TY - JOUR AU - Durkan, Stephen AU - Richardson, Vincent AU - Forembski, Andrew AU - Varvarezos, Lazaros AU - Cubaynes, Denis AU - Düsterer, Stefan AU - Juranić, Pavle AU - Li, Wenbin AU - Richter, Mathias AU - Tiedtke, Kai AU - Meyer, Michael AU - Nikolopoulos, Lampros AU - Costello, John TI - Multiphoton single and double ionization of neon in the EUV JO - Journal of physics / B VL - 58 IS - 1 SN - 0953-4075 CY - Bristol PB - IOP Publ. M1 - PUBDB-2024-07400 SP - 015601 PY - 2024 AB - New information demonstrating the importance of both sequential and simultaneous (or direct) multiphoton ionization of inner shell electrons from neon is discussed in this paper. Ne was irradiated with intense 93 eV free electron laser (FEL) pulses at FLASH and studied with the aid of photoelectron spectrometry. This resulted in two and three photon, single and double ionization of neon, removing electrons from 2s and 2p subshells of the neutral Ne atom in multiple different pathways. The spectral features of the photoelectrons were identified through comparison with the NIST database and field averaged time-dependent density matrix theory. The calculations show the direct multiphoton ionization processes to be extremely sensitive to the focused FEL intensity. LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:001370822800001 DO - DOI:10.1088/1361-6455/ad4078 UR - https://bib-pubdb1.desy.de/record/619113 ER -