Welcome to Palo Verde

The Palo Verde experiment is a long-baseline neutrino oscillation experiment using (anti-)neutrinos from the Palo Verde Nuclear Generating Station , a commercial power plant located 60 miles West of Phoenix, AZ.

Since the neutrino oscillation probablity can be written (at least in the simple 2-favor case) as P(nux -> nuy) = sin2(2 theta) sin2(Delta m2 L/4E), with Delta m2 expressend in eV2, L in km and E in MeV, by working with low energy (small E) neutrinos from a reactor we are sensitive to very small mass-differences (Delta m2) with a modest baseline (L) for the oscillation. The palo Verde experiment, located at about 1 km from the reactor cores can detect Delta m2 as low as 10-3 eV2. While this sensitivity is similar to the one of the Minos experiment to be performed between FNAL and the Soudan mine with a much simpler setup, our experiment can only detect oscillations involving anti-nu_e (that are emitted by the reactor).

The Palo Verde experiment is a collaboration between our group at Stanford and groups from University of Alabama, Arizona State University and Caltech. The Stanford group has built all the analog electronics, trigger and data acquisition system for the experiment, together with parts of the veto counter. Our trigger processor uses rather advanced technology and is described in a NIM paper. The Stanford group is also the main data analysis, and computing center for the experiment.

Stable running has started in Oct 98 and from the data collected in the Oct-Dec period we observed no oscillations and were able to exclude large set of parameters for oscillations involving anti-nue. Our result, together with the results of others, allow us to determine that the oscillations detected by SuperKamiokande, does NOT involve electron neutrinos. Palo Verde will continue to take data during all 1999 to explore more subtle oscillation effect and perform other measurements in cosmic-ray physics.

Data analysis opportunities exist in this experiment that offers the rare match of top-notch physics with a 10 people collaboration in which students contribute to a very broad range of activities.


This page not maintained. For information, contact Giorgio Gratta .
Last modified: Sat Aug 25 05:13:20 PDT 2001