Multi-turn Mass Spectrometer Research Articles

Development of an Ultra-High Performance Multi-Turn TOF-SIMS/SNMS System “MULTUM-SIMS/SNMS”

A new system incorporating a multi-turn time-of-flight secondary ion/sputtered neutral mass spectrometer (TOF-SIMS/SNMS) with laser post-ionization was designed and constructed. This system consists of a gallium focused ion beam, femtosecond (fs) laser for post-ionization, and multi-turn TOF mass spectrometer. When laser post-ionization was used, the secondary ion signal strengths for several metals increased by up to 650 times, and were greater than the values obtained in conventional TOF-SIMS experiments. Use of the multi-turn mass spectrometer resulted in an increase in mass resolving power with increase in the total TOF. The mass resolving power reached to 23,000 after 800 multi-turn cycles, corresponding to a flight path length of 1040 m. These results indicated that this system is very effective for the analysis of valuable materials such as space samples with high sensitivity, high mass resolving power, and high lateral resolution.

Ultra‐high performance multi‐turn TOF‐SIMS system with a femto‐second laser for post‐ionization: investigation of the performance in linear mode

AbstractThe performance of a newly developed TOF‐SIMS System with a femtosecond laser postionization and a multiturn mass spectrometer was investigated in linear mode. This system would be very effective for analyzing valuable material such as space samples. By using postionization the secondary ion signals of Ag were increased (up to 100 times), compared with the conventional TOF‐SIMS experiments. The laser power dependence on the signal intensities was also investigated and it was confirmed that the signal intensities reached specific values above the specific laser power. Lateral resolution of the elemental map was calculated to be about 40 nm. Copyright © 2010 John Wiley & Sons, Ltd.

Application of a multi-turn time-of-flight mass spectrometer, MULTUM II, to organic compounds ionized by matrix-assisted laser desorption/ionization.

The circuit shape of the ion path, or the multi-turn, provides a solution for achieving unrestricted mass resolution from time-of-flight mass analyzers. The potential of a multi-turn type mass spectrometer, the MULTUM II, with a 1.308 m circuit controlled by four toroidal electric sector fields in biological applications was examined. With matrix-assisted laser desorption/ionization, the ion flight of 18 cycles gave a mass resolution of 10,000 for MH+ of protophorphyrin IX. This resolution was correlated with the flight length, and a resolution of 61,000 was achieved for MH+ of angiotensin I after 75 cycles or a 98.75 m total flight. The results demonstrate that the multi-turn mass spectrometer allows not only high resolution but also very high separation of the ions of molecular species from organic compounds.

Mass measurements of exotic nuclei at the ESR

We plan to measure masses of exotic nuclei far from the valley of β-stability using the Experimental Storage Ring (ESR) at GSI, Darmstadt, as a time-of-flight (TOF), multi-turn mass spectrometer. For this purpose the ring must be tuned to an isochronous mode, so that the flight time per turn of an ion depends only on its mass-to-charge ratio and not on its velocity spread. For these measurements the timing detector is planned to be placed directly in the ESR to record each circulating ion.