Massachusetts Institute of Technology

Other

Harold F Hemond

Ian W Hunter

Brian D Hemond

Charles David Harvey

Chee Loon Ng

Alan T Gardner

Ann E Mulligan

Schuyler Senft-Grupp

Terence Hammar

A miniature, low cost mass spectrometer capable of unit resolution over a mass range of 10 to 50 AMU. The mass spectrometer incorporates several features that enhance the performance of the design over comparable instruments. An efficient ion source enables relatively low power consumption without sacrificing measurement resolution. Variable geometry mechanical filters allow for variable resolution. An onboard ion pump removes the need for an external pumping source. A magnet and magnetic yoke produce magnetic field regions with different flux densities to run the ion pump and a magnetic sector mass analyzer. An onboard digital controller and power conversion circuit inside the vacuum chamber allows a large degree of flexibility over the operation of the mass spectrometer while eliminating the need for high-voltage electrical feedthroughs. The miniature mass spectrometer senses fractions of a percentage of inlet gas and returns mass spectra data to a computer.

Methods, apparatus, and system for mass spectrometry

A highly compact multi-optical-junction optical flowcell includes a housing having an internal channel, to which a plurality of source optical signal modules can be coupled, e.g., in a peripheral manner. The source optical signal modules can include a set of LEDs and/or semiconductor lasers, and can be coupled to the flowcell by way of a standard optical coupling such as an SMA-type optical connector. An excitation detection apparatus or subsystem can also be coupled to the flowcell to facilitate multiple types of optical measurements, including fluorescence spectroscopy, absorption spectroscopy, and turbidity measurements. A sensing apparatus or system that includes a multi-optical-junction optical flowcell, a plurality of source optical signal modules, and an excitation detection apparatus can be carried by or deployed on a wide variety of platforms, such as Autonomous Underwater Vehicles (AUVs), Autonomous Surface Vehicles (ASVs), buoys, or other platforms, in a space efficient and power efficient manner.

Highly compact multi-optical-junction optical flowcell and flexibly deployable optical sensing assemblies and systems for in-situ real-time spectroscopic measurements

The systems and methods described herein related to measuring hydraulic parameters across a surface water-aquifer interface. In particular, the systems include a pressure differential sensor within a watertight housing. The pressure differential sensor has two inlets, one of which is connected to a piezometer located in an aquifer, and the other of which is connected to a surface water body. A solenoid valve allows the systems to switch between a first, measurement configuration and a second, calibration configuration. A pump and a conductivity-temperature sensor enable a third and fourth configuration for measuring the electrical conductivity and temperature of surface water and groundwater. The collected data is then locally stored or transmitted wirelessly. The low-power components and calibration capabilities of the systems allow for long-term deployment, on the order of six months or more.

Differential pressure systems and methods for measuring hydraulic parameters across surface water-aquifer interfaces

A portable mass spectrometer system. The system includes a sample inlet for receiving a sample of analyte molecules and an ion source for producing sample ions by ionization of the sample molecules. A cycloid mass analyzer is provided and adapted to receive the sample ions. The mass analyzer has a means for inducing an electric field in an analysis region and a rear earth permanent magnet material for inducing a static magnetic field in the analysis region, oriented substantially normal to the electric field. A detector is provided for detection of said sample ions in the analysis region. A vacuum means maintains a low pressure in the analysis region. In various embodiments, the system is hand-portable and self-contained, including a 12V rechargeable battery power supply, and a magnet that includes a rare earth permanent magnetic material such as neodymium-iron and samarium-cobalt alloys.

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Lexington, MA, United States of America

Harold F Hemond