CHARLES D MARTIN
Broker in Arlington, MA
License number
Massachusetts 9015173
Issued Date
Nov 29, 1995
Expiration Date
Dec 10, 2001
Type
Salesperson
Address
Address
Arlington, MA 02474
Professional information
In-Line Reflecting Time-Of-Flight Mass Spectrometer For Molecular Structural Analysis Using Collision Induced Dissociation
US Patent:
6674069, Jan 6, 2004
Filed:
Sep 12, 2001
Appl. No.:
09/868345
Inventors:
Charles D. Martin - Arlington MA
Gary L. Samuelson - Amesbury MA
Edward E. Owen - Nashua NH
Jeffrey W. Finch - Mendon MA
Gary L. Samuelson - Amesbury MA
Edward E. Owen - Nashua NH
Jeffrey W. Finch - Mendon MA
Assignee:
Jeol USA, Inc. - Peabody MA
International Classification:
H01J 4940
US Classification:
250287
Abstract:
A tandem mass spectrometer apparatus includes an ion source ( ); a first mass spectrometer MS-1 having a magnetic sector ( ) and an electric sector ( ); and a second mass spectrometer MS-2 having a CID cell ( ), an offset parabolic ion mirror ( ) and an ion detector ( ).
Cryomagnet System With A Low-Loss Helium Cryostat Of Minimized Disturbances
US Patent:
5267445, Dec 7, 1993
Filed:
Feb 21, 1992
Appl. No.:
7/839966
Inventors:
Werner Schittenhelm - Westford MA
Charles Martin - Arlington MA
Beat Weber - Spreitenbach, CH
Beat Mraz - Hombrechtikon, CH
Charles Martin - Arlington MA
Beat Weber - Spreitenbach, CH
Beat Mraz - Hombrechtikon, CH
Assignee:
Spectrospin AG
International Classification:
F17C 704
US Classification:
62 481
Abstract:
A cryomagnet system, in particular for use with nuclear magnetic resonance (NMR) experiments or ion cyclotron resonance (ICR) experiments, with a low-loss helium cryostat (1) comprising a helium container (2) and one or a plurality of tubes for the feed or exit of helium into or out of the helium container (2), respectively, the tubes being sealed to the atmosphere outside the helium container (2) by at least one non-return low-pressure valve (4), wherein at least one exhaust pipeline (3) is provided with a device for dissipating the energy of the expanding helium. Such a device may consist of a chamber which is deviated from the exhaust pipeline (3) and has a wall material of very high extensibility, e. g. a folding balloon. Yet the device may also consist of a flow baffle which is provided in the exhaust pipeline (3), for example a porous disc (6).
Split Shield For Magnetic Resonance Imaging
US Patent:
5243286, Sep 7, 1993
Filed:
Jun 29, 1990
Appl. No.:
7/546503
Inventors:
Richard Rzedzian - Lexington MA
Charles Martin - Arlington MA
Charles Martin - Arlington MA
Assignee:
Advanced NMR Systems, Inc. - Wilmington MA
International Classification:
G01Y 300
US Classification:
324318
Abstract:
Narrower conductive strips are provided in a segmented RF shield to reduce the gradient coil power loss attributable to the shield. Narrower conductive strips reduce the eddy current losses experienced by the gradient coil, thereby reducing the power required to operate the gradient coil, especially in high speed imaging where high frequencies up to 10 KHz are used. The conductive strips can be made sufficiently narrow to substantially reduce the gradient coil power loss attributable to the shield. When these strips are made in this manner, a third conductive layer may be placed over a transition region where there is a substantial change in the direction of the conductive strips. In such a transition region, RF current tends to travel in curved paths across the pattern of conductive strips instead of along the lengths of the strips, with resulting decrease in coil quality factor, Q. The third conductive layer provides a lower impedance path for RF currents in the transition region, to reduce RF power loss. An ancillary conductor is connected to the RF shield in such a manner as to be insulated from the shield at the lower frequencies at which the gradient coil operates but capacitively connected at RF frequencies.