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The kinetic energy imparted to charged particles in a unit mass of material by uncharged particles such as neutrons; it may be expressed as joules per kilogram or ergs per gram.



(ancient Egyptian, Inbu Amenemhet—“Walls of Amenemhet”), a Cushitic settlement south of the third cataract of the Nile, on its right bank (Sudan). Excavations conducted from 1913 to 1916 have revealed a settlement dating from the time of Egypt’s Middle Kingdom (20th-18th centuries B.C.), a necropolis of local rulers buried with their relatives and slaves (as many as 400 persons in one burial); and numerous remains of material culture and art, both of local and Egyptian origin. Kerma lost its importance after Cush was conquered by Egypt (by the 15th century B.C.).


Katsnel’son, I. S. “Problemy istoricheskogo razvitiia drevneishei Nubii.” Vestnik drevnei istorii, 1948, no. 2.
Reisner, G. A. Excavations at Kerma, vols. 1–2. Cambridge, 1923.
Hintze, F. “Das Kerma-Problem.” Zeitschrift für ägyptische Sprache und Altertumskunde, 1964, vol. 91.
References in periodicals archive ?
To measure air kerma in a small, swept beam of x rays using a large-volume IC calibrated in a continuously- and fully-illuminated reference beam, one must be able to (1) operate the IC system in an integrating mode, (2) ensure that leakage current is negligible or accounted for over the integration time, (3) fully raster ("paint") the IC as it would be during an operational scan, and (4) account for any incomplete charge collection due to incident fluence rates.
By way of illustration, we report the incident air kerma for the Rapiscan Secure 1000 Single Pose scanner that employed an x-ray tube potential of 50 kV.
g] is the mean value of g averaged over the distribution of the air kerma with respect to electron energy.
Thus the initial charge created by the interaction of the photons should, in principle, be discounted when transferring the exposure measurement for the determination of air kerma.
The object was to compare the value of the air kerma calibration coefficient of the chamber determined at the KEBS with the value obtained at the NIST.
The air kerma rates at both of these facilities are well established and are determined using the NIST primary standard instruments.
The quantities exposure and air kerma can be related through use of the mean energy per unit charge, W/e, where W is the mean energy expended in air per ion pair formed when the initial kinetic energy of a charged particle is completely dissipated in the air, and e is the elementary charge.
Exposure and air kerma can be expressed at a point in a material other than air, such as water or a vacuum.
The goal of such measurements is to directly realize the air kerma (or exposure) at a point in the gamma-ray field.
Treurniet, Monte Carlo calculated wall and axial non-uniformity corrections for primary standards of air kerma, National Research Council Canada Report PIRS-663, Ottowa, Canada (1999).
The data are in air kerma rate units, since the calibration and field responses were recorded using exposure units, even though the chamber was tissue equivalent and its response would more appropriately be observed in absorbed dose units.