LCW-200 Chevron Wedge

The LCW-200 is an acrylic (PMMA) dual wedge that can be used to measure Proton beam and X-ray depth-dose relationships. It was designed to quickly provide accurate proximal edge measurements of an ion beam’s Bragg peak penetration range. The height of 212 mm allows proton beam equivalent penetration depths in water of up to 235 mm to be directly captured and measured.

The chevron wedges overlap so that measurements on the edge of one range can be duplicated at the beginning of the next. The wedge angle of 45 degrees enables symmetrical measurements to be made on each side of the center line and averaged for greater precision.

The 100 × 70 mm footprint allows the LCW-200 to be mounted securely above the scintillator of the XRV. The LCW-200P has wider chevrons (24 mm) and is recommended for the XRV-2000 Falcon, XRV-3000 Eagle, and XRV-4000. Mounting hardware firmly locks the LCW above the XRV target so that measurements can be easily made at any angle by rotating the phantom in its gantry cradle.

The acrylic (PMMA) composition of the LCW-200 has a water equivalent density of 1.17 for direct measurements of Bragg peak Proton depths up to 235 mm. More energetic beams can be accommodated by padding the bottom surface with additional acrylic or tissue equivalent plastic. The patent pending design may be enhanced with additional chevrons, so please contact us for custom configurations.

Features and Benefits:

• Fast Bragg peak measurement of water equivalent Proton beam range up to 235 mm
• 212 mm tall
• Acrylic (PMMA) composition
• Regular 100 × 70 mm and plus-size 100 × 140 mm footprints
• Accuracy better than 0.5 mm
• Measures Proton and X-ray beam depth-dose relationships
• Mounting hardware available for XRV-2000/3000/4000
• Easy handling for use at all gantry angles
• Compatible with film
• Automated image analysis and software measurement
• 35 energy layer Excel analysis template provided

The LCW-200P acrylic (PMMA) dual wedge has 24 mm thick chevrons yielding an overall footprint of 100 × 140 mm.

The WinLVS capture software has a built-in scripting language that facilitates automatic real-time capture of the multi-energy even-dose delivery pattern needed for Bragg peak measurements.

After each layer has been delivered, WinLVS merges the captured PBS image streaks to form complete radiographs. Once the 35 layers of the plan have been delivered, the Bragg peak regions on the radiographs are isolated and measured with the CSV formatted data being output to file. This CSV file can then be imported into an Excel template where the Bragg peak penetration depths are calculated.