  We present an approach to create pulse sequences extending beyond
150~picoseconds in duration, comprised of $100~\mu$J femtosecond pulses. A
quarter of the pulse train is produced by a high-resolution pulse shaper, which
allows full controllability over the timing of each pulse. Two nested Michelson
interferometers follow to quadruple the pulse number and the sequence duration.
To boost the pulse energy, the long train is sent through a multi-pass
Ti:Sapphire amplifier, followed by an external compressor. A periodic sequence
of 84~pulses of 120~fs width and an average pulse energy of 107~$\mu$J,
separated by 2~ps, is demonstrated as a proof of principle.
