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X-ray safety

The 丁香园AV X-ray safety program facilitates and ensures safe use of X-ray Emitting Devices (XEDs) in research, teaching and the environment.

X-ray Emitting Devices (XEDs) present unique safety concerns. Consultation with EH&S is required to determine specific hazards for each facility housing such equipment in order to indentify hazardous areas and review safety measures. All X-ray equipment must be registered on the Laboratory Hazard Inventory System.

Equipment

X-rays are a type of ionizing radiation that is typically produced using machines, instead of radioactive materials. X-rays, like gamma rays, are made up of individual packets of energy called photons and are emitted when:

  • high speed electrons (or any charged particles) are slowed down or change direction within a strong electric field. The resulting X-rays are called continuous as they can have energies ranging from 0 - maximum energy equal to the original energy of the incoming electron.
  • electrons move from a higher energy level to a lower energy inside of an atom. The resulting X-rays are called characteristic 

Electron Microscopy

Electron microscopes produce X-rays when the primary electron beam or back scattered electrons strike metal components with sufficient energy to produce continuous or charactersitic X-rays. 

Two hazardous aspects of electron microscopes are:

  • the compostion of the components which are struck with electrons, and their efficiency as x-ray sources. Higher voltage and atomic number of the materials results in higher efficiency x-ray production
  • The effectiveness/integrity of the shielding provided by the metal casing of the micrsocope

Electron microcopes are well shielded and do not produce exposure rates greater than background. However, electron microscopes are radiation-generating devices and need to be inventoried. When setting up an electron microscope, please follow the procedures for acquiring and installing an XED, and 丁香园AV safety requirements.

Dual-Energy X-ray Diffractiometry (DEXA) Scanner

Used for bone densitometry to measure bone mineral density and test for osteopenia and osteoporosis. The DEXA Scanner is comprised of two X-ray beams with two energy levels. Regulations: Follow 

X-ray Diffraction (XRD)

X-ray crystallography is a technique used to determine the atomic and molecular structure of a crystal. The angle between the incident and the diffracted X-rays provides information about the spacing of atoms in the crystalline material. X-rays are filtered and collimated to hit crystalline materials. Some X-rays are diffracted. Diffracted X-rays are collected, counted and analyzed by the detector. Regulations: Follow .

X-ray Fluorescence (XRF)

Portable, hand-held, X-ray tube based open beam XRF devices fall under 鈥楢nalytical X-ray Equipment鈥� of the Radiation Emitting Devices Regulations. Under the RED Act it is required that X-ray devices are accompanied by instructions from the manufacturer regarding installation, interconnection, testing, operation and maintenance of the device. These instructions must be embodied in the product specific manual.

The owner of an XRF device is directly and ultimately responsible for its management, control an application. The user must follow the guidance under the Addendum to Safety Code 32.

  • Owner of an XRF device: The owner of a portable, hand-held, X-ray tube-based, open beam XRF device is directly and ultimately responsible for its management, control and application. Any delegation to another individual does not relieve the XRF device owner of these responsibilities. The owner must follow the guidance provided in the  for implementing safety precautions and measures to eliminate or mitigate the radiation risks associated with the device

  • User of the XRF device: The user of a portable, hand-held, x-ray tube-based, open beam XRF device, whether the XRF device is used in a hand-held mode, open beam mode, or in a closed beam system, must also follow the guidance provided in the Addendum Safety Code 32 for taking safety precautions and measures to eliminate or mitigate the radiation risks to himself or herself and to allied personnel. Regulations: Follow