CYGNUS Update Directional WIMP Detector Vision reminder - - PowerPoint PPT Presentation

• Vision reminder
• Sensitivity and cost studies
• Some R&D

Special thanks to Sven Vahsen, Ciaran O’Hare and many others for contributions to the slides

CYGNUS Update

Neil Spooner (for CYGNUS), University of Sheffield

Directional WIMP Detector

CYGNUS Vision

A multi-site Galactic Nuclear Recoil Observatory

Probe Dark Matter below the Neutrino Floor Measure 8B solar neutrinos with directionality Extend searches to low mass with electron and nuclear recoils

CYGNUS Science

this is an old plot!

exposure

• Search for low WIMP mass
• Nuclear recoils AND
• Electron recoils
• Observe galactic dipole,

directionality

• Detecting solar neutrinos
• Penetrate the neutrino floor
• Measure DM particle

properties and physics

• Measure Geoneutrinos
• WIMP Astronomy
• Coherent neutrino-nucleus scattering 


CYGNUS Collaboration

• Most groups working on directional dark

matter detection have formed CYGNUS

• Members from the Australia, China, Italy,

Japan, Spain, UK, US etc (25 institutes)

• Includes activity in Emulsions and TPC gas

technology (focus in this talk on TPCs)

2007 Boulby, UK 2009 MIT, US 2011 Modane, France 2013 Toyama, Japan 2015 Los Angeles, USA 2017 JinPing, China 2018 l’Aquila, Italy 2019 Rome, Italy

• CYGNUS evolved

from a series of directional workshops

June 2018 l’Aquila, Italy

Steering group:

• Neil Spooner (Sheffield, UK)
• Sven Vahsen (Hawaii, USA)
• Kentaro Miuchi (Kobe, Japan)
• Elisabetta Baracchini (GSSI/INFN, Italy)
• Greg Lane (ANU, Australia)

CYGNUS Collaboration

• Most groups working on directional dark

matter detection have formed CYGNUS

• Members from the Australia, China, Italy,

Japan, Spain, UK, US etc (25 institutes)

• Includes activity in Emulsions and TPC gas

technology (focus in this talk on TPCs)

2007 Boulby, UK 2009 MIT, US 2011 Modane, France 2013 Toyama, Japan 2015 Los Angeles, USA 2017 JinPing, China 2018 l’Aquila, Italy 2019 Rome, Italy

• CYGNUS evolved

from a series of directional workshops

June 2018 l’Aquila, Italy

TPC working groups

Engineering (T. Baroncelli, Melbourne, Australia) Simulations (S. Vahsen, Hawaii, USA) Neutrons (E. Baracchini, Frascati, Italy) Gas R&D (K. Miuchi, Kobe, Japan) Calibrations (E. Baracchini, Frascati, Italy) Steering (N. Spooner, Sheffield, UK)

CYGNUS: Gas TPC Concept

• Gas Mixtures: SF6:He, p ~1atm, CF4:SF6:He etc
• Can switch between higher density (search

mode) and lower density gas for (improved) directional confirmation of WIMP signal

• Threshold at <1 keVe
• Use of high gain stages
• Ultimate is W~30 eV
• Reduced diffusion via -ve ion drift
• 3D Fiducialisation
• SF6 minority carriers
• charge cloud profile
• He target
• Improved sensitivity to low mass WIMP
• Longer recoil tracks, extending directionality to lower energies
• Reasonable detector volumes (10 m3 to 1000 m3)
• Active electron rejection at ~GeV

New CYGNUS Funding

New CYGNUS Funding

JAPAN CYGNUS-KM 1m3 funded

New CYGNUS Funding

JAPAN CYGNUS-KM 1m3 funded AUSTRALIA new $5M Stawell site pending ARC $9M

New CYGNUS Funding

JAPAN CYGNUS-KM 1m3 funded AUSTRALIA new $5M Stawell site pending ARC $9M new €2M ERC new €0.2M INFN ITALY

Scale of DRIFT-II (with all shielding) CYGNUS 10 (~10 m3) ?

Stawell site, CYGNUS

Australia

• Funded, at ~1.6 km depth
• First in southern hemisphere

Italy - CYGNO

Italy - CYGNO

CYGNUS-KM and Kobe-Sheffield

• Collaboration between Kobe and Sheffield funded for

travel by JSPS and the UK Royal Society

• Aims to apply Kobe electronics to new charge readout

techniques for directional dark matter detection

PhD Students: Warren Lynch, Callum Eldridge, Rob Gregorio

ThGEM prototype (Sheffield group)

Penetrating the Neutrino Floor

• Directionality significantly

enhances the DM sensitivity below neutrino floor

• 3D again “best”
• But note:
• True Figure of Merit: 


sensitivity / unit cost

• A realistic detector has

strongly energy-dependent

• directionality. This was not

considered in past studies.

Readout strategies for directional dark matter detection beyond the neutrino background Ciaran A. J. O'Hare, Anne M. Green, Julien Billard, Enectali Figueroa-Feliciano, Louis E. Strigari

Ciaran A. J. O'Hare

simulated examples of a 20 keV electron track after 25 cm of drift

• Simulations work by Hawaii (shown here), Sheffield, Kobe,
• Many types of readout possible - parallel routes need:

Challenge is to find Optimum Readout Approach

SRIM (modified), Degrad, GEANT4…

• R&D on readout by all groups

Sensitivity per Unit Cost

‹#›

Paper…

• Can we do electron - nuclear recoil

discrimination in the low WIMP mass region (<10 GeV)?

• What is the discrimination power in

this region?

• What are the intrinsic

backgrounds?

• What is the possible directional

sensitivity in this region?

• What is the cost vs sensitivity

trade-off?

Cost benefit comparison of readout technology, 1D, 2D, 3D, strip, pixel etc…

“Feasibility of a Nuclear Recoil Observatory with Directional Sensitivity to WIMPs and Solar Neutrinos”

Feasibility of a Nuclear Recoil Observatory with Directional Sensitivity to WIMPs and Solar Neutrinos

• B. Simpson1

Abstract Now that conventional WIMP dark matter searches are approaching the neutrino floor, there has been a resurgence of interest in the possibility of introducing recoil direction sensitivity into the field. Such directional sensitivity would

• ffer the powerful prospect of reaching below this floor, introducing both the possibility of identifying a clear signature

for dark matter particles in the galaxy below this level but also of exploiting observation of coherent neutrino scattering from the Sun and other sources with directional sensitivity. We survey the experimental status of all technologies proposed to date, and perform a cost-benefit analysis to identify the optimal choice in different WIMP and neutrino

• scenarios. Based on our findings, we propose a large-scale directional nuclear recoil observatory with directional

WIMP sensitivity below the neutrino floor and capability to explore Solar neutrino coherent scattering with direction sensitivity Keywords: keyword1, keyword2 Contents 1 Introduction 3 2 Science Case for a large Nuclear Recoil Observatory 3 2.1 WIMP Scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1.1 WIMP scattering review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1.2 Galactic signal detection below the neutrino floor . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1.3 WIMP astrophysics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1.4 Particle models and directionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.2 Solar Neutrino Coherent Scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.2.1 Solar neutrino scattering review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.2.2 Advantages of directional detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.2.3 Science with source and detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.3 Other Physics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.3.1 Non-solar neutrinos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.3.2 Axions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.3.3 Exotic models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3 Existing Directional Detection Technologies 7 3.1 Detectors that reconstruct the recoil track . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1.1 Gas-based TPCs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1.2 Nuclear Emulsions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1.3 DNA strand detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.1.4 Planar targets (graphene) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.2 Detectors that indirectly determine the recoil direction . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.2.1 Anisotropic scintillators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.2.2 Columnar recombination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Prototypes, Experiments, R&D….

Name Technology Directionality Status NEWAGE Gas TPC, strip readout 3d Running underground DRIFT Gas TPC, NID, wire readout 1.5d Running underground MIMAC Gas TPC, strip readout 3d Ran underground, scaling up DMTPC Gas TPC, optical readout 2d Ran underground, scaled up, stopped D3 / Hawaii readout R&D Gas TPC, pixel readout 3d Prototypes evaluated, ran above-ground New Mexico readout R&D Gas TPC, NID, optical readout 2d Prototypes evaluated LEMON, ORANGE, INITIUM, CYGNO Gas TPCs, CMOS + PMT optical readout 3d Prototypes evaluated, funded to scale up NEWSdm Nuclear Emulsions 2d Prototyping / going underground PTOLEMY Graphene 2d Prototyping / going underground

All directional that have set limits use <=1m3 gas TPCs NEWAGE: best limit using directionality DRIFT: best limit with a directional detector Sheffield R&D…….

(i) GEM-wire hybrid, (ii) micromegas-strip, (iii) gas/radon….

GEM-Wire 2D-HT hybrid Readout

• What is the simplest possible readout that might just work?

(Sheffield group)

Board produced by Quick Circuits UK, 35 x 35 cm to fit CYGNUS-KM vessel

Solder pads vertically separated by 600 microns and staggered to help with soldering the wires in place Hole to place 10 cm diameter THGEM:

• 600 micron pitch
• 400 micron width

New Scale-up Design Test

600 microns position resolution

Setup

1 mm spacing between THGEM and wires. 0.6 mm spacing between wires. x2 9-pin D-sub feedthroughs 18 wires each grounded via 1 Mohm resistor.

THGEM- wire readout Cathode Field Ring 9 cm 1 cm 1 cm

Setup

Am241 source located behind shutter. Cremat pre-amps and shapers (16 in total)

Setup

Card-edge connector ( 5145154-8) THGEM (10 cm diameter) Cremat pre-amp and shaper 100 MΩ Wires grounded via SMC cable LAB VIEW DAQ (Max channels 16) Array of 18 wires

Wire Connections

Adapter board 2x 9-pin D-SUB feedthroughs INSIDE VESSEL OUTSIDE VESSEL

SF6 15 Torr Alpha Signal Showing -ve ion Delay

2 Channels removed due to electronic noise.

Readout A Readout B Cathode

CYGNUS 10m3 - Sheffield R&D…….

2.2 m

10-1 100 101 102 103 104 10-47 10-46 10-45 10-44 10-43 10-42 10-41 10-40 10-39 10-38 10-37 10-36 10-35 10-34

• 10m3 SF6:He
• Thin central cathode
• Charge readout, head-tail
• Water block shielding

DRIFT-II with water blocks

• Possible Boulby site

UNM thin cathode in DRIFT

DRIFT Lives! (yesterday)

Simulations

• Measure spatial ionisation

distribution resulting from nuclear recoils

• Advantages:

• Technologically

challenging, but now achievable via multiple technologies

• Axial Directionality

• Head/tail

• Background rejection 

• Particle ID

• 3D fiducialization

Sven Vahsen et al. (Hawaii)

SRIM (modified), Degrad, GEANT4…

‹#›

Input Parameters: Diffusion, gain etc Readout

• Sven Vahsen (Hawaii, USA)

‹#›

Simulations

‹#›

Simulations

F He

• Lower is better
• Detector is pressure/diffusion

limited

• F: bad
• He: better
• Pixels close to optimal
• Strips not bad

preliminary

Example Results: Axial Vector Angular Resolution

• Sven Vahsen (Hawaii, USA)

Example Results: 3D Electron Rejection Factors

• Nice!
• Gets somewhat worse

after diffusion

• Algorithm can be

much improved - BDT etc

F He

preliminary

• Sven Vahsen (Hawaii, USA)
• Potential for 104

discrimination at O(1 keV)?

Example Results: Backgrounds

Sensitivity per Unit Cost

Conclusion/recommendation: build a 1000 m3 detector with strip readout for $35M

preliminary

10-1 100 101 102 103 104 10-47 10-46 10-45 10-44 10-43 10-42 10-41 10-40 10-39 10-38 10-37 10-36 10-35 10-34

• 3 years of running time • 3 keVr F threshold • 1 keVr He threshold
• Directional mode (20 torr SF6 740 torr He4) • Search mode (200 torr SF6 560 torr He4)

thanks to Ciaran O’Hare

CYGNUS SD Sensitivity - 1000m3

preliminary

10-1 100 101 102 103 104 10-51 10-50 10-49 10-48 10-47 10-46 10-45 10-44 10-43 10-42 10-41 10-40 10-39 10-38 10-37 10-36

CYGNUS SI Sensitivity - 1000m3

preliminary

The Neutrino Floor

• Reminder of the task

Solar Neutrino Coherent Rates

Louis E. Strigari arXiv: 0903.3630v2

1keVrec threshold —> ~70 events per ton year 10m3 SF6 at 200 torr for 3 years operation yields 4 neutrinos.

Hartlepool Estimates

Callum Eldridge

Fluorine in SF6 at 10m from a single reactor Electron and nuclear recoils c.f solar

Boulby Opportunities for DM

• WATCHMAN includes two 7-8m dia. x 7-8m ht. high purity water tanks

Conclusions

• The directional community has expanded to form a collaboration -

CYGNUS - a global directional network

• Much recent progress on many key technical issues
• Help us proceed to build the next phase - towards neutrinos