Westmacott G, Zhong F, Frank M, Friedrich S, Labov SE, Benner WH
Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
Rapid Commun Mass Spectrom. 2000;14(7):600-7. doi: 10.1002/(SICI)1097-0231(20000415)14:7<600::AID-RCM915>3.0.CO;2-0.
The performance of an energy sensitive, niobium superconducting tunnel junction (STJ) detector is investigated by measuring the pulse height produced by impacting molecular and atomic ions at different kinetic energies. Ions are produced by laser desorption and matrix-assisted laser desorption in a time-of-flight mass spectrometer. Our results show that the STJ detector pulse height decreases for increasing molecular ion mass, passes through a minimum at around 2000 Da, and then increases with increasing mass of molecular ions above 2000 Da. The detector does not show a decline in sensitivity for high mass ions as is observed with microchannel plate ion detectors. These detector plus height measurements are discussed in terms of several physical mechanisms involved in an ion-surface collision.
通过测量不同动能的分子离子和原子离子撞击产生的脉冲高度，研究了一种能量敏感型铌超导隧道结（STJ）探测器的性能。离子由飞行时间质谱仪中的激光解吸和基质辅助激光解吸产生。我们的结果表明，随着分子离子质量的增加，STJ探测器的脉冲高度降低，在约2000 Da处达到最小值，然后随着分子离子质量在2000 Da以上增加而增加。与微通道板离子探测器不同，该探测器对高质量离子未表现出灵敏度下降。根据离子-表面碰撞中涉及的几种物理机制对这些探测器脉冲高度测量结果进行了讨论。
