CNGS Secondary Beam Monitors: Design and Performance

NBI, 8 September 2006 E. Gschwendtner, CERN 1

CNGS Secondary Beam Monitors:

Design and Performance

1. Design

2. Commissioning

3. Performance



Secondary Beam Design and Layout


43.4m100m

1095m 18m 5m 5m67m

2.7m

CNGS Secondary Beam Layout

TBID/2IonCh Muon Detectors

TBID: Target Beam Instrumentation Downstream IonCh: Ionization Chamber

Cross-hair/2IonCh

NBI, 8 September 2006 E. Gschwendtner, CERN 5Target magazine installation inside target station (25 Nov. 2005)

see Luca’s talk

Target

NBI, 8 September 2006 E. Gschwendtner, CERN 6Installation of the horn in the target chamber

Horn

see Stephane’s and Ans’ talk


Helium Tubes


Decay Tube

steel pipe 1mbar 994m long 2.45m diameter entrance window: 3mm Ti exit window: 50mm carbon steel,

water cooled

April 2004: vacuum tests ok


Shutter

Decay tube is closed with → 3mm Titanium window

Must be protected by a

‘shutter’ when access

→ Hardware Interlocked!!!


graphite

cooling modules

Hadron Stopfinished Sept. 2003

•Cooling modules: stainless steel tubes in Al blocks• Several temperature sensors (both in target chamber and in hadron stop)

Hadron Stop


Secondary Beam Instrumentation


TBID + 2 Ionization Chambers

TBID2 IonCh L/R

Purpose: Check efficiency with which protons are converted into

secondaries → Multiplicity (Compare with BFCT upstream of the target)

→ Misalignment of the Beam

2. Sec. Beam Instrumentation


TBID (Target Beam Instrumentation Downstream)

U

D

L R

L RBSPH BSPV

DUBSI BSH

BSPH Horizontal beam position

BSPHV Vertical beam position

BSIBeam intensity

BSHHalo foil .

TBID : Target Beam Instrumentation Downstream

L RU

D

BSI

Bias

Beam

TBID Monitor ● Secondary emission monitor● 12 µm Ti foils ● better than 10-4 mbar vacuum

2. Sec. Beam Instrumentation


TBID

TBID

Getter-pump

Ion-pump


TBID Monitor might not survive if high intensity beam misses the target

Ionization Chambers as back-up

SPS type BLM• N2 filled ionization chamber • Radius = 4.75 cm• Gap-width = 0.55 cm• 30 gaps• Bias: 800V-1500V

Ionization ChambersIonization Chambers in Target Chamber


Cross-Hair Monitors

beam

Cross-hair beam view(schematic)

Layout:• 4mm wide• appendix 10mm long• 20mm thick along the beam-axis•Beam 10mm off X-hair

Cross-Hairobserved by 2 IonCh L/R


Muon Monitors

Monitoring of: muon intensity muon beam profile shape muon beam profile centre

Muon intensity: Up to 7.7x107 per cm2 and 10.5µs

Dynamic range: 105

Accuracies: absolute 10 % relative 3 % reproducibility: cycle to cycle 1%,

one year 5%


Muon Monitor Layout

LHC type BLMs (Beam Loss Monitors for LHC) Parallel electrodes separated by 0.5 cm Stainless steel cylinder Al electrodes N2 gas filling at 100 mbar over pressure Diameter=8.9cm, length=60cm, 1.5 litre

37 fixed monitors (Ionization Chambers) 1 movable chamber behind fixed monitors

for relative calibration Movement by stepping motors

60cm


11.25cm

270cm


Secondary Beam Commissioning


beam

target horncollimator

Ionization Chambers

TBID

Target Region Layout

BPM2


Horizontal Beam Scan, Target Out

horizontal scan, no target

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

-8 -7.5 -7 -6.5 -6 -5.5 -5 -4.5 -4 -3.5 -3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10

mm BPG412444

BLM-L

BSI1

Reading from TBID and collimator’s ionization chambers vs. BPM2

pcollimatorBPM2

BPM2


vertical scan

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

-11 -11 -10 -9.5 -9 -8.5 -8 -7.5 -7 -6.5 -6 -5.5 -5 -4.5 -4 -3.5 -3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9

mm 412444

BSI1

BLM-L

Reading from TBID and collimator’s ionization chambers vs. BPM2

pcollimatorBPM2

BPM2

Vertical Beam Scan, Target Out


horizontal scan, target in original position

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

-5 -4.5 -4 -3.5 -3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7mm BPG412444

no

rm B

SI

Intensity on TBID vs. BPM2 position

BPM2

pTargetBPM2

Horizontal Beam Scan, Target IN


A.E. Ball et al. SL-2001-016-EA

target vs. horn misalignment: 3 mm 10.1 cm shift in Muon Pit16 mm 19.1 cm9 mm 24.3 cm

Target vs. Horn Alignment

Pit 1 Pit 2


0.14

0.19

0.24

0.29

0.34

0.39

-112.5 -101.3 -90 -78.75 -67.5 -56.25 -45 -33.75 -22.5 -11.25 0 11.25 22.5 33.75 45 56.25 67.5 78.75 90 101.25 112.5

cm

ch

arg

es

/po

t

target aligned with beam zero

target moved by 2mm upwards

Target vs. Horn Alignment

Muon pit 1: more sensitive to target vs. horn alignment

pTargetBPM2 Horn

pTarget HornBPM2

270cm


Vertical Beam vs. Target Alignment

0.004

0.006

0.008

0.01

0.012

0.014

-158 -146 -135 -124 -113 -101 -90 -78.8 -67.5 -56.3 -45 -33.8 -22.5 -11.3 0 11.3 22.5 33.8 45 56.3 67.5 78.8 90 101 113 124 135 146 158

cm

ch

arg

es

/po

t

0.5 mm-1.5 mm1 mmnominal, 0 mm

Muon pit 2: more sensitive to beam vs. target alignment


Final Alignment

HL

R

horn

1.9 mm

target

coll. =14 mm

BPM2

VU

D

horn

1.4 mm

target

coll. =14 mm

BPM2

2 mm

target ref. system

target ref. system

beam ref. system

beam ref. system


Horizontal Angular Scan, Target Out

horizontal muon detectors pit1, target out, horn/refl off, ~ 3E11 protons

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

0.05

-158 -146 -135 -124 -113 -101 -90 -78.8 -67.5 -56.3 -45 -33.8 -22.5 -11.3 0 11.25 22.5 33.75 45 56.25 67.5 78.75 90 101.3 112.5 123.8 135 146.3 157.5

cm

ch

arg

es/p

ot

0mrad

0.2mrad

0.25mrad

0.05mrad

-0.15mrad

-0.2mrad

-0.25mrad


Horizontal Angular Scan, Target Out

vertical muon detectors pit1, target out, horn/refl off, ~3E11 protons

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

0.05

-158 -146 -135 -124 -113 -101 -90 -78.8 -67.5 -56.3 -45 -33.8 -22.5 -11.3 0 11.25 22.5 33.75 45 56.25 67.5 78.75 90 101.3 112.5 123.8 135 146.3 157.5

cm

ch

arg

es/p

ot

0 mrad

0.2 mrad

0.25 mrad

0.05 mrad

-0.15 mrad

-0.2 mrad

-0.25 mrad


Horn/Reflector Timing Tests

beam

beam

horn pulse

reflector pulse

50ms

50ms


Horn/Reflector Timing Tests

timing tests horn/reflector

0

0.5

1

1.5

2

2.5

3

3.5

4

-2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4ms

cen

tral

mu

on

mo

nit

or

(ch

arg

es/p

ot)

horn on/refl on

horn on/refl off

horn off/refl on

Poly. (horn on/refl on)

Poly. (horn on/refl off)

Poly. (horn off/refl on)

10E-1


Comparison Nominal-Negative Polarity Ihorizontal pit1

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

-157.5 -146.3 -135 -123.8 -112.5 -101.3 -90 -78.75 -67.5 -56.25 -45 -33.75 -22.5 -11.25 0 11.25 22.5 33.75 45 56.25 67.5 78.75 90 101.25

112.5 123.75

135 146.25

157.5

cm

char

ges/

pot

nominal polarity

neg. polarity


Comparison Nominal-Negative Polarity IIvertical pit1

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

-157.5 -146.3 -135 -123.8 -112.5 -101.3 -90 -78.75 -67.5 -56.25 -45 -33.75 -22.5 -11.25 0 11.25 22.5 33.75 45 56.25 67.5 78.75 90 101.25 112.5 123.75 135 146.25 157.5

cm

char

ges/

pot

nominal polarity

neg. polarity


Comparison Nominal-Negative Polarity III

horizontal pit2

0.002

0.003

0.004

0.005

0.006

0.007

0.008

0.009

0.01

0.011

0.012

-157.5 -146.3 -135 -123.8 -112.5 -101.3 -90 -78.75 -67.5 -56.25 -45 -33.75 -22.5 -11.25 0 11.25 22.5 33.75 45 56.25 67.5 78.75 90 101.3 112.5 123.8 135 146.3 157.5

cm

charg

es/po

t

nominal polarity

neg. polarity

vertical pit2

0.002

0.003

0.004

0.005

0.006

0.007

0.008

0.009

0.01

0.011

0.012

-157.5 -146.3 -135 -123.8 -112.5 -101.3 -90 -78.75 -67.5 -56.25 -45 -33.75 -22.5 -11.25 0 11.25 22.5 33.75 45 56.25 67.5 78.75 90 101.3 112.5 123.8 135 146.3 157.5

cm

charg

es/po

t

nominal polarity

neg. polarity


unit 1 : polycrystalline graphite by Carbone-Lorraine 2020 PT density 1.76 g/cm3

unit 3: carbon-carbon composite by Carbone-Lorraine A035 density >1.75 g/cm3

Target Unit Tests


comparison target unit 1 and unit 3, average of 2 extractions, ~1.2E13 pot, hp1

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

-157.5 -135 -112.5 -90 -67.5 -45 -22.5 0 22.5 45 67.5 90 112.5 135 157.5cm

ch

arg

es

/po

t

unit 1

unit 3

comparison target unit 1 and unit 3, average of 2 extractions, ~1.2E13 pot, hp2

0

0.002

0.004

0.006

0.008

0.01

0.012

-157.5 -135 -112.5 -90 -67.5 -45 -22.5 0 22.5 45 67.5 90 112.5 135 157.5

unit 1

unit 3

Comparison Unit 1 and Unit 3

Muon pit 1

Muon pit 2

Average of 2 extraction, ~1.2E13 protons


PRELIMINARYmore on Friday, 8 Sept. (Edda’s talk)

Quality check – muon monitors(example: Pit 1 - horizontal plane)

data <> Fluka

3. Status


comparison measurement-simulation, horizontal pit1

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

-157.5 -146.3 -135 -123.8 -112.5 -101.3 -90 -78.75 -67.5 -56.25 -45 -33.75 -22.5 -11.25 0 11.25 22.5 33.75 45 56.25 67.5 78.75 90 101.25

112.5 123.75

135 146.25

157.5

cm

char

ges

/po

t

meas: nominal

sim: nominal

Comparison Meas.-Sim. I (Preliminary)

Muon Monitors, Horizontal Pit 1

■ Measurement■ Simulation

Fluka simulation; P. Sala et al


comparison measurement-simulation, vertical pit1

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

-157.5 -146.3 -135 -123.8 -112.5 -101.3 -90 -78.75 -67.5 -56.25 -45 -33.75 -22.5 -11.25 0 11.25 22.5 33.75 45 56.25 67.5 78.75 90 101.25

112.5 123.75

135 146.25

157.5

cm

char

ges

/po

t

meas: nominal

sim: nominal

Comparison Meas.-Sim. II (Preliminary)

Muon Monitors, Vertical Pit 1




comparison measurement-simulation, horizontal pit2

0.002

0.003

0.004

0.005

0.006

0.007

0.008

0.009

0.01

0.011

0.012

-168.8

-157.5

-146.3

-135 -123.8

-112.5

-101.3

-90 -78.75

-67.5 -56.25

-45 -33.75

-22.5 -11.25

0 11.25 22.5 33.75 45 56.25 67.5 78.75 90 101.3 112.5 123.8 135 146.3 157.5 168.8

cm

char

ges

/po

t

meas: nominal

sim: nominal

Comparison Meas.-Sim. III (Preliminary)

Muon Monitors, Horizontal Pit 2




comparison measurement-simulation, vertical pit2

0.002

0.003

0.004

0.005

0.006

0.007

0.008

0.009

0.01

0.011

0.012

-168.8

-157.5

-146.3

-135 -123.8

-112.5

-101.3

-90 -78.75

-67.5 -56.25

-45 -33.75

-22.5 -11.25

0 11.25 22.5 33.75 45 56.25 67.5 78.75 90 101.3 112.5 123.8 135 146.3 157.5 168.8

cm

char

ges

/po

t

meas: nominal

sim: nominal

Comparison Meas.-Sim. IV (Preliminary)

Muon Monitors, Vertical Pit 2




Secondary Beam Instrumentation Performance during Operation


Muon Monitor Repeatability

average muon monitor signal, ~1.5E12 protons, horizontal pit1

0.16

0.18

0.2

0.22

0.24

0.26

0.28

0.3

0.32

0.34

0.36

-150 -140 -130 -120 -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150

cm

char

ges/

pot

accuary < 1% !


TBID Performance

12

15

18

21

24

27

30

8/18/20060:00:00

8/19/20060:00:00

8/20/20060:00:00

8/21/20060:00:00

8/22/20060:00:00

8/23/20060:00:00

8/24/20060:00:00

8/25/20060:00:00

8/26/20060:00:00

8/27/20060:00:00

8/28/20060:00:00

8/29/20060:00:00

date

mu

ltip

lic

ity

0.00000001

0.0000001

0.000001

0.00001

0.0001

mb

ar

an

d c

ha

rge

s/p

ot/

10

00

multiplicity

TBID vacuum [mbar]

Ionization Chamber @ TBID * 1E-3


0.328

0.33

0.332

0.334

0.336

0.338

0.34

0.342

0.344

0.346

0.348

2E+12 3E+12 4E+12 5E+12 6E+12 7E+12 8E+12 9E+12 1E+13 1E+13 1E+13 1E+13 1E+13 2E+13 2E+13 2E+13 2E+13

proton on target/extraction

ch

arg

es/p

ot

(cen

tr. d

et.

pit

1)

0.002

0.004

0.006

0.008

0.01

0.012

0.014

0.016

0.018

0.02

0.022

ch

arg

es/p

ot

(cen

tr. d

et.

pit

2)

central detector pit1

central detector pit2

Muon Monitor Linearity

1.4E13 1.7E134E12 1.1E13


Summary

Detailed hardware commissioning ‘Dry runs’ paid off!

Hardly any problems with the control system Secondary beam line has been successfully commissioned

CNGS is operational

Now operational work starts: Performance studies, Systematics, etc………

Documents

CNGS Secondary Beam Monitors: Design and Performance