The ${\mathrm{H}}_3^{+}$ ion is the simplest polyatomic molecule. Apart from its fundamental role as a benchmark system for theoretical calculations, it has attracted a lot of attention as one of the main drivers of an active interstellar ion-neutral chemistry network. ${\mathrm{H}}_3^{+}$ spectroscopy has contributed greatly to astrochemistry, and experiment and theory have both developed tremendously throughout the years, following the ground-breaking work by Oka. To date, the highest-lying identified ${\mathrm{H}}_3^{+}$ transitions were obtained using an action spectroscopy technique, employing stored ${\mathrm{H}}_3^{+}$ ions in a cryogenic ion trap. This approach was pioneered by Schlemmer and Gerlich for ${\mathrm{N}}_2^{+}$, and is widely used today – in one form or another – for spectroscopic studies of interstellar ions. In this work, we explore the possibility to extend the range for ${\mathrm{H}}_3^{+}$ action spectroscopy even further, into the regime above 20 000 cm⁻¹, in order to bridge the gap to the rich pre-dissociation spectrum of states near the dissociation limit that was obtained by Carrington et al. and remains unassigned after more than 30 years.

这 ${\mathrm{H}}_3^{+}$离子是最简单的多原子分子。除了作为理论计算基准系统的基本作用外，它还作为主动星际离子中性化学网络的主要驱动力之一，引起了人们的广泛关注。${\mathrm{H}}_3^{+}$光谱学对天体化学做出了巨大贡献，并且在Oka的开创性工作之后，多年来，实验和理论都取得了巨大的发展。迄今为止，确定的地势最高${\mathrm{H}}_3^{+}$ 使用动作光谱技术获得了转变，采用了 ${\mathrm{H}}_3^{+}$低温离子阱中的离子。这种方法由Schlemmer和Gerlich率先提出，${\mathrm{ñ}}_{\mathrm{2个}}^{+}$，如今已以一种形式或另一种形式广泛用于星际离子的光谱研究。在这项工作中，我们探索了扩大范围的可能性${\mathrm{H}}_3^{+}$甚至在20  000  cm ^-1以上的范围内进行作用光谱分析，以弥合Carrington等人获得的接近解离极限的丰富的预解离态谱。并在30 多年后仍未分配。