Data Rates

Disclaimer

This page is under construction. It was originally developed for LBNE and is yet to be updated with more recent information contained in the CDR revisions and other documents.

Overview

According to the physics goals of the experiment, we need to consider the following main sources of signal:

• The "beam neutrino" signal
• The Supernova Burst (SNB) signal
• Proton Decay
• Solar neutrinos

All these signals have distinct energy scales, topologies and other characteristics. In terms of buffering and processing data in real or near time, they pose different requirements.

Beam Neutrinos

Because of the energy scale (~GeV range) neutrino interactions will be characterized by TPC signals well above radiological background. Zero-suppression will lead to significant reduction of data volume and rates (the detector will appear "empty" for the most part).

SNB

Reactions

ν_e+⁴⁰Ar ⇒ e^-+⁴⁰K^*

ν _e+⁴⁰Ar ⇒ e⁺+⁴⁰Cl^*

ν_x+⁴⁰Ar ⇒ ν_x+⁴⁰Ar^*

ν_e,x+e^- ⇒ ν_e,x+e^-

References

SNB

• DocDB 6977 - Software for low-energy signals
• DocDB 8481 - Summary of SNB Working Group Progress (February 2014)

Some reference curves from DocDB 6977:

In a nutshell:

• approximately 100 events per kiloton, spread over ~30 seconds, ~½ in first second
• all flavors, few tens of MeV

Other material

• Measurement of the neutrino-oxygen neutral-current interaction cross section by observing nuclear deexcitation

Proton Decay

References

• Very massive underground detectors for proton decay searches
• Nucleon Decay Searches with large Liquid Argon TPC Detectors at Shallow Depths: atmospheric neutrinos and cosmogenic backgrounds
• PDK at LBNF Meeting in Jan'15

Solar

References

• DocDB 6212 - M.Smy's slides from 2012 (LBNE solar studies potential)

Backgrounds

Background Sources

References

• DocDB 4482 - Craig Thorn's summary of Ar properties
• Measurement of the specific activity of Ar-39 in natural argon

Important radiologicals

• ³⁹Ar 1.01 Bq/kg β^- End-point: 0.565MeV
• ⁸⁵Kr 0.1-0.3 Bq/kg β^- End-point: 0.687MeV

Plots

Muon and Neutron Backgrounds (⁴⁰Cl)

Summary Plots

Caveat - in the plots below the neutron data reflect the number of neutrons, not tracks, hits or counts created by neutrons. TBD!

Same plot, but in large (5MeV) bins: