April 19, 2023 Snowmass Workshop

IP Instrumentation

Wolfgang Lohmann, DESY

Measurement of:

•Luminosity (precise and fast)

•Energy

•Polarisation

Precise Luminosity Measurement

e e e e

LumCal bgr

Bhabha

N NL

IP

VTX

FTD

300 cmBeamCal

L* = 4m

Accuracy (from Physics) O(<10-3)

4 4

4 4

( : / 3 10 ( ) 5.4 10 ( ))

( : / 6 10 ( ) 6.1 10 ( ))

OPAL L L stat theo

ALEPH L L stat theo

Gauge process: Bhabha ScatteringDevice: LumiCal 26 < < 82 mrad

Beampipe

Inner Radius of Cal.: < 4 μm

Distance between Cals.: < 100 μm

Radial beam position: < 0.6 mm

Requirements on Alignment

and mechanical Precision(MC simulations, BHLUMI)

LumiCal

LumiCalIP

Requirements on the Mechanical Design

< 4 μm

< 0.6 mm

410 0.2L

bmtilt mradL

Beam Tilt

Beam Size

No effect

)]}ln()([,0max{T

ibeami E

EEconstW

i

ii

W

WXX

Constant value))(_( radmean genrec

))(( rad

value of the constant

0.11e-3 rad

0.13e-3 rad

30 layers 15 rings

20rings

10ring

s

4 layers

15 layers

11 layers

10rings

Performance Simulations for e+e- e+e-()Event selection: acceptance, energy balance, azimuthal and angular symmetry.

Simulation: Bhwide(Bhabha)+CIRCE(Beamstrahlung)+beamspread

•More in the talks by Halina Abramowicz

20 mrad crossing angle

Beamstrahlung pair background

using serpentine field

0.E+00

1.E+09

2.E+09

3.E+09

4.E+09

5.E+09

6.E+09

8 9 10 11 12 13 14 15 16

R min (cm)

Nm

ber

of

Bh

abh

a ev

ets

per

yea

r

0

500

1000

1500

2000

2500

3000

3500

Bac

kgro

un

d (

GeV

)

Events per year

Background (GeV)

250 GeV

Number of Bhabha events as a function of the innerRadius of LumiCal

Background from beamstrahlung

A design for 20 mrad crossing angle will be done(needs time)

Decouple sensor framefrom absorber frame

Sensor carriers

Absorber carriers

Concept for the Mechanical Frame

Fast Lumi Measurement and Beam Diagnostics

Use Electrons from Rad. Bhabha events

Trajectories of off momentum electrons in the first dublett

Energy and spatial distributions

Fast Lumi Measurement and Beam Diagnostics

Needs a spectrometer

there

Fast Lumi Measurement and Beam Diagnostics

• 15000 e+e- per BX 10 – 20 TeV

(10 MGy per year)

• e+e- Pairs from Beamstrahlung are deflected into the BeamCal

GeV

• direct Photons for < 200 rad

Zero (or 2 mrad) crossing

angle

20 mradCrossing

angle

Beam Parameter Determination with BeamCal

total energyfirst radial momentthrust valueangular spreadL/R, U/D F/B asymmetries

Observables

QuantityNominal Value

Precision

x 553 nm 1.2 nm

y 5.0 nm 0.1 nm

z 300 m 4.3 m

y 0 0.4 nm

Beam Parameter Determination with BeamCal

zero or 2 mradCrossing angle

√s = 500 GeV

QuantityNominal Value

Precision

x 553 nm 4.8nm

y 5.0 nm 0.1 nm

z 300 m 11.5 m

y 0 2.0nm

Beam Parameter Determination with BeamCal

PRELIMINARY!

20 mrad crossing angle

total energyfirst radial momentthrust valueangular spreadL/R, U/D F/B asymmetries

Also simultaneous determination of several beam parameter is feasible, but: Correlations!Analysis in preparation

Observables

Beam Parameter Determination with BeamCal

Beam Parameter Determination with BeamCal

nominal setting(550 nm x 5 nm)

>100mIP

L/R, U/D F/B asymmetriesof energy in the angulartails

QuantityNominal Value

Precision

x 553 nm 4.2 nm

z 300 m 7.5 m

y 0 0.2 nm

Heavy gas ionisation Calorimeter

and with PhotoCalPhotons from Beamstrahlung

Heavy crystalsW-Diamond sandwich

sensorSpace for electronics

Technologies for the BeamCal:

•Radiation Hard

•Fast

•Compact

Detection of High Energy Electrons and Photons(Detector Hermeticity) √s = 500 GeVSingle Electrons of 50, 100 and 250 GeV, detection efficiency as a function of R (‘high background region’)(talk by V. Drugakov and P. Bambade)

Detection efficiency as a function of the pad-size (Talk by A. Elagin)

Message: Electrons can be

detected!

Red – high BGblue – low BG

Includes seismic motions, Delay of Beam Feedback System, Lumi

Optimisation etc.(G. White)

Efficiency to identify energetic electrons and photons(E > 200 GeV)

Fake rate

√s = 500 GeV

Realistic beam simulation

•Detection of High Energy Electrons and Photons

Sensor prototyping, Diamonds

ADC

Diamond (+ PA)

Scint.+PMT&

signal gate

May,August/2004 test beams

CERN PS Hadron beam – 3,5 GeV

2 operation modes:

Slow extraction ~105-106 / s

fast extraction ~105-107 / ~10ns (Wide range intensities)

Diamond samples (CVD):

- Freiburg

- GPI (Moscow)

- Element6

Pm1&2

Pads

Linearity Studies with High Intensities

(PS fast beam extraction)105 particles/10 ns

Response to mip

Diamond Sensor Performance

Upstream momentum spectrometer

ESA Test Beam Plans for 2005/2006

2x1010 electrons per bunch @ 28.5 GeV (ILC buch charge and length)Compare different measurments (this spectrometer,A- line BPMs, Synchrotron spectrometer)Accuracy goal: < 100 ppmProof of principle!

Energy Measurement

Downstream SR spectrometerEnergy spectrum

After bunch crossing

Goals: •peak position,•width, •tail

Downstream SR spectrometer

Downstream SR spectrometer

Upstream polarimeter

Polarimetry

250 GeV

25 GeV

45.59 GeV

K Moffeit 4 Apr 05

2 mradenergystripe

2 mradenergystripeBVX1

z=59.69 m

3 mradenergystripe

3 mradenergystripe

Shielding

Energy Chicane

Polarimeter Chicane

10 cm

10 meters

SynchrotronStripe Detector

SynchrotronStripe Detector

CerenkovDetector

Wiggler

Low Field

25.1 GeV

BVX2z=61.99 m

BLEXz=64.29 m

BLEXz=66.89 m

WEX1z=65.59 m

BVX3z=68.19 m

BVX4z=70.49 m

BVX5z=72.79 m

BVX6z=75.09 m

BLEXz=77.39 m

BLEXz=79.99 m

WEX1z=78.69 m

BVX7z=81.29 m

BPM BPM

BVX8z=83.59 m

BVX9z=100.59 m

BVY1z=120.59 m

BVY2z=132.59 m

BVY3z=152.59 m

Compton IP

17.8cm

QFX4z=156.59 m

35.7 GeV 12.0cm

Synchrotron StripeDetector z=143.69 m

Document on polarimetry design in Feb 2006

+ Downstream polarimeter

The needs from Detector and Machine side are different. Lets find solutions