The DarkLight experiment - Thomas Jefferson National...

The DarkLight experiment

Jan C. Bernauer

APEX collaboration meeting, April 2015

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CollaborationR. Alarcon, D. Blyth, R. Dipert, L. Ice, G. Randall

Arizona State University, Phoenix, AZ

B. Dongwi, N. Kalantarians, M. Kohl, A. Liyanage, J. Nazeer

Hampton University, Hampton, VA

S. Benson, J. Boyce, D. Douglas, P. Evtushenko, C. Hernandez-Garcia, C. Keith,

C. Tennant, S. Zhang

Thomas Jefferson National Accelerator Facility, Newport News, VA

J. Balewski, J. Bernauer, J. Bessuille, R. Corliss, R. Cowan, C. Epstein, P. Fisher*, D. Hasell,

E. Ihloff, Y. Kahn, J. Kelsey, R. Milner*, S. Steadman, J. Thaler, C. Tschalär, C. Vidal

MIT, Cambridge, MA

M. Garçon

CEA Saclay , Gif-sur-Yvette, France

R. Cervantes, K. Dehmelt, A. Deshpande, N. Feege

Stony Brook University, Stony Brook, NY

B. Surrow

Temple University, Philadelphia, PA

To come: Johannes Gutenberg University, Mainz, Germany

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Current and future exclusion limitscurrent future

invi

sible

visib

le

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Design goals

Measure e−+p −→ e−+p +A′ −→ e−+p + (e+ +e−)100 MeV beam =⇒ below pion threshold, simple finalstateComplete reconstruction of final state: e+e−pair fromdecay, scattered electron, recoil proton=⇒ large acceptance=⇒ proton only has 1-5 MeV =⇒ gas targetResolution of reconstructed A′ of 1-3 MeVFinal state leptons 10-100 MeV =⇒multiple scatteringdominant =⇒minimize material0.5 Tesla solenoidal magnet for momentummeasurement and to bottle up Møller electronsDefinitive measurement in about 1 month: highluminosity: 10 mA @ 1019 Atoms/cm2

=⇒ JLAB LERF world’s only such accelerator

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JLab LERF

Low Energy Recirculating FacilityEnergy recovering linacup to 10 mA @ 100 MeVMegawatt beam

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Successful beam test July 2012

Target systemdesigned andconstructed atMIT-Bates R&E

center

4.3 mA, 100 MeV (430 kWatt beam power) transmittedthrough 2 mm hole, 127 mm longMaximum loss of 3 ppm in 7 hoursERL has required stability

Phys. Rev. Lett. 111, 165801 (2013)Nucl. Instr. Meth A729, 233 (2013)Nucl. Instr. Meth. A729, 69 (2013)

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Phased approach

Phase 1Accelerator studiesMeasure SM physics / detector testPilot DM search

Phase 2Full DM searchInvisible searchFull streaming readout

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J. Balewski et al., arXiv:1412.4717 [physics.ins-det]

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Detector setup

Procured existing magnet0.5 Tesla max fieldInner diameter 712mmNow at MIT-Bates

Hydrogen gas targetThickness: 1019 Atoms/cm2

2mm apertures to limit flowMultiple stages of pumping1mm thin berrylium pipeInvestigating jet target

12 ladders, 6 sensors each300 µm thicknessExperience from STAR IST

Thin, high rate capableCylindrical detectorspossible

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Solenoid magnet

TargetProton silicondetectorLepton tracker4 layers MicroMegasDesign is still in flux!

Detector setup

Procured existing magnet0.5 Tesla max fieldInner diameter 712mmNow at MIT-Bates

Hydrogen gas targetThickness: 1019 Atoms/cm2

2mm apertures to limit flowMultiple stages of pumping1mm thin berrylium pipeInvestigating jet target

12 ladders, 6 sensors each300 µm thicknessExperience from STAR IST

Thin, high rate capableCylindrical detectorspossible

10

Solenoid magnet

TargetProton silicondetectorLepton tracker4 layers MicroMegasDesign is still in flux!

Detector setup

Procured existing magnet0.5 Tesla max fieldInner diameter 712mmNow at MIT-Bates

Hydrogen gas targetThickness: 1019 Atoms/cm2

2mm apertures to limit flowMultiple stages of pumping1mm thin berrylium pipeInvestigating jet target

12 ladders, 6 sensors each300 µm thicknessExperience from STAR IST

Thin, high rate capableCylindrical detectorspossible

11

Solenoid magnetTarget

Proton silicondetectorLepton tracker4 layers MicroMegasDesign is still in flux!

Detector setup

Procured existing magnet0.5 Tesla max fieldInner diameter 712mmNow at MIT-Bates

Hydrogen gas targetThickness: 1019 Atoms/cm2

2mm apertures to limit flowMultiple stages of pumping1mm thin berrylium pipeInvestigating jet target

12 ladders, 6 sensors each300 µm thicknessExperience from STAR IST

Thin, high rate capableCylindrical detectorspossible

12

Solenoid magnetTarget

Proton silicondetectorLepton tracker4 layers MicroMegasDesign is still in flux!

Detector setup

Procured existing magnet0.5 Tesla max fieldInner diameter 712mmNow at MIT-Bates

Hydrogen gas targetThickness: 1019 Atoms/cm2

2mm apertures to limit flowMultiple stages of pumping1mm thin berrylium pipeInvestigating jet target

12 ladders, 6 sensors each300 µm thicknessExperience from STAR IST

Thin, high rate capableCylindrical detectorspossible

13

Solenoid magnetTargetProton silicondetector

Lepton tracker4 layers MicroMegasDesign is still in flux!

Detector setup

Procured existing magnet0.5 Tesla max fieldInner diameter 712mmNow at MIT-Bates

Hydrogen gas targetThickness: 1019 Atoms/cm2

2mm apertures to limit flowMultiple stages of pumping1mm thin berrylium pipeInvestigating jet target

12 ladders, 6 sensors each300 µm thicknessExperience from STAR IST

Thin, high rate capableCylindrical detectorspossible

14

Solenoid magnetTargetProton silicondetector

Lepton tracker4 layers MicroMegasDesign is still in flux!

Detector setup

Procured existing magnet0.5 Tesla max fieldInner diameter 712mmNow at MIT-Bates

Hydrogen gas targetThickness: 1019 Atoms/cm2

2mm apertures to limit flowMultiple stages of pumping1mm thin berrylium pipeInvestigating jet target

12 ladders, 6 sensors each300 µm thicknessExperience from STAR IST

Thin, high rate capableCylindrical detectorspossible

15

Solenoid magnetTargetProton silicondetectorLepton tracker4 layers MicroMegas

Design is still in flux!

Detector setup

Procured existing magnet0.5 Tesla max fieldInner diameter 712mmNow at MIT-Bates

Hydrogen gas targetThickness: 1019 Atoms/cm2

2mm apertures to limit flowMultiple stages of pumping1mm thin berrylium pipeInvestigating jet target

12 ladders, 6 sensors each300 µm thicknessExperience from STAR IST

Thin, high rate capableCylindrical detectorspossible

16

Solenoid magnetTargetProton silicondetectorLepton tracker4 layers MicroMegas

Design is still in flux!

Detector setup

Procured existing magnet0.5 Tesla max fieldInner diameter 712mmNow at MIT-Bates

Hydrogen gas targetThickness: 1019 Atoms/cm2

2mm apertures to limit flowMultiple stages of pumping1mm thin berrylium pipeInvestigating jet target

12 ladders, 6 sensors each300 µm thicknessExperience from STAR IST

Thin, high rate capableCylindrical detectorspossible

17

Solenoid magnetTargetProton silicondetectorLepton tracker4 layers MicroMegasDesign is still in flux!

Kinematics

, Can detect full final state, Large acceptance/ How to trigger?

Signal tracks do not reach beyond lepton trackerCan not identify reaction on trigger levelCan not trigger on ”3 particles”: background tohigh

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Background rates: Elastic scattering

90 patchesindependent2D strip readout>20 tracks every 25 ns frame

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Normal electronics

Trigger

APV

64..256 Channels

ADC

APV/DREAM/... multiplex N channels to 1 ADCTheoretical maximum readout rate: 1/N of ADC clock

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Streaming front end electronics: NSA Scale

ADCADCADCADCADCADCADCADC

FPGA

Continuous readout80k ch, 40 MSps @ 12 bit =⇒ 4.8 Terabyte/s∼ 80 M ch, 40 KSps=⇒Listening to every German citizen in CD quality.Zero suppression: 250 Gigabyte/s

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Streaming back end electronics

Transport data from FEE to CPU farmSolve transposition problem (”Event building”)

Data aggregated per channelMust be processed by time slice

Common problem at intensity frontier

Solve once and reuseOpen design

wire protocolhardware

Use standard hardware

cheapereasier to extend

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Streaming back end electronics

Transport data from FEE to CPU farmSolve transposition problem (”Event building”)

Data aggregated per channelMust be processed by time slice

Common problem at intensity frontier

Solve once and reuseOpen design

wire protocolhardware

Use standard hardware

cheapereasier to extend

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Phase 1

Beryllium −→ Aluminum pipeCylindrical MicroMegas −→ planar GEMsOnly one proton detector ladderOnly partial streaming readout

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Phase 1 current design

proton, pT = 8 MeV

e−, pT = 20 MeV

e+, pT = 30 MeV

e−, pT = 10 MeV

Tripple coincidence to select QED background / A′

candidate events at reasonable ratesInvestigate if we can run double coincidenceRun APV in quasi-streaming mode - free runningtrigger, mutiple frames

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Summary

Phase 1:

Proof of target conceptSM processes: Møller, elastic scatteringDM search mock upPrototyping of streaming readoutWill run 2016

Phase 2:

Full acceptance with full streaming readoutVisible and invisible search

Low energy, intense beam physics

Intense Electron Beams WorkshopCornell University, June 17-19, 2015

http://www.classe.cornell.edu/NewsAndEvents/IEBWorkshop

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Backup slides

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Current status: Hardware

Xilinx Virtex-7 development board: VC 707XC7VX485T-2FFG1761Gigabit Ethernet + SFP/SFP+FMC connectors

TI ADS5295 evaluation module + adapter board8 channels80 MSPS / 12 bit

Signed up for Xilinxuniversity program

XUP donatedhardware &software

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Current status: Hardware

Xilinx Virtex-7 development board: VC 707XC7VX485T-2FFG1761Gigabit Ethernet + SFP/SFP+FMC connectors

TI ADS5295 evaluation module + adapter board8 channels80 MSPS / 12 bit

Signed up for Xilinxuniversity program

XUP donatedhardware &software

29

Current status: Hardware

Xilinx Virtex-7 development board: VC 707

XC7VX485T-2FFG1761Gigabit Ethernet + SFP/SFP+FMC connectors

TI ADS5295 evaluation module + adapter board

8 channels80 MSPS / 12 bit

Signed up for Xilinxuniversity program

XUP donatedhardware &software

30

Current status: FPGA firmware

Milestones:SetupEthernet send/receive

OSI layer 2

Readout of ADC:

Full data of 1 ch.8 ch. with zerosuppression

Planned:

Partial streamingreadout for DL phase 1Full streaming readoutfor DL phase 2

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Current status: FPGA firmware

Milestones:SetupEthernet send/receive

OSI layer 2

Readout of ADC:

Full data of 1 ch.8 ch. with zerosuppression

Planned:

Partial streamingreadout for DL phase 1Full streaming readoutfor DL phase 2

32

Current status: FPGA firmware

Milestones:SetupEthernet send/receive

OSI layer 2

Readout of ADC:

Full data of 1 ch.8 ch. with zerosuppression

Planned:

Partial streamingreadout for DL phase 1Full streaming readoutfor DL phase 2

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