Dan ClaesUniversity of Nebraska-Lincoln

Messages From Deep SpaceDeep Underground

The Henderson Mine ProjectThursday, December 15, 2005

Henri Becquerel (1852-1908) received the 1903 Nobel Prize in Physics for the discovery of natural radioactivity.

Wrapped photographic plate showed clear silhouettes, when developed, of the uranium salt samples stored atop it.

1896 While studying the photographic images of various fluorescent & phosphorescent materials, Becquerel finds potassium-uranyl sulfate spontaneously emits radiation capable of penetrating thick opaque black paper

aluminum plates copper plates

Exhibited by all known compounds of uranium (phosphorescent or not) and metallic uranium itself.

•In ordinary photographic applications light produces spots of submicroscopic silver grains•a fast charged particle can leave a trail of individual Ag grains

•1/1000 mm (1/25000 in) diameter grains

•plates coated with thick emulsions (gelatins carrying silver bromide crystals) clearly trace the tracks of charged particles

1898 Marie Curie discovers thorium (90Th) Together Pierre and Marie Curie discover polonium (84Po) and radium (88Ra)

1899 Ernest Rutherford identifies 2 distinct kinds of rays emitted by uranium - highly ionizing, but completely

absorbed by 0.006 cm aluminum foil or a few cm of air

- less ionizing, but penetrate many meters of air or up to a cm of

aluminum.

1900 P. Villard finds in addition to rays, radium emits - the least ionizing, but capable of penetrating many cm of lead, several feet of concrete

B-fieldpoints

into page

1900-01 Studying the deflection of these rays in magnetic fields, Becquerel and the Curies establish rays to be charged particles

1900-01 Using the procedure developed by J.J. Thomson in 1887 Becquerel determined the ratio of charge q to mass m for

: q/m = 1.76×1011 coulombs/kilogram identical to the electron!

: q/m = 4.8×107 coulombs/kilogram 4000 times smaller!

Hess lands following a historic 5,300 meter flight.August 7, 1912 National Geographic photograph

1911-12 Austrian physicist Victor Hess, of the Vienna University, and 2 assistants, carried Wulf ionization chambers up in a series of hydrogen balloon flights.

• taking ~hour long readings at several altitudes

• both ascending and descending• radiation more intense above 150 meters than at sea level• intensity doubled between 1000 m to 4000 m• increased continuously through 5000 meters

Dubbed this “high” level radiation Höhenstrahlung

50m

Cosmic ray strikes a nucleuswithin a layer of

photographicemulsion

1937 Marietta Blau andHerta Wambacher

report “stars” of tracks resulting from cosmic

ray collisions with nuclei within the emulsion

1936 Millikan’s group shows at earth’s surface cosmic ray showers are dominated by electrons, gammas, and

X-particles capable of penetrating deep underground (to lake bottom and deep tunnel experiments) and yielding isolated single cloud chamber tracks

primary proton

The Cosmic Ray Energy SpectrumCosmic Ray Flux

Energy (eV)

(1 particleper m2-sec)

(1 particleper

m2-year)

(1 particle per km2-year)

Colliding galaxies

Active galacticnucleus

Two possible sources of the highest energy cosmic rays

m2

Before the explosion:

vo = 0

m1

v1 v2

Mass, M

After the explosion:

p = 0 pgas procket

pi = 0 = pf pgas = – procket= pgas + procket

A cannon rests on a railroad flatcar with a total mass of 1000 kg. When a 10 kg cannon ball is fired at a speed of 50 m/sec, as shown, what is the speed of the flatcar?

A) 0 m/sB) ½ m/s to the rightC) 1 m/s to the leftD) 20 m/s to the right

For these two vehicles to be stopped dead in

their tracks by a collision at this intersection

A) They must have equal massB) They must have equal speedC) both A snd BD) is IMPOSSIBLE

650 kg10 m/sec

500 kg20 m/sec

Car A has a 650 kg mass and is traveling east at 10 m/sec. Car B has a 500 kg mass and is traveling north 20 m/sec. The two cars collide, and lock bumpers. Neglecting friction which arrow best represents the direction the combined wreck travels?

A B

C

A bomb at rest explodes into four fragments. The momentum vectors for three of the fragments are shown. Which arrow below best represents the momentum vector of the fourth fragment?

?

?

-decay

-decay

E = mc2

Some Alpha Decay Energies and Half-lives

Isotope KE(MeV) 1/2 (sec-1)

232Th 4.01 1.41010 y 1.61018

238U 4.19 4.5109 y 4.91018

230Th 4.69 8.0104 y 2.81013

238Pu 5.50 88 years 2.51010

230U 5.89 20.8 days 3.9107

220Rn 6.29 56 seconds 1.2102

222Ac 7.01 5 seconds 0.14216Rn 8.05 45.0 sec 1.510

212Po 8.78 0.30 sec 2.310

216Rn 8.78 0.10 sec 6.910

B

Before decay:

After decay:

Potassium nucleus

A

1930 Series of studies of nuclear beta decay, e.g.,

Potassium goes to calcium 19K40 20Ca40

Copper goes to zinc 29Cu64 30Zn64 Boron goes to carbon 5B12 6C12 Tritium goes to helium 1H3 2He3

1932 Once the neutron was discovered, included the more fundamental

n p + e

For simple 2-body decay, conservation of energy and momentum demand both the recoil of the nucleus and energy of the emitted electron be fixed (by the energy

released through the loss of mass) to a single precise value.

but this only seems to match the maximum value

observed on a spectrum of beta ray energies!

Ee = (mA2 - mB

2 + me2)c2/2mA

No.

of

cou

nts

per

un

it e

ner

gy r

ange

Electron kinetic energy in KeV5 10 15 200

The beta decay spectrum of tritium ( H He). Source: G.M.Lewis, Neutrinos (London: Wykeham, 1970), p.30)

Energy spectrum of betadecay electrons from 210Bi

Kinetic energy, MeV

Inte

nsity

-decay spectrum for neutrons

Electron kinetic energy in MeV

dE

d

1932 n p + e +

charge 0 +1 1 ?mass 939.56563 938.27231 0.51099906 MeV MeV MeV

neutrino mass < 5.1 eV < me /100000

???neutrino

0?

the Fermi-Kurie plot.

The Fermi-Kurie plotlooks for any gap between

the observed spectrumand the calculated Tmax

spin ½½ ½ ?

<0.78232 MeV

0

½

Niels Bohr hypothesized some new quantum mechanical restriction on the principle of energy conservation, but Pauli couldn’t buy that:

Wolfgang Pauli1900-1958

Dear Radioactive Ladies and Gentlemen, as the bearer of these lines, to whom I graciously ask you to listen, will explain to you in more detail, how because of the "wrong" statistics of the N and Li6 nuclei and the continuous beta spectrum, I have hit upon a desperate remedy to save the "exchange theorem" of statistics and the law of conservation of energy. Namely, the possibility that there could exist in the nuclei electrically neutral particles, that I wish to call neutrons, which have spin 1/2 and obey the exclusion principle and which further differ from light quanta in that they do not travel with the velocity of light. The mass of the neutrons should be of the same order of magnitude as the electron mass and in any event not larger than 0.01 proton masses. The continuous beta spectrum would then become understandable by the assumption that in beta decay a neutron is emitted in addition to the electron such that the sum of the energies of the neutron and the electron is constant...

I agree that my remedy could seem incredible because one should have seen those neutrons much earlier if they really exist. But only the one who dare can win and the difficult situation, due to the continuous structure of the beta spectrum, is lighted by a remark of my honoured predecessor, Mr Debye, who told me recently in Bruxelles: "Oh, It's well better not to think to this at all, like new taxes". From now on, every solution to the issue must be discussed. Thus, dear radioactive people, look and judge. Unfortunately, I cannot appear in Tubingen personally since I am indispensable here in Zurich because of a ball on the night of 6/7 December. With my best regards to you, and also to Mr Back. Your humble servant . W. Pauli, December 1930

"I have done a terrible thing. I have postulated a particle that cannot be detected."

1953, 1956, 1959Savannah River (1000-MWatt) Nuclear Reactor in South Carolinalooked for the inverse of theprocess:

n p + e- + neutrino

p + neutrino n + e+

Cowan & Reines

with estimate flux of 51013 neutrinos/cm2-sec

observed 2-3 p + neutrino events/hour

n + neutrino p + e-We have never observed

What does that tell us?

The Nuclear pp cycle producing energy in the sun

6 protons 4He + 6+ 2e + 2p 26.7 MeV

Begins with the reaction

eedpp

0.26 MeV neutrinos

500 trillion solar neutrinos every second!

+ energy always

predictably fixedby E

Under the influence of a magnetic field

simple 2-body decay!

+ + + neutrino?charge +1 +1 ?spin 0 ½ ?

0½

n p + e + neutrino?

+ + + neutrino?Then

- e- + neutrino????

As in the case of decaying radioactive isotopes, the electrons’s energy varied, with a maximum cutoff (whose value was the 2-body prediction)

3 body decay!

p

e

e

2 neutrinos

1962 Lederman,Schwartz,Steinberger Brookhaven National Laboratory

using a as a source of antineutrinos

and a 44-foot thick stack of steel (from a dismantled warship hull) to shield everything but the ’s

found 29 instances of

+ p + + n

but none of

+ p e+ + n

1988 Nobel Prize in Physics

"for the neutrino beam method and the demonstration of the doublet structure of the leptons through the discovery of the muon neutrino"

1967 •built at Brookhaven labs•615 tons of tetrachloroethylene•Neutrino interaction 37Cl37Ar(radioactive isotope, ½ = 35 days)Chemically extracting the 37Ar, its radioactivity gives the number of neutrino interactions in the vat(thus the solar neutrino flux). Results: Collected data 1969-1993 (24 years!!) gives a mean of 2.5±0.2 SNU while theory predicts 8 SNU (1 SNU = 1 neutrino interaction per second for 10E+36 target atoms). This is a neutrino deficit of 69%.

Homestake MineExperiment

The energy spectrum of solar neutrinos predicted by the BP04 solar model. For continuum sources, the neutrino fluxes are given in number of neutrinos cm-2s-1 MeV-1

at the Earth's surface. For line sources, the units are number of neutrinos cm-2s-1. Total theoretical uncertainties are shown for each source.

The difficulttodetect CNO neutrino fluxes have been omitted in this plot.

Solar models predict the spectrum and flux of solar neutrinos reaching the earth

The Solar Neutrino ProblemThe rate of detection of solar e’s from

ee

ArCl 3737is 3 smaller than expected!

Is the sun’s core cooler than we thought? 6%

Is it a different age than we had assumed?

New and extraordinarily precise measurements of “solar sound speeds”

1998

• small oscillations in spectral line strengths• studied by solar seismologists• due to pressure waves traversing the solar volume

confirm the predictions of internal temperature and pressure bystandard solar models to with 0.1%

Atmospheric Neutrino Detection

all showers start

e

(all Ks decaying rapidly into s)with s and Kaons

e

e

e

e

e

→ +

Each pion decays by

→ e + e +

and each muon decays by

Note: at sea level

N

Ne

= 2

MCee

DataeeR)/()(

)/()(

One detector measures this significantly more accurately than any otherSuperKamiokande

They find

Rsub-GeV = 0.63 0.06

Rmulti-GeV = 0.65 0.09

Given the time dilation of muon lifetimes (and the probabilisticnature of their decays) we can still calculate/simulate the ratiowe expect to observe at the ground, and compare:

“Evidence for an oscillatory signature in atmospheric neutrino oscillation”Y. Ashie, et. al. (the Super-Kamiokande Collaboration)

Phys. Rev. Lett. 93, 101801 (2004).

Underground Neutrino Observatory

The proposed next-generation underground water Čerenkov detector

to probe physics beyond the sensitivity of the highly successful Super-Kamiokande detector in Japan

The SuperK detector is a

water Čerenkov detector

40 m tall40 m diameter

stainless steel cylinder

containing 50,000 metric tons of ultra pure water

The detector is located 1 kilometer below Mt. Ikenoyama inside the Kamioka zinc mine.

The main sensitive region is 36 m high, 34 m in dia viewed by 11,146 inward facing Hamamatsu photomultiplier tubes surrounding 32.5 ktons of water

Underground Neutrino Observatory

• 650 kilotons

• active volume: 440 kilotons

20 times larger than Super-Kamiokande

major components: photomultiplier tubes, excavation, water purification system.

$500M The optimal detector depth to perform the full proposed scientific program ofUNO 4000 meters-water-equivalent

or deeper

DUSEL: A National Science Foundation initiative to establish a national underground laboratory for research in physics, Earth and environmental sciences, civil and Mining engineering, and the Biosciences.

“The science cuts across disciplines and Directorates (ENG, GEO, and MPS) and provides opportunities for transformational breakthroughs and to educate the scientists & engineers of the 21stcentury” Michael S. Turner, Assistant Director for Mathematics and Physical Science Division (NSF)

Icicle CreekCascades, WA

Henderson MineEmpire, CO

Homestake MineLead, SD

Kimballton Mine Giles Co.,West VA

WIPPCarlsbad, NM

Soudan MineSoudan, MN

Mount San Jacinto, CA

Lt Blue proposed access ramps

Green exploratory drill holes

Dk Blue – Geo research areas

Red – Added geo access

Geo-outposts will explore below the ore body!Geo-outposts will explore below the ore body!

Ore Geology, Magmatic- Hydrothermal Processes, and PetrogeneisHydrogeology

Coupled Processes

GeophysicsGeophysical imagingStress in the earth

*SASFiG-9 (isolated)

Detected within a water-bearing dyke/fracture at 3.2 Km depth.

strictly anaerobic; iron-reducer

optimal growth temperature = 60 oC

virgin rock temp = ~ 45 oC

* SASFiG-1

SASFiG-2

SASFiG-3SASFiG-4

SASFiG-5

SASFiG-6

SASFiG-7SASFiG-9

SASFiG-8

*

image courtesy of Gordon Southam

What do we know so far?New, unusual microbes and sequences indicative of ancestral linkages, less evolved sequences (early life?), biomedical and biotech applications

Novel bacterial lineages that appear unique to the South African deep-subsurface:

South Africa Subsurface Firmicutes Groups (SASFiG)

1 m

Major Questions in GeomicrobiologyMajor Questions in GeomicrobiologyHow deeply does life extend into the Earth?

What are the lower limits of life in the biosphere? Temperature, Pressure, Nutrients/ energy

Fig. 2 of Earthlab report

Cells/ml or Cells/g

Dep

th (

km)

107105103101

0

1

2

3

4

5?

S. African data + Onstott et al. 1998

101 103 105 107

0

1

2

3

4

5

6

Henderson DUSEL Biology Questions• What’s down there? Bacteria? Archaea? Eukaryotes? Viruses?

• Did life 1st evolve deep underground, and spread to the surface?

• Are the most ancient lineages of life found deep below the surface?

• What are the genetic and physiological adaptations to such “life in the slow lane”?

• How do microbes harness energy (interaction of water and rock?)

• Isotopic analyses to infer chemical or biological origin

• Genomics and proteomics—search for new genes, proteins (to include functional gene analyses, geochemical analyses, and stable- isotope analyses to identify sources of energy)

• What limits life? Depth, temperature, pH, substrate, energy source?

• Survey the biodiversity: “what” is “where”?

Geobiology Opportunities and Facilities at HendersonNear Term: S2 project -- exploratory borehole(s)Long Term: 20-30 life of DUSEL

Deep ExplorationStation (DES) for drilling to great depth

Outpost sites forgeomicrobiologyexploration and experiments

Central campusDedicatedmicrobiologylab

Surface lab andfreezer storage

Sampling minerals and bio-film surrounding a flowing borehole, December 2005

• Aspen High School, Aspen, CO

• Basalt High School, Basalt, CO

• Roaring Fork Valley High School, Carbondale, CO

• Lake County High School, Leadville, CO The highest-elevation school in U.S. -- 10,152 feet above sea level

SALTA: Snowmass Area Large Time-Coincidence Array

Empire

• Clear Creek High School, Empire, CO

Polishing scintillatoredges outside

Conference Center

Making detectors light-tight

SALTA Workshop, July 2001, Snowmass, CO

massphototube

gluing

CROPSummer Workshops

http://crop/unl.edu/

CROP article in Lincoln Journal Star, 7 August 2003

PMMA (polymethyl methacrylate)doped with a scintillating fluor

2 ft x 2 ft x ½ inch

Read out by 10 stage

EMI 9256 photomultiplier tube

The Chicago Air Shower ArrayThe Chicago Air Shower Array

recycling retired detectors from

the Chicago Air Shower Array

located in the Utah Desert:

1089 stations, 15m spacing

covering 0.23 square km

U.S. Army PhotoSeptember 30,

1999

The CROP team at Chicago Air Shower Array (CASA) site

CASA detectors’ new home at the University of Nebraska

2000 scintillator panels, 2000 PMTs, 500 low and power supplies at UNL

Aspen Center for Physics Education & Outreach WorkshopJuly 6-8, 2004 SALTA schools take over the library, setting up

cosmic ray telescopes, for training in the new DAQcard that will be used in all their data-taking.

A portable stand held each muon telescope.

Detectors•telescoped pair with coincidence requirement against noise•sandwiching a ¼ inch lead sheet

were configured into muon telescopes

2 modules taken

down into the mine

Detectors moved at 2-3 week intervals

since dust posed a problem for a PC

we housed a low-power serial digital data loggeralongside the DAQcard

Acumen Instruments Databridge development kit

Desktop Base StationAn ~identical pair of modules ran in a fixedlocation (surface office) to establish our baseline

SALTA’s Henderson Project was launched September 29, 2004

Clear CreekHigh School

studentsset up thesatellitemodulesat the 1st

undergroundlocation

Basalt High Schoolstudents move the

detectors to their 2nd location

Rates at Henderson surface base station (10,337 ft above sea level)= 2.5rates at Lincoln, NE (elevation: 1189 ft)

•Data collected between Sept 29 – Dec 8, 2004•monitored 4 locations between depths of 2800-3900 ft

Raw rates in muon telescopes seen to drop from

10 Hz (surface rate) → 1.5 Hz → 0.5 Hz → 0.3 Hz

Some preliminary observations

0

50

100

150

200

548

556

564

572

580

588

596

604

612

620

628

636

644

652

660

668

676

Rate (per minute)

0

200

400

600

800

1000

1200

1400

1600

1800

1 25 49 73 97 121 145 169 193 217 241 265 289 313 337 361 385 409 433 457

0

500

1000

1500

2000

2500

3000

3500

1 29 57 85 113 141 169 197 225 253 281 309 337 365 393 421 449 477

Channel 0,1 coincidences

Channel 2,3 coincidences

SALTA high school students are now analyzing the data

• identifying stable data run periods• bad data channels

…and learning about the statisticalnature of random events

Students will next learn to calculate accidental coincidence rates and statistical error