Uses of Radiation | Physics for GCSE/IGCSE - Year 11 PDF Download

Uses of Radiation

• Radiation finds diverse applications in different fields:
  • Medical Procedures: Used for diagnosing and treating cancer.
  • Sterilizing Food: By irradiating it to eliminate bacteria.
  • Sterilizing Medical Equipment: Utilizing gamma rays for disinfection purposes.
  • Age Determination: Assisting in determining the age of ancient artifacts.
  • Material Thickness Check: Employed to measure the thickness of materials.
  • Smoke Detectors: Utilized in smoke alarms for safety purposes.
• The choice of radiation type depends on the specific application requirements.

Smoke Detectors

• Smoke detectors utilize alpha particles for their operation.
• Alpha radiation ionizes the air inside the detector, which establishes a current.
• When smoke interferes with the alpha emitter, the current flow is disrupted.
• This disruption triggers the alarm through a connected microchip.

Measuring the Thickness of Materials

• Radiation, particularly beta particles, is commonly utilized for tracing and gauging thickness.
• As a material passes over a beta radiation source, a detector monitors the particles that can penetrate it.
• When the material thickens, more particles are absorbed, resulting in fewer particles passing through; conversely, when the material thins, the opposite effect occurs.
• This process enables the machine to make necessary adjustments to maintain a consistent material thickness.

• Beta radiation is chosen for its partial absorption by materials, allowing some particles to pass through.
  • Alpha particles, if utilized, would be entirely absorbed, hindering their detection on the other side.
  • Gamma radiation, on the other hand, would almost entirely penetrate the material, making it challenging to detect changes in thickness.

Diagnosis and Treatment of Cancer

• Radiotherapy is a cancer treatment involving radiation, distinct from chemotherapy which uses chemicals.
• While radiation can potentially cause cancer, it is a highly effective method for treating it.
• Radiation has the ability to destroy living cells, with certain cells like bacteria and cancer cells being more vulnerable to its effects.

• Usage of Gamma Rays

  • Gamma rays are directed at cancerous tumors due to their capacity to penetrate the body, reaching the tumor site.
  • To minimize damage to healthy tissue, the beams of gamma rays are carefully manipulated while targeting the tumor.

• Role of Tracers and PET Scans

  • A tracer, a radioactive isotope, is employed to monitor the movement of substances like blood within the body.
  • PET scans utilize emissions from tracers to diagnose cancer and pinpoint the location of tumors.
  • A PET Scan in Cancer Diagnosis: A PET scan is a diagnostic imaging technique that uses a tracer to detect emissions in the body, aiding in the diagnosis of cancer and pinpointing the location of tumors.

Sterilising Food and Medical Equipment

Gamma radiation finds extensive application in sterilizing medical equipment due to several reasons:

• Gamma radiation boasts the highest level of penetration among all radiation types, ensuring thorough irradiation.
• Its penetrating capability enables it to irradiate all facets of instruments effectively.
• Medical instruments can be sterilized without necessitating the removal of packaging.
• Additionally, gamma radiation is employed in irradiating food items to eliminate microorganisms, enhancing their longevity and diminishing the likelihood of food-borne infections.