Super D-Helix

We study `Myers effect' for a bunch of $D1$-branes with $IIB$ superstrings moving in one direction along the branes. We show that the `blown-up' configuration is the helical $D1$-brane, which is self-supported from collapse by the axial momentum flow. The tilting angle of the helix is determined by the number of $D1$-branes. The radius of the helix is stabilized to a certain value depending on the number of $D1$-branes and the momentum carried by $IIB$ superstrings. This is actually T-dual version of the supertube recently found as the `blown-up' configuration of a bunch of $IIA$ superstrings carrying $D0$-brane charge. It is found that the helical $D1$ configuration preserves one quarter of the supersymmetry of $IIB$ vacuum.