1. Beam Noise APEX May 1, 2009 Carl Schultheiss Michiko Minty

2. Experiment Summary Four ramps were executed with different configurations of the electrostatic shield and a capacitor across the grounding resistors.

3. RMMPS Power Circuit

4. RMMPS Output Filter

5. Ramp 1 Results

6. Ramp 2 Results

7. Ramp 3 Results

8. Ramp 4 Results

9. Conclusions Floating the Electrostatic Shields in the Dipole Ramp PM reduced the noise during the ramp. Yellow showed more reduction than Blue. The Capacitor had a less dramatic reduction in the noise. The present configuration is with the shields floating and no capacitor.

10. Next Steps Float the shields in the Quad Ramp PM. Try the capacitor again with both Ramp PM Electrostatic Shields Floating. Try different impedances in the grounding of the ring –Try a 100 Ohm resistor. –Try an inductor. There is probably more than one source of noise. The search is not over.