1. Conductance Control Iris for the K150 Cyclotron H- ion SourceBY
ARMANDO MALDONADO
ADVISORS: DR. HENRY CLARK,
DR. GABRIEL TABACARU

2. Introduction Negative Hydrogen Ion source Hardware Set-up Operation
General operation, problem
Improvement, basis for my project
Hardware
Set-up
Operation
Programming an Interface
Possible problems
Future Plans
Acknowledgements

3. Negative Hydrogen Ion Source
H- Source for intense proton beams for Upgrade Project
Large hydrogen gas flow needed for H- operation
H2 travels past turbo pumps
Poor vacuum limits intensity
~10-8 torr – source off,
~10-6 torr – source on
Install conductance Iris below turbo pumps
Failsafe and reproducible
H- ion source
turbo molecular pumps (remove hydrogen)
to K150 Cyclotron
Cryogenic pumps (don’t remove hydrogen well)

4. Project Aim

5. Hardware 8” OD Conflat DV Manufacturing Inc. iris
~4.7” diameter when fully open
~0.3” diameter when fully closed

6. Hardware Cont. optical encoder present non-volatile memory
MDrive 17 Plus control motor
Modern step-by-step motor
optical encoder present
accurate determination of the movement
non-volatile memory
store variables
rich programming capabilities

7. Set-up
Coupling apparatus
Power Supply
Data Fitting

8. Set-up: Coupling apparatus

9. Set-up: Assembled Product
Connecting shaft
Set screw couplers for dampening
Aluminum
Spring Loaded

10. Set-up: Power Supply Power Supply Storage 120 VAC, 24 VDC output
Unregulated power source
Low Noise
Storage
Stored away from ion source
Indicator light
Grounded to box

11. Fitting Data Conversion factor needed
Linear or something else?
Iris Diameter as a function of Motor steps
Measured with venire caliper at increments of 200 motor step intervals
Plotted data and fitted regressions
Linear fit
Cubic fit
Cubic function fits data better

12. Plotted Data

13. Flow Chart

14. Programming an Interface
Control Iris Diameter input
Increment/Decrement Resolution
Reading diameter
True diameter of iris
Error Status
Input bounds/motor state
Initialize Set-up
Read Position without moving
Reset Motor and Diameter

15. Block Diagram

16. Future Projects
Gas Baffle for the Light Ion Guide for the Upgrade Project
Conductance control
Similar application as with H- ion source
Beam intensity attenuator for any ECR (Electron Cyclotron Resonance) ion source
Rapid reduction of beam intensity into the cyclotron
Compact and will replace attenuator screen system

17. References – H- ion source
[1] H. L. Clark, F. Abegglen, G. Chubarian, G. Derrig, G. Kim, D. May, G. Souliotis and G. Tabacaru, Progress in Research, Cyclotron Institute, Texas A&M University ( ), p.V-12 – V-17
[2] H. L. Clark, F. Abegglen, G. Chubarian, G. Derrig, G. Kim, D. May, G. Souliotis and G. Tabacaru, Progress in Research, Cyclotron Institute, Texas A&M University ( ), p.V-2

18. Thank you! Andy Clark Steve Russel Robert Burch Control Systems
Machine Shop
Steve Russel
Electronic Shop
Robert Burch
Control Systems