Biomaterial Database

Photoactivation ratios for specification of high-energy x-ray quality: part II, 4-15-MV x rays. 1977

R J Schulz, and R Nath

A sensitive and relatively simple method for obtaining an index of the spectral quality of x rays in the 4-15-MV range is presented. The method is based upon the simultaneous production of 115mIn by inelastic scattering of x rays by an indium foil and the production of 116mIn by neutron capture, where the neutrons are obtained from the photodisintegration of deuterium. Since the cross sections for the production of 115mIn and 116mIn have markedly different energy response functions, the ratio of radioactivities is very sensitive to the incident x-ray spectrum. Using a detector consisting of an indium foil sandwiched between two plastic bottles of D2O, photoactivation ratios (PAR) have been measured for 4-, 6-, and 10-MV x rays. It is shown that the PAR method offers a sensitive and practical means for quality control of x-ray spectra and comparison of high-energy accelerators.

UI	MeSH Term	Description	Entries
D007204	Indium	A metallic element, atomic number 49, atomic weight 114.818, symbol In. It is named from its blue line in the spectrum.
D010825	Physics	The study of those aspects of energy and matter in terms of elementary principles and laws. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Physic
D011839	Radiation, Ionizing	ELECTROMAGNETIC RADIATION or particle radiation (high energy ELEMENTARY PARTICLES) capable of directly or indirectly producing IONS in its passage through matter. The wavelengths of ionizing electromagnetic radiation are equal to or smaller than those of short (far) ultraviolet radiation and include gamma and X-rays.	Ionizing Radiation,Ionizing Radiations,Radiations, Ionizing
D003903	Deuterium	The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.	Deuterons,Hydrogen-2,Hydrogen 2
D004735	Energy Transfer	The transfer of energy of a given form among different scales of motion. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed). It includes the transfer of kinetic energy and the transfer of chemical energy. The transfer of chemical energy from one molecule to another depends on proximity of molecules so it is often used as in techniques to measure distance such as the use of FORSTER RESONANCE ENERGY TRANSFER.	Transfer, Energy
D012542	Scattering, Radiation	The diversion of RADIATION (thermal, electromagnetic, or nuclear) from its original path as a result of interactions or collisions with atoms, molecules, or larger particles in the atmosphere or other media. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Radiation Scattering,Radiation Scatterings,Scatterings, Radiation
D013057	Spectrum Analysis	The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Spectroscopy,Analysis, Spectrum,Spectrometry
D014965	X-Rays	Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard X-rays are the higher energy, shorter wavelength X-rays. Soft x-rays or Grenz rays are less energetic and longer in wavelength. The short wavelength end of the X-ray spectrum overlaps the GAMMA RAYS wavelength range. The distinction between gamma rays and X-rays is based on their radiation source.	Grenz Ray,Grenz Rays,Roentgen Ray,Roentgen Rays,X Ray,X-Ray,Xray,Radiation, X,X-Radiation,Xrays,Ray, Grenz,Ray, Roentgen,Ray, X,Rays, Grenz,Rays, Roentgen,Rays, X,X Radiation,X Rays,X-Radiations
D055585	Physical Phenomena	The entities of matter and energy, and the processes, principles, properties, and relationships describing their nature and interactions.	Physical Concepts,Physical Processes,Physical Phenomenon,Physical Process,Concept, Physical,Concepts, Physical,Phenomena, Physical,Phenomenon, Physical,Physical Concept,Process, Physical,Processes, Physical