On a New Possibility of Pulsed Accumulation of Ultra Cold Neutrons in a Trap

The concept of an ultracold neutron (UCN) source is considered based on the deceleration of very cold neutrons (VCNs) by a local decelerating device. The latter is proposed to be a gradient spin flipper. It is shown that, in this case, the flux of VCNs, which are converted to UCNs after deceleration, has a pulsed structure, and the duration of neutron bunches can be significantly shorter than their repetition period. Accordingly, the density of the neutron flux in the bunch significantly exceeds the average value. This opens up the possibility of the pulsed filling of the UCN trap without preliminary time focusing.