Weber Peter K, Debliqui Marc, Defouilloy Céline, Mayali Xavier, Liu Ming-Chang, Hestrin Rachel, Pett-Ridge Jennifer, Stuart Rhona, Morris Megan, Ramon Christina, Jorgens Danielle M, Zalpuri Reena, Arnoldi Laurent, Farcy Jérôme, Saquet Nicolas, Vitcher Fichou Sarah, Renaud Ludovic, Thomen Aurélien
Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, California 94505, United States.
CAMECA, 29 quai des Grésillons, 92230 Gennevilliers, France.
Anal Chem. 2024 Dec 10;96(49):19321-19329. doi: 10.1021/acs.analchem.4c03091. Epub 2024 Nov 26.
The high lateral resolution and sensitivity of the NanoSIMS 50 and 50L series of dynamic SIMS instruments have enabled numerous scientific advances over the past 25 years. Here, we report on the NanoSIMS-HR, the first major upgrade to the series, and analytical tests in a suite of sample types, including an aluminum sample containing silicon crystals, microalgae, and plant roots colonized with a symbiotic fungus. Significant improvements have been made in the Cs ion source, high voltage (HV) control, stage reproducibility, and other aspects of the instrument that affect performance. The modified design of the NanoSIMS-HR thermal-ionization Cs source enables a 5 pA primary ion beam to be focused into a 100 nm spot, a ∼2.5-fold increase compared to Cs sources on previous instruments (∼2 pA at 100 nm). The brightness of the new Cs source enables an ultimate lateral resolution as high as 30 nm and improved detection limits for a given analysis area. Sample stage movement accuracy is higher than 500 nm, enabling many-fold higher throughput automated analyses. With the new HV control, the primary ion beam impact energy can be reduced from 16 to 2 keV, which enables higher depth resolution during depth profiling (a 2-fold improvement), albeit with a 5-fold decrease in lateral resolution. In the NanoSIMS-HR, the secondary ion column and detection system are identical to those used in the previous series, and the isotopic analysis performance is as precise as in previous NanoSIMS instruments.
在过去25年里，NanoSIMS 50和50L系列动态二次离子质谱仪（Dynamic SIMS instruments）的高横向分辨率和灵敏度推动了众多科学进展。在此，我们报告该系列的首次重大升级产品——NanoSIMS-HR，并展示了对一系列样品类型的分析测试，包括含硅晶体的铝样品、微藻以及被共生真菌定殖的植物根系。该仪器在铯离子源、高压（HV）控制、样品台重现性以及其他影响性能的方面都有了显著改进。NanoSIMS-HR热电离铯源的改进设计能够将5 pA的一次离子束聚焦到100 nm的光斑中，与之前仪器上的铯源相比（100 nm处约为2 pA），提升了约2.5倍。新型铯源的亮度使得最终横向分辨率高达30 nm，并在给定分析区域内改善了检测限。样品台移动精度高于500 nm，可实现自动化分析通量提高数倍。借助新的高压控制，一次离子束撞击能量可从16 keV降至2 keV，这在深度剖析过程中能够实现更高的深度分辨率（提高了2倍），尽管横向分辨率降低了5倍。在NanoSIMS-HR中，二次离子柱和检测系统与之前系列中使用的相同，同位素分析性能与之前的NanoSIMS仪器一样精确。
