Search

The MTV-G project was started in 2011 to explore a strong gravitational field at a nuclear scale in an electron double scattering experiment, utilizing an experimental technique of the MTV experiment, which searches a electron’s T-Violating transverse polarization in nuclear beta decay at TRIUMF-ISAC. In addition to this new experiment, we have also performed a re-analysis of spectroscopic data of exotic atoms, in a gravitational point of view. From these two studies, we set new constraints on possible new Yukawa interaction at sub-mm scale, as a test of gravitational inverse square law.

Motivated by a search for a new physics beyond the standard model, the MTV experiment (Mott Polarimetry for T-Violation Experiment) is intended to achieve the highest precision test of time-reversal symmetry in polarized nuclear beta decay by measuring a triple correlation (the R -correlation). The first physics run of the MTV experiment was performed in 2010 at TRIUMF-ISAC. This paper gives preliminary results and describes the next generation setup, which involves a cylindrical drift chamber.

The Fukushima Daiichi nuclear power plant accident was triggered by the 2011 Great East Japan Earthquake. The main radioactivity concerns after the accident are I-131 (half-life: 8.0 days), Cs-134 (2.1 years), Cs-137 (30 years), Sr-89 (51 days), and Sr- 90 (29 years). We are aiming to establish a new nondestructive measurement and detection technique that will enable us to realize a quantitative evaluation of strontium radioactivity without chemical separation processing. This technique is needed to detect radiation contained in foods, environmental water, and soil, to prevent us from undesired internal exposure to radiation.