(Edit: please see more recent articles here for more information about T-576)

The T-576 experiment at the SLAC National Accelerator Laboratory seeks to detect a radar scatter from a particle shower in a dense medium. The high-energy electron beam at SLAC is directed into a 4 m long plastic target, initiating a particle shower. The dense ionization electrons left behind should be dense enough to reflect transmitted radio-frequency energy (RF) to a distant receiver. The first run happened in May 2018, and the second run happened in October 2018.

Why perform this experiment?

The high energy electron beam at SLAC is a proxy for an ultra-high energy neutrino. The plastic target is a proxy for ice, for example, the ice in Antarcita. If validated, this technique can be used to detect the highest energy neutrinos in the universe, allowing physicists to study their properties, propagation, and maybe even their source.

The plastic target installed on site at SLAC.

The T-576 collaboration consists of members from the Ohio State University, IIHE/Vrije University Brussels, University of Kansas, UCLA, Cal-Poly, UW Madison, and National Tiawan University.

some papers on the radar method:


results from the first run:


Our first run found suggestion of an excess in the signal region at a significance of 2.3 sigma, as shown in the figure. more details on this analysis can be found in the above paper.

The significance of the result from run 1. The lower x axis denotes the signal-region excess from background. The solid black line is the distribution of excess for various events in the null set, that is, constructed data without signal. The red dashed line is the distribution of signal region excess for real events. In units of standard deviations of the null distribution, the data distribution mean has a significance of 2.3 sigma.

More information to follow as the analysis of run-2 data is performed.