William K Gallagher

US Patent:

41432754, Mar 6, 1979

Filed:

Sep 28, 1977

Appl. No.:

5/837552

Inventors:

Philip J. Mallozzi - Columbus OH
Harold M. Epstein - Columbus OH
Richard G. Jung - Columbus OH
David C. Applebaum - Columbus OH
Barry P. Fairand - Columbus OH
William J. Gallagher - Worthington OH
Ronald L. Uecker - Wausau WI
Myron C. Muckerheide - Schofield WI

Assignee:

Battelle Memorial Institute - Columbus OH

International Classification:

G03B 4100

US Classification:

250503

Abstract:

Method and apparatus for applying radiation by producing X-rays of a selected spectrum and intensity and directing them to a desired location. Radiant energy is directed from a laser onto a target to produce such X-rays at the target, which is so positioned adjacent to the desired location as to emit the X-rays toward the desired location; or such X-rays are produced in a region away from the desired location, and are channeled to the desired location. The radiant energy directing means may be shaped (as with bends; adjustable, if desired) to circumvent any obstruction between the laser and the target. Similarly, the X-ray channeling means may be shaped (as with fixed or adjustable bends) to circumvent any obstruction between the region where the X-rays are produced and the desired location. For producing a radiograph in a living organism the X-rays are provided in a short pulse to avoid any blurring of the radiograph from movement of or in the organism. For altering tissue in a living organism the selected spectrum and intensity are such as to affect substantially the tissue in a preselected volume without injuring nearby tissue.

US Patent:

40024032, Jan 11, 1977

Filed:

Oct 11, 1973

Appl. No.:

5/405444

Inventors:

Philip J. Mallozzi - Columbus OH
Harold M. Epstein - Columbus OH
David C. Applebaum - Columbus OH
William J. Gallagher - Worthington OH
Bernerd E. Campbell - Columbus OH

Assignee:

Battelle Memorial Institute - Columbus OH

International Classification:

G02B 523

US Classification:

350160R

Abstract:

Methods and apparatus for directing a radiation pulse from a laser to a target or other selected location and preventing undesired earlier radiation from the laser having less than a selected intensity from reaching the selected location. A beam splitter directs a major portion of the radiation pulse energy along a longer main path to a predetermined region and continuing on toward the selected location, and directs a minor portion along a shorter secondary path to the predetermined region. A reflective surface on a transparent support in the predetermined region prevents energy having less than the selected intensity from continuing on toward the selected location. The surface comprises a thin layer, as of aluminum, that remains substantially unimpaired until it is subjected to radiation having at least the selected itensity, and then is substantially removed in the area impinged by such radiation, so that when the minor portion of the radiation pulse energy along the shorter secondary path has at least the selected intensity, and thus substantially removes the impinged area of the reflective layer, the major portion of the radiation pulse reaching the predetermined region thereafter can continue on through the area of removal toward the selected location. Alternatively, the minor energy portion actuates an electrical discharge to vaporize the reflective layer at least substantially.

US Patent:

40607690, Nov 29, 1977

Filed:

Sep 20, 1974

Appl. No.:

5/507877

Inventors:

Philip J. Mallozzi - Columbus OH
Harold M. Epstein - Columbus OH
David C. Applebaum - Columbus OH
William J. Gallagher - Worthington OH
Bernerd E. Campbell - Columbus OH

Assignee:

Battelle Memorial Institute - Columbus OH

International Classification:

H01S 300
G02B 2714

US Classification:

330 43

Abstract:

Methods and apparatus for directing radiation pulses to a region wherein either a pulse or a substance in the region is adversely affected by the presence of more than a given power density therein. A laser pulse is split into a plurality of portions and each portion is directed along a path of different length to provide in rapid succession a plurality of pulses each having less than the given power density. Each pulse is caused to arrive at the region at an angle differing by at least its divergence angle from the arrival angle of every other pulse (or, if at a smaller angle from another pulse, with opposite polarization therefrom) and at a time enough later than the arrival time of the preceding pulse that the total power density in the region at any instant is less than the given power density. Thus, the effective total power density of the radiation directed through the region may exceed the given power density without adversely affecting any pulse or substance in the region. Typically, the region comprises an amplifier from which each pulse emerges at an angle differing by at least its divergence angle from the emergence angle of every other pulse (or, if at a smaller angle from another pulse, with opposite polarization therefrom).

US Patent:

40584860, Nov 15, 1977

Filed:

Dec 29, 1972

Appl. No.:

5/319756

Inventors:

Philip J. Mallozzi - Columbus OH
Harold M. Epstein - Columbus OH
Richard G. Jung - Columbus OH
David C. Applebaum - Columbus OH
Barry P. Fairand - Columbus OH
William J. Gallagher - Worthington OH

Assignee:

Battelle Memorial Institute - Columbus OH

International Classification:

G21G 400

US Classification:

250493

Abstract:

A method of producing X-rays by directing radiant energy from a laser onto a target. Conversion efficiency of at least about 3 percent is obtained by providing the radiant energy in a low-power precursor pulse of approximately uniform effective intensity focused onto the surface of the target for about 1 to 30 nanoseconds so as to generate an expanding unconfined coronal plasma having less than normal solid density throughout and comprising a low-density (underdense) region wherein the plasma frequency is less than the laser radiation frequency and a higher-density (overdense) region wherein the plasma frequency is greater than the laser radiation frequency and, about 1 to 30 nanoseconds after the precursor pulse strikes the target, a higher-power main pulse focused onto the plasma for about 10. sup. -3 to 30 nanoseconds and having such power density and total energy that the radiant energy is absorbed in the underdense region and conducted into the overdense region to heat it and thus to produce X-rays therefrom with the plasma remaining substantially below normal solid density and thus facilitating the substantial emission of X-rays in the form of spectral lines arising from nonequilibrium ionization states. The X-rays may be produced essentially as from a point source (i. e.