Louis Harold Gray
Encyclopedia
Louis Harold Gray was a British
physicist who worked mainly on the effects of radiation
on biological
systems, inventing the field of radiobiology
as he went. A summary of his work is given below. Amongst many other achievements, he defined a unit of radiation dosage which was later named after him as an SI
unit, the Gray
.
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
physicist who worked mainly on the effects of radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...
on biological
Organism
In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...
systems, inventing the field of radiobiology
Radiobiology
Radiobiology , as a field of clinical and basic medical sciences, originated from Leopold Freund's 1896 demonstration of the therapeutic treatment of a hairy mole using a new type of electromagnetic radiation called x-rays, which was discovered 1 year previously by the German physicist, Wilhelm...
as he went. A summary of his work is given below. Amongst many other achievements, he defined a unit of radiation dosage which was later named after him as an SI
Si
Si, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...
unit, the Gray
Gray (unit)
The gray is the SI unit of absorbed radiation dose of ionizing radiation , and is defined as the absorption of one joule of ionizing radiation by one kilogram of matter ....
.
Career
- 1933 - Hospital physicist at Mount Vernon HospitalMount Vernon HospitalMount Vernon Hospital is one of two hospitals run by The Hillingdon Hospitals NHS Foundation Trust, located in Northwood.-History:The hospital was founded in 1860 as The North London Hospital for Consumption and Diseases of the Chest in Fitzroy Square and moved in 1864 to Mount Vernon in Hampstead...
, LondonLondonLondon is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its... - 1936 - Developed the BraggWilliam BraggWilliam Bragg may refer to:* William David Bragg , cricketer* William Henry Bragg , joint 1915 Nobel Prize winning physicist* William Lawrence Bragg , joint 1915 Nobel Prize winning physicist...
-Gray equation, the basis for the cavity ionizationBragg-Gray Cavity TheoryAccording to the Bragg–Gray cavity theory, the ionization produced within a gas-filled cavity inside a medium is related to the energy absorbed in that surrounding medium....
method of measuring gamma-ray energyEnergyIn physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...
absorption by materials - 1937 - Built an early neutron generatorNeutron generatorNeutron generators are neutron source devices which contain compact linear accelerators and that produce neutrons by fusing isotopes of hydrogen together. The fusion reactions take place in these devices by accelerating either deuterium, tritium, or a mixture of these two isotopes into a metal...
at Mount Vernon Hospital - 1938 - Studied biological effects of neutronNeutronThe neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of...
s using the generator - 1940 - Developed concept of RBE (Relative Biological EffectivenessRelative biological effectivenessIn radiology, the relative biological effectiveness is a number that expresses the relative amount of damage that a fixed amount of ionizing radiation of a given type can inflict on biological tissues...
) of doses of neutrons - 1952 - Initiated research into cellsCell (biology)The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
in hypoxic tumors and hyperbaric oxygenHyperbaric oxygen therapyHyperbaric medicine, also known as hyperbaric oxygen therapy , is the medical use of oxygen at a level higher than atmospheric pressure. The equipment required consists of a pressure chamber, which may be of rigid or flexible construction, and a means of delivering 100% oxygen... - 1953 - Established the Gray Laboratory at Mount Vernon Hospital
- 1953 - 1960 - Under Gray's direction, Jack W. Boag developed pulse radiolysis
- 1962 - Ed Hart, of Argonne National Laboratory, and Jack Boag discovered the hydrated electron using pulse radiolysis at the Gray Laboratory - This discovery initiated a new direction of research that is still very active today and is vital for understanding the effects of radiation on biological tissue, for instance in cancer treatmentRadiation therapyRadiation therapy , radiation oncology, or radiotherapy , sometimes abbreviated to XRT or DXT, is the medical use of ionizing radiation, generally as part of cancer treatment to control malignant cells.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control...
.
External links
- Definition of RBE
- The LH Gray Memorial Trust founded in 1967