Back to CINP FunSym

BL3: a more precise determination of the decay rate of neutrons to protons

Location: NIST
Participating Canadian institutions: Manitoba
International partners: USA

The BL3 experiment seeks an improvement on the precision of the neutron lifetime using the “beam” method that will resolve or confirm the long-standing discrepancy between the “beam” and “bottle” methods. The decay protons from a collimated beam of cold neutrons are trapped in the electrostatic and electromagnetic fields of a quasi-Penning trap. Periodically the fields are lowered and the protons are counted, allowing a measurement of the weak decay lifetime. The project infrastructure proposal is currently under review by the US National Science Foundation. The experiment intends to run by 2025. Near term focus of the Canadian contribution will be on simulations of the decay protons in the trap and on their way to the proton detector, and proton detector prototype testing in the University of Manitoba 30 keV refurbished mass spectrometer.