Update on the BL2 in-beam measurement of the neutron lifetime

Neutron beta decay is the simplest example of semi-leptonic decay. A precise measurement of the neutron lifetime, as well as the coupling constant λ allows for a determination of the CKM matrix element V_ud that is free from nuclear structure effects. The neutron lifetime provides an important test of unitarity and consistency of the Standard Model. The neutron lifetime is also the largest uncertainty in Big Bang Nucleosynthesis calculations of light element abundance. There is currently a large discrepancy between different experimental methods of measuring the neutron lifetime. A new measurement of the neutron lifetime using the in-beam method is ongoing at the NIST Center for Neutron Research. This method requires the absolute counting of the decay protons in a neutron beam of precisely known flux. Improvements in the neutron and proton detection systems as well as the use of a new analysis technique should permit an overall uncertainty of 1s. The experimental status, technical improvements, analysis techniques and early data will be presented.