  We propose a new experiment to search for a sterile neutrino in a few keV
mass range at the "Troitsk nu-mass" facility. The expected signature
corresponds to a kink in the electron energy spectrum in tritium beta-decay.
The new goal compared to our previous experiment will be precision spectrum
measurements well below end point. The experimental installation consists of a
windowless gaseous tritium source and a high resolution electromagnetic
spectrometer. We estimate that the current bounds on the sterile neutrino
mixing parameter can be improved by an order of magnitude in the mass range
under 5 keV without major upgrade of the existing equipment. Upgrades of
calibration, data acquisition and high voltage systems will allow to improve
the bounds by another order of magnitude.
