The Development of an Ionization Profile Monitor for use in the Tevatron

Lawrence Short BullSJSU, San Jose, CA

Supervisor: Andreas Jansson Beams Division, FNAL

SIST Summer 2003

Agenda

Introduction Principles of Operation Design Details Experiments Conclusion Acknowledgements

Introduction

Quantities of InterestLuminosityEmittance

Emittance Monitoring Devices at FNALFlying WireSynchrotron Light Monitor Ionization Profile Monitor (IPM)

Luminosity

Run II Goals: peak L 5.1E31 cm^-1sec^-1, integrated 2fb^-1

Emittance

projection onto x/y axis provides transverse beam dist. r.m.s. value of beam density distribution provides

measure of beam size Beam size given as r.m.s of Gaussian beam profiles Initial distribution not quite Gaussian, by time final

energy reached is very good approximation.

Emittance monitoring in Tevatron

Flying Wires Evasive diagnostic tool

Synchrotron Light Monitor Non-evasive

Reported emittances show discrepancy Potential emittance monitoring in Tev

IPM Schottky Detector

Why an IPM for the Tev?

Run II Instrumentation Motivations Transverse and longitudinal emittance

preservation Real time operational tuning & monitoring

Tev IPM provides turn-by-turn profile measurements for transverse injection matching

Sync lite only “on-line” transverse profile monitor available during store (insuff. Light @ 150 Gev)

IPM Fundamentals

Provide transverse beam profiles: vertical & horizontal Residual gas ionization occurs with each bunch passage Collection of ions/electrons with electric clearing field Combat space charge effects Utilizes microchannel plate(MCP) for charge multipliction Amplified signal of charge collected on anode strip Signal integrated, amplified, and digitized Sent from memory to processor to provide histogram

profiles

MCP fundamentals

Array of dynodes Contain large number ~1E4-

1E7 Aspect ratio: 40-400 Diameter: 5-25 microns Intrinsic impedance: ~1E9ohm Intrinsic capacitance: ~ 30pF Gain: 1E4-1E7 Gain degradation proportional

to extracted charge

QIE ASIC

Charge, Integration, Encoding Input current integrated over 4

ranges Pipelined into 4 stages at

25nsec per stage Output is 5 bit mantissa, 2 bit

range exponent, 2 bit cap ID in calibration mode the FADC

is strictly linear with 32 linear counts @ 0.87 fC/count

Input charge: 6.1fC – 26fC

5I

I

I

I

Signal Amp.

/ Splitter

5I

I

I

I

ReferenceAmp.

/ Splitter

Comparator and

Multiplexor

Sig. Input

Ref. Input

Range Encoder

FADC

C

C

5C

25C

C

C

5C

25C

State Machine 4(Reset Integrate Compare MuxOut)

Digitize

Mantissa

Range/Exponent

Cap. ID

2

2

5

A Choice of Two Amplifiers with

G= (-2.7) / (1)

1 2 3 4 5 6 7 8 9101112131415161718192021222324252627282930313233

10

20

30

40

50

E B

Anode strips

Beam

MCP

Tev IPM Design 36 X 36 proton and pbar bunches Time between bunches ~396ns Bunch length ~ 3ns r.m.s., 18-20ns Only ~1000 e liberated during

ionization Electronics must be low noise Need Faraday screen to protect

detector from image current @ 53MHz

Pull only signal through vacuum flange, reference terminated @ vacuum

Anode to ground completely floating

screen

Block diagram/data flow chart

seri

aliz

er

16 serial links(optical fiber)~1.6 Gbits/s/link~23 Gbit/s total

Sam

ple

cloc

k (1

7.6

MH

z)

Ano

de s

tirp

sig

nals

(~1

28)

16

Proton revolution marker

Kwame Vince, Mark et al

PCIX busDMA xferBurst mode~1 Gbit/s

Pbar revolution markerQ

IEQ

IE(8

QIE

s)

opti

cal d

rive

r

Fas

t (w

ide)

mem

ory

FP

GA Data

Hea

der

byte

QIE

res

et

QIE

mod

e

Header card53 MHz RF

Timing card Injection eventoff-the-shelf

in tunnel in upstairs PC

GPIB controller

To power supplies

PC

I B

US

MI IPM Studies

Utilized IPMM1H & IPMM2H Investigate effects of a varying bias

voltage for MCP in detectors ACNET variables I:HxMCPV,

I:HxPMEM[ ] ,I:HxPMSG[ ] datalogged at node TevJA

Settings on LabView interface determine what turn number was datalogged

Two ranges were studied

IMPM1H

IPMM2H

MI_IPM: H1 results

1150

2350

950

1050 11

25 1200 12

75

0

10

20

30

40

50

Emittance

turn

MCP_V

H1 IPM: turn vs. MCP_V vs. emit

40-50

30-40

20-30

10-20

0-10

H1 IPM: MC_ V vs. Emittance array

0

5

10

15

20

25

30

35

40

45

50

750 850 950 1050 1150 1250 1350

MCP_V (vol ts)

1000

1150

1300

1600

1750

1900

2050

2200

2350

2650

2800

2950

3100

3250

H1 IPM: MCP_V = 1200V

0

5

10

15

20

25

30

1150 1300 1600 1750 1900 2050 2200 2350 2650 2800 2950 3100 3250

turn

1200

H1 IPM: MCP_V = 1275V

0

5

10

15

20

25

30

35

40

45

50

1150 1300 1600 1750 1900 2050 2200 2350 2650 2800 2950 3100 3250

turn

1275

H1 IPM: MCP_V = 1075V

0

5

10

15

20

25

30

1150 1300 1600 1750 1900 2050 2200 2350 2650 2800 2950 3100 3250

turn

1075

H1 IPM: MCP_V = 1100V

0

5

10

15

20

25

30

1150 1300 1600 1750 1900 2050 2200 2350 2650 2800 2950 3100 3250

turn

1100

MI_IPM: H2 resultsH2 IPM: MCP_V vs Emmittance array

0

5

10

15

20

25

30

35

40

45

50

1175 1225 1275 1325 1375 1425

volts

Emm

ittan

ce

[0]

[25]

[50]

[100]

[125]

[150]

[175]

[200]

[225]

[275]

[300]

[325]

[350]

[375]

1000

1300

1750

2050

2350

2800

3100

1200

1225

1250

1275

1300

1325

1350

1375

1400

0

5

10

15

20

25

30

35

40

Emittance

turn

MCP_V

H2 IPM: turn vs MCP_V vs emit

35-40

30-35

25-30

20-25

15-20

10-15

5-10

0-5

1000

1300

1750

2050

2350

2800

3100

1200

1225

1250

1275

1300

1325

1350

1375

1400

0

5

10

15

20

25

30

deviation

turn

MCP_V

H2 IPM: turn vs. MCP_V vs. deviation

25-30

20-25

15-20

10-15

5-10

0-5

H2 IPM: MCP_V = 1400V

0

5

10

15

20

25

30

35

40

1000 1150 1300 1600 1750 1900 2050 2200 2350 2650 2800 2950 3100 3250

turn

Em

mit

tan

ce

1400

H2 IPM: MCP_V = 1300V

0

5

10

15

20

25

30

35

40

1000 1150 1300 1600 1750 1900 2050 2200 2350 2650 2800 2950 3100 3250

turn

Em

mit

tan

ce

1300

H2 IPM: MCP_V vs. Emit array

0

5

10

15

20

25

30

35

40

45

50

1270 1280 1290 1300 1310 1320 1330

volts

Em

mit

tan

ce

1000

1150

1300

1600

1750

1900

2050

2200

2350

2650

2800

2950

3100

3250

MI_IPM: H2 better resolution

1000

1600

2050

2650

3100

1275 1280

1285

1290 1295

1300

1305

1310

1315

1320

1325

0

5

10

15

20

25

30

35

Emmittance

turn

MCP_V

H2 IPM:turn vs. MCP_V vs. emit

30-35

25-30

20-25

15-20

10-15

5-10

0-51000

1600

2050

2650

3100

1275 1280 1285 1290 1295

1300 1305 1310

1315

1320 1325

0

1

2

3

4

5

6

deviation

turn

MCP_V

H2 IPM: turn vs. MCP_V vs. deviation

5-6

4-5

3-4

2-3

1-2

0-1

H2 IPM: MCP_V = 1295V

0

5

10

15

20

25

30

35

1000 1150 1300 1600 1750 1900 2050 2200 2350 2650 2800 2950 3100 3250

turn

Em

mit

tan

ce

1295

H2 IPM:MCP_V = 1300V

0

5

10

15

20

25

30

35

1000 1150 1300 1600 1750 1900 2050 2200 2350 2650 2800 2950 3100 3250

turn

Em

mit

tan

ce

1300

H2 IPM: MCP_V = 1325V

0

5

10

15

20

25

30

35

1000 1150 1300 1600 1750 1900 2050 2200 2350 2650 2800 2950 3100 3250

turn

Em

mit

tan

ce

1325

H2 IPM: MCP_V = 1320V

0

5

10

15

20

25

30

35

1000 1150 1300 1600 1750 1900 2050 2200 2350 2650 2800 2950 3100 3250

turn

Em

mit

tan

ce

1320

MI_IPM: H2 up the rampH2 IPM : MCP_V vs. Emit array

0

20

40

60

80

100

120

1175 1225 1275 1325 1375 1425

vol ts

20

4445

8870

17720

22145

26570

30995

35420

39845

48695

53120

57545

61970

66395 20

2214

5

3984

5

6197

012

00 1285 13

10 1375

02040

60

80

100

120

140

Emmittance

tur n

MCP_V

H2 IPM: turn vs. MCP_V vs. emit

120-140

100-120

80-100

60-80

40-60

20-40

0-20

H2 IPM: MCP_V = 1295V

0

10

20

30

40

50

2044

4588

70

1772

0

2214

5

2657

0

3099

5

3542

0

3984

5

4869

5

5312

0

5754

5

6197

0

6639

5

tur n

1295

H2 IPM: MCP_V = 1300V

0

10

20

30

40

50

60

2044

4588

70

1772

0

2214

5

2657

0

3099

5

3542

0

3984

5

4869

5

5312

0

5754

5

6197

0

6639

5

turn

1300

QIE Noise Measurements The noise floor of the CKM QTBB floor was determined Noise for various cable configurations was to be determined

Data Multiplexing

QIE A

QIE B

16 bit SERDES w/ 8B/10B

Clock dist. ckt. 40MHz

QIE A: noise floor

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30M

ore

Bin

Fre

qu

ency

Frequency

Pedestal = 19.481 r.m.s = 0.6919

Noise floor channel A: input impedance = 50 ohm

Noise floor per cap ID: input impedance = 50 ohm

0

200

400

600

800

1000

1200

1400

1600

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30M

ore

Bin

Fre

qu

ency

Frequency

0

200

400

600

800

1000

1200

1400

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30M

ore

Bin

Fre

qu

ency

Frequency

0

200

400

600

800

1000

1200

1400

1600

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30M

ore

Bin

Fre

qu

ency

Frequency

0

200

400

600

800

1000

1200

1400

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30M

ore

Bin

Fre

qu

ency

Frequency

Cap ID 0 Cap ID 1

Cap ID 2 Cap ID 3

r.m.s = 0.6647 r.m.s = 0.6642

r.m.s = 0.6709 r.m.s = 0.6814

calibration mode: gain factor

0

5

10

15

20

25

-4 -2 0 2 4 6 8 10 12 14

injected charge (fC)

ou

tpu

t b

in

cap id 0

cap id 1

cap id 2

cap id 3 noise, e- gain factor

cap id 0 3152 0.7598

cap id 1 3142 0.7579

cap id 2 3158 0.7540

cap id 3 3232 0.7598

Gain factor for channel: 0.7579

Noise for channel: 3171e

Determination of Gain Factor per cap ID: Zin = 50 ohm

QIE_A: capacitance in signal input only

0

0.5

1

1.5

2

2.5

0 50 100 150 200 250 300 350

input capacitance (pF)

RM

S (

cou

nts

)

cap_id 0

cap_id 1

cap_id 2

cap_id 3

QIE_A: capacitance to refrence input only

0

0.5

1

1.5

2

2.5

0 50 100 150 200 250 300 350

input cap. (pF)R

MS

(cn

ts)

cap_id 0

cap_id 1

cap_id 2

cap_id 3

Capacitance input to either signal or reference inputs

Peculiar behavior displayed, further investigation required

QIE_A: capacitance to both inputs

0

0.5

1

1.5

2

2.5

0 50 100 150 200 250 300 350

input cap. (pF)

RM

S (

cnts

)

cap_id 0

cap_id 1

cap_id 2

cap_id 3

QIE_A: calcualted noise

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

0 50 100 150 200 250 300

input cap (pF)el

ectr

on

s cap id 0

cap id 1

cap id 2

cap id 3

Configuration of interest: input cap. To both signal & reference

Noise levels appear within tolerances for design

Noise floor channel A: input impedance = 93 ohm

QIE A: noise floor

0

1000

2000

3000

4000

5000

6000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30M

ore

Bin

Fre

qu

ency

Frequency

Pedestal = 12.7432 r.m.s. = 0.6848

Similar results as 50 ohm case when individual cap id’s examined

Determination of Gain Factor per cap ID: Zin = 93 ohm

Noise for channel: 3123e

Gain factor for channel: 0.7571

noise egain factor

cap id 0 3132 0.7605

cap id 1 2996 0.7588

cap id 2 3141 0.7499

cap id 3 3221 0.7592

input impead. = 93 ohm

0

5

10

15

20

25

30

-10 -8 -6 -4 -2 0 2 4 6 8

input charge (fC)

ou

tpu

t (b

in)

cap_id 0

cap_id 1

cap_id 2

cap_id 3

Less noise, relatively the same gain factor for the channel than the 50 ohm setting

ict: 93

0

500

1000

1500

2000

2500

3000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30M

ore

Bin

Fre

qu

ency

Frequency

ntd: 50

0

200

400

600

800

1000

1200

1400

1600

1800

2000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30M

ore

Bin

Fre

qu

ency

Frequency

Cable Test

100 ohm twisted pair cable connected to both signal and reference

Length of cable = 3.75 m Shield of each cable

connected Return for each cable

connected Zin = 93 ohm, noise is

6,808 e Zin = 50 ohm, noise is

10,844 e

Zin = 93 ohm

Zin = 50 ohm

Conclusion Emittance as reported by IPM very sensitive to output

current; N2 leak must be added with care, low gain MCP MCP test stand will be used to study MCP properties for

this project in addition to future projects. Also to diagnose MCP’s coming out of the machine

If QIE noise results correct, good thing. Seem slightly low.

Tev IPM up for technical DOE review in Oct., things look good and will more than likely be commissioned

Encouraging to see CMS & Beams Div. Collaborating on project

FNAL is a rocking place to work

Acknowledgements

I would like to thank Andreas Jansson, Claudio Rivetta, Hogan Nyugen, Jim Zagel, Kwamie Bowie, Dianne Engram, Elliot McCrory, Dr. Davenport and rest of SIST committee.

The 2003 SIST summer interns