1. Development of the DC Electronics for the TAMUTRAP RFQ Cooler/Buncher Louis Cooper Cyclotron Institute Texas A&M University

2. Top View of the TAMUTRAP (left) Production and Transport Route for the ion beam (bottom right)
Decay scheme for the events of interest (bottom left)

3. RFQ Cooler/Buncher Cut-away of the RFQ Cooler/Buncher
A picture of the electrode structure inside the RFQ chamber

4. DC Electronics for the RFQ
Building a voltage divider circuit for RFQ
Testing the voltage divider circuit at high voltages
Testing high voltage switches using National Instruments FPGA
Building the filter circuit for Behlke switch
Mounting the setup on high voltage platform
Testing the high voltage switches and its associated circuits at a floating ground
Voltage Divider
Multichannel DC Power Supply
The proposed location for the DC electronics

5. A voltage divider will produce an electric field across the middle segments to create an almost linear decrease in potential
The Ions will interact with the field in such a manner that they accumulate in the shallow potential at the end of the RFQ
An appropriate setting of the last segment's potential will prevent ions from escaping
The resistance values are proportional to the center-to-center distance of the assigned segment

6. The extraction from the RFQ will be achieved by switching down the voltage applied to the last segment
A rapid, precise signal will efficiently guide the ions back into the beam line
A Behlke high voltage (ultra-fast switch) will be used to switch the voltage of the last segment
A National Instruments FPGA will be used to satisfy the precise timing condition of the signal.
Behlke fast, high voltage
transistor switch

7. Top view of the FPGA circuit board
Front panel of the FPGA circuit board

8. Output of the FPGA Module

9. A 3.3V-5V level shifter will meet the operating conditions of the Behlke switch
This circuit supplies the DC power for the Behlke switch along with the signal to extract ion bunches out of the RFQ
The level shifter will be mounted outside the high voltage platform because it does not need a floating ground

10. Output of the Level Shifter

11. Output of the Level Shifter

12. The signal from the switch is filtered to give a clean and precise signal
The output of this filter circuit will control the cooler/buncher’s last segment
Large deviations in the signal can lead to serious problems during extraction

13. 0 V Output of the filter using 5.1V from a DC power supply

14. Output of the Filter

16. Output of the New Filter

17. Output of the New Filter

18. Level Shifter
FPGA Module

19. Filter
Behlke Switch
Voltage Divider

20. Conclusion
I have assembled, tested, and/or mounted these DC electronics in the RFQ control system
All circuits were tested with several instruments for successful operation
The electronics that will operate at a high voltage have been successfully floated
The best output observed for the RFQ extraction process was a smooth pulse with a rise and fall time of about 500 nanoseconds
Plug configurations and layouts have been created for future modifications.
A short guide to the FPGA controller has also been created to easily change the frequency of the extraction signal
The next step is to confirm accumulation and extraction in the RFQ itself in addition to maximizing the efficiency of both processes.

21. Acknowledgments M. Mehlman, P. Shidling, D. Melconian, R
Acknowledgments M. Mehlman, P. Shidling, D. Melconian, R. Burch Cyclotron Institute Texas A&M University