Extending teh studies of ICD in the time domain

实时观察原子间库仑衰变中的电子将为这一过程的基本原理提供新的见解。我们建议利用汉堡自由电子激光器（FLASH）提供的联合锁相太赫兹和扩展紫外（EUV）辐射，以及多粒子重合动量谱，进行一项实验。在我们的实验中，我们将在太赫兹（“条纹”）场的存在下，用来自FLASH的超短（10-50秒）EUV光子脉冲电离Ne二聚体。然后将发生条纹场与带电粒子的动量交换，其值取决于粒子方向和太赫兹场的相位。由于我们打算测量反应中产生的所有粒子的一致性和动量分辨率，我们能够通过条纹非常清楚地检测到ICD电子的影响：在ICD中，离子和ICD电子的动能之和是一个常数。因此，与预期能量总和的偏差与条纹场施加到ICD电子上的能量直接相关。因此，可以从每一个事件中提取关于ICD时间动态的信息。

Observing the electrons in an Interatomic Coulombic Decay in real time will offer novel insights into the fundamentals of this process. We propose to carry out an experiment doing exactly that, by using combined, phase locked THz and Extended UV (EUV) radiation, which is available at the Free Electron Laser in Hamburg (FLASH), together with multiparticle coincidence momentum spectroscopy. In our experiment, we will ionize Ne dimers by ultrashort (10-50 fs) EUV photon pulses from FLASH in the presence of a THz ('streaking') field. A momentum exchange of the streaking field with the charged particles will then take place, the value of which depends on the particle direction and on the phase of the THz field. As we intend to measure all particles produced in the reaction in coincidence and with momentum resolution, we are able to detect the effect of the ICD electrons by streaking very clearly: In ICD, the sum of kinetic energy of the ions and the ICD electron is a constant. Therefore deviations from the expected sum energy are directly related to the energy imposed onto the ICD electron by the streaking field. The information on the temporal dynamics of ICD can therefore be extracted for each event.