Convert millirad [mrd] to joule/centigram [J/cg] Online | Free radiation-absorbed-dose Converter

Millirad [mrd]: A Subunit of Radiation Absorbed Dose

The millirad (mrd) is a unit of absorbed radiation dose equal to one-thousandth of a rad. The rad (radiation absorbed dose) is an older, non-SI unit that was commonly used before the gray (Gy) became the standard.

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  1 rad = 0.01 gray (Gy)

  
  
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  Therefore, 1 millirad = 0.001 rad = 0.00001 Gy (10⁻⁵ Gy)

  
  

The millirad was used to measure the amount of energy absorbed from ionizing radiation per unit mass, primarily in radiation protection and medical contexts.

Though the rad and its subunits like the millirad have largely been replaced by the gray and its subunits (milligray, microgray, etc.), they may still be encountered in older literature or certain regions.

In summary, the millirad is a very small dose unit equal to one-thousandth of a rad, useful historically for quantifying low-level radiation exposures before the universal adoption of the gray.

Joule per Centigram [J/cg]: A Unit of Energy per Mass

The joule per centigram (J/cg) expresses the amount of energy absorbed or delivered per unit mass, specifically joules of energy per centigram (1 centigram = 0.01 grams). This unit represents energy density on a small mass scale.

To relate it to standard radiation dose units: since 1 gray (Gy) equals 1 joule per kilogram (J/kg), and 1 centigram equals 10⁻⁵ kilograms, then

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  1 J/cg = 1 joule per 0.00001 kg = 100,000 J/kg = 100,000 Gy.

  
  

This means that 1 J/cg corresponds to a very high absorbed radiation dose, much greater than typical doses used in medicine or radiation safety.

J/cg could be useful in very specialized fields where energy deposition is considered over tiny masses, such as microdosimetry, materials science, or radiation effects at microscopic scales.

In general, joule per centigram is a high-precision measure for energy density per small mass, but it’s not commonly used in everyday radiation measurement, where grays or their subunits are preferred.