January 19, 2006PEP TFB R.Akre PEP II Transverse Feedback System Ron Akre William Colocho Anatoly Krasnykh Vojtech Pacak Dmitry Teytelman Uli Wienands.

PEP II Transverse Feedback SystemRon Akre

William Colocho

Anatoly Krasnykh

Vojtech Pacak

Dmitry Teytelman

Uli Wienands

MAC January 18, 2006

PEP II Transverse Feedback System

The PEP TFB system takes the vector sum of 2 BPMs, delays the signal by the remainder of 1 turn and delivers a kick to the beam the next time around. Two stripline kickers, one for X and one for Y, are used.

PEP II TFB Highlights for Run 5

New Moly Kicker Electrodes and larger, 7/16 DIN, connectors allow higher current running in LER – LER has run for 3 days at 3 Amps.

Added phase shifters to HER receivers to independently phase X and Y

Removal of orbit offset electronics increases gain in receiver chassis.

Replace HER BPM Attenuators with higher power units

The new data acquisition system and analysis software is running and collecting Gigabytes of data.

New LBNL 2 Tap Filter / Delay installed in LER Y since August and in HER for a few weeks in December

G-proto in LER Y for a week in September and LER X for a few weeks in December

PEP II Transverse Feedback SystemRun 5 Resolved Hardware Problems

• 18 Log Entries associated with hardware problems– 16 Power Amp Problems

• 14 transistors

• 5 regulator boards

– 1 High Power Filter Blown: LER Y-– 1 Failed BPM Attenuators: LER 2C

PEP II TFB Receiver

Orbit offset correction are done by changing beam orbit to minimize dX and dY signals. Receiver chassis have been modified to eliminate orbit offset adjustment and give more gain.

Manual phase shifters added to phase HER X and HER Y independently

PEP II TFB Digital Delays• Lawrence Berkeley Laboratory

Phase 1: 2 - 12 bit ADC to clock data into FPGA at 238MHzTwo tap filter with 1 turn delay plus variable delay238MHz DAC with differential outputProgrammable through COM port.Completed – Installed in LER Y August 2005

Phase 2: Record 16MS, 70mS, of data to external memoryThree trigger modes

Grow/ Damp MeasurementsFault File DataSoftware trigger to capture data during running

On board EPICS control with Ethernet for programmingFinal Software being completed

Principal Investigators: Walter Barry and John ByrdAlex Chin, Larry Doolittle, Alex Ratti, Jonah Weber

PEP II TFB Digital Delays

New Digital Delays – 2 tap filter and diagnostics are being developed by LBNL

ADC0

ADC1

DDRSDRAM

HybridSplitter DAC

PowerSplitter

Attenuator

FrequencyDoubler

TranformerCoupling

PECLGate

Tuning Cables

FPGA

Xilinx ML300 Power I/O Board

PowerConnector I/O Connectors

2 TTL Inputs

MonitorSignal

Clock Input119 MHz Sine

ControlSignal

Red = 119 MHz Clock

Blue = 238 MHz Clock

SLAC TFB CPU Board

Ethernet

Compact FlashCard

SystemACE

LocalNetwork

JTAG Configuration Port

2 NIM Inputs

Jonah Weber LBNL

PEP II TFB Power Amplifiers and Filters

Power Amplifiers

Reliability of the power amplifiers still remain a large concern. Each of the 8 amplifiers has 8 power transistors summed for the output. During this run 5 so far we have lost about 14 output power transistors.

Largest reliability concern

During the past down time all the amplifiers have been tested and repaired

The orbit offsets and phase transients cause the amplifiers to run close to saturation. The new digital delay two tap filters eliminate orbit offsets and greatly reduce power requirements in the amplifers.

Filters

So far only 1 filter failure – the new 7/16 DIN connector in LER Y- did not fail, but internal LC components did.

PEP II TFB Kickers Uli Wienands, Anatoly Krasnykh, Artem Kulikov, Jay Langton, Many Others

New kickers with moly electrodes, redesigned coax to stripline transition, and 7/16 DIN connectors have been installed in LER.

PEP II TFB Data Acquisition System

GAGE 82G PCI 8bit 2GHz 2 Channel Digitizer 16Mb Memory

2 Cards 4 Channels – HER X and Y and LER X and Y

3rd card is on order to monitor other signals

GAGE card is clocked at 238MHz bunch frequency

Inputs are from vector sum out of Analog Signal Processor for X and Y

Programmable triggers: Inputs from HER / LER Fault, HER / LER Injection, HER / LER Software. Output trigger for grow/damp measurements. PEP TFB TRIGGER CHASSIS

PEP II TFB Data Acquisition System

Files are stored in central NFS space

Compiled MatLab routines for analysis of data sets are run from a GUI

ANALOG SIGNAL PROCESSOR

dXdY

dXdY

Network Connection

238MHzClock

Trigger

GAGEPCI Scope Card2GSPS 8bitMS Windows XP

476MHz CLKTurns CLKSCP TrigFault TrigInjection Trig

X+X-

Y+Y-

DIGITALDELAY1 TURNY

dY

dX

MonitorCalibrated Cable Lengths

dX2dY2

D

dX1dY1

BPM1

BPM2 #2

ABCDB

C

B

ABCD

ARECEIVER

#1C

D

RECEIVERA

LO

AD

S

X+X-

Y+Y-

PREAMPS

X K

ICK

ER

POWER AMPS

BEA

M

To Y KICKER

FILTERS

80pS Step10nS Delays

dX1dY1

dX2dY2

DIGITALDELAY1 TURNX

Trigger Chassis

PEP II TFB Data Acquisition SystemAnalysis Software

Display All Data

Display Selected Data

Plot RMS FFT

Plot Modes

Plot Mode Phase

Plot Mode Growth Fit

High Resolution FFT

High Resolution FFT 2

Plot Spectrogram

W. Colocho, V. Pacak

Compiled MatLab Software Run from GUI

12-08-05 21:17 ~2200mA LER

LER CURRENT

X

Y

X Y

Grow Damp Measurements August 16, 2005Mode -1

Grow Damp Measurements August 16, 2005

0.74 1/mS 0.96 1/mS

0.69 1/mS 0.63 1/mS

Grow Damp Measurements August 16, 2005

Growth Rates vs. Beam CurrentsMode -1

0

0.2

0.4

0.6

0.8

1

1.2

0 1000 2000 3000

Beam Current mA

Gro

wth

Rat

e 1/

mS

Grow Damp Measurements August 16, 2005

PEP II TFB Concerns for Higher Current Running

Feedback Gain and Output Power

Plan to do grow / damp measurements in both HER and LER.

LBNL two tap filters have shown large increases in system gain, postponing the need for larger power amplifiers. The new delays require less rack space if larger power amps are required.

Filters are currently working well – 1 failures with new connector

Only 1 filter, LER Y-, has 7/16DIN connector – the rest use N connectors

(This same filter is the only one which failed during this run)

Kickers

New Moly electrodes in LER, they have handled up to 3 amps and are expected to work to 4.5 amps.

7/16DIN Feed-through connectors replaced SC, and eliminate SC to N adapters.

As the bunch length shortens higher frequencies of beam induced power will need to be directed to proper loads.

Measurements of beam induced power from kicker to amplifiers need to be done.

PEP II TFB Near Term Run 5 Tasks

• Set up collaboration with LBNL to assist with measurements

• Measure power reflected to amplifier from kicker – Especially LER Y-

• Grow / damp measurements both planes of both rings• Transfer function measurements in both rings• Install 2 tap filters in both planes of both rings• Install 3rd GaGe card to monitor 2 additional channels