Ultrafast ion detection by superconducting NbN thin-film nanowire detectors for time-of-flight mass spectrometry

✍ Scribed by K. Suzuki; S. Miki; S. Shiki; Y. Kobayashi; K. Chiba; Z. Wang; M. Ohkubo

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 373 KB
• Volume: 468
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2008.05.115

✦ Synopsis

Superconducting nanowire detectors (SND) have been applied for time-of-flight mass spectrometry (TOF-MS). In this study, we used the SND having a meander pattern, which consists of a very thin niobium nitride (NbN) stripline with a thickness of 6.8 nm and a width of 200 nm on a MgO substrate. The experiment was carried out for Angiotensin I, which is a peptide with a molecular weight (MW) of 1296, and a NIST-B peptide of 2950. These molecules with a kinetic energy of 17.5 keV incident on the SND. We have successfully observed the pulse signals corresponding to individual impact events and obtained mass spectra. It has been demonstrated that the response of the SND detector is extremely fast; the observed rise time of the pulses is about 540 ps, which is already comparable to that of the best microchannel plate (MCP) detectors for macromolecules. The SND detectors are expected to have faster response time and in principle mass independent sensitivity, unlike MCP detectors, which exhibit a rapid decrease of the sensitivity above a MW of 4000 for molecules of 20 keV.