An Update on Progress at KamLAND

The first generation of solar neutrino experiments narrowed the allowed flavor mixing and mass parameter solutions (for νe ↔ νx) to a few isolated regions of sin 2 2θ − ∆M 2 parameter space. Recently, the Small Mixing Angle (SMA) solution (sin 2 2θ ∼ 10 −3 → 10 −2 and ∆M 2 ∼ 10 −5 eV 2), and the " just so " (∆M 2 < 10 −9 eV 2) solutions have been disfavored by results from Super-Kamiokande 1 2 and SNO 3. The Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND) recently became operational, and is particularly sensitive to the Large Mixing Angle (LMA) region (sin 2 2θ ∼ 1 and ∆M 2 ∼ 10 −5 → 10 −3 eV 2). We believe the background impurity levels in the detector are low enough to conduct a successful experiment. The stability of the central balloon and PMTs has also been confirmed.