Premium designs provide the best performances but have a PMT with a diameter slighter larger than the scintillation crystal diameter. Compact designs use a PMT with the same diameter as the scintillation crystal.
For “Premium” designs, we are able to guarantee 3.0% @ 662keV for LaBr and 2.5% @ 662keV for Enhanced LaBr.
Typically, for “Compact” designs, we are able to guarantee 3.5% @ 662keV for LaBr and 3.0% @ 662keV for Enhanced LaBr.
To illustrate, here is the design of the compact 51S51/2/LaBr (2-4-5994) and the equivalent premium design 51S51/3/LaBr (2-3-6214). The crystal dimensions are the same, but the PMT diameter is different.
Plastic scintillator can be bent to hold a shape. Typically, the temperature would need to be in the 80 – 90 °C range, and the surface being bent should be one of the polished surfaces. Cool the plastic completely before removing from the bending fixture. If done correctly, the performance properties of the plastic should not be affected.
This is related to the number of dynodes the PMT has. Your electronics should match with the dynode structure.
This is an option with our MCA offerings
Our standard warranty is two years for workmanship issues and we pass on the one year warranty from the photomultiplier tube vendor. The expected lifetime is approximately 5-10 years. This time frame is based upon limited data from non-warranty returns provided to Saint-Gobain for scrap or refurbishment. Many of the detectors have been in the field for more than ten years without any issues. NaI(Tl) crystals and photomultiplier tubes are thermally and mechanically shock sensitive. Overexposure to either can cause premature failures. Care should be taken when handling the detectors. Photomultiplier tubes should function for many thousands of hours, and particularly long life is commonplace in scintillation counting experiments where incident light levels and output current demands are fairly low. Factors shortening the life of the tube include high current operation, excessive voltage operation, high light levels and increased temperature. If the detector is exposed to high levels of gamma radiation, the lifetime of the photomultiplier can be reduced.
The pulse width is typically measured with a small scintillator (1” dia x 1”) coupled to a very fast PMT (XP2020). The anode pulse from the PMT is viewed on an oscilloscope that is terminated 50 Ohms. The width is the FWHM of the pulse.
The cladding thickness is 3% for round fibers and 4% for square. That means for a 1mm diameter fiber, there are 30 microns of cladding surrounding the core. The core will be 940 microns in diameter. For 1mm square fiber, the cladding is 40 microns and the core is 920.
Fiber is wound on a spool that measures 30" (762mm) outer diameter x 27.4" (698.5mm) core x 2.25" (57mm) with 1" (50.8mm) center hole. It will fit 1000 meters of 1mm fiber.