US 6,008,496 A · High resolution resonance ionization imaging detector and method

Abstract

A resonance ionization imaging device (RIID) and method for imaging objects using the RIID are provided, the RIID system including a RIID cell containing an ionizable vapor including monoisotopic atoms or molecules, the cell being positioned to intercept scattered radiation of a resonance wavelength .lambda..sub.1 from the object which is to be detected or imaged, a laser source disposed to illuminate the RIID cell with laser radiation having a wavelength .lambda..sub.2 or wavelengths .lambda..sub.2, .lambda..sub.3 selected to ionize atoms in the cell that are in an excited state by virtue of having absorbed the scattered resonance laser radiation, and a luminescent screen at the back surface of the RIID cell which presents an image of the number and position of charged particles present in the RIID cell as a result of the ionization of the excited state atoms. The method of the invention further includes the step of initially illuminating the object to be detected or imaged with a laser having a wavelength selected such that the object will scatter laser radiation having the resonance wavelength .lambda..sub.1.

Claims24

Dependent claims

A resonance ionization imaging device comprising:

a cell having an ionizable vapor of monoisotopic atoms or molecules contained therein;
said cell having means for receiving laser radiation scattered by an object to be imaged, said scattered laser radiation being of a first predetermined wavelength .lambda..sub.1, said first predetermined wavelength being a resonance wavelength of said ionizable vapor;
means for illuminating said cell with laser radiation sufficient to ionize a portion of said ionizable vapor, said portion being the atoms that have absorbed said scattered resonance laser radiation and are in an excited state;
and
means for detecting a number and a position of charged particles created within said cell as a result of said ionization of said portion of said ionizable vapor.

2 more elements

A method for imaging an object comprising the steps of:

positioning a detector cell having contained therein an ionizable vapor comprising monoisotopic particles to intercept scattered radiation from an object to be detected, a front surface of said detector cell facing and defining a direction of observation;
illuminating an object to be detected with laser radiation of a frequency and wavelength selected such that a wavelength .lambda..sub.1 of radiation scattered from said object corresponds to a resonance wavelength of said monoisotopic particles;
receiving at least a portion of said scattered radiation of wavelength .lambda..sub.1 in said detector cell, said scattered radiation being absorbed by a portion of said monoisotopic particles in said ionizable vapor, thereby producing an excited state in said portion of monoisotopic particles;
ionizing said portion of said monoisotopic particles that are in said excited state, by illuminating said ionizable vapor in said detector cell with narrowband ionization laser radiation of at least one wavelength .lambda..sub.2 selected to ionize said portion of said monoisotopic particles that are in said excited state;
and
detecting a number and position of charged particles in said detector cell created by said ionization of said excited state monoisotopic particles.

3 more elements

Dependencies are inferred from the claim text.

High resolution resonance ionization imaging detector and method

Life of this patent

High resolution resonance ionization imaging detector and method

Life of this patent

Abstract

Claims24