Radiation Converter

Convert between equivalent dose units for radiation protection and medical applications

About Radiation Units

What is Radiation?

Radiation is energy that travels through space or matter in the form of waves or particles. It can be classified into two main categories: ionizing radiation (which has enough energy to remove electrons from atoms) and non-ionizing radiation (which doesn't have sufficient energy for ionization). Ionizing radiation includes alpha particles, beta particles, gamma rays, X-rays, and neutrons, while non-ionizing radiation includes radio waves, microwaves, and visible light.

Fundamental Radiation Quantities and Units

Radiation measurement involves several fundamental quantities, each with specific units and applications:

QuantitySI UnitTraditional UnitDefinition
ActivityBecquerel (Bq)Curie (Ci)Decay rate: 1 Bq = 1 decay/second
Absorbed DoseGray (Gy)RadEnergy absorbed per unit mass: 1 Gy = 1 J/kg
Equivalent DoseSievert (Sv)RemBiological effect: H = D × wR
ExposureCoulomb/kg (C/kg)Roentgen (R)Ionization in air: 1 C/kg = 3876 R
Dose RateSv/h, Gy/hrem/h, rad/hDose per unit time

Radiation Weighting Factors and Biological Effects

The equivalent dose accounts for the different biological effects of various radiation types through radiation weighting factors (wR). The fundamental formula is:

H = D × wR

Where: H = equivalent dose (Sv), D = absorbed dose (Gy), wR = radiation weighting factor

Radiation TypeWeighting Factor (wR)Biological Effectiveness
Photons (X-rays, gamma rays)1Low - penetrate deeply, low ionization density
Electrons and beta particles1Low - similar to photons
Protons2Medium - higher ionization density
Alpha particles20High - very high ionization density
Neutrons2.5-20Variable - depends on energy

Common Radiation Unit Conversions

Understanding conversion factors is essential for radiation protection and medical applications:

Activity Conversions

  • • 1 Curie (Ci) = 3.7 × 10¹⁰ Becquerel (Bq)
  • • 1 Bq = 2.7 × 10⁻¹¹ Ci
  • • 1 mCi = 37 MBq
  • • 1 μCi = 37 kBq

Dose Conversions

  • • 1 Gray (Gy) = 100 rad
  • • 1 rad = 0.01 Gy
  • • 1 Sievert (Sv) = 100 rem
  • • 1 rem = 0.01 Sv

Radiation Measurement Instruments

Various instruments are used to measure different aspects of radiation:

InstrumentMeasuresApplications
Geiger-Müller CounterCount rate, exposure rateEnvironmental monitoring, contamination surveys
Ionization ChamberExposure, absorbed doseMedical dosimetry, calibration
Scintillation DetectorEnergy spectrum, activityNuclear medicine, spectroscopy
Thermoluminescent Dosimeter (TLD)Accumulated dosePersonal dosimetry, retrospective dosimetry
Film BadgeAccumulated doseOccupational monitoring, legal records

Real-World Applications and Examples

Radiation units are used across various industries and applications:

Medical Applications

  • Diagnostic X-rays: 0.1-10 mSv per procedure
  • CT Scans: 1-20 mSv depending on body part
  • Radiation Therapy: 20-80 Gy total dose
  • Nuclear Medicine: 1-30 mCi (37-1110 MBq) per procedure
  • PET Scans: 10-20 mCi (370-740 MBq) of FDG

Industrial Applications

  • Radiography: 1-10 Ci (37-370 GBq) sources
  • Level Gauges: 10-100 mCi (370-3700 MBq)
  • Density Gauges: 50-500 mCi (1.85-18.5 GBq)
  • Thickness Gauges: 100 mCi-1 Ci (3.7-37 GBq)
  • Sterilization: 25-50 kGy dose

Radiation Safety Limits and Guidelines

Regulatory bodies establish safety limits to protect workers and the public:

CategoryAnnual LimitEquivalent
Occupational Workers20 mSv2 rem
General Public1 mSv0.1 rem
Lens of Eye (Occupational)20 mSv2 rem
Skin (Occupational)500 mSv50 rem
Extremities (Occupational)500 mSv50 rem

Natural Background Radiation

Humans are constantly exposed to natural background radiation from various sources:

Terrestrial Sources

  • Soil and rocks: 0.3-1.0 mSv/year
  • Building materials: 0.1-0.3 mSv/year
  • Radon gas: 1.0-10 mSv/year
  • Food and water: 0.2-0.4 mSv/year

Cosmic Sources

  • Sea level: 0.3 mSv/year
  • High altitude: 0.5-1.0 mSv/year
  • Air travel: 0.01-0.1 mSv per flight
  • Space travel: 50-200 mSv/year

Why Radiation Measurement is Critical

Accurate radiation measurement is essential for:

Safety

Protecting workers and public from harmful exposure

Medical

Ensuring accurate diagnosis and treatment

Regulatory

Compliance with international standards

Key Takeaway

Understanding radiation units and their relationships is fundamental for anyone working with radiation, whether in medicine, industry, research, or environmental monitoring. The ability to convert between different units ensures accurate communication and proper safety practices across all applications.

Frequently Asked Questions About Radiation Conversion