Search for nuclear excitation by laser-driven electron motion.
Search for nuclear excitation by laser-driven electron motion.
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通过激光驱动的电子运动寻找核激发。
DOI：
10.1103/physrevc.46.852
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Dyer
中科院分区：
文献类型：
--
作者：
Bounds;Dyer
有人提出，原子核可以通过首先用紫外光激发原子的电子来激发。入射的光子耦合到电子，然后电子通过虚拟光子耦合到原子核。作为测试用例，对$^{235}\mathm{U}$进行了实验。脉冲红外激光产生原子蒸气，然后被高亮度的紫外光激光轰击。产生的离子被收集起来。第一激发核态具有26min的半衰期，并通过内转换衰变，导致原子电子的发射。这些转换电子由沟道电子倍增器检测。得到了在2 48 nm紫外束中激发原子核的几率的4.0\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}5}$上限，该原子在2 4 8 nm紫外束中照射700fs，照度范围从1.0\ifmmode\times\else\texttimes\fi{}${10}^{15}$到2.5次{10}^{15}$W/${\mathm{cm}}^{2}$。
It has been proposed that a nucleus may be excited by first exciting the atom's electrons with UV photons. The incident photons couple to the electrons, which would then couple via a virtual photon to the nucleus. As a test case, experiments with $^{235}\mathrm{U}$ have been performed. A pulsed infrared laser produces an atomic vapor of $^{235}\mathrm{U}$ which is then bombarded by a high-brightness UV laser beam. The resulting ions are collected. The first excited nuclear state of $^{235}\mathrm{U}$ has a 26-min half-life and decays by internal conversion, resulting in emission of an atomic electron. These conversion electrons are detected by a channel electron multiplier. An upper limit of 4.0\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}5}$ has been obtained for the probability of exciting the nucleus of a $^{235}\mathrm{U}$ atom that is in the 248-nm UV beam for 700 fs at an irradiance in the range of 1.0\ifmmode\times\else\texttimes\fi{}${10}^{15}$ to 2.5\ifmmode\times\else\texttimes\fi{}${10}^{15}$ W/${\mathrm{cm}}^{2}$.