Electric Field Heating during Ultracold Plasma Formation*

Ultracold  plasmas  are  interesting  in  part  because  they  are  cold  enough  that  strong  coupling effects  can be  made  manifest  in  these  systems  at  their  typical  densities.   In  order  to  study  strong  coupling  effects, sufficiently low  temperatures  need  to  be  obtained.  While DC electric fields are useful in manipulating and detecting electrons from ultracold plasmas, a DC  electric  field  applied  during  ultracold  plasma  formation  can  result  in  significant heating of  the  electron  component.   We used molecular dynamics simulations to study this heating process and to determine its impact as a function of ultracold plasma initial electron temperature, density, and spatial size.  We find that this heating can have a significant impact on the lowest achievable temperatures for lower-density ultracold plasmas in particular.