Beam NoiseAPEX May 1, 2009

Carl Schultheiss

Michiko Minty

Experiment Summary

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

Ramp Number

Blue Dipole Ramp Electrostatic Shield

Yellow Dipole Ramp Electrostatic Shield

Capacitor in Yellow Dipole Ramp OCC

1 Floating Switched In and Out Not Installed 2 Floating Grounded Installed for

Entire Ramp 3 Grounded Grounded Switched In and Out 4 Floating Floating Not Installed

RMMPS Power Circuit

RMMPS Output Filter

Ramp 1 Results

Ramp 2 Results

Ramp 3 Results

Ramp 4 Results

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.

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.