| Περίληψη: | The X-ray beam spectrum is a critical aspect of imaging radiology as it is what determines, to a large extent, the image quality. The spectrum is influenced by several factors. Therefore, the user is able to select the optimum spectrum to have optimum performance in terms of the finest image quality with minimum dose. The most complete description of X-ray beam provided spectral distribution. Given that with contemporary detector system, all quality control programs (QC) involve assessing the spectrum indirectly: mainly a parameter of the spectrum, such as the HVL. The usefulness of spectrum knowledge has led many research groups to suggest methods that predict the spectrum, such as Monte Carlo or analytically. Of course, it is of significant interest to measure the X-ray spectrum directly with special instruments.
In this work we test experimental measurement results by calculating the HVL from the acquired spectrum with X-123 CdTe spectrometer detector and compare it with the X-ray analyser Barracuda MPD, which is in permanent clinical use: its instrumental reliability is well established.
The X-123 uses a Cadmium Telluride (CdTe) crystal as X-ray and gamma-ray detector. The detector is a diode with a bias voltage applied to sweep the electron-hole pairs and is mounted on a thermoelectric cooler, which reduces the electric noise in the detector and the preamplifier. The cooler can achieve an 85 oC temperature differential without requiring cryogenics. So, it operates like a room temperature system and the cooling is transparent to the user.
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