Booster Dampers Update

Nathan EddyPIP Meeting

4/30/14

Transverse Damper

• RF Lock – No loss of lock since “fix”• New Firmware with Timofey Zolkin’s n-turn filter coefficients

installed

• Testing and verification underway– Basic Timing, Filter Algorithm, Tune Monitor

Longitudinal Damper

LD Block Diagram

ADC

x

x

CICDec

CICDec

BP FIR-45°

BP FIR+45°

Mɸ

Mɸ

CICInterp

CICInterp

x

x

Σ DAC

+

+ -

Same NCO generates sin, cos for I,Q mixing NCO frequency is centered on rev harmonic of interestSet CIC decimation so that notches on RevFBP FIR is a N tap filter for signal conditioningMɸ correspond to programmable magnitude/phase shiftFor output sum, +/- select upper/lower sideband (SSB) Will also suppress carrierNote, this same firmware design can be used for “direct sideband” detection by adjusting the NCO frequency and modifying the FIR filter coefficients

NCOcos

NCOsin

NCOsin

NCOcos

4*RF ~211MS/s

4*RF ~211MS/s

~25KHz

Test Installation

WCMPhase PickupMode 1

DigitalDamper

Mode N

NotchFilter

BPFilter

Pickup

RF RefTCLK

RF Ref

RAW Data

MODE 50

15ms

RAW Data ZoomAfter 90MHz LP Filter

Mode 50 after DDC

Import into Matlab

Simple Matlab Simulation

Summary

ADC

x

x

CICDec

CICDec

BP FIR-45°

BP FIR+45°

Mɸ

Mɸ

CICInterp

CICInterp

x

x

Σ DAC

+

+ -

ADC through CICdec implemented and tested in BoosterCICint and DAC tested on benchDesign as shown under checkout right now Expect to begin testing in Booster this week

To Do List Develop complete Matlab Simulation Allow ability to optimize filtering Implement Beam Transfer Function Measurement for open and closed loop measurements Straightforward method to optimize gain/phase Demonstrate damping on single Booster Mode

NCOcos

NCOsin

NCOsin

NCOcos

4*RF ~211MS/s

4*RF ~211MS/s

~25KHz