Status of Forward Calorimetry R&D: Report from the FCAL Collaboration

Status of Forward Calorimetry R&D: Report

from the FCAL Collaboration

Bruce A. SchummSanta Cruz Institute for Particle Physics

University of California, Santa Cruz

Americas Workshop on Linear Colliders

Fermi National Accelerator Laboratory

May 12-16, 2014

April 21, 2023 Detector Workshop Terascale 2

Example Very Forward Region of the ILD and a CLIC Detector

Optimisation of the design of the very forward region of LC detector •Precision luminosity measurement•Fast feedback and beam tuning•Detector hermeticityChallenge: Fast readout

(Wolfgang Lohmann)


Luminosity Measurement

• Precise measurement of the luminosity• (10-3 at ILC, 10-2 at CLIC)• Low angle physics• New challenge: Beamstrahlung

Gauge process for the luminosity measurement: Bhabha scattering

e+e- e+e- (

L = N /

Count Bhabha events

From theory

(Wolfgang Lohmann)


Beam Tuning and electron tagging

BeamCal (+Pair Monitor)• Fast luminosity estimate using beamstrahlung

(bunch-by-bunch at ILC)• Beam parameter estimation• Fast feedback to the machine• Low angle electron tagging

Beam parameter determination and fast feed-backBunch-by-bunch at ILC

(Wolfgang Lohmann)

AWLC-14 Fermilab 5Bruce Schumm

FCAL Collaboration Goals and Activities

FCAL aims to generate complete designs of both forward detection elements (LumiCal, BeamCal)

Challenges include: Alignment and precision, data throughput, radiation hardness

Current activities include

•Sensor development

•Prototypes for full beam testing

•Application-specific electronics development

•Alignment systems

•Radiation damage studies

•Simulation for instrumentation design and physics studies (not discussed here)


Sensors Development

Characterisation of a GaAs sensor on the probe-station

Silicon sensor prototype for LumiCal

p on n, strip pitch 1.8 mm

40 sensors available

Institutes: IFJ PAN Cracow, DESY, Tel Aviv (TAU)

Electrical characterization done, matches quality criteria

Compensated GaAs

Institutes: Tomsk, DESY-JINR collaboration (BMBF supported)

Electrical characterization at JINR and DESY, 30 sensors of sufficient quality

(Wolfgang Lohmann)


Heading

Oleksandr Borysov

20


Beam-test Results

Scan across a pad boundary

BeamCal sensor

LumiCal sensor

Wolfgang Lohmann


Heading

Oleksandr Borysov


Testbeam Prototype Structure Status and PLans

Oleksandr Borysov


Heading

Marek Idzik


Radiation Damage Studies

Marek Idzik


Heading Marek Idzik


Dedicated BeamCal Readout

• 180 nm TSMC technology• 10 bit SAR ADC • 4 channel version in summer 2014• Assembled sensor planes for beam tests after 2015

Wolfgang Lohmann

18

Mechanical aspects of LumiCal alignment

Leszek Zawiejski

19

The design of the LAS system The alignmen system may include two components: ● IR laser + PSD system:infra-red laser beam and semi-transparent position sensitive detectors ● FSI system: tunable laser(s), beam splitters, isolator, Fabry-Perot interferometer, retroreflectors, fibers, collimators, photodetectors, lens

FSI - Frequency Scanned Interferometry):The absolute distance measurements between LumiCal’s

IR Laser + PSDLeszek Zawiejski

20

Position Sensitive Detectors

Laser beam position measurements

An example: beam profile signals from the X-strips along the moving beam.The available aperture for laser beamis 5 x 5 mm2 for sensor. The mean positions mxi were obtained from a Gaussian fit to observed signals

Fluctuations increasing with distance along the laser beam. They can be related to:laser instability with an increase of beam diameter and noise of the sensor.Data from laser working since hours show smaller fluctuations

Light transmission: above 85% for > 780 nm

Leszek Zawiejski

21

Summary

● The accuracy received in preliminary measurements of the beam position was less than 20 micrometers, using the layout of 6 semi-transparent sensors. An improvement of the conditions of measurement (like thermal insulation) will lead to a smaller value.

● For beam test measurements and further development of the prototype a new complete system (PSD with readout and DAQ) seems to be necessary. Question is if this will be possible? Another option which can provide the measurement of transverse displacements is optical system RASNIK (Red Alignment System NIKHEF)

● FSI elements which recently were collected allow to build a simple prototype.The FSI studies will be continued after finished some tests performed by the producer for tunable laser.

● Several steps are planned during such studies, leading towards the final prototype.This will be continued inside the AIDA2 project.

Leszek Zawiejski


Radiation Damage Studies

SLAC Experiment T506: Electromagnetically-Induced Radiation Damage to Solid State Sensors

Tungsten

radiatorsSensor

Beam

Beam


Example Radiation Damage Result

Further T506 goals:•Explore different Si sensor technologies (p-type, float-zone•Explore GaAs sensors •Higher doses

• N-type bulk

• Magnetic Czochralski

• Exposures up to 220 mrad

• Including (accidental) annealing


Summary and Conclusions

Large, international group collaborating well towards development of forward calorimetry

Good progress towards prototype BeamCal and LumiCal systems

Challenging questions of alignment (prototype mechanical stack, alignment system development) and data rate (electronics development) being met

In good shape for potential drive to build detectors for a realized Linear Collider


Heading

Status of Forward Calorimetry R&D: Report from the FCAL Collaboration

Documents

Transcript of Status of Forward Calorimetry R&D: Report from the FCAL Collaboration