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Booster Collimator Overview

Todd SullivanDean Still

6/24/2004

Collimator Design paper:

“Commissioning of the Beam Collimation System at the

Fermilab Booster.”

Drozhdin, Kasper, Lackey, Mokhov, Prebys, Syphers

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Why do we have collimators?

Their purpose is to clean up the beam halo and localize the proton losses particularly in shielded Booster periods Long 6 Long 7 and immediately downstream.

Lower the losses around the rest of the machine, especially the RF cavities.

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2-Stage Collimation

Two primary collimators made up of copper foils and are moved close to the edge of the circulating beam after injection.

Secondaries H&V (3) are positioned to intercept most of the particles scattered from the foil

45 0 45 90 135 180 225 270 315 360 4051.5

1

0.5

0

0.5

1

1.52 Stage Collimator System

Phase Adv. (degrees)

Am

plitu

de

1.5

1.5

y x( )

ymin x( )

ymax x( )

40545 x

5-1 D 5-2 F 5-3 F 5-4 D 6-1 D 6-2 F 6-3 F 6-4 D 7-1 D6A 6B 7A

B:BLML05

B:BLM051

B:HORPC B:VERPC

B:BLM061

B:BLM062

B:BLML06

B:BLMS06

B:BLML07

B:BLMS05

B:BLM052

B:BLM071

Long 7Long 6

B:S5PCH - upstream mini-straight of Period 5B:S5PCV - downstream mini-straight of Period 56A - upstream end of Long 66B - downstream end of Long 67A – upstream end of Long 7

B:BLM072

Short 6Short 5

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Long 6 Collimator L6A&B

Four Separate Degrees of Freedom:VerticalHorizontalYawPitch

All four motorized with stepper motors. One complete collimator with stand weighs

14.6 tons.

Four Separate Degrees of Freedom:VerticalHorizontalYawPitch

All four motorized with stepper motors. One complete collimator with stand weighs

14.6 tons.

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Long 6 Collimator

Vertical Drives: 170 Volt motor drive system,

900 RPM max speed 4 10 ton screw jacks ± 1.5 inches of travel

Vertical Drives: 170 Volt motor drive system,

900 RPM max speed 4 10 ton screw jacks ± 1.5 inches of travel

Horizontal Drives: 48 Volt motor drive, 900 RPM max Single 5 ton jack ± 1.5 inches of travel

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Targets/Primary Foils

Horizontal at S5 Vertical at S5

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Copper Target 0.3mm

Copper side Carbon side

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Overview of New Software

X0 Xi

N*

Front End

OAC Application

Fast Processing :

Loss Monitor & Intensity Feedback.

Global Orchestration:

Employs states and collimator moving map.

Configure/view,Initiate Process:

Can use sequencer initiate scraping.

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Booster Collimator Hardware

VME based.

BLM and B:CHG

Inputs for feedback.

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Collimator Controls Block Diagram

Collimator Global Controls Layout

Collimator Application

OAC

V:TEVCOL

Coll FE(n)

read/set seq map

read state

read

read

set

set V:TEVCOL T:XXXenable - verify T:(mode) - go

init abort

coll status T: (mode)

calc xi(N,seq,ect)

mdat

tclkmcast

read status map

Local Parameters[NUM_COLL]{ xi [NUM_SEQ] xo[NUM_SEQ] dx[NUM_SEQ]

BPM LATTICE FLYING WIRE

manual control

read/set coll local params

C48 app

dt[NUM_SEQ]

Mode[NUM_SEQ] enable[NUM_SEQ]

sq NL PL Loss[NUM_SEQ]

process

T:CCTLXX[NUM_COL]

graphics

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B110 Application Page

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Controls from Booster Sequencer

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.

Slow Loss Monitor Feedback

•Local BLM’s and B:CHG0 are sampled from event.•Collimator moves under feedback and stops at loss limit.•Protection for no beam movement and no beam in given time.

Loss Limit

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Fast Lost Monitor Feedback

1) Have to bump the beam into the collimator. Need hardware to process. Intend to bump on $1D.

Collimator

BLM

3 bump1

2

3

Bump box: Inputs 4

dipoles and scales

4 bumps output

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.

Orbits at Collimators

Collimator placement

Collimator placement

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Positioning the Collimators

Perform a collimator scan in small steps to detect beam edge (move into beam)

Retract to edge of beam Observe beam intensities ($1D and

$14) and lossesRepeat for remaining primary and

secondary collimators

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.

Collimator Loss Scans

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.

Collimator Loss Scans

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Effects of Collimators on Ring Losses

Collimator being inserted

Effects of Ring losses

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Ring Loss difference for Collimators In and Out

If > 0 increased loss

If < 0 decreased loss

If > 0 increased loss

If < 0 decreased loss

Collimator location

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Rad Survey at week 7

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Problems/On going Work $1D cycles are difficult for BLM and BPMs to

gather data consistently and accurately. SNP have similar problems with $1Ds plotting

beam intensity and BLMs. Horizontal collimator movement has shown

slippage. Still need to assess and maximize collimator

efficiency.

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Orbit differences vs. 2 stage performance

Vertical Collimator and VL6 Bump

S5 L6 L7Horizontal Collimator and HS5 Bump

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Conclusion:

Are the collimators working – Yes at some level.

The losses are being reduced around the ring.

Have seen radiation levels at certain locations decreasing and/or staying constant.

Gaining operational experience with using the collimators.

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Happy people make happy Collimating