Preliminary Demonstration of an IonCCD as an Alternative Pixelated Anode for Direct MCP Readout in a Compact MS-Based Detector

Abstract

We report on the preliminary testing of a new position-sensitive detector (PSD) by combining a microchannel plate (MCP) and a charge-sensitive pixilated anode with a direct readout based on charge-coupled detector (CCD) technology, which will be referred to as IonCCD (Hadjar et al. , allowing it to be used directly behind an MC. This MCP-IonCCD configuration potentially obviates the need for electro-optical ion detector systems (EOIDs), which typically feature a relatively difficult-to-implement 5-kV power source as well as a phosphorus screen behind the MCP for conversion of electrons to photons prior to signal generation in a photosensitive CCD. Thus, the new system (MCP-IonCCD) has the potential to be smaller, simpler, more robust, and more cost efficient than EOID-based technologies in many applications. The use of the IonCCD as direct MCP readout anode, as opposed to its direct use as an ion detector, will benefit from the instant three-tofour-order-of-magnitude gain of the MCP with virtually no additional noise. The signal/noise gain can be used for either sensitivity or speed enhancement of the detector. The speed enhancement may motivate the development of faster IonCCD readout speeds (currently at 2.7 ms) to achieve the 2 kHz frame rate for which the IonCCD chip was designed, a must for transient signal applications. The presented detector exhibits clear potential not only as a trace analysis detector in scan-free mass spectrometry and electron spectroscopy but also as a compact detector for photon and particle imaging applications.

Fabrication and characterization of monolithically integrated microchannel plates based on amorphous silicon

“…These could be used in applications where both single-photon sensitivity and high temporal resolution are required, like simultaneous positron emission tomography and magnetic resonance imaging3334, today's hot topic in medical diagnostic. Finally, an AMCP vertically integrated on charge-coupled arrays (CCDs) could provide a variant of electron-bombarded CCD3536 (ebCCD) to be used in single-molecule spectroscopy1037 or mass spectrometry9.…”

“…Microchannel plates1 (MCPs) are well-established electron multipliers that were initially developed for night vision applications and astrophysics23 and progressively spread into different fields such as nuclear45 and plasma67 physics, mass spectrometry89 and biotechnology10. Electron multiplication in MCPs takes place inside long thin channels (also called pores), which replace the cascade of discrete dynodes in traditional photomultipliers.…”

Distance-of-Flight Mass Spectrometry with IonCCD Detection and an Inductively Coupled Plasma Source

“…One possibility to increase the sensitivity (and improve the detection limits for ICP-DOFMS) of the IonCCD camera is to add a preamplification stage to the detector. In a previous study, the IonCCD camera was shown to function as an effective anode for direct-MCP readout [28]. By the addition of an MCP as a pre-amplification stage, the IonCCD camera would gain three to four orders of magnitude in sensitivity.…”

High-efficiency cross-beam magnetic electron-impact source for improved miniature Mattauch-Herzog mass spectrometer performance

“…This source, along with a narrower object slit, may also be considered for use in conjunction with the MCP-enhanced IonCCD in an MH-MS. 25,29 Here the increased resolving power attributed to the narrower slit would be expected to more than offset the loss in resolving power caused by the MCP, and most of the large anticipated sensitivity increase for this system would arise from the inherently high gain of the MCP.…”

“…24) used in the work reported here, offer virtually no inherent signal gain, which places them at an inherent disadvantage relative to secondary electron-multiplier type detectors, even though much of the resulting sensitivity deficit can be offset by the simultaneous and continuous nature of non-scanning MH-MS detection. In another previous study, 25 therefore, we demonstrated the potential for addressing this sensitivity issue by using the IonCCD as an anode to directly readout a microchannel plate (MCP), by analogy to an earlier work using a different chip design. 26,27 The MCP increased the signal-tonoise ratio by a factor of about 3000 while keeping the instrument size unchanged, although mass spectral peaks were somewhat broadened, causing a loss of resolving power.…”