GAFChromic Film, EBT-XD, 8"x10" (25/Box)

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GAFChromic Film, EBT-XD, 8"x10" (25/Box)

GAFCHROMIC™ EBT-XD is designed for the measurement of absorbed doses of ionizing radiation particularly suited  for high-energy photons. The dynamic range of this film is specifically designed for best performance in the dose range from 0.4 to 40 Gy which makes it best suited for applications such as SRS and SBRT. The structure of Gafchromic™ EBT-XD radiochronic film is comprised of an active layer, nominally 15μm thick, containing the active component, marker dye, stabilizers and other components giving the film its near energy-independent response. The thickness of the active layer may vary slightly from batch to batch. The active layer is sandwiched between two (2) 125μm matte polyester substrates.

Key Technical Features of Gafchromic™ EBT-XD include:

• Dynamic dose range: 0.1 Gy to 200 Gy
• Optimum dose range: 0.4 Gy to 40 Gy, best suited for applications such as SRS and SBRT
• Develops in rea time without post-exposure treatment
• Enery-dependence: minimal respnse difference from 100 keV into the MV range
• Near tissue equivalent
• High spatial resolution - can resolve features to at least 5μm
• Propietary new technology incorporating a marker dye in the active layer
• Enables non-uniformity correction by using multichannel dosimetry
• Decreases UV/light sensitivity
• Excellent uniformity
• Stable at temperatures up to 60°C (140°F)

The incorporation of a yellow marker dye, when used in conjunction with an RGB film scanner and FilmQAPro™ software  the EBT-XD film enables all the benefits of multi-channel dosimetry. 

Performance Data and Practical User Guidelines:

Like all other Gafchromic™ films, EBT-XD dosimetry film can be handled in normal room light for at least several hours without noticeable effects. However, it is suggested that the film should not be left exposed to room light indefinitely, but rather should be kept in the dark when it is not being handled. When the active component in Gafchromic™ EBT-XD film is exposed to radiation, it reacts to form a blue colored polymer with absorption maxima at approximately 633 nm.

Gafchromic™ EBT-XD radiochromic dosimetry film is recommended to be digitalized to obtain 2 dimensional information in speedy fashion using 48 bit color depth flatbed color scanners. The commonly available professional photo scanners such as EPSON Expression 11000XL, V750, V700 and 1680 flatbed color scanners can be used. These scanners are color scanners and measure the red, green, and blue color components of the film at a color depth of 16 bit per channel. EPSON Expression 11000XL is particularly recommended due to its large scanning area that allows the least amojnt of lateral effect. 

Performance Comparison between EBT3 and EBT-XD film:

As mentioned earlier, Gafchromic™ EBT-XD is specifically designed to obtain optimum results for the applications or SRS and SBRT. The high dose associated with these applications poses many challenges when EBT3 films are used. The two (2) main problems are the increased uncertaintly at high dose and potentially unacceptable lateral scan effect. 

Due to the chromatic nature of Gafchromic™ film, it does not have clear color saturation points. This is especially important when FilmQA Pro software is used for the analysis, since it takes advantage of all available color channels that effectively extend the dynamic range of the film. However, a shallow slope for the dose response curve can cause increased dosimetric error for high dose region. For the dose range between 10 and 20 Gy, EBT-XD film provides a more desirable calibration than EBT3.

As noted by many users, flatbed scanners used for film measurement exhibit a lateral scan effect, i.e., the color value measured can vary depending upon the location of the film placement relative to the center of the scanner. Typically film scanned away from the center location will have lower color pixel values which result in higher calculated doses. The variation (lateral effect) increases with color density of the film as results of the increased dose. 

The active particles in EBT-XD film are significantly smaller than those in EBT3 film. The smaller particle size reduces light scattering and polarization and in combination with lower color density when compared to EBT3 films exposed to the same dose, is believed to reduce the lateral effect. 

Specifications:

Configuration: Active layer (25 μm) sandwiched between on 5 mil(125 μm) matte surface clear polyester substrate

Size: 8" x 10"

Dynamic Dose Range: 0.1 to 200 Gy

Energy Dependency: <5% difference in net optical density when exposed at 100 keV and 18 MeV

Dose Fractional Response: <5% difference in net optical density for a single 25 Gy dose and five cumulative 5 Gy doses at 30 minute intervals

Dose Rate Response: <5% difference in net optical density for 10 Gy exposures at rates of 3.4 Gy/min. and 0.034 Gy/min.

Stability in Light: <5x10-3 change in optical density per 1000 lux-day

Stability in Dark (Pre-exposure): <5x10-4 optical density change/day at 23°C (73.4°F) and <2x10-4 density change/day refrigerated

Uniformity: Better than 3% in sensitometric response from mean