The HVL of sound waves is determined by both the medium through which it travels, and the frequency of the beam. A "thin" half-value layer (or a quick drop of -3 dB) results from a high …

The thickness of any given material where 50% of the incident energy has been attenuated is know as the half-value layer (HVL). The HVL is expressed in units of distance (mm or cm). …

2022年9月1日 · One of the most important methods of understanding the efficiency of a shielding material against the radiation used is to calculate the half-value layer (HVL) of the material …

Technetium-99m pertechnetate (99mTc04) is obtained directly from the "molly" generator using saline as the eluting solution. This radiopharmaceutical is used for brain, thyroid, salivary …

2019年12月14日 · There are two main features of the half value layer: The half value layer decreases as the atomic number of the absorber increases. For example 35 m of air is needed …

HVL (Half Value Layer): The amount (thickness) of a given shielding material needed to reduce the radiation emissivity by one-half its value. We use the following math formula to determine …

2025年3月15日 · Half-value layer (HVL) is the thickness of a material required to reduce the air kerma of an X-ray or gamma-ray beam to half its original value. HVL is most accurately …

2023年9月1日 · The half-value layer (HVL) is a proportion of the entrance depth of electromagnetic radiation in a material that is closely related to the direct linear attenuation …

2023年6月16日 · The quality of the X-ray beam can be measured using the half value layer (HVL), that is, the thickness of the material needed to reduce the intensity of the X-ray by half its initial …

半值层（缩写为hvl）是现代成像中使用的一种度量。 它表示将特定辐射减少一半强度水平的材料的厚度。 hvl可以通过实验或数学方法确定。 推导半值层公式。