Why the ProSpector 3 Performs Material Composition Analysis Four Times Faster Than Other Portable XRF Analyzers

What Factors Can Increase the Speed of XRF Spectrometers?

The first factor is the use of Silicon Drift Detectors (SDD) instead of PIN diode detectors. Currently, SDDs are utilized in nearly all handheld XRF analyzers. However, not all SDDs are created equal. Primarily, the speed of the spectrometer is influenced by the detector's area - with a constant flux of X-rays from the sample, the number of photons hitting the detector per unit of time is proportional to its area. Therefore, in the ProSpector 3, only large and extra-large area detectors are used.

Even with the same area, different types of SDDs can "let through" and register a varying number of X-ray photons in the spectrum. This depends on the type of preamplifier used in the detector. In standard SDDs, the preamplifier is based on a Junction Field-Effect Transistor (JFET), while in "fast" (so-called Fast SDD) detectors, special low-noise CUBE modules are used as the headstage of the preamplifier, and in ultra-fast models, ultra-low-noise Charge Sensitive Amplifier (CSA) modules are used. Detectors equipped with a CSA module, although more expensive than standard SDD and FastSDD, provide not only significantly higher speed but also better resolution. It is these innovative SDDs that equip the portable ProSpector 3 analyzers.

But That's Not All: The Key to Unprecedented XRF Speed

Even though similar detectors are equipped in some other premium handheld XRF models, a decisive factor in achieving record-breaking speed, all other things being equal, is the digital pulse processor (DPP), which converts the pulses from the detector's preamplifier into X-ray spectra of analyzed samples. The challenge is that the DPP requires a certain amount of time to "process" each pulse caused by the absorption of an X-ray photon in the detector. During this time, the DPP cannot receive and process the next pulse. Therefore, with a high rate of incoming pulses (so-called input statistical load), some of these pulses are lost because the DPP simply cannot process them fast enough. This results in the loss of two pulses: the first, which did not have enough time to be processed, and the second, which arrived before the processing of the first was completed. Consequently, not all X-ray photons make it into the spectrum, and the potential high speed of the SDD is not fully utilized. To increase the throughput of the DPP, one could reduce the processing time for each pulse. However, this would lead to a decrease in processing accuracy and, as a result, a deterioration in the spectrometer's resolution. How did Elvatech solve this issue? We developed a special type of DPP in which the processing time for each pulse is not constant but dynamically adjusts. Our Dynamically Adaptive Shaping (DAS) technology allows for the processing of most pulses from the detector with optimal timing, ensuring the best resolution while not losing those pulses that arrive during the processing of others. The DPP automatically shortens the processing duration of the current pulse and immediately starts processing the next one. Thus, we managed to increase the throughput of the spectrometer by more than three times, to > 500,000 pulses per second, without compromising energy resolution, positioning us as industry leaders in XRF performance.