Ionization and radiative decays in atomic and molecular systems

在理论和计算物理中的几个主题将被追求：1）通过离子碰撞和超强激光照射的简单分子的多重电离。利用离子或激光轰击使水分子电离在放射医学中起着重要的作用。我们以前关于原子电离的工作将推广到这种更复杂的情况。这将导致更准确的理论结果，将与分子碎裂的实验进行比较。2）用半经典方法研究反氢在磁场和电场中的辐射衰变。 这主要是数值研究将有助于了解反氢的磁阱，这将是在欧洲核子研究中心（日内瓦，瑞士）在不久的将来实施的ATRAP合作的捕获。这些实验是为了探索自然界中物质和反物质之间的对称性。这些计算将有助于实验工作者在这样的水平上形成反氢，使损失最小化。3）相对论重离子碰撞中的电离和电子-正电子对产生。我们发展了极端相对论情形下狄拉克方程的新计算方法。这项工作与正常真空状态的崩溃有关：在库仑势垒处的铀-铀碰撞中，产生了电子-正电子对。随着目前对地球同步轨道国际公司加速器和储存环（达姆施塔特，德国）的升级，将对这类碰撞进行新的测量。我们的计算将有助于解释这些数据。

Several topics in theoretical and computational physics will be pursued:1) Multiple ionization of simple molecules by ion impact, and by superintense laser irradiation. The ionization of water molecules by ion or laser bombardment plays an important role in radiation medicine. Our previous work on ionization of atoms will be extended to this more complicated case. It will lead to more accurate theoretical results which will be compared with experiments on molecule fragmentation.2) Radiative decays of anti-hydrogen in magnetic and electric fields using semiclassical methods.  This mostly numerical study will help to understand the capture of anti-hydrogen in a magnetic trap, which will be implemented at CERN (Geneva, Switzerland) in the near future by the ATRAP collaboration. These experiments are conducted to explore the symmetry in nature between matter and anti-matter. The calculations will help experimentalists to form anti-hydrogen in such levels that losses will be minimized.3) Ionization and electron-positron pair production in relativistic heavy-ion collisions. We have developed anew computational method for the Dirac equation in extreme relativistic situations. The work is related to the breakdown of the normal vacuum state: in uranium-uranium collisions at the Coulomb barrier electron-positron pairs are created. With the current upgrade of the GSI accelerator and storage ring (Darmstadt, Germany) new measurements of such collisions will be undertaken. Our calculations will serve to explain these data.