Solid state gamma ray dosimeter which measures radiation in terms of absorption in a material different from the detector material

• US 4,859,853 A
• Filed: 02/04/1988
• Issued: 08/22/1989
• Est. Priority Date: 02/04/1988
• Status: Expired due to Term

• Current Assignee: United States Of America As Represented By The Secretary Of The Army (Government of the United States of America)
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Kronenberg, Stanley
• Primary Examiner(s): FIELDS, CAROLYN
• Application Number:
  US07/152,128
• Time in Patent Office: 565 Days
• Field of Search: 250/370.07, 250/370.14, 250/370.13, 250/370.01
• US Class Current: 250/370.07
• CPC Class Codes: G01T 1/026 Semiconductor dose-rate meters
• CPC Class Codes: G01T 1/24 with semiconductor detectors

Abstract

A solid state gamma ray dosimeter which measures radiation in terms of absorption in a material different from the detector material. A solid state detector, an amplifier, an analog-to-digital interface and a microprocessor are combined in circuit to correct for differences between absorption of radiation in detector material and absorption in other materials, especially tissue. A suitable cladding may surround the detector. A method of generating dose translation data for calibrating the microprocessor is also disclosed. The solid state detector is attached to a multichannel analyzer circuit and subject to known doses of various monochromatic gamma rays. Output pulses from the detector are amplified and introduced into the multichannel analyzer. The spectrum produced is used to determine an average channel number (or pulse height) for a given dose of monochromatic radiation. The given dose is in units specific to material different from the detector material. The partial dose represented by a single detector pulse at that energy is computed. Partial doses for other energies are likewise computed. Dose translation data associates a partial dose with a given detector pulse height. Dose translation data is set in the microprocessor of the dosimeter. Such dose translation data can be used to calculate total dose and dose rate in units peculiar to material other than detector material.

Claims

1. A radiation dosimeter, comprising:

A solid state detector which produces an output pulse when radiation is absorbed;

an amplifier connected to said solid state detector which receives said output pulse and which produces an amplified pulse proportional to said output pulse;

an analog-to-digital interface connected to said amplifier which receives said amplified pulse and which converts said amplified pulse into a corresponding digital output;

a microprocessor connected to said analog-to-digital interface which receives said digital output and which associates said digital output with non-tissue dose translation data to produce a non-tissue dose measurement.

2. A radiation dosimeter, comprising:

A solid state detector which produces an output pulse when radiation is absorbed;

an amplifier connected to said solid state detector which receives said output pulse and which produces an amplified pulse proportional to said output pulse;

an analog-to-digital interface connected to said amplifier which receives said amplified pulse and which converts said amplified pulse into a corresponding digital output; and

a microprocessor connected to said analog-to-digital interface which receives said digital output and which associates said digital output with dose translation data to produce a dose measurement;

wherein the solid state detector is substantially surrounded by a cladding material identical to the detector material;

wherein the thickness of said cladding material is greater than the maximum range of energetic electrons emitted upon absorption of gamma rays which constitute the radiation to which the dosimeter is exposed; and

wherein the dimensions of the solid state detector and said cladding material are less than the maximum range of the gamma rays which constitute the radiation to which the dosimeter is exposed.

3. The dosimeter as recited in claim 2 wherein the dose measurement is expressed in units of rads (tissue).