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NJV
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What thickness of lead is needed to neutralize brief exposure to gamma radiation, or at least reduce it to below 5 gray?
NJV said:What thickness of lead is needed to neutralize brief exposure to gamma radiation, or at least reduce it to below 5 gray?
Bob S said:The most penetrating x-ray (or photon) energy is about 1 or 2 MeV. Below about 0.5 MeV, the photoelectric effect off of bound electrons is significant, and above 2 MeV, pair production (of an electron and positron) becomes significant. I seem to recall that 2 inches of lead reduces Cobalt 60 radiation by about a factor of 10.
Lead shields protect against X-rays by absorbing the radiation energy and preventing it from passing through the shield and harming living tissue. This is because lead is a dense element that is able to absorb high amounts of radiation.
The thickness of a lead shield needed to effectively block X-rays depends on the energy of the X-rays being emitted. For lower energy X-rays, a thinner shield may be sufficient, while higher energy X-rays may require a thicker shield. Generally, a lead shield with a thickness of at least 0.5 mm is recommended for protection against X-rays.
While lead is the most commonly used material for X-ray shielding, other materials such as concrete, steel, and tungsten can also be effective. However, lead is often preferred due to its high density and low cost.
No, lead shields cannot completely eliminate X-ray exposure as some radiation may still scatter or leak through small gaps in the shield. However, they can greatly reduce the amount of radiation exposure and protect against harmful effects.
In medical settings, lead shields are commonly used to protect patients and healthcare workers from X-ray exposure during procedures such as diagnostic imaging and radiation therapy. They may also be used to shield sensitive equipment from radiation damage.