The second is the SI unit of time. Definition: The length of time taken for 9192631770 periods of vibration of the caesium-133 atom.

(mA s) The product of the x-ray tube operating current and the exposure time in minutes.
See Milliampere and X-Ray Tube.

Secondary radiation is the result of absorption of other radiation in matter. It could be either electromagnetic or particulate in nature.

Planck is a MKS unit of energy (expended over time to angular momentum, etc.). One Planck unit is equal to 1 joule second (J x s) or about 0.7375 foot pound second (ft x lb x s). Atomic nuclei possess an intrinsic angular momentum referred to as spin, measured in multiples of Planck's constant. The unit is named for the German physicist Max Planck.

(A or amp) The SI base unit of electric current.
Definition: Two parallel conductors, infinitely long and having negligible cross section should be placed 1 meter apart in a perfect vacuum. One ampere is the current that creates between them a force of 0.2 µN (micronewton) per meter of length.
One ampere represents a current flow of 1 coulomb of charge per second.
One ampere of current results from a potential distribution of 1 volt per ohm of resistance, or from a power production rate of 1 watt per volt of potential.
The unit is known informally as the amp, but A is its official symbol and is named for the French physicist André-Marie Ampère.
See also System International.