用于离子分析的高分辨率汤姆孙抛物线。

High-resolution Thomson parabola for ion analysis.

作者信息

Cobble J A, Flippo K A, Offermann D T, Lopez F E, Oertel J A, Mastrosimone D, Letzring S A, Sinenian N

机构信息

Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.

出版信息

Rev Sci Instrum. 2011 Nov;82(11):113504. doi: 10.1063/1.3658048.

DOI:10.1063/1.3658048

PMID:22128973

Abstract

A new, versatile Thomson parabola ion energy (TPIE) analyzer has been designed, constructed, and used at the OMEGA-EP facility. Laser-accelerated multi-MeV ions from hemispherical C targets are transmitted through a W pinhole into a multi-kG magnetic field and subsequently through a parallel electric field of up to 25 kV/cm. The ion drift region has a user-selected length of 10, 50, or 80 cm. With the highest fields, 400-MeV C(6+) and C(5+) may be resolved. TPIE is ten-inch manipulator (TIM)-mounted at OMEGA-EP and can be used opposite either of the EP ps beams. The instrument runs on pressure-interlocked 15-Vdc power available in EP TIM carts. Flux control derives from the insertion depth into the target chamber and the user-selected pinhole dimensions. The detector consists of CR39 backed by an image plate. A fully relativistic simulation code for calculating ion trajectories was employed for design optimization. Excellent agreement of code predictions with the actual ion positions on the detectors is observed. Through pit counting of carbon-ion tracks in CR39, it is shown that conversion efficiency of laser light to energetic carbon ions exceeds ~5% for these targets.

摘要

一种新型的通用汤姆逊抛物线离子能量（TPIE）分析仪已在欧米伽 - EP装置上设计、制造并投入使用。来自半球形碳靶的激光加速多兆电子伏离子通过一个钨针孔传输到一个多千高斯的磁场中，随后通过一个高达25 kV/cm的平行电场。离子漂移区的长度可由用户选择，为10厘米、50厘米或80厘米。在最高场强下，可以分辨出400兆电子伏的C(6+)和C(5+)。TPIE安装在欧米伽 - EP装置的十英寸机械手（TIM）上，可用于与EP皮秒束中的任何一束相对使用。该仪器由EP TIM推车中可用的压力互锁15伏直流电源供电。通量控制源于插入靶室的深度和用户选择的针孔尺寸。探测器由CR39和一个成像板组成。使用了一个用于计算离子轨迹的全相对论模拟代码进行设计优化。观察到代码预测与探测器上实际离子位置的极佳一致性。通过对CR39中碳离子轨迹的蚀坑计数表明，对于这些靶，激光到高能碳离子的转换效率超过约5%。