1. The Rutgers 12” Cyclotron The Pursuit of Resonance!

2.  Where Hydrogen gas is inserted and ionized

3.  Primary Source of Capacitance in Cyclotron

4.  Where Hydrogen gas is inserted and ionized  Primary Source of Capacitance in Cyclotron  This is the inductor used to turn the cyclotron into an LRC circuit  Tim wound it from a refrigerator coil!

5. Our Problem: During the Cyclotron’s normal operation, its resonance frequency changes on its own

6. Our Problem: During the Cyclotron’s normal operation, its resonance frequency changes on its own Our Solution: Build an adjustable capacitor plate that responds to the changing resonant frequency of the cyclotron and behaves appropriately

7. Implementation:  Takes signal from signal generator and output of cyclotron and send it through a mixer  For our purposes, the mixer takes the two inputs and converts them to a positive or negative DC voltage depending on the phases of the inputs

8. Implementation:  Takes signal from signal generator and output of cyclotron and send it through a mixer  Put signal through H-bridge and switch logic, which are in turn connected to… H-Bridge Switching Logic

9. Implementation:  Takes signal from signal generator and output of cyclotron and send it through a mixer  Put signal through H-bridge and switch logic, which are in turn connected to… H-Bridge Switching Logic LM 311 Comparators PNP trans. NPN trans.

10. Implementation:  Takes signal from signal generator and output of cyclotron and send it through a mixer  Put signal through H-bridge and switch logic, which are in turn connected to… H-Bridge Switching Logic The And Gates The Switches

11. Implementation:  Takes signal from signal generator and output of cyclotron and send it through a mixer  Put signal through H-bridge and switch logic, which are in turn connected to…  an adjustable capacitor plate whose distance from the high voltage is governed by an electric motor

12.  A second idea for the adjustable Capacitor plate

13. Pros: Greater adjustable range of resonant frequency, around 70 kHz of play vs. 20 kHz with the single plate only

14.  A second idea for the adjustable Capacitor plate Pros: Greater adjustable range of resonant frequency, around 70 kHz of play vs. 20 kHz with the single plate only Cons: oThe additional plate causes a shift in the cyclotron’s resonant frequency

15. Turns out this doesn’t matter, so we decided to go with the second idea Unfortunately we were not able to get that far

16. Here’s a summary of how things should’ve gone: The signal applied across the cyclotron and the output of the cyclotron are compared in a device called a mixer The mixer sends either a positive, negative, or zero DC volt signal into our H-bridge/switching logic depending on the relative phases of the two input signals The positive or negative voltage either withdrawal or extend an adjustable capacitor plate. The response of the adjustable plate is designed to respond in a manner that automatically corrects the change in the cyclotron’s resonant frequency After installation of the equipment and some testing, the unit is meant to be left alone, operating on the feedback of the cyclotron

17. Where did we get stuck? H-Bridge Switching Logic Anthony and I were unable to integrate the switching logic and the H-bridge

18. It turns out that these little devices are a pain(!!). LM 311 Comparators

19. But we both sure learned a lot and enjoyed our experience!