The shielding mechanism of tungsten alloy shielding containers is based on multi-mechanism synergistic absorption and attenuation processes that rapidly convert incident ionizing radiation energy into local heat and secondary charged-particle deposition within limited thickness while causing ray intensity to decrease exponentially along the wall depth, thereby minimizing external environmental contribution.
For γ-rays and X-rays, the photoelectric effect first transfers full photon energy to inner-shell electrons of tungsten atoms, generating photoelectrons accompanied by characteristic X-ray emission that is immediately re-absorbed by neighboring atoms. At medium energies Compton scattering prevails, with photons undergoing inelastic collisions with outer-shell electrons that randomize direction and energy; repeated scattering gradually drives remaining photons into the low-energy regime for final photoelectric absorption. At high energies pair production dominates, converting photons into electron-positron pairs in the nuclear field, with the pairs quickly losing kinetic energy through ionization loss and bremsstrahlung. These three mechanisms heavily overlap within tungsten alloy’s very short mean free path, forming a continuous local energy deposition chain.
Fast neutrons first lose energy through inelastic scattering with tungsten nuclei, then undergo multiple elastic scatterings to reach thermal energies for capture, with lower-energy capture gamma rays promptly re-attenuated within the thick wall. Secondary radiation experiences extremely short ranges in the high-electron-density environment and completes essentially all energy deposition inside the wall.
Through the coordinated action of these mechanisms, tungsten alloy shielding containers achieve efficient and stable absorption and attenuation of broad-spectrum incident radiation along the thickness direction, making them a commonly employed container in nuclear medicine, isotope production, and industrial irradiation facilities.
