0220123

We propose 260 ks of INTEGRAL time to perform a ToO observation of a transient millisecond X-ray pulsar in outburst. The target can be either one of the five known transient accreting millisecond X-ray pulsars in the case of a new outburst or a newly observed object of this class. Since these sources are a new class of astronomical objects INTEGRAL observations will give a fundamental contribution providing a sufficiently detailed spectrum at energies higher than 20 keV. In particular we will be able to study the energy spectrum of these sources which is usually observed to be quite hard even in outburst in a broad band energy range and with unprecedented high sensitivity above 20 keV which will allow us to disentangle the contribution of soft reflection and hard spectral components.The INTEGRAL observation will also allow to perform a timing analysis in an interesting and yet unexplored energy range. [truncated! Please see actual data for full text]