Dissertation

Mesoscale Ceramic Cylindrical Ion Trap Mass Analyzers for In Situ Sample Analysis

Roman, Patrick A

2019

Overview

As wireless network devices and IOT connectivity develop, the application and demand for small, low power, in situ sensors and instruments will expand. There are continuous efforts in the miniaturization of sensors and scientific instrument systems for conventional to field deployable and rugged hand held units for personal use to extreme harsh environment applications. This work investigates mesoscale cylindrical ion trap (CIT) mass analyzer design and the benefits of CITs realized via additive manufactured metalized ceramic material systems for improved ion signal, low power performance, and extended dynamic range. Rugged monolithic miniature mass spectrometer ceramic CIT chips have been produced that have increased signal output with reduced power consumption. We have demonstrated via simulation and experiment ~80% and greater CIT ion detection efficiency, signal improvement of the percentage of analyzed ions detected, from 50% detection for conventional CIT designs. Utilizing a unique notched ring electrode design that increases the ion signal output to the detector, the electron ionization quantity and power required for mass spectrum generation and tuning was reduced by ~1 watt or 33%, as well as the required gain of the ion detector. Increased CIT ion detection efficiency effectively increases the total amount of the sample analyzed versus what is lost, thus increasing the instrument sensitivity and data collected, reducing duty cycle and power. Identical CITs of a ring electrode radius, ro = 1 mm, were fabricated from low temperature co-fired ceramic (LTCC) and the stainless steel (SS) for performance comparison and were tested in mass instability scanning and resonance ejection modes to produce Perfluorotribuytlamine (PFTBA) mass spectra. The ceramic material system offers design anFd material benefits which reduce the CIT power consumption by 29x from ~10.20 mW power consumption of the stainless steel CIT design to 0.36 mW for the ceramic CIT, as well as enabling batch fabrication, reduced cost and manufacturing defects. While the stated design and material system benefits may facilitate CIT and MS system miniaturization, and the production of the ceramic CIT chip, the proof of concept of CIT ion ejection efficiency via the notched ring electrode may enhance ion trap designs at any scale.

• Publisher: ProQuest Dissertations & Theses
• Subject: Engineering / Materials science
• ISBN: 9798684602382