Characterization of multiterawatt laser-solid interactions for proton acceleration by McKenna, P, Ledingham, K, Spencer, I, McCany, T, Singhal, R, Ziener, C, Foster, P, Divall, E, Hooker, C, Neely, D, Langley, A, Clarke, R, Norreys, P, Krushelnick, K, Clark, E