TY - JOUR AU - H. van der Hart AU - K. Meyer AU - Chris Greene BT - Physical Review A DA - Jan-05-1998 DO - 10.1103/PhysRevA.57.3641 PY - 1998 SP - 3641 EP - 3645 T2 - Physical Review A TI - Double photoionization and ionization excitation of the metastable helium S states VL - 57 SN - 1050-2947 ER -