Browse Definitions:
Definition

ionizing radiation

Ionizing radiation, also (imprecisely) called radioactivity, is electromagnetic ( EM ) radiation whose waves contain energy sufficient to overcome the binding energy of electron s in atom s or molecule s, thus creating ion s. The wavelength is shorter than that of ultraviolet ( UV ).

Ionizing radiation can occur as a barrage of photon s having a nature similar to that of visible light, but with far shorter wavelength and consequently higher frequency . This type of radiation includes X rays and gamma rays. More massive particles also comprise ionizing radiation if they travel at sufficient speed. These include high-speed electrons (beta particles), protons, neutrons, and helium nuclei (alpha particles). Ionizing radiation is dangerous because it damages the internal structures of living cells. This can cause cell death in high doses over a short period of time, and errors in the reproductive process (mutations) in lower doses over longer periods of time.

Examples of non-ionizing EM radiation include radio ( RF ) waves, extremely low frequency ( ELF ) fields, infrared ( IR ), visible light, and UV. These forms of EM energy are generally not dangerous, with some exceptions: high-energy radio microwave s and IR which can cause destructive heating of biological tissue; intense visible light which can cause blindness; and intense UV which can cause blindness and superficial skin burns in high doses over a short period of time, and skin cancer and cataracts of the eye at lower doses over long periods of time. There is debate as to whether long-term exposure to moderate-to-intense radio-frequency (RF) fields and ELF fields is harmful to human beings.

The most common unit of ionizing radiation is the becquerel (Bq), equal to one disintegration or nuclear transformation per second. Reduced to base units in the International System of Units ( SI ), 1 Bq = 1/s or 1 s -1 . An alternative unit is the curie (Ci), equivalent to 3.7 x 10 10 disintegrations per second or 2.2 x 10 12 disintegrations per minute. To convert from curies to becquerels, multiply by 3.7 x 10 10 . To convert from becquerels to curies, multiply by 2.7 x 10 -11 .

This was last updated in September 2005

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

  • PCAOB (Public Company Accounting Oversight Board)

    The Public Company Accounting Oversight Board (PCAOB) is a Congressionally-established nonprofit that assesses audits of public ...

  • cyborg anthropologist

    A cyborg anthropologist is an individual who studies the interaction between humans and technology, observing how technology can ...

  • RegTech

    RegTech, or regulatory technology, is a term used to describe technology that is used to help streamline the process of ...

SearchSecurity

  • email spam

    Email spam, or junk email, is unsolicited bulk messages sent through email with commercial, fraudulent or malicious intent.

  • distributed denial of service (DDoS) attack

    A distributed denial-of-service attack occurs when an attack originates from multiple computers or devices, usually from multiple...

  • application whitelisting

    Application whitelisting is the practice of identifying applications that have been deemed safe for execution and restricting all...

SearchHealthIT

  • athenahealth Inc.

    Based in Watertown, Mass., athenahealth Inc. is a leading vendor of cloud-based EHRs for small to medium-sized physician ...

  • Affordable Care Act (ACA or Obamacare)

    The Affordable Care Act (ACA) is legislation passed in 2010 that changed how uninsured Americans enroll in and receive healthcare...

  • HIPAA Privacy Rule

    The Standards for Privacy of Individually Identifiable Health Information, commonly known as the HIPAA Privacy Rule, establishes ...

SearchDisasterRecovery

  • disaster recovery as a service (DRaaS)

    One approach to a strong disaster recovery plan is DRaaS, where companies offload data replication and restoration ...

  • data recovery

    Data recovery restores data that has been lost, accidentally deleted, corrupted or made inaccessible. Learn how data recovery ...

  • disaster recovery plan (DRP)

    A company's disaster recovery policy is enhanced with a documented DR plan that formulates strategies, and outlines preparation ...

SearchStorage

  • virtual memory

    Virtual memory is a memory management capability of an OS that allows a computer to compensate for physical memory shortages by ...

  • yottabyte (YB)

    A yottabyte is a measure of theoretical storage capacity and is 2 to the 80th power bytes, or, in decimal, approximately 1,000 ...

  • Kilo, mega, giga, tera, peta, exa, zetta and all that

    Kilo, mega, giga, tera, peta, exa, zetta are among the list of prefixes used to denote the quantity of something, such as a byte ...

SearchSolidStateStorage

  • PCIe SSD (PCIe solid-state drive)

    A PCIe SSD (PCIe solid-state drive) is a high-speed expansion card that attaches a computer to its peripherals.

  • SSD caching

    SSD caching, also known as flash caching, is the temporary storage of data on NAND flash memory chips in a solid-state drive so ...

  • NVDIMM (Non-Volatile Dual In-line Memory Module)

    An NVDIMM (non-volatile dual in-line memory module) is hybrid computer memory that retains data during a service outage.

SearchCloudStorage

  • RESTful API

    A RESTful application program interface breaks down a transaction to create a series of small modules, each of which addresses an...

  • cloud storage infrastructure

    Cloud storage infrastructure is the hardware and software framework that supports the computing requirements of a private or ...

  • Zadara VPSA and ZIOS

    Zadara Storage provides block, file or object storage with varying levels of compute and capacity through its ZIOS and VPSA ...

Close