Apparatuses and methods for laser reading of thermoluminescent phosphors

Patent · Sun Jan 01 00:00:00 EST 1989

OSTI ID:867002

Braunlich, Peter F ^[1]; Tetzlaff, Wolfgang ^[2]

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1. SW. 730 City View, Pullman, WA 99163
2. Pullman, WA

Apparatuses and methods for rapidly reading thermoluminescent phosphors to determine the amount of luminescent energy stored therein. The stored luminescent energy is interpreted as a measure of the total exposure of the thermoluminescent phosphor to ionizing radiation. The thermoluminescent phosphor reading apparatus uses a laser to generate a laser beam. The laser beam power level is monitored by a laser power detector and controlled to maintain the power level at a desired value or values which can vary with time. A shutter or other laser beam interrupting means is used to control exposure of the thermoluminescent phosphor to the laser beam. The laser beam can be equalized using an opitcal equalizer so that the laser beam has an approximately uniform power density across the beam. The heated thermoluminescent phosphor emits a visible or otherwise detectable luminescent emission which is measured as an indication of the radiation exposure of the thermoluminscent phosphors. Also disclosed are preferred signal processing and control circuits including one system using a digital computer. Also disclosed are time-profiled laser power cycles for pre-anneal, read and post-anneal treatment of phosphors.

• Research Organization: INTERNATIONAL SENSOR TECHNOL
• DOE Contract Number: AC03-84ER80165
• Assignee: Braunlich; Peter F. (Pullman, WA) [*] Notice: portion of term of this patent subsequent to January 20, 2004 has been disclaimed.
• Patent Number(s): US 4839518
• OSTI ID: 867002
• Country of Publication: United States
• Language: English

Related Subjects

apparatuses
methods
laser
reading
thermoluminescent
phosphors
rapidly
determine
amount
luminescent
energy
stored
therein
interpreted
measure
total
exposure
phosphor
ionizing
radiation
apparatus
generate
beam
power
level
monitored
detector
controlled
maintain
desired
value
values
vary
time
shutter
interrupting
means
control
equalized
opitcal
equalizer
approximately
uniform
density
heated
emits
visible
otherwise
detectable
emission
measured
indication
thermoluminscent
disclosed
preferred
signal
processing
circuits
including
digital
computer
time-profiled
cycles
pre-anneal
post-anneal
treatment
luminescent energy
control circuits
thermoluminescent phosphors
thermoluminescent phosphor
signal processing
control circuit
power level
laser beam
ionizing radiation
power density
beam power
power cycle
digital computer
radiation exposure
laser power
reading thermoluminescent
stored luminescent
stored therein
approximately uniform
phosphor emits
circuits including
energy stored
luminescent emission
rapidly reading
signal process
desired value
luminescent phosphor
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