Ken Moffeit BDIR Session

6-10 November 2006 Ken Moffeit, ILC GDE Valencia 1

Performance of Extraction Line Energy Spectrometers and Polarimeters at 500 GeV and 1 TeV Center-of-Mass Collision Energy

Ken Moffeit BDIR SessionInternational Linear Collider (ILC) Workshop

( ILC-ECFA and GDE Joint Meeting ) Valencia, 6-10 November 2006

Ken Moffeit, Takashi Maruyama, Yuri Nosochkov, Andrei Seryi and Mike Woods SLAC

William P. OliverTufts University

Eric TorrenceUniversity of Oregon


14 mrad Extraction Line

250 GeV

2 mrad energystripe

2 mradenergy stripe

BVEX1Ez=46.782 m

SynchrotronRadiation Shielding

for Cerenkov Detectorz=164.25

y=12.25cm

Energy Chicane Polarimeter Chicane

10 cm

10 meters

Synchrotron StripeDetector

z=147.682x=0 y= -19.85

Cerenkov Detectorz= ~175 m

Wiggler Magnets

25.1 GeV

BVEX2Ez=49.082 m

WEX1z=52.682 m

BVEX3Ez=55.282 m

BVEX4Ez=57.582 m

BVEX5Ez=59.882 m

BVEX6Ez=62.182 m

WEX2z=65.782 m

BVEX1Pz=120.682 m

BVEX2Pz=140.682 m

BVEX3Pz=152.682m

BVEX4Pz=172.682 m

Compton IP

31.2 GeV

Synchrotron StripeDetector z= 147.682 m

x=0 y=15.3cm

VacuumChamber

VacuumChamber

Synchrotron Radiation limit toCherenkov Detector

14

cm

17

.8 c

m

QDEX1Az=6.0 m

QDEX1Bz=7.941 m

QFEX2Az=9.881 m

QFEX2Bz=15.5 m

QFEX2Cz=17.943 m

QFEX2Dz=20.386 m

QDEX3Az=22.829 m

QDEX3Bz=25.235 m

QDEX3Cz=27.641 m

QDEX3Dz=30.047 m

QDEX3Ez=32.453 m

QFEX4Az=34.858 m

QFEX4Bz=37.103 m

QFEX4Cz=39.348 m

QFEX4Dz=41.593 m

IP

-0.75mrad

0.75mrad

QFEX4Ez=43.838 m

BVEX7Ez=68.382 m

BVEX1Ez=70.682 m


2 mrad Extraction LinePolarimeter Chicane

Plan View

10 m

10 cm

BHEX2z=163.778 mx=80.38 cm

BHEX2z=166.077 mx=81.63 cm

Angle2.0 mrad at IR

QEX1Az=34.6799 mx=14.98 cm

QEX1Bz=37.9798 mx=16.81 cm

BHEX1z=44.580 mx=20.45 cm

Angle -3mrad

5 cm

-5 cm

0Angle 3

mrad

ElevationView

QEX3z=127.678mx=62.24 cm

QEX3z=130.978 mx=63.902 cm

Beam StayClear +- 7.5 cm

Photon BeamstrahlungCone

+- 0.5 mrad

Energy Chicane

Wiggler

QEX4z=138.778 mx=67.820 cm

-10 cm

10 cm

2 mrad extraction line

Angle 5.023 mrad

BYCHICz=66.179 mx=31.351 cm

Angle3 mrad

17.8

cm

CherenkovDetector

25.1 GeV

Dispersion = 69mm250 GeV

QF1z=15.868 m

x=0 cm

HCOLL+-7.5cm

z=61.57 mx=29.041 cm

VCOLL+-1.2cm

z=61.87 mx=29.191 cm

BYCHICz=68.48 m

x=32.507 cm

BYCHICz=70.78 m

x=33.662 cm

BYCHICMz=89.179 mx=42.905 cm



VCOLL2+-5cm

z=95.779 mx=46.220 cm

Dispersion = 69 cm250 GeV

VCOLL+-7.5cm

z=153.578 mx=75.254 cm

ECOLL0+-7.5 cm

z=240.276 mx=129.471 cm

HCOLL2+-5 cm

z=118.479 mx=57.623 cm

BYCHICz=119.079 mx=57.924 cm

BYCHICz=121.379 mx=59.080 cm

BYCHICz=123.679 mx=60.235 cm

QEX4z=142.078 mx=69.478 cm

QEX4z=145.378 mx=71.135 cm

QEX4z=148.678 mx=72.793 cm

QEX5z=159.778 mx=78.369 cm

QEX5z=156.478 mx=76.711 cm

Angle 5.740 mrad

Angle 6.458 mrad




BYENEz=169.078 mx=83.492 cm

BYENEz=171.378 mx=84.977 cm

BYENEz=173.678 mx=86.463 cm

BYENEMz=192.077 mx=98.345 cm

BYENEMz=194.377 mx=99.830 cm

BYENEMz=196.677 mx=101.315cm

BYENEMz=198.977 mx=102.801cm

BYENEMz=201.277 mx=104.286cm

BYENEMz=203.577 mx=105.771cm

Angle-3 mrad

Wiggler

BYENEz=221.977 mx=117.653cm

BYENEz=224.277 mx=119.138cm

BYENEz=226.577 mx=120.624cm

Wiggler

BHEX3z=240.876 mx=129.858cm

BHEX3z=243.176 mx=131.199cm

BHEX3z=245.476 mx=132.283cm

BHEX3z=247.776 mx=133.110cm

ECOLL0+-7.5 cm

z=240.276 mx=129.471

cm

Photon BeamstrahlungCone

+- 0.5 mrad

BYPOLz=250.776 mx=133.822cm

BYPOLz=253.076mx=134.282cm

BYPOLMz=260.776 mx=135.822cm

BYPOLMz=263.076mx=136.282cm

BYPOLMz=273.076 mx=138.282cm

BYPOLMz=275.376mx=138.742cm

BYPOLz=283.076 mx=140.282cm

BYPOLz=285.376mx=140.742cm

12.3

cm

35 GeV

Angle2.0 mrad

Compton IPz=269.076mx=137.482cm

BHEX4z=289.376 mx=141.542cm

Dispersion = 20 mm250 GeV

ComptonIP

Shielding

QD0z=4.5 mx=0 cm

SD0z=8.19 mx=0 cm

SF1z=18.38 m

x=0 cm

Angle 5.523 mrad

3.68 mrad5.0 mrad

3.54 mrad

Synchrotron Stripe Detectorz=269.076 my= -28.7 cm

Synchrotron Stripe Detectorz=269.076 my= 12.7 cm

Angle-2 mrad

Angle2 mrad

Synchrotron StripeDetectors


Disrupted beam events were taken from files prepared by Andrei Seryi.

The extraction line transport is simulated using the program GEANT

Name File x

(nm)

y

(nm)

z

(nm)

E (Mean)(GeV)

E (RMS)(GeV)

Normal ILC cs21 554 3.5 300 475.5 40.72

Large-y cs23 367 7 600 463.0 47.54

Large-y dy=4nm

cs23_dy4 461.5 48.23

Large-y dx=200nm

cs23_dx200

464.4 46.38

Low Power cs24 350 2.7 200 439.6 73.94


0.5 TeV CMS 1 TeV CMS


0.5 TeV CMS 1 TeV CMSNormal ILC Beam


2mrad

Compton IP

14 mradCompton IP z=147.682 m

-2.019<y<-1.999 cmabs(x)<0.01cm

0.01-0.01 0

-2.0

-2.01

-2.02

X (cm)

Y (

cm)

137.46137.44

16682/34883 (47.8%) beamtracks are within +/- 100 microns

Compton IP z=269.07 mabs(y+2)<0.01 cm

abs(x-137.45)<0.01cm

4407/30000 (14.7%) beamparticles are within +/- 100 microns

-1.99

-2

-2.01

137.45

0.5 TeV CMS

Dispersion = -2 cm Dispersion = -1 cm

Beam within +-100 microns of the peak


Nor

mal

ILC

Bea

m

Larg

e-y

Larg

e-y

dx20

0nm

Larg

e-y

dy4n

m

Low

Pow

er

Nor

mal

ILC

Bea

m

Larg

e-y

Larg

e-y

dx20

0nm

Larg

e-y

dy4n

m

Low

Pow

er

1 TeV 14mrad Extraction Line

0

10

20

30

40

50

0 1 2 3 4 5 6

% B

eam

wit

hin

+-1

00m

icro

ns


0

10

20

30

40

50

0 1 2 3 4 5 6%

Bea

m w

ith

in +

-100

mic

ron

s

0.5 TeV 14 mrad Extraction Line

0

10

20

30

40

50

0 1 2 3 4 5 6

% B

eam

wit

hin

+-1

00 m

icro

ns


0

10

20

30

40

50

0 1 2 3 4 5 6

% B

eam

wit

hin

+-1

00 m

icro

ns


bendbendspin

GeVEgP

44065.0

)(cos

2

2coscos

IRanglextedosityWeighSpinLutedosityWeighLu

GeVECosCosP

2

1

44065.0

)(minmin

%84.99min tedosityWeighLuP %80.99min tedosityWeighLuP

P=99.81% P=99.81%P=99.86% P=99.82%

0.5 TeV CMS50 rad bend gives 56.7 mrad change in spin direction and P= 99.84% at 500GeV


0.5 TeV CMS 1 TeV CMS

Beam accepted within +-100 microns about the peak and polarization projection



Polarization at Compton IP within 0.21% of the Luminosity weighted Polarization



99

99.25

99.5

99.75

100

0 1 2 3 4 5 6

Po

lari

zati

on

(%

)

No

rma

l IL

CB

ea

m

La

rge

-y

La

rge

-y d

x20

0n

m

La

rge

-y d

y4n

m

Lo

w P

ow

er

Luminosity WeightedPolarization at IR

Polarization Projectionat Compton IP


99

99.25

99.5

99.75

100

0 1 2 3 4 5 6

Po

lari

zati

on

(%

)


99

99.25

99.5

99.75

100

0 1 2 3 4 5 6

Po

lari

zati

on

(%

)


99

99.25

99.5

99.75

100

0 1 2 3 4 5 6

Po

lari

zati

on

(%

)

No

rma

l IL

CB

ea

m

La

rge

-y

La

rge

-y d

x20

0n

m

La

rge

-y d

y4n

m

Lo

w P

ow

er

Polarization at Compton IP within 0.21% of the Luminosity weighted Polarization

0.25%


0.5 TeV CMS

2 mrad Crossing Angle Extraction Line


Condition (file name) Losses # Beam Lost Beam

Nominal Beam Condition (cs11)cs11 tail1 < 0.65E0 or angle > 500mrad

54604

348831.8*106

1.4*10-4

2.6*10-4

Large y (cs13) 32 34907 9.2*10-4

Large y horizontal offset 200nm (cs13_dx200) 32 34898 9.2*10-4

Large y vertical offset 4nm (cs13_dy4) 29 34923 8.3*10-4

Low Power (cs14) 437 34913 1.25%

Condition (file name) Losses # Beam Lost Beam

Normal ILC Beam Condition (cs11)cs11 tail1 < 0.65E0 or angle > 500mrad

00

348831.8*106

<0.5*10-4

<10-7

Large y (cs13) 0 34907 <0.5*10-4

Large y horizontal offset 200nm (cs13_dx200) 0 34898 <0.5*10-4

Large y vertical offset 4nm (cs13_dy4) 0 34923 <0.5*10-4

Low Power (cs14) 4 34913 1.1*10-4

from the e+e- IR to the Compton Detector Plane

Beam Losses



14 mrad Crossing Angle Extraction LineCondition (file name) Losses Beam Lost Beam


057

299213.2* 106

<0.6 * 10-4

1.8 * 10-5

Large y (cs23) 3 29916 1.0 * 10-4

Large y horizontal offset 200nm (cs23_dx200) 2 29918 0.7 * 10-4

Large y vertical offset 4nm (cs23_dy4) 3 29928 1.0 * 10-4

Low Power (cs24) 186 34905 0.53 %

Condition (file name) Losses Beam Lost Beam


26128,263

349073.9* 106

0.75 %0.72 %

Large y (cs23) 494 34901 1.42 %

Large y horizontal offset 200nm (cs23_dx200) 355 34904 1.02 %

Large y vertical offset 4nm (cs23_dy4) 507 34915 1.45 %

Low Power (cs24) 2545 34905 7.29 %

1 TeV CMSfrom the e+e- IR to the Compton Detector Plane

Beam Losses


Estimate ~460 photons/cm2 are in the region of the Cherenkov counter cells for each bunch of 2*1010 electrons. Spectrum of photons mainly below 10 MeV

14 mrad extraction line loss of 1.8*10-5 of the 3.2

million original beam tracks

2 mrad extraction line loss of 0.72% of the 3.92

million original beam tracks

Compton Signal ~650 backscattered electrons per GeV or >1000 per 1cm cell

No background in region of Cerenkov Detector per 3.2*10 6 beam particles

Beam Loss Background at Cherenkov Detector


Synchrotron Radiation


14 mrad Crossing Angle Extraction Line 0.5 TeV CMS

2 mrad Crossing Angle Extraction Line 0.5 TeV CMS

Condition (file name) Energy Loss (MeV)

Energy Loss (MeV) for E>240GeV

Nominal Beam Condition (cs11) 117 120

Large y (cs13) 121 125

Large y horizontal offset 200nm cs13dx200

121 124

Large y vertical offset 4nm cs13dy4 121 125

Low Power (cs14) 117 126

Energy Loss from Synchrotron Radiation between the e+e- IR and the Center of the Energy Chicane

Condition (file name) Energy Loss (MeV)

Energy Loss (MeV) for E>240GeV

Nominal Beam Condition (cs11) 829 851

Large y (cs13) 831 852

Large y horizontal offset 200nm (cs13_dx200)

806 827

Large y vertical offset 4nm (cs13_dy4) 832 854

Low Power (cs21) 802 862

0.5 TeV CMS



14 mrad Crossing Angle Extraction Line 1 TeV CMS

2 mrad Crossing Angle Extraction Line 1 TeV CMS

Condition (file name) Energy Loss (GeV)

Energy Loss (GeV) for

E>480 GeV

Nominal Beam Condition (cs21) 1.70 1.83

Large y (cs23) 1.71 1.86


1.72 1.87

Large y vertical offset 4nm cs23dy4 1.70 1.85

Low Power (cs24) 1.56 1.87

Condition (file name) Energy Loss (GeV)

Energy Loss (GeV) for

E>480 GeV

Nominal Beam Condition (cs21) 12.37 13.13

Large y (cs23) 12.16 13.08


11.75 12.71

Large y vertical offset 4nm cs23dy4 12.04 12.99

Low Power (cs24) 11.62 13.16

Energy Loss from Synchrotron Radiation between the e+e- IR and the Center of the Energy Chicane



1 TeV CMS

0.5 TeV CMS


1.6*106 /cm2 photons >15MeV per 2*1010 electrons

1 TeV CMS

0.5 TeV CMS 0.1*106 /cm2 photons >15MeV per 2*1010 electrons

Scattered synchrotron radiation photons give background in the region of the Cherenkov detector

<104/cm2 photons per 2*1010 electrons

<2*104 /cm2 photons >15MeV per 2*1010 electrons


Conclusions14 mrad extraction line0.5 TeV CMS•Performance of Energy Spectrometer and Polarimeter Meets Goals1 TeV CMS•Performance of Energy Spectrometer and Polarimeter Meets Goals•Large background from scattered synchrotron radiation photons at the Cherenkov Detector•Concern about large beam losses for Low Power beam parameters

2 mrad extraction line0.5 TeV CMS•Performance of Energy Spectrometer and Polarimeter Meets Goals•Large background from scattered synchrotron radiation photons at the Cherenkov Detector•Concern about large beam losses for Low Power beam parameters1 TeV CMS•Performance of Polarimeter Meets Goals for Normal ILC Beam Parameters•Performance of Energy Spectrometer does not meet goals•Large background from scattered synchrotron radiation photons at the Cherenkov Detector•Extreme concern about very large beam losses


•Core of beam within +-100microns has 48% of the beam.

•The polarization projection at the Compton IP is in good agreement with the luminosity weighted polarization at the e+e- interaction region. A precision measurement of +-0.25% will be possible.

•No beam losses from e+e- IR to Compton detector plane out of 17.6 million beam tracks for Normal ILC and Large-y beam parameter data sets. The Low Power beam parameter data set has losses of 1.1 * 10-4.

•Beam energy loss due to synchrotron radiation to the middle of energy chicane (z=59.7 m) is ~120 MeV and shows small variations of less than 10 MeV with different beam parameter conditions for the disrupted beam.

•The collimator at z=164.25 meters needs to be designed. It absorbs the synchrotron radiation above the 0.75 mrad beam stay clear allowing the Cherenkov detector to begin at y~14 cm. Background from scattered synchrotron radiation occurs at the Cherenkov detector and will require careful design of the collimation and shielding.

Conclusions14 mrad extraction line 0.5 TeV CMS

•Performance of Energy Spectrometer and Polarimeter Meets Goals


•Core of beam within +-100microns has 43% of the beam. The large-y and low power parameter data sets have a lower Compton luminosity by a factor 2.


Beam losses of 1.8*10-5 occur between the e+e- IR and the Compton detector plane for the Normal ILC beam parameter data set. Beam losses are also small but not negligible for the Large-y beam parameter data set. There are large losses of 0.53% of the beam for the Low Power beam parameter data set that will require insertion of a new collimator between the e+e- IR and the Compton detector plane or an increase in the beam stay clear from 0.75 mrad.

•Both the Normal ILC and Large-y beam parameter data sets have beam energy losses of ~1.70 GeV due to synchrotron radiation in the magnets between the e+e- IR and the middle of energy chicane with variations less than 20 MeV. The Low Power beam parameter data set has beam energy loss due to synchrotron radiation of 1.56 GeV or 140 MeV less than the other data sets. This is due to the larger beamstrahlung energy tail having smaller synchrotron radiation losses. Measuring the high energy part of the beam energy spectrum will allow the energy loss due to synchrotron radiation to be understood to the precision required.

•The collimator at z=164.25 meters absorbs the synchrotron radiation above the 0.75 mrad beam stay clear allowing the Cherenkov detector to begin at y~14 cm. Background from scattered synchrotron radiation is very large at the Cherenkov detector and will require careful design of the collimation and shielding (<2*104 /cm2 photons >15MeV per 2*1010 electrons).

1 TeV CMS14 mrad extraction line

•Performance of Energy Spectrometer and Polarimeter Meets Goals•Large background from scattered synchrotron radiation photons at the Cherenkov Detector•Concern about large beam losses for Low Power beam parameters


•There are large beam losses between e+e- IR and Compton detector plane (>2.6*10-4 are lost) giving secondary backgrounds of mainly photons in the region of the Cherenkov Detector. The Low Power beam parameter data set has beam losses ~ 1.25% giving very large backgrounds at the Cherenkov detector. •A small percentage of beam is hit by laser spot +-100 microns (~15%) at the Compton IP and results in low Compton luminosity.


•There are large beam energy losses (~850 MeV) due to synchrotron radiation between IR and the center of the energy chicane at z=198.82 meters. Beam collision jitter in the horizontal plane of 200 nanometers gives changes in the beam energy loss due to synchrotron radiation of ~25 MeV comparable to the goal of the precision measurement of the energy.

•Synchrotron radiation at Cherenkov Detector is favorable. The detector only sees the synchrotron radiation from the magnets of the polarimeter chicane, and this is contained between -9 and +2 cm. The first cell of the Cherenkov Detector starts at +10 cm. Background from scattered synchrotron radiation occurs at the Cherenkov detector and will require careful design of the collimation and shielding (0.1*106 /cm2 photons >15MeV per 2*1010 electrons).

2 mrad extraction line 0.5 TeV CMS

•Performance of Energy Spectrometer and Polarimeter Meets Goals•Large background from scattered synchrotron radiation photons at the Cherenkov Detector•Concern about large beam losses for Low Power beam parameters


•There are large beam losses between the e+e- IR and the Compton detector plane (0.74% of the beam is lost for the Normal ILC beam parameter data set) giving secondary backgrounds of mainly low energy photons with energy <10 MeV. For the Low Power beam parameter data set 7.3% of the beam is lost giving large backgrounds at the Cherenkov detector.

•At the Compton IP only 18.9% of the beam with Normal ILC beam parameters is contained within +-100microns of the peak giving a lower luminosity for Compton scattering of the laser light on the disrupted electron beam.

The polarization measurement at the Compton IP is within the desired precision of +- 0.25% of the estimated luminosity weighted polarization.

There are large beam energy losses (12.4 GeV) due to synchrotron radiation between IR and the center of the energy chicane at z=198.82 meters. Beam collision jitter in the horizontal plane of 200 nanometers gives large variations in the beam energy loss due to synchrotron radiation of ~450 MeV. The collision offset data from instruments near the e+e- interaction region can be used to reduce the uncertainty in the synchrotron radiation loss due to horizontal jitter.

Synchrotron radiation at Cherenkov Detector is favorable, but, scattered synchrotron radiation photons give large background in the region of the Cherenkov detector (1.6*106 /cm2 photons >15MeV per 2*1010 electrons).

2 mrad extraction line 1 TeV CMS

•Performance of Polarimeter Meets Goals for Normal ILC Beam Parameters•Performance of Energy Spectrometer does not meet goals•Large background from scattered synchrotron radiation photons at the Cherenkov Detector•Extreme concern about very large beam losses

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Ken Moffeit BDIR Session

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