Ultra low energy results and their impact to dark matter and low energy neutrino physics

TL;DR

This paper reports ultra low energy detection using a novel spherical proportional counter with a threshold of 25 eV, enabling new possibilities in dark matter and low energy neutrino research.

Contribution

It introduces a new low energy detection technique with a spherical proportional counter achieving unprecedented energy thresholds and calibration methods.

Findings

Achieved a 25 eV energy threshold with the detector.

Detected a 270 eV peak due to carbon fluorescence.

Demonstrated potential for neutrino and dark matter detection.

Abstract

We present ultra low energy results taken with the novel Spherical Proportional Counter. The energy threshold has been pushed down to about 25 eV and single electrons are clearly collected and detected. To reach such performance low energy calibration systems have been successfully developed: - A pulsed UV lamp extracting photoelectrons from the inner surface of the detector - Various radioactive sources allowing low energy peaks through fluorescence processes. The bench mark result is the observation of a well resolved peak at 270 eV due to carbon fluorescence which is unique performance for such large-massive detector. It opens a new window in dark matter and low energy neutrino search and may allow detection of neutrinos from a nuclear reactor or from supernova via neutrino-nucleus elastic scattering