Bielawski Serge, Blomley Edmund, Brosi Miriam, Bründermann Erik, Burkard Eva, Evain Clément, Funkner Stefan, Hiller Nicole, Nasse Michael J, Niehues Gudrun, Roussel Eléonore, Schedler Manuel, Schönfeldt Patrik, Steinmann Johannes L, Szwaj Christophe, Walther Sophie, Müller Anke-Susanne
Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers, Atomes et Molécules, Centre d'Étude Recherches et Applications (CERLA), F-59000, Lille, France.
Karlsruhe Institute of Technology (KIT), D-76131, Karlsruhe, Germany.
Sci Rep. 2019 Jul 17;9(1):10391. doi: 10.1038/s41598-019-45024-2.
In recent and future synchrotron radiation facilities, relativistic electron bunches with increasingly high charge density are needed for producing brilliant light at various wavelengths, from X-rays to terahertz. In such conditions, interaction of electron bunches with their own emitted electromagnetic fields leads to instabilities and spontaneous formation of complex spatial structures. Understanding these instabilities is therefore key in most electron accelerators. However, investigations suffer from the lack of non-destructive recording tools for electron bunch shapes. In storage rings, most studies thus focus on the resulting emitted radiation. Here, we present measurements of the electric field in the immediate vicinity of the electron bunch in a storage ring, over many turns. For recording the ultrafast electric field, we designed a photonic time-stretch analog-to-digital converter with terasamples/second acquisition rate. We could thus observe the predicted link between spontaneous pattern formation and giant bursts of coherent synchrotron radiation in a storage ring.
在近期和未来的同步辐射设施中，需要具有越来越高电荷密度的相对论电子束来产生从X射线到太赫兹等各种波长的明亮光。在这种情况下，电子束与其自身发射的电磁场相互作用会导致不稳定性，并自发形成复杂的空间结构。因此，了解这些不稳定性是大多数电子加速器的关键。然而，由于缺乏用于记录电子束形状的无损记录工具，相关研究受到了阻碍。在储存环中，大多数研究因此集中在产生的发射辐射上。在此，我们展示了在储存环中对电子束紧邻区域电场进行的多圈测量。为了记录超快电场，我们设计了一种具有太样本/秒采集速率的光子时间拉伸模数转换器。由此，我们能够观察到储存环中自发图案形成与相干同步辐射巨脉冲之间的预测联系。
