Small Neutrino Detectors -Purpose of small neutrino detectors -Beams at Fermilab -Design Criteria -Three Sizes and their

1. Small Neutrino Detectors -Purpose of small neutrino detectors -Beams at Fermilab -Design Criteria -Three Sizes and their Neutrino Rates Acknowledgement: Material stolen from many sources Hans Jostlein, May 13th 2006, LAr group mtg

2. Purpose of Small Neutrino Detectors • Physics development using existing technology • Record complete neutrino interactions (nm and ne) in the presence of cosmic rays • Establish physics collaboration by: • Developing event identification • Developing reconstruction • Developing analysis • Measure  interactions in the quasi-elastic and resonance region (?) Where to find 2 GeV electrons ? Hans Jostlein, May 13th 2006, LAr group mtg

3. Requirements to do the Neutrino Study • -see real neutrino interactions in Liquid Argon • -sufficient containment (define !) • -Sufficient rate (define!) • -measure Nu-e from nu-mu discrimination with actual events • -of the right energy ! • -measure overall detection efficiency (e.g. acceptable y-range) Hans Jostlein, May 13th 2006, LAr group mtg

4. Neutrino Beams at Fermilab • -Two beams (from Booster and from Main Injector • -Hot Beams ! (Even at the surface) • -Electron and Muon Neutrinos in comparable numbers • -Can match spectra rather well to future far detectors Hans Jostlein, May 13th 2006, LAr group mtg

5. Neutrino Beams at Fermilab, continued • -Rates were calculated for NOVA originally • -some questions of geometry are being sorted out • -will use rates that are a little too high, we expect • -experts are calculating real spectra very soon Hans Jostlein, May 13th 2006, LAr group mtg

6. Neutrino Beams at Fermilab Hans Jostlein, May 13th 2006, LAr group mtg

7. Electron Neutrinos in MINOS Surface Building From the NOvA Proposal March 15, 2005 • The charged current ne event spectrum in the MINOS surface building. • The ne event spectrum peaks just below 2 GeV. • There are ~2,000 ne events shown here for 6.5E20 POT and the 20.4 ton fiducial mass NOvA near detector. neCC events / 50 MeV NuMI is presently providing ~2E20 POT per year. Hans Jostlein, May 13th 2006, LAr group mtg

8. nm CC events / 50 MeV Muon Neutrinos in MINOS Surface Building From the NOvA Proposal March 15, 2005 • The nm peak at ~2.8 GeV is from Kaon decay. Hans Jostlein, May 13th 2006, LAr group mtg

9. Event Containment For the rate calculation (later in the talk) we will use a required event length of 1.5 m from the vertex. This is 11 radiation length in liquid Argon. We must catch all relevant event topological features. Maybe 50 cm is enough ? This would increase the “target mass” substantially. See next slide. Hans Jostlein, May 13th 2006, LAr group mtg

10. Event Containment –how much depth ? Event Containment 50 cm Hans Jostlein, May 13th 2006, LAr group mtg

11. Detector Sizes Considered: “5 m Drift Detector Hans Jostlein, May 13th 2006, LAr group mtg

12. Detector Sizes Considered: “ 3 Meter Detector” Hans Jostlein, May 13th 2006, LAr group mtg

13. Hans Jostlein, May 13th 2006, LAr group mtg

14. Conclusions • -Crucial Need for real neutrino interactions in Argon • -A surface detector of about 30 ton total mass is • the minimum requirement • -smaller detector below ground would suffice, • but may be the more difficult project Hans Jostlein, May 13th 2006, LAr group mtg