat top (180 usec). Despite the fact that at the time of the meeting there was no definitive information regarding the specs for the RFQ source, the group agreed with Trevor's argument that regardless of what the new source is cabaple of, one can not expect to have a beam pulse larger than the 800 MHz pulse length which is in the order of 110 usec. Also, the new LLRF acquire data inside a 6 usec window prior the beam pulse.There is an interval in the order of 2-4 usec prior the beam arrival. Therefore, a 10 usec requirement was added before and after the beam pulse totalizing a flat top of 130 usec (a reduction of ~ 25%) .
2. Rise Time
The 125 usec rise time was found adequate.
3. Fall time
No conclusion was drawn about this fall time at this meeting.
Another important topic discussed was the rise/flat top/fall time during beam time. Questions discussed:
1) What is the maximum ever needed Voltage the Modulator has to produce during beam time?
2) Is there a need to have steps rise control during the beam pulse? what about the fall time?
Answer: after some discussion the group decided that a squarewave with tilt should be sufficient. Specifications of rise/fall time still remains to be determined. Dan Wolff would like to see a screen capture together with the raw data of the rise/fall time during beam time. Trevor and Fernanda will provide such data for the next meeting.
So, below is a table showing the Modulator specification identified during the meeting so far.
Current Spec | New Spec | |
---|---|---|
Max. Modulator V | 40 kV | 35 kV |
Max. Modulator I | 375 A | |
Rise time | 125 usec | |
Flat top | 130 usec |