title: Wakes formed by dust grains in supersonically flowing plasmas.
abstract: Interesting wake effects are found in simulations of dust grains in supersonically flowing plasma. A Mach cone is formed at an angle to the flow determined by the ratio of flow to Bohm speed. The latter is well approximated by [k(T(e)+γT(i))/m(i)](1/2) with γ=3. For ion temperatures significantly lower than the electron temperature, a second (inner) cone forms due to flow convergence. An "ion vacuum" and stagnation point occur downstream. These latter effects cannot be described by conventional (cold-ion) gas dynamics. Critically, none of the cones observed are shocks but are more akin to weak discontinuities.
authors.affiliation: Blackett Laboratory, Imperial College, Prince Consort Road, London SW7 2BW, United Kingdom.
authors.forename: C T N
authors.initials: CT
authors.lastname: Willis
authors.forename: J E
authors.initials: JE
authors.lastname: Allen
authors.forename: M
authors.initials: M
authors.lastname: Coppins
authors.forename: M
authors.initials: M
authors.lastname: Bacharis