Scientific Questions

Detector Requirements and Capabilities

Lab Requirements

Discovery Potential

Solar Neutrinos

·   What is origin of solar neutrino problem?

·   Do we understand nuclear physics of stars?

·   What is the nature of neutrino mixing?

·   What can we learn about neutrino masses and mixing angles?

·   Do neutrinos have non-Standard Model properties?

·   Ability to directly observe
p-p neutrinos.

4 Low energy threshold (200-400 keV)

4 Ultra-low activity materials

·   Detectors have potential multiple physics capabilities: solar, supernovae, atmospheric and long-baseline neutrinos

·   Depths ³ 5,000 mwe

·   Space of 7,500 to 500,000 m³

·   Clean room environment

·   Low radon levels

·   Ability to safely handle cryogens and mineral-oil based scintillators

·   Neutrino mass hierarchy and mixing parameters.

·   Quantitative understanding of stellar evolution and nucleosynthesis.

·   Physics beyond current standard model.

·   Role that neutrinos play in cosmology and nuclear astrophysics.

Double Beta Decay

·   Is lepton number conserved?

·   How does the neutrino transform under charge conjugation?

·   What is the nature of neutrino mixing?

·   What is the absolute scale of neutrino masses?

·   What role do neutrinos play in new phenomena beyond the Standard Model?

·   Need sensitivities of
<m_eff> ~ 0.01-0.05 eV

4 Increased detector masses ~100-1000 kg

4 Isotopically enriched material (for some experiments)

4 Excellent energy resolution

4 Ultra low activity materials

·   Potential multiple physics capabilities: solar neutrinos, dark matter

·   Depths ³ 4,000 mwe

·   Space of 700 - 4500 m³

·   Clean room environment

·   Low radon levels

·   Ability to safely handle cryogens

·   Special shielding from external radioactivity.

·   Lepton number violation in the early universe is crucial to cosmology.

·   Opportunity to study rare second-order weak interactions in nature.

·    Absolute scale of neutrino masses is crucial to dark matter studies and understanding the large-scale structure of the universe.

Dark Matter

·   What is the composition of dark matter?

·   How does it interact with ordinary matter?

·   What role does dark matter play in cosmology, the evolution of the universe, and structure formation?

·   Extend sensitivities to the regions predicted by minimal supersymmetric models.

4 Increased detector masses ~100-1000 kg

4 Ultra low activity materials

4 Directionality sensitivity useful.

·   Potential multiple physics capabilities: double beta-decay

·   Depths ³ 4,000 mwe

·   Space of 700 – 4,500 m³

·   Clean room environment

·   Low radon levels

·   Ability to safely handle cryogens

·   Special shielding from external radioactivity.

·   Nature of the lightest supersymmetric particle.

·   Existence of weakly interacting massive particles.

·   Possible relevance to models of extra dimensions, string theories, and quintessence.

·   Insight into unification of gravity.

Scientific Questions

Detector Requirements and Capabilities

Lab Requirements

Discovery Potential

Nucleon Decay

·   Is baryon number conserved?

·   Are protons stable?

·   What models lie beyond the Standard Model?

·   Sensitivities of proton lifetime > 10^33-34 years

4 Increased detector masses ~500,000 kg

·   Potential multiple physics: solar, supernova, atmospheric, long-baseline neutrinos

·   Depths ³ 4,000 mwe

·   Space up to 900,750 m³

·   Clean room (construction)

·   Low radon levels

·   Large staging area

·   Ability to safely handle cryogens and mineral-oil based scintillators

·   Baryon number violation is crucial to understanding physics beyond the standard model.

·   Direct tests of most grand unified theories.

·   Direct probe of GUT scale.

Neutrino Oscillations: Atmospheric and Long-Baseline

·   What is the nature of the neutrino mixing matrix?

·    Do neutrinos oscillate to non-active flavors?

·   What can be learned about neutrino properties from controlled, terrestrial source measurements?

·   What is the strangeness content of the nucleon?

·   Do we know neutrino-nucleus cross-sections important to supernovae and the solar neutrino problem?

·   Need larger statistics for more precise measurement of the mixing angle, hence bigger mass detectors.

·   Ability to observe tau neutrino appearance

·   Better sensitivity to oscillations

·   More statistics on neutral current events;

·   Depths ³ 4,000 mwe

·   Space up to 900,750 m³

·   Clean room during construction

·   Low radon levels

·   Large staging area

·   Ability to safely handle cryogens and mineral-oil based scintillators

·   Laboratory confirmation of neutrino oscillations.

·   Perform quantitative tests of the accuracy of calculated neutrino-nucleus cross sections.

·   Accurate cross section can provide information crucial for understanding supernova physics, and nucleosynthesis.

·   Understanding of GeV neutrino interactions in nuclei.

Supernovae Neutrinos

·   Can we use the neutrino flux from the next galactic supernova to learn about the explosion mechanism and, probe properties of the proto-neutron star?

·   Can we exploit supernovae to search for new phenomena, including neutrino oscillations and neutrino masses?

·   Need flavor sensitivity and ability to distinguish neutrinos and antineutrinos

·   good spectral sensitivity

·   sensitivity to events on the tail of the cooling curve

·   Depths of ³ 2,000 mwe

·   Space 15,000 m³

·   Ability to safely handle cryogens and mineral-oil based scintillators

·   SN neutrino detection is a key component of the "supernova watch'' program involving gravitational wave detectors and optical observatories.

·   Direct detection of neutrino mass.

·   Potential observation of tau neutrino oscillations.

Nuclear Astrophysics

·   Do we understand the low-energy nuclear physics reactions that power stars?

·   What is the influence of nuclear structure and reactions on the evolution, energy generation, and time scales in stars and stellar explosions?

·   What is the origin of the elements that make up the present day Universe?

·   Extremely low rate measurements are dominated by backgrounds when done above ground.

·   A high-intensity low-energy heavy-ion accelerator would allow inverse kinematics experiments.

·   Depths of ³ 4,000 mwe

·   Space of 6,000 m3

·   Will need to be isolated from ultra low background experiments.

·   safety issues related to operation of an accelerator

·   More precise understanding of fundamental low-rate
p-p & CNO stellar processes

·   Understanding of nuclei far-from stability.

·   Understanding the origin of the heavy elements.

Scientific Questions

Detector Requirements and Capabilities

Lab Requirements

Discovery Potential

Geoscience

·   Do we understand the extremely long-term stability of hard rock cavities?

·   How do environmental factors influence stability?

·   How well do our predictive models work?

·   Widely placed sensors and monitoring readout system.

4 seismic monitors

4 strain gauges

4 temperature

4 pressure

·   Access to all available levels.

·   Access during mining.

·   Instrumentation readout system.

·   Special dedicated cavities and drifts for long term testing.

·   Assist in the design of long-term nuclear waste storage.

·   Assist in future cavity design.

Precision Radioassay

·   What sensitivity levels can be reached in counting low-background materials?

·   Can cleaner materials be found and utilized in the next generation science experiments ?

·   Low-background Germanium counting systems.

·   Whole body scintillator based counter.

·   Space for specialized, dedicated counting systems

·   Depths ³ 5,000 mwe

^·     Space 4000 m³

·   Clean room environment

·   Low radon levels

·   Special water shield to eliminate external radioactivity

·   Verification of nuclear testing treaties

·   Facilitate the construction of next generation double beta decay, dark matter, and solar neutrino experiments.

·   Production of ultra-radiopure materials for commercial applications.

Microbiology

·   How do organisms survive in harsh, non-traditional environments?

·   What level of microbial activities are possible in such an environment?

·   Are the deep subsurface microbial communities present in fluid-filled fractures distinct from those embedded in the rock strata?

·   Widely placed sensors and monitoring readout with some overlap to the geoscience system.

·   Access to all available levels

·   Space 1200 m³

·   Some special bore holes.

·   Instrumentation readout system

·   Anaerobic glove box

·   Chemistry and biology facilities

·   Understanding the relationship between the indigenous microbial communities and their environment.

·   Insight into life in extreme environments, such as ocean ridges and at the allowed zone of microbial thermophilicity.