May 31, 2007 Preprint of PRL of latest results ( PDF , arXiv )
April 14, 2007 - NEW XENON10 RESULTS (

XENON (movie,pdf) is a Dark Matter Direct Detection experiment which uses liquid xenon as a sensitive detector medium to search for WIMPs (Weakly Interacting Massive Particles) . These particles, postulated by Super Symmetry (SUSY), are believed to have a mass in the neighborhood of 100 GeV, to ignore Electromagntic Interactions, and to permeate the Universe. A scale-up of the XENON concept will probe the lowest SUSY parameter space, with a sensitivity of 1 event/100 kg/year. The project is funded by the NSF and the DOE.

XENON10 has just unblinded ~60 live-days of Dark Matter Search science data, with results to be released at the April 2007 APS meeting. The original concept is described in astro-ph0407575 , astro-ph0207670 and astro-ph0609714 (see Brown Particle Astrophysics side-bar link for more talks & publications).

(below) Schematic of LNGS Underground Lab

(above left) a few of the members of XENON10 collaboration including the Brown Group, with detector (in shield) in background.

(above left): Scematic of XENON10 detector showing 89 PMTs, 15 cm active region, and field-shaping rings (actual photos of PMTs / Stainless Steel Vessel / Teflon are below the schematic)
(2nd from left):XENON10 detector outer cryostat with all signal/slow control connections (prior to installation in shield).
(2nd from right):XENON10 installed in shield (20cm Poly / 20cm Pb) in LNGS underground Lab.
(above right):Shield closed, detector operational! Xe purification / circulation panel, and HV / signal connections are visible.

(above) A typical Compton scatter background event in XENON10. Prompt primary scintillation (S1) at ~13 us, followed by a 1st scatter (S2) at ~ 16 us, and a second scatter (S2) at ~47 us. The drift-time delay between S1 and S2 gives the z coordinate of the interaction, and the S2 hit pattern gives the (x,y) coordinates.

(above) A 3D rendering (from GEANT4) of the XENON10 geometry (J. Angle).

( see Brown Particle Astrophysics side-bar link for publications, talks and other news)
(see Collaboration side-bar link for more details)