Cấu trúc động của phân tử từ phổ nhiễu xạ electron

Một nghiên cứu lý thuyết về phương pháp quan sát cấu trúc động của phân tử có thể được quan sát bằng phương pháp dùng các tia electron sinh ra từ xung laser cực ngắn của Nhóm nghiên cứu Vật lý Nguyên tử phân tử và Quang học (AMOG) được đăng trên tạp chí Journal of Physics B. 

JournalJournal of Physics B Vol 50

Authors: Dinh-Duy T Vu, Ngoc-Loan T Phan, Van-Hung Hoang, and Van-Hoang Le

DOI10.1088/1361-6455/aa95ac / Linkhttp://iopscience.iop.org/article/10.1088/1361-6455/aa95ac

Abstract

A recently developed quantitative rescattering theory showed that a laser-free elastic cross section can be separated from laser-induced electron diffraction (LIED) spectra. Based upon this idea, Blaga et al investigated the possibility of reconstructing molecular structure from LIED spectra (2012 Nature 483 7388). In the above study, an independent atoms model (IAM) was used to interpret high-energy electron–molecule collisions induced by a mid-infrared laser. Our research aims to extend the application range of this structural retrieval method to low-energy spectra induced by more common near-infrared laser sources. The IAM is insufficient in this case, so we switch to a more comprehensive model—the multiple scattering (MS) theory. From the original version concerning only neutral targets, we upgrade the model so that it is compatible with electron–ion collisions at low energy. With available LIED experiment data of CO2 and O2, the upgraded MS is shown to be greatly effective as a tool for molecular imaging from spectra induced by a near-infrared laser. The captured image is at about 2 fs after the ionization, shorter than the period 4–6 fs by using the mid-infrared laser in Blaga's experiment.