Looking for Dark Matter with Olivine
Sebastian Baum
1806.05991 1811.06844 1811.10549 1906.05800
2004.08394 2106.06559 2107.02812
with++Andrzej Drukier, Katie Freese, Maciej Górski & Patrick Stengel
Tom Edwards, Bradley Kavanagh & Christoph Weniger
Johnathon Jordan, Paola Sala, Joshua Spitz
Will DeRocco & Saarik Kalia+

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Can old rocks teach us about the history of ourGalaxy and what makes up our Universe?

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

2100 Myr old mineral
samples from the rightgeological environments

Imaged with modern
nanometer-resolution
microscopy

Can old rocks teach us about the history of ourGalaxy and what makes up our Universe?

What was the Milky Way’s starformation rate 500 million
years ago?

Sebastian Baum|2022-08-09

What is Dark Matter?

| Frontier of Understanding Earth's Interior and Dynamics

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Dark Matter - the missing 85%

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Dark Matter - the missing 85%

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Weakly Interactive Massive Particle (WIMP) DMDark Matter could be made up of new particles
with mass comparable to ordinary atomic nuclei,and feeble interactions with ordinary matter.

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Direct Detection of Dark Matter
WIMP

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Direct Detection of Dark Matter[LZ collaboration]

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics8

# of recoils ∝ exposure = (target mass) ⨉ (time)

1987: 750 g of Ge

2022: 8 tonnes of Xe[XENON collaboration][Ahlen+ ‘87, Avignone+ ‘86]

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Solid State (Nuclear) Track Detectors (SSTDs)
Fission fragment tracks
in synthetic Mica, TEM

Fossil Tracks inMadagascar Phlogopite;
optical microscopy after
chemical etching.

[Price&Walker ‘63]

[Price&Walker ‘63]

Sebastian Baum|2022-08-09

High-resolution TEM| Frontier of Understanding Earth's Interior and Dynamics[Toulemonde+ ‘06]
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Paleo-Detectors● Many (natural) minerals are good SSTDs(need to be insulator or poor semiconductor)

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

14Paleo-Detectors● Many (natural) minerals are good SSTDs(need to be insulator or poor semiconductor)● Once created, damage tracks can be preserved for ≫ 109 years

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

15Paleo-Detectors● Many (natural) minerals are good SSTDs(need to be insulator or poor semiconductor)● Once created, damage tracks can be preserved for ≫ 109 years● Natural minerals are as old as ~ 109 years

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

16Paleo-Detectors● Many (natural) minerals are good SSTDs(need to be insulator or poor semiconductor)● Once created, damage tracks can be preserved for ≫ 109 years● Natural minerals are as old as ~ 109 years● Modern microscopy technology allows for nanometer-scale resolution!

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

17Paleo-Detectors● Many (natural) minerals are good SSTDs(need to be insulator or poor semiconductor)● Once created, damage tracks can be preserved for ≫ 109 years● Natural minerals are as old as ~ 109 years● Modern microscopy technology allows for nanometer-scale resolution!

Exposure through time
100 g ⨉ 1 Gyr = 10 kilotonne ⨉ 10 yr

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

18Paleo-Detectors● Many (natural) minerals are good SSTDs(need to be insulator or poor semiconductor)● Once created, damage tracks can be preserved for ≫ 109 years● Natural minerals are as old as ~ 109 years● Modern microscopy technology allows for nanometer-scale resolution!

Exposure through time
100 g ⨉ 1 Gyr = 10 kilotonne ⨉ 10 yr≲ keV recoil thresholds
Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Backgrounds, Backgrounds, Backgrounds● Cosmogenic

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Backgrounds, Backgrounds, Backgrounds● Cosmogenic
Exponentially suppressed with depth*:
Depth [km]2567

Neutron flux [1/cm2/Gyr]

106

100

100.1Note, that storage close to the surface until read-out is ok:
Depth [m]

100

250

500

Neutron flux [1/cm2/yr]

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82*Neutron production from atmospheric neutrinos
becomes relevant at depths larger than ~ 6 km
Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Backgrounds, Backgrounds, Backgrounds● Cosmogenic ➝ use target samples from deep underground

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Backgrounds, Backgrounds, Backgrounds● Cosmogenic ➝ use target samples from deep underground● Radioactivity

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Backgrounds, Backgrounds, Backgrounds● Cosmogenic ➝ use target samples from deep underground● Radioactivity○Get radiopure samples

Rock forming minerals
TypeMarine Evaporites

ExamplesFormed from Crust

Formed from Mantle

Quartz, Feldspar,
Mica

Olivine,Nchwaningite

Gypsum, Halite

10-6 (ppm)

10-10 (0.1 ppb)

10-11 (0.01 ppb)

238

U level(in weight)[SB+ 1906.05800]
Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Backgrounds, Backgrounds, Backgrounds● Cosmogenic ➝ use target samples from deep underground● Radioactivity ➝ get radiopure samples (containing hydrogen)Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Backgrounds, Backgrounds, Backgrounds● Cosmogenic ➝ use target samples from deep underground● Radioactivity ➝ get radiopure samples (containing hydrogen)● Neutrinos ➝ background or signal?

[NASA/CXC/SAO][NASA / SDO / Seán Doran]
Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Backgrounds vs Dark Matter

𝜎𝑝SI = 10-43 cm2
𝜎𝑝SI = 10-46 cm2

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Read-Out Methods (i): X-ray Ptychography[Schaff+ ‘15]

Single “pixel” ofsample

Sebastian Baum|2022-08-09

Combine “pixels”
into 2D picture

Reconstruct 3D image
from 2D pictures| Frontier of Understanding Earth's Interior and Dynamics

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Read-Out Methods (i): X-ray Ptychography● 16 nm isotropic 3D resolution demonstrated!
● Requires synchrotron light source[Holler+ ‘14 ]160

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Read-Out Methods (ii): He-Ion Beam Microscopy[van Gastel+ 12]

backscatteredHe+

Sebastian Baum|[Carl Zeiss]secondaryelectrons2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Read-Out Methods (ii): He-Ion Beam Microscopy
Edge of graphite flake

Sebastian Baum|2022-08-09[Hill+ ‘12 ]| Frontier of Understanding Earth's Interior and Dynamics

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Read-Out Methods (ii): He-Ion Beam Microscopy
Overview & Zoom-in of rodent kidney

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics[Hill+ ‘12 ]32

Dark Matter Sensitivity Projections“High-Resolution” read-out: ●●●●Sebastian Baum

1 nm spatial resolution
Exposure: (10 mg) x (1 Gyr)

Halite -- NaCl
Gypsum -- Ca(SO4)•2(H2O)|

2022-08-09● Olivine -- Mg1.6Fe0.4(SiO4)● Phologopite --KMg3AlSi3O10F(OH)| Frontier of Understanding Earth's Interior and Dynamics

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Dark Matter Sensitivity Projections“High-Exposure” read-out:●●Sebastian Baum●●15 nm spatial resolution
Exposure: (100 g) x (1 Gyr)

Halite -- NaCl
Gypsum -- Ca(SO4)•2(H2O)|

2022-08-09● Olivine -- Mg1.6Fe0.4(SiO4)● Phologopite --KMg3AlSi3O10F(OH)| Frontier of Understanding Earth's Interior and Dynamics

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Switching gears...

Guaranteed signals!

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

35Paleo-Detectors for Galactic Supernovae[NASA/CXC/SAO]

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Measuring the Galactic Supernova Rate?
[SB+ 1906.05800]

Detectable with
sufficiently radiopureminerals!

● Halite -- NaCl
● Epsomite -- MgSO4•7(H2O)
Sebastian Baum|2022-08-09● Olivine -- Mg1.6Fe0.4(SiO4)● Nchwaningite -- Mn2SiO3(OH)2•(H2O)| Frontier of Understanding Earth's Interior and Dynamics

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Beyond the rate: Time-varying Signals[SB, DeRocco, Edwards, Kalia, 2107.02812]

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Learning about the Time-Dependence of the SN rate?
[SB+ 1906.05800]

Epsomite -- MgSO4•7(H2O)
Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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What About a Little More Energetic Neutrinos?

[Gaisser&Honda ‘02]

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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What About a Little More Energetic Neutrinos?

𝜈𝜈/ℓ±[Gaisser&Honda ‘02]

[Jordan, SB+ 2004.08394]

Halite -- NaCl

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Cosmic Rays & Atmospheric Neutrinos
Halite -- NaCl

[Jordan, SB+ 2004.08394]

Background Free Signal Regions!

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Cosmic Rays & Atmospheric Neutrinos
Could we learn about the rate ofcosmic rays hitting Earth goingback one billion years?
[Jordan, SB+ 2004.08394]

50% drop over 1 Gyr
100% enhancementfor 100 Myr

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Feasibility studies by Shigenobu Hirose @ JAMSTEC

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Feasibility studies by Tatsuhiro Naka @ Toho U

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Learning about this Universe from Rocks● Old (10 Myr – 1 Gyr) rocks store information about nuclear recoils○ Large age brings large exposure: 100 g x 1 Gyr = 100 kt yr!
○ Read-Out promising thanks to modern nano-technology■ nuclear recoil energy thresholds of 0.1 – 1 keV?
● Reading out a time-series of rocks, one could measure thetime-dependence of signals over 10 Myr – 1 Gyr scales!

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Track Formation
Thermal Spike [Seitz ‘49]

[Skupiński, ‘06]
Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Track Formation
Ion Explosion Spike [Fleischer,Price,Walker ‘65]

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Ion Range Calculations
Semi-analytic treatment

SRIM[Wilson,Haggmark,Biersack +76]
Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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From Recoil Energies to Track Length

Energy loss due to● Electronic stopping(off electron clouds)● Nuclear stopping(off other nuclei)

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Radioactive Backgrounds: Single-𝛼238

𝛼UeVk2

7234

ThVeM
2.

4

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Background Interlude: Neutrons
Spontaneous Fission(𝛼, n)-reactions

238

U~2 neutrons with ~ MeV energies

Rare process, but the number of
𝛼-particles is about 107 times larger
than the number of SF events[Drukier, SB+ 1811.06844]
Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Background Interlude: Moderating Neutrons with H

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Neutrons from Atmospheric Neutrinos[Aharmim+ ‘09]

muons from atmospheric neutrinos
w/o (w) neutrino oscillations

cosmic-ray muons(@ 6 km w.e)

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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[SB+ ‘19 (1811.06844) ]Dark Matter Against The Rest
High-Resolution read-out● 1 nm spatial resolution● Exposure: (10 mg) x (1 Gyr)Sebastian Baum|2022-08-09

Low-Resolution read-out● 15 nm spatial resolution● Exposure: (100 g) x (1 Gyr)

| Frontier of Understanding Earth's Interior and Dynamics

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Backgrounds vs Supernova Neutrinos
Epsomite -- MgSO4•7(H2O)

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Sensitivity Projections: SD Proton-Only[SB+ ‘19 (1811.06844) ]Good resolution, small target mass
● 1 nm spatial resolution● Exposure: (10 mg) x (1 Gyr)

Larger target mass, worse resolution● 15 nm spatial resolution● Exposure: (100 g) x (1 Gyr)

Borax -- Na2(B4O5)(OH)2•8(H2O)
Mirabilite -- Na2SO4•10(H2O)

Nchwaningite -- Mn2SiO3(OH)2•(H2O)
Phlogopite -- KMg3AlSi3O10F(OH)

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Robustness Against Errors in Background Shape“High Resolution”

Sebastian Baum|2022-08-09“High Exposure”| Frontier of Understanding Earth's Interior and Dynamics

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DM sensitivity for different radiopurities“High Resolution”

Sebastian Baum|2022-08-09“High Exposure”| Frontier of Understanding Earth's Interior and Dynamics

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Measuring the Dark Matter mass
[Edwards, SB+ 1811.10549]

Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Digging a Signal out of the Background“High Resolution”

Sebastian Baum|2022-08-09“High Exposure”| Frontier of Understanding Earth's Interior and Dynamics

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What has changed?
Fission fragment tracks
in synthetic Mica, TEM

High-resolution TEM
pictures of ion tracks
Pb on Mica
Xe on Y3Fe5O12[Price&Walker ‘63]
Sebastian Baum|2022-08-09[Toulemonde+ ‘06]

| Frontier of Understanding Earth's Interior and Dynamics

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Read-Out Methods: Optical Microscopy
Etched fission tracks in Apatitetransmissionreflection● Widely available● Cheap● Resolutions of a few
100 nm● Requires etching[Thomson ‘16]
Sebastian Baum|2022-08-09| Frontier of Understanding Earth's Interior and Dynamics

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Read-Out Methods: Confocal Microscopy
𝛼-tracks in Al2O3:C,Mg (without etching!)
Single picture

Longest projection of 3D

2 𝜇m[Kouwenberg+ ‘18]●●●

Sebastian Baum|2022-08-09

Widely available
Resolution ~100 nm
Requires fluorescent targets| Frontier of Understanding Earth's Interior and Dynamics

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