Nuclear Associates
37-040 (HD-810) and 37-041 (MD-55)
GAFCHROMIC® Therapy Dosimetry Media
March 2005
Manual No. 37-040-1 Rev. 2
©2004, 2005 Fluke Corporation, All rights reserved. Printed in U.S.A.
All product names are trademarks of their respective companies
Users Manual
Fluke Biomedical
Radiation Management Services
6045 Cochran Road
Cleveland, Ohio 44139
440.498.2564
www.flukebiomedical.com/rms
Table of Contents
Section 1: Introduction................................................................................................ 1-1
1.1 GAFCHROMIC Dosimetry Media ................................................................ 1-1
1.2 Description................................................................................................... 1-1
1.3 Labeling ....................................................................................................... 1-2
1.4 Handling....................................................................................................... 1-2
1.5 Storage of unexposed Dosimeters/Dosimetry Media................................... 1-2
1.5.1 Temperature........................................................................................... 1-2
1.5.2 Relative Humidity.................................................................................... 1-2
1.5.3 Visible Light ............................................................................................ 1-2
1.5.4 Ultraviolet Light....................................................................................... 1-3
1.5.5 Microwave Radiation .............................................................................. 1-3
1.5.6 Solvents.................................................................................................. 1-3
1.6 Storage of Exposed Dosimeters/Dosimetry Media ...................................... 1-3
1.6.1 Temperature........................................................................................... 1-3
1.6.2 Relative Humidity.................................................................................... 1-3
1.6.3 Visible Light ............................................................................................ 1-3
1.6.4 Ultraviolet Light....................................................................................... 1-4
1.6.5 Microwave Radiation .............................................................................. 1-4
1.6.6 Solvents.................................................................................................. 1-4
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1.1 GAFCHROMIC™
Dosimetry Media
• Sensitive to Gamma, Electron, X-ray, Deep
uv and Ionizing Radiation
• Self developing - no processing
• White light insensitive
• Dose rate independent
• Easy to use
Introduction
GAFCHROMIC Dosimetry Media
Section 1
Introduction
1
1.2 Description
GAFCHROMIC Dosimetry Media has been
developed for use with ionizing radiation. The
indicating film does not require any processing to
develop or fix the image; the image is available for use immediately after the exposure has been
completed.
The GAFCHROMIC Dosimetry Media is particularly useful for routine dosimetry, dose mapping, beam
profiling and high-resolution radiography.
Exposed and unexposed dosimetry media has remarkable stability. Nevertheless, since there is no step
analogous to the fixing step whereby unexposed silver halide is removed from conventional film, the film
remains active indefinitely.
GAFCHROMIC dosimetry media have a 7-micron radiation sensitive layer on a 4-mil polyester base. It is
colorless, grainless and transparent before exposure. The color is a function of the radiation exposure;
higher exposures result in progressively darker blue. This change can be measured accurately (with a
spectrophotometer or other device that measures optical density or absorbance) to calculate applied
dosage.
GAFCHROMIC dosimetry media is composed of materials with low atomic numbers and will not alter the
radiation fields of most products. Further, the material is insensitive to normal room light.
GAFCHROMIC dosimetry media may be used over a wide range of absorbed doses. Typical dose
calibration tables are provided in Tables 1-1 and 1-2 for measurement with a spectrophotometer at 400,
500 and 580 nanometers. (When using a device other than a spectrophotometer the device should be
calibrated using reference dosimeters.) Since there is some post-exposure darkening and changes in
dose/density response at elevated temperatures, care should be taken to adjust readings using Table 1-
4. It is recommended that measurements be taken 24 hours after the end of irradiation. However, Table
1-5 allows for readings made at other times.
These instructions deal with the precautions that should be exercised when using or storing exposed or
unexposed dosimeters/dosimetry film. When optimum storage conditions are maintained, it is believed
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Operators Manual
that the exposed dosimetry media are likely to have archival qualities. This manual also contains specific
directions for the labeling of all dosimetry media samples.
1.3 Labeling
Unexposed dosimetry media should always be labeled with the batch number of the product. In addition,
a user label to identify the exposure conditions, date, time, etc., should always be used in conjunction with
an exposed dosimeter. The batch numbers provide an audit trail whereby process conditions and raw
materials can be identified and traced if a problem occurs.
The batch number is to be found printed on the package containing sheets of dosimetry media.
1.4 Handling
Unexposed and exposed dosimetry media should be handled only by the edges. It is recommended that
the paper covering the coated side be left on, until immediately prior to reading the dosimeters, to protect
the active coating. When writing on the media be careful not to exert pressure on the active area of other
sheets of dosimetry media.
Prior to reading the dosimetry media, visually inspect the reading area to ensure that there are no flaws or
marks, which might affect the reading. Remove loose particles by light rubbing with a lint-free paper or
cloth. If flaws or marks cannot be removed and readings cannot be taken in other areas of the dosimeter,
discard the dosimeter.
Unexposed dosimetry media should be handled by the edges or corners, taking care not to place
fingerprints in areas of the film that are to be imaged. Wearing cotton gloves while handling film is
recommended as the best way to avoid fingerprinting or scratching the film.
1.5 Storage of Unexposed Dosimeters/Dosimetry Media
1.5.1 Temperature
Where possible, store below 25°C (77°F). Although experiments have consistently shown that
GAFCHROMIC dosimetry media suffer no ill effects at temperatures up to 50°C (122°F), adherence to a
maximum storage temperature of 25°C (77°F) will provide the longest life. Never expose dosimetry media
to temperatures exceeding 65°C (149°F).
1.5.2 Relative Humidity
When the dosimetry media are kept below 25°C (77°F), they should be unaffected by any humidity below
100%. However, a dry storage location at 50% RH, or less, is preferred.
1.5.3 Visible Light
Unopened boxes of dosimeters/dosimetry media are adequately protected against all visible light
conditions. Although the dosimetry media have almost insignificant sensitivity towards visible light, it is
recommended that opened packages of the media be kept away from all unnecessary exposure to light,
particularly because visible light sources sometimes have an ultraviolet component that can be
deleterious to the dosimeters. Therefore, store unexposed dosimeters/dosimetry media in their packages,
with the covers closed.
1-2
Introduction
Storage of Unexposed Dosimeters/Dosimetry Media
1
1.5.4 Ultraviolet Light
The dosimetry media have increasing sensitivity to radiation at decreasing wavelengths below the visible
region. Therefore, exposure to any source containing an ultraviolet component, including sunlight, is not
recommended.
1.5.5 Microwave Radiation
Exposure to microwave radiation may cause heating of the dosimetry media and is therefore not
recommended.
1.5.6 Solvents
The vapors of organic solvents may diffuse into the active layer of the dosimetry media and have adverse
effects upon the radiation sensitive component. Incidental contact with such vapors is unlikely to cause
harm, but continuous exposure is to be avoided. Neither is it recommended that any liquid solvent,
aqueous or nonaqueous, be allowed to contact the surface of the dosimetry media. If an aqueous or nonaqueous solvent were to wet the surface of unexposed
contaminated dosimeters or media be discarded.
dosimeters or media, it is recommended that the
1.6 Storage Of Exposed Dosimeters/Dosimetry Media
1.6.1 Temperature
The normally blue color of exposed dosimetry media rapidly converts to an orange-red color at
temperatures above 65°C (149°F). Therefore, never subject exposed dosimeters/dosimetry media to
temperatures exceeding 60°C (140°F). For optimum results store exposed
where the temperature will be
below 25°C (77°F).
dosimetry media in the dark,
1.6.2 Relative Humidity
Although high relative humidity, i.e. <80%, is not deleterious at low temperatures, i.e. <25°C (77°F),
the combination of high temperature, i.e. <60°C (140°F), and high relative humidity can increase the rate
at which the blue to red-orange color change occurs.
Therefore, do not subject exposed dosimetry media to high humidity and high temperature, i.e. <85% RH
and <60°C (140°F). Where possible, it is recommended that exposed dosimeters/dosimetry media be
stored in the dark where the relative humidity is less than 50% and the temperature is below 25°C (77°F).
1.6.3 Visible Light
Although the dosimeters/dosimetry media have almost insignificant sensitivity towards visible light, it is
recommended that unnecessary exposure be avoided, so that the maximum lifetime may be obtained.
This is particularly so because visible radiation sources frequently have an ultraviolet component that will
cause more rapid increases in optical density. Therefore, when exposed dosimeters/dosimetry media are
not being used, do not leave them laying on a laboratory bench or table, the measurement stage of a
densitometer, the sample holder of a spectrophotometer, desktop, etc. Store exposed dosimetry media in
the dark. Exposed dosimetry media should be stored in a glassine, plastic or paper envelope, preferably
black.
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1.6.4 Ultraviolet Light
The radiation sensitive component in the dosimetry media has increasing sensitivity to radiation as the
wavelength of the radiation decreases below that of visible light. Therefore, exposure to any source
containing an ultraviolet component, including sunlight, is not recommended.
1.6.5 Microwave Radiation
Microwave radiation may cause heating or other deleterious effects in exposed dosimeters/dosimetry
media, and exposure to such sources should be avoided.
1.6.6 Solvents
Long-term contact with many aqueous and non-aqueous solvents has been found to cause exposed
dosimetry media to change irreversibly from blue to red. It is therefore recommended that exposed
dosimeters/dosimetry media be kept away from all aqueous and non-aqueous solvents, as well as the
vapors of solvents. If a solvent is accidentally spilled on an exposed dosimeter/dosimetry media, the spill
should be blotted up with an absorbent, lint-free paper or cloth. If the solvent is volatile, the last traces
may be removed by drying in an airstream at ambient temperature (<25°C).
If the liquid is not volatile, it is permissible to quickly rinse the dosimeter/dosimetry media in isopropanol.
The excess isopropanol should be immediately blotted dry and the last traces removed by blowing in a
cool airstream (<25°C).
Table 1-1. Typical Dose Calibration Curves with a Spectrophotometer (24 hours after irradiation at 25°C)
400 Nanometers
Optical Density
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Absorbed Dose, kRads
Optical
Density
0.370 100 1.025 700 1.460 1,750
0.400 120 1.035 720 1.475 1,800
0.430 140 1.050 740 1.490 1,850
0.465 160 1.060 760 1.505 1,900
0.500 180 1.070 780 1.520 1,950
0.535 200 1.080 800 1.535 2,000
0.570 220 1.092 820 1.562 2,100
0.602 240 1.105 840 1.587 2,200
0.635 260 1.115 860 1.612 2,300
0.662 280 1.125 880 1.637 2,400
0.690 300 1.135 900 1.662 2,500
0.715 320 1.145 920 1.685 2,600
0.737 340 1.155 940 1.707 2,700
0.760 360 1.160 960 1.728 2,800
0.782 380 1.170 980 1. 750 2,900
0.802 400 1.180 1,000 1.770 3,000
0.822 420 1.205 1,050 1.788 3,100
0.837 440 1.225 1,100 1.807 3,200
0.857 460 1.245 1,150 1.825 3,300
0.872 480 1.265 1,200 1.843 3,400
0.890 500 1.285 1,250 1.860 3,500
0.905 520 1.305 1,300 1.877 3,600
0.920 540 1.325 1,350 1.893 3,700
0.935 560 1.342 1,400 1.910 3,800
0.947 580 1.360 1,450 1.925 3,900
0.962 600 1.380 1,500 1.940 4,000
0.975 620 1.395 1,550 1.955 4,100
0.987 640 1.412 1,600
1.000 660 1.430 1,650
1.015 680 1.445 1,700
Absorbed
Dose, kRads
Optical
Density
Absorbed
Dose, kRads
Optical
Density
Absorbed
Dose, kRads
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Table 1-2. Typical Dose Calibration Curves with a Spectrophotometer (24 hours after
irradiation at 25°C)
500 Nanometers
Optical Density
1-6
Introduction
Storage of Exposed Dosimeters/Dosimetry Media
1
Absorbed Dose, kRads
Optical
Density
0.175 10 0.742 95
0.180 11 0.775 100
0.187 12 0.840 110
1.195 13 0.905 120
0.200 14 0.967 130
0.205 15 1.030 140
0.212 16 1.090 150
0.220 17 1.145 160
0.225 18 1.205 170
0.230 19 1.260 180
0.237 20 1.310 190
0.250 22 1.365 200
0.265 24 1.465 220
0.277 26 1.560 240
0.290 28 1.652 260
0.305 30 1.740 280
0.317 32 1.825 300
0.330 34 1.905 320
0.345 36 1.985 340
0.357 38 2.060 360
0.370 40 2.135 380
0.385 42 2.205 400
0.397 44 2.275 420
0.410 46 2.345 440
0.425 48 2.410 460
0.437 50 2.475 480
0.470 55 2.540 500
0.505 60 2.605 520
0.540 65 2.667 540
0.575 70 2.730 560
0.607 75 2.790 580
0.640 80 2.852 600
0.675 85 2.912 620
0.710 90
Absorbed
Dose, kRads
Optical
Density
Absorbed
Dose, kRads
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Operators Manual
Table 1-3. Typical Dose Calibration Curves with a Spectrophotometer (24 hours after
580 Nanometers
Optical Density
irradiation at 25°C)
1-8
Introduction
Storage of Exposed Dosimeters/Dosimetry Media
1
Absorbed Dose, kRads
Optical
Density
0.210 5 1.215 48
0.235 6 1.265 50
0.255 7 1.305 52
0.280 8 1.350 54
0.305 9 1.395 56
0.325 10 1.440 58
0.350 11 1.485 60
0.375 12 1.535 62
0.400 13 1.575 64
0.425 14 1.625 66
0.450 15 1.670 68
0.475 16 1.715 70
0.500 17 1.780 72
0.525 18 1.850 74
0.550 19 1.855 76
0.575 20 1.895 78
0.625 22 1.935 80
0.670 24 2.025 84
0.720 26 2.100 88
0.765 28 2.175 92
0.815 30 2.235 96
0.860 32 2.300 100
0.905 34 2.350 104
0.950 36 2.400 108
0.995 38 2.450 112
1.040 40 2.490 116
1.085 42 2.530 120
1.130 44 2.560 124
1.175 46
Absorbed
Dose, kRads
Optical
Density
Absorbed
Dose, kRads
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Table 1-4. Optical Density* of GAFCHROMIC Media at Various Temperatures
Wavelength 400nm 500nm 580nm
Absorbed Dose Temperature Temperature Temperature
50 kRads 0.257 0.266 0.284 0.416 0.437 0.493 1.190 1.265 1 .453
100 kRads 0.353 0.370 0.408 0.723 0.775 0.895 2.142 2.300 2.659
500 kRads 0.825 .0.890 0.913 2.306 2.540 2.632
1,000 kRads 1.135 1.180 1.201
* Data read 24 hours after irradiation.
10°C 25°C 40°C 10°C 25°C 40°C 10°C 25°C 40°C
Table 1-5. Post-Irradiation Density Growth at 25°C
Wavelength 400nm 500nm 580nm
Time After
Absorbed
Dose kRads 5 Hrs 24 Hrs 5 Hrs 24 Hrs 5 Hrs 24 Hrs
5.1 0.165 0.166 0.138 0.173 0.208 0.212
10.0 0.177 0.177 0.140 0.175 0.315 0.325
20.0 0.197 0.198 0.232 0.237 0.560 0.575
30.0 0.220 0.221 0.300 0.305 0.801 0.815
40.0 0.239 0.241 0.361 0.370 1.021 1.040
50.0 0.264 0.266 0.427 0.437 1.232 1.265
60.0 0.284 0.286 0.498 0.505 1.464 1.485
70.0 0.306 0.311 0.563 0.575 1.684 1.715
80.0 0.325 0.329 0.629 0.640 1.896 1.935
90.0 0.346 0.351 0.696 0.710 2.097 2.137
100.0 0.363 0.370 0.760 0.775 2.263 2.300
200.0 0.529 0.535 1.346 1.365
300.0 0.680 0.690 1.791 1.825
400.0 0.790 0.802 2.166 2.205
500.0 0.876 0.890 2.487 2.540
600.0 0.944 0.962 2.791 2.852
700.0 1.008 1.025
800.0 1.063 1.080
900.0 1.114 1.135
1000.0 1.160 1.180
1500.0 1.343 1.380
2000.0 1.494 1.535
2500.0 1.603 1.662
3000.0 1.708 1.770
3500.0 1.783 1.860
4000.0 1.856 1.940
Irradiation
Time After
Irradiation
Time After
Irradiation
1-10
Storage of Exposed Dosimeters/Dosimetry Media
Net Optical Density
GAFCHROMIC Film
Equiv Photon
28 keV
44 keV
79 keV
97 keV
127 keV
142 keV
1.71 MeV
Dose (Gy)
Introduction
1
X – omat V Film
LiF TLD Chips
GAFCHROMIC Film
Relative Sensitivity
Equivalent Photon Energy (keV)
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Operators Manual
Y Distance mm
Yale Ir–192 10-Ci Source as cGy/s
X Distance mm
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Fluke Biomedical
Radiation Management Services
6045 Cochran Road
Cleveland, Ohio 44139
440.498.2564
www.flukebiomedical.com/rms
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