Simon Foner

Author:

Simon Foner

ISBN #:

0306357216

Author:

Simon Foner

ISBN #:

0306357011

Author:

Simon Foner

ISBN #:

0306407507

Author:

Simon Foner

ISBN #:

0677153902

US Patent:

40053580, Jan 25, 1977

Filed:

Oct 7, 1974

Appl. No.:

5/513090

Inventors:

Simon Foner - Belmont MA

International Classification:

G01R 3312

US Classification:

324 34R

Abstract:

An improved magnetometer for measuring the magnetic moment of a sample. Signals representative of magnetic moment are provided in known phase relation with respect to a driving signal and in phase with the motion of the sample, while spurious signals, such as produced by eddy currents are in an out-of-phase relationship with sample motion. Distortions in the measured magnetic moment due to eddy currents and other out-of-phase spurious signals are eliminated by cancellation of the out-of-phase signals through an AC feedback network. An output signal comprising the magnetic moment signal and spurious signals is applied to a phase sensitive detector whose DC output represents the amplitude of the spurious out-of-phase signal which it is sought to eliminate. The detector output may be used to control a variable amplifier which in turn supplies an AC signal in a feedback arrangement to either a reference signal source or to summing means which combines the reference signal with the output signal in order to cancel the out-of-phase signal. Alternatively, the AC feedback signal may be supplied by a manually controlled attenuator or amplifier in response to the detector output.

US Patent:

40371492, Jul 19, 1977

Filed:

Dec 18, 1975

Appl. No.:

5/641741

Inventors:

Simon Foner - Belmont MA

International Classification:

G01R 3312

US Classification:

324 34R

Abstract:

A magnetometer in which at least two modes of drive are employed in exciting sensor and/or sample so that the sensor provides an output indication of magnetic moment which is a function of both drive modes. The drive modes may be periodic at specific driving frequencies, aperiodic or may comprise a unidirectional portion of a mode. The output of the sensor contains components representative of the frequency or frequencies of the first mode modulated at the frequency or frequencies of the second mode. This sensor output is then analyzed to provide an indication of sample magnetic moment as a function of the frequency components of both modes of drive in order to eliminate contributions to the indicated magnetic moment from background signals or other perturbations which may be present under single mode operation. The multiple mode magnetometer is useful in several embodiments for production line applications, investigations of magnetic properties of inhomogeneous magnetic materials, as well as for general magnetic moment measurements. The concept of a multimode magnetometer also may be extended to include a multiplicity of modes.

US Patent:

40061078, Feb 1, 1977

Filed:

Aug 13, 1975

Appl. No.:

5/604384

Inventors:

Simon Foner - Belmont MA
Edward J. McNiff - Danvers MA
Edwin J. Alexander - Danvers MA

Assignee:

The United States of America as represented by the United States Energy
Research and Development Administration - Washington DC

International Classification:

C01B 1700
H01L 3900

US Classification:

252518

Abstract:

The method of preparing Pb. sub. x Mo. sub. y S. sub. z where x = 0. 8-1. 1, y = 4. 5-5. 6, and z = 5. 4-7. 2 comprising the steps of mixing commercial reagent grade powders of the reactants, heating in a sealed, evacuated reaction vessel to a temperature of 950. degree. -1150. degree. C, maintaining the temperature until the compound is formed, and then cooling the compound at a controlled rate not in excess of 4. degree. C per minute.