Space-slice ion imaging: High slice resolution imaging in the polarization plane of arbitrarily polarized ionizing light
Space-slice ion imaging: High slice resolution imaging in the polarization plane of arbitrarily polarized ionizing light
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DOI：
10.1063/1.5110690
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发表时间：
2019-10
影响因子：
1.6
通讯作者：
Kenta Mizuse;R. Fujimoto;Y. Ohshima
中科院分区：
文献类型：
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作者：
Kenta Mizuse;R. Fujimoto;Y. Ohshima
我们提出了一种用于离子成像实验的概念性新的基于狭缝的切片成像技术，为电离激光脉冲的偏振平面中的高分辨率切片成像提供了一种方法。在本方法中，在离子飞行的漂移区域中安装可机械调节的狭缝，使得只有三维膨胀的离子云（牛顿球）的薄的中心切片通过狭缝。然后将切片云投影到平行于切片平面安装的二维位置敏感离子检测器上。与传统的二维成像相比，目前的“空间切片成像”方案有两个主要创新点：（1）狭缝作为切片的理想门，原则上对于典型的几厘米离子云使用亚毫米狭缝宽度可以实现1％或更高的切片分辨率。 （2）无论偏振状态如何，成像平面都可以自动平行于激光脉冲的偏振平面，从而产生迄今为止未实现的“相机角度”。我们开发了一种空间切片离子成像装置来实现和验证本方案。为了评估其性能，我们对 N2 分子进行了库仑爆炸成像。通过调整狭缝宽度，可实现约 0.33% 的切片，且图像没有明显失真。偏振相关成像表明，可以从任何偏振态获得的观察图像中直接读取离子的喷射角。目前激光偏振平面的成像测量为激光诱导动力学的研究开辟了新的途径；这些动态无法用现有的二维设置来完全表征。作为一个例子，我们将本方法应用于激光驱动的 N2 旋转波包的时间分辨成像，使用圆偏振爆炸脉冲作为成像平面中的各向同性探针。我们成功地观察到了清晰的时间相关图像，其中包含波包动力学的完整时空信息。本文介绍了我们设备的概念、设计和操作的详细信息。我们提出了一种用于离子成像实验的概念上新的、基于狭缝的切片成像技术，为电离激光脉冲的偏振平面中的高切片分辨率成像提供了一种方法。在本方法中，在离子飞行的漂移区域中安装可机械调节的狭缝，使得只有三维膨胀的离子云（牛顿球）的薄的中心切片通过狭缝。然后将切片云投影到平行于切片平面安装的二维位置敏感离子检测器上。与传统的二维成像相比，目前的“空间切片成像”方案有两个主要创新点：（1）狭缝作为切片的理想门，原则上对于典型的几厘米离子云使用亚毫米狭缝宽度可以实现1％或更高的切片分辨率。 (2)无论偏振状态如何，成像平面都可以自动平行于激光脉冲的偏振平面，结果...
We present a conceptually new, slit-based slice imaging technique for ion-imaging experiments, offering a way for high slice resolution imaging in the polarization plane of an ionizing laser pulse. In the present method, a mechanically adjustable slit is installed in the drift region of the flight of the ions so that only a thin central slice of a three-dimensionally expanding ion cloud (Newton sphere) passes through the slit. The sliced cloud is then projected onto a two-dimensional position-sensitive ion detector installed parallel to the slice plane. Compared to the conventional two-dimensional imaging, the present “space-slice imaging” scheme has two principle novelties: (1) The slit acts as an ideal gate for the slicing, and a slice resolution of 1% or higher can be achieved, in principle, using submillimeter slit width for a typical a few-centimeter ion cloud. (2) The imaging plane can be automatically parallel to the polarization plane of a laser pulse regardless of the state of polarization, resulting in a hitherto unrealized “camera angle.” We developed a space-slice ion imaging apparatus to realize and validate the present scheme. To evaluate its performance, we carried out the Coulomb explosion imaging of the N2 molecule. By adjusting slit width, slicing up to approximately 0.33% was achieved without remarkable image distortion. The polarization-dependent imaging shows that the ejection angles of ions can be directly read from the observed images obtained with any polarization states. The present imaging measurements in the laser polarization plane opens new avenues for the study of laser-induced dynamics; these dynamics cannot be fully characterized with the existing two-dimensional setups. As an example, we applied the present approach to the time-resolved imaging of a laser-driven rotational wave packet of N2, using a circularly polarized exploding pulse as an isotropic probe in the imaging plane. We successfully observed clear time-dependent images containing full spatiotemporal information of the wave packet dynamics. Details of the concept, design, and operation of our apparatus are presented in the present paper.We present a conceptually new, slit-based slice imaging technique for ion-imaging experiments, offering a way for high slice resolution imaging in the polarization plane of an ionizing laser pulse. In the present method, a mechanically adjustable slit is installed in the drift region of the flight of the ions so that only a thin central slice of a three-dimensionally expanding ion cloud (Newton sphere) passes through the slit. The sliced cloud is then projected onto a two-dimensional position-sensitive ion detector installed parallel to the slice plane. Compared to the conventional two-dimensional imaging, the present “space-slice imaging” scheme has two principle novelties: (1) The slit acts as an ideal gate for the slicing, and a slice resolution of 1% or higher can be achieved, in principle, using submillimeter slit width for a typical a few-centimeter ion cloud. (2) The imaging plane can be automatically parallel to the polarization plane of a laser pulse regardless of the state of polarization, resul...