%\cite{Prince:FEL2015-FRA04} \bibitem{Prince:FEL2015-FRA04} K.C.~Prince, \textquotedblleft{Measurements and Future Prospects for Coherent Control with FEL Radiation}\textquotedblright, % presented at FEL2015, Daejeon, Republic of Korea, August 2015, paper FRA04, unpublished. presented at the 37th International Free Electron Laser Conference (FEL2015), Daejeon, Republic of Korea, August 2015, paper FRA04, unpublished.