A search for anomalous hydrogen in enriched D 2O, using a time-of-flight spectrometer

In a previous paper we reported a mass spectrometer search for heavy hydrogen-like atoms in an enriched D ₂O sample produced by the electrolysis of 6×10 ³l commercial D ₂O, the latter manufactured from 1.2×10 ⁸l natural water. This set a limit X/H (anomalous/natural hydrogen) ∼10 ^-21-10 ^-22 for the mass range 6 to 350 proton masses. In this paper we report new concentration limits for the same D ₂O sample, obtained with a spectrometer system designed specifically for the detection of new charged particles of unknown mass. The spectrometer utilises energy loss and time-of-flight techniques to distinguish low- Z heavy particles from normal atomic and molecular ions and covers the mass range 12 to 1200 proton masses. No abnormal events were observed in over 60 hours running (16 μl enriched D ₂O) from which we infer concentration limits X/D ∼ 10 ^-16-10 ^-17 in the sample and X/H ∼ 10 ^-28 to 10 ^-29 in terrestrial water for most of the above mass range. The possible use of the time-of-flight system for other particle searches, for example anomalous nuclei of fractionally charged quarks, is discussed briefly.