Robert P English

US Patent:

7015463, Mar 21, 2006

Filed:

Apr 9, 2003

Appl. No.:

10/508322

Inventors:

Robert J Cotter - Baltimore MD, US
Robert D. English - Galveston TX, US
Benjamin D. Gardner - Kalamazoo MI, US

Assignee:

The Johns Hopkins University - Baltimore MD

International Classification:

B01D 59/44
H01J 49/40

US Classification:

250288, 250281, 250282, 250283, 250286, 250287

Abstract:

A mass spectrometer that includes an ionizing source, a sample holder arranged in a beam path of the ionizing source, an ion detector disposed to receive ions extracted from a sample when held by the sample holder and irradiated by the ionizing source. The mass spectrometer also includes an extraction electrode arranged proximate to the sample holder, and a drift tube arranged between the extraction electrode and the ion detector. In the mass spectrometer, the extraction electrode and the drift tube are movable together relative to the sample holder, which is held at a fixed position.

US Patent:

7825374, Nov 2, 2010

Filed:

Feb 23, 2004

Appl. No.:

10/546323

Inventors:

Robert James Cotter - Baltimore MD, US
Benjamin D. Gardner - Colton CA, US
Robert D. English - Galveston TX, US
Serguei A. Ilchenko - Solon OH, US

Assignee:

The Johns Hopkins University - Baltimore MD

International Classification:

H01J 49/00

US Classification:

250287, 250281, 250396 R

Abstract:

A tandem mass spectrometer includes a linear time-of-flight mass analyzer and curved field reflectron mass analyzer. The curved-field reflectron mass analyzer is disposed at an end of the linear time-of-flight mass analyzer such that ions having a plurality of ion masses formed in the linear time-of-flight analyzer such that ions having a plurality of ion masses formed in the linear time-of-flight analyzer enter the curved-field reflectron mass analyzer. The tandem mass spectrometer also includes a mass selection gate disposed between the time-of-flight mass analyzer and the curved-field reflectron mass analyzer. The mass selection gate selects an ion mass from the plurality of ion masses. Furthermore, the tandem mass spectrometer also includes a dissociating component located in a path of the ions formed in the linear time-of-flight analyzer. The dissociating component causes dissociation of the ions into a plurality of ion fragments.