BOOSTER SOLID-STATE DRIVER RF UPGRADE

Tom Kubicki

The Basics

Booster HLRF System to be upgraded using 1kW Solid State Driver (SSD) Amplifiers. Used to drive the 200kW Power Amplifier Eliminates the tube amplifier components Significant improvement in reliability

Each station uses 4 1kW SSD Amps, along with a combiner, provides up to 4kW of RF power

Components are modular, allows for quick repair and minimizes downtime

Solid State Amplifier

Design based on Cubic Corp. 1kW amplifier used in the Main Injector RF Upgrade

Uses water-cooled heat sinks on the high power components

Design uses a pre-amplifier stage, 2 amplifier boards that each have 2 channels capable of 250W per channel, and an output combiner that sums all 4 outputs into one 1kW output (50 Ω system).

Solid State Amplifier

Why build them here? Cost of each amplifier built by Cubic

would be ~$12K per amp. All parts have been ordered, at a cost of

~$1.5K per amp. Substantial cost savings!

Does not include labor, but that is “free” 84 Amplifiers to be built.

Solid State Amplifier

Failure rate is essentially 0 No problem running 15Hz Possibility to employ feedback for gain

and phase regulation (local and global) Far off into the future on this one, but

impossible with current RF system Plenty of additional drive power for

additional beam requirements, and/or to provide beam loading compensation if necessary

Accomplishments

This has been ongoing since 2006, but really ramped up in late 2009.

As stated previously, all major parts have been ordered for the SSD amps. Main amplifier board is stuffed, ferrites ordered, etc.

SSD control units: 20 have been built and tested. This is complete!

SSD Metering chassis: 10 units have been built and tested. 10 remaining, but have all the parts Low priority on the remaining 10 All diode detectors built, 10 need to be calibrated

Accomplishments

To date, NIM modules used in the SSD rack and Modulator have been built and tested. 20 of each module built, includes spares and

possible test station in the future A few loose ends remaining, but have plenty of

modules to complete East Gallery and most of West Gallery.

Booster SSD uses a Low-Level RF chassis, consisting of a phase shifter, variable gain amplifier (VGA), and output amplifier for increased gain.

Accomplishments

The LLRF chassis drives the 1kW SSD amps. LLRF chassis provides phase adjustment, a

linear RF output in proportion to the Solid State Drive Program

16 of these have been built and tested. Parts have been ordered to build VGA’s, and

the remaining LLRF chassis. Stations 5 & 6 in the East gallery have

been upgraded to solid-state.

Future Plans

In near term, get cables pulled for upgrade to stations 1 & 2. Cables can be phased-matched during normal

operations. Possible retrofit of Station 19, would get us 4

additional amps for either Station 1 or 2. Order the rest of the cable needed,

Heliax, RG-58, etc. List of cables required for tunnel and rack, RF

engineers have been doing this

Future Plans

Order NIM Power Supplies Acquired 10 from surplus previously Need 30 more At a cost of $2.5K per supply, NIM supplies

alone will cost an additional $75K! One area with a large expenditure required!

Order 15 SSD Racks ($1.2K a rack, $18K) Order any additional parts for SSD Rack

(plumbing, connectors, etc.)

Future Plans

BUILD AMPLIFIERS!! Requires special jig for brazing heat sinks.

This item should be received shortly May want to consider outside vendor to

assemble the plumbing. May be costly, but personnel is in short supply

currently. Would allow for more assembly line fabrication May be necessary to meet future FY goals

Pre-fabrication of as many wires, cables, circuit boards, etc. as can be done

Future Plans

In near term, one Screen Current Power Supply and Grid Bias Power Supply are being built for the Modulator. Some parts remain to be ordered, but nothing

show-stopping at the moment 20 of each supply will be built

Labor Requirements

Labor estimate for SSD Amplifier Fabrication Assumes heat sinks and as much pre-fabrication as

possible (pre-assembly work) Need at least 2 days for assembling first couple

of amplifier modules (~ first 10), will progress faster once experienced.

Assuming 1.5 days on average, all 84 modules will require 126 days to be fabricated. Very optimistic, will take longer depending on time to

put heat sinks together. Testing will (hopefully) be done in parallel with

assembly. T. Kubicki or J. Holm doing the testing?

Labor Requirements

Testing of SSD Amps will take 1-2 days each. Some are easier to calibrate than others.

Need RF tech(s) to build SSD relay racks. 5 have been built, just waiting for SSD amps.

Time consuming, depending on pre-assembly, can take up to 3 weeks to build one rack.

Verification of final assembly At least one day to check out fully assembled

rack at MI-60 test station

Labor Requirements

Building Grid Bias and Screen Current Power Supplies A lot of cables, wires need to be fabricated. Assembly of components can begin.

Estimating ~3 weeks to fabricate either one Grid Bias or Screen Supply.

Very time consuming Upgrading a Booster RF station

Takes about 2 days with prep work (i.e. cables cut, terminated, and phased matched)

Schedule

End of August Have at least 1 SSD amplifier built and tested

Work out any “kinks” that may occur At least One Grid Bias Supply and Screen Current

Power Supply built and tested Finish with the remaining NIM modules left to be

tested September-December ‘11

Have station 1 and 2 upgraded Continue on building Amps, Power Supplies,

Modulators, etc. Would like to see 20 SSD amps by Dec.

Assembly of SSD racks, cabling (rack and tunnel)

Schedule

January-March ‘12 Continue building racks, finish up with any

remaining cables that need to be fabricated for the SSD rack. Digital I/O cable

Have 40 amplifiers built and tested Have at least 10 Grid Bias and Screen Current

Power Supplies built and tested April-June ‘12

All racks should be built by now

Schedule

Have at least 60 SSD amplifiers built and tested

Have at least 15 Grid Bias and Screen Current Power Supplies built and tested

East Gallery converted to Solid State by now, progression in the West Gallery

July-September ’12 Finish up with the remaining Solid State

amplifiers Finish up with the remaining Grid Bias and

Screen Current Power Supplies Finishing up converting the West Gallery to

Solid State

Conclusion

Needless to say, the RF group has a lot to do! To meet FY 12 goals, we need additional

personnel to assist. Operations and other ongoing projects (NML, HTS,

A0PI, etc.) still require our attention. Additional Funding for FY 11 (we could use a

chunk of the $1.4M) to help achieve FY 12 goal of an all Solid-State Booster RF System

Proven designs work well and are reliable, but much assembly work is left to do!

Questions/Comments