radioactive decay kuliah ke2

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is the process by which an unstable atomic nucleus loses energy by emitting ionizing particles or radiation. The emission is spontaneous in that the nucleus decnt nuclide  , transforming to an atom of ays without collision with another particle. This decay , or loss of energy, results in an atom of one type, called the pare  a different type, named the daughter nuclide, 14 C ------- 15 N Radioactive decay 

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  • is the process by which an unstable atomic nucleus loses energy by emitting ionizing particles or radiation. The emission is spontaneous in that the nucleus decnt nuclide, transforming to an atom of ays without collision with another particle. This decay, or loss of energy, results in an atom of one type, called the parea different type, named the daughter nuclide, 14C ------- 15N Radioactive decay

  • Atom (nuclei) yang mempunyai rasio proton neutron berada di luar Belt of stability secara langsung akan mengalami radioactive decay secara Spontan Tipe Decay tergantung dimana posisi atom berada relative terhadap band of stability Radioactive particle are emitted with different kinetic energy - Energy change is related to the change in binding energy from reactant to product

  • Mode of decayParticipating particlesDaughter nucleusDecays with emission of nucleons:Alpha decayAn alpha particle (A=4, Z=2) emitted from nucleus(A4, Z2)Proton emissionA proton ejected from nucleus(A1, Z1)Neutron emissionA neutron ejected from nucleus(A1, Z)Double proton emissionTwo protons ejected from nucleus simultaneously(A2, Z2)Spontaneous fissionNucleus disintegrates into two or more smaller nuclei and other particlesCluster decayNucleus emits a specific type of smaller nucleus (A1, Z1) smaller than, or larger than, an alpha particle(AA1, ZZ1) + (A1, Z1)Different modes of beta decay: decayA nucleus emits an electron and an electron antineutrino(A, Z+1)Positron emission (+ decay)A nucleus emits a positron and a electron neutrino(A, Z1)Electron captureA nucleus captures an orbiting electron and emits a neutrino the daughter nucleus is left in an excited and unstable state(A, Z1)Double beta decayA nucleus emits two electrons and two antineutrinos(A, Z+2)Double electron captureA nucleus absorbs two orbital electrons and emits two neutrinos the daughter nucleus is left in an excited and unstable state(A, Z2)Electron capture with positron emissionA nucleus absorbs one orbital electron, emits one positron and two neutrinos(A, Z2)Double positron emissionA nucleus emits two positrons and two neutrinos(A, Z2)Transitions between states of the same nucleus:Isomeric transitionExcited nucleus releases a high-energy photon (gamma ray)(A, Z)Internal conversionExcited nucleus transfers energy to an orbital electron and it is ejected from the atom(A

  • An example is the natural decay chain of 238U which is as follows:

    decays, through alpha-emission, with a half-life of 4.5 billion years to thorium-234which decays, through beta-emission, with a half-life of 24 days to protactinium-234which decays, through beta-emission, with a half-life of 1.2 minutes to uranium-234which decays, through alpha-emission, with a half-life of 240 thousand years to thorium-230which decays, through alpha-emission, with a half-life of 77 thousand years to radium-226which decays, through alpha-emission, with a half-life of 1.6 thousand years to radon-222which decays, through alpha-emission, with a half-life of 3.8 days to polonium-218which decays, through alpha-emission, with a half-life of 3.1 minutes to lead-214which decays, through beta-emission, with a half-life of 27 minutes to bismuth-214which decays, through beta-emission, with a half-life of 20 minutes to polonium-214which decays, through alpha-emission, with a half-life of 160 microseconds to lead-210which decays, through beta-emission, with a half-life of 22 years to bismuth-210which decays, through beta-emission, with a half-life of 5 days to polonium-210which decays, through alpha-emission, with a half-life of 140 days to lead-206, which is a stable nuclide.

  • Nuclear Stability and Radioactive DecayBeta decayDecrease # of neutrons by 1Increase # of protons by 1Positron decayIncrease # of neutrons by 1Decrease # of protons by 1

  • Electron capture decayIncrease # of neutrons by 1Decrease # of protons by 1Nuclear Stability and Radioactive DecayAlpha decayDecrease # of neutrons by 2Decrease # of protons by 2Spontaneous fission23.2HITUNG PERUBAHAN ENERGI BINDINGPADA PROSES DECAY DIATAS ?

  • HALF-LIFEHALF-LIFE is the time that it takes for 1/2 a sample to decompose.The rate of a nuclear transformation depends only on the reactant concentration.

  • HALF-LIFE

    Decay of 20.0 mg of 15O. What remains after 3 half-lives? After 5 half-lives?

  • 263Sg ----> 259Rf + 4He

  • Terjadi pada Solar Energi dan Proses terjadinya alam semestaTerjadi pada proses bom nuklir dan reaktor nuklir kini

  • For each duration (half-life), one half of the substance decomposes.For example: Ra-234 has a half-life of 3.6 days If you start with 50 grams of Ra-234

    After 3.6 days > 25 gramsAfter 7.2 days > 12.5 gramsAfter 10.8 days > 6.25 grams

  • The probability of decay (dN/N) is proportional to dt:The solution to this first-order differential equation is the following function:Dimana,The half life is related to the decay constant as follows:

  • Kinetics of Radioactive Decayrate = lNN = N0e(-lt)lnN = lnN0 - ltN = the number of atoms at time tN0 = the number of atoms at time t = 0l is the decay constant (sometimes called k)23.3 k =

  • ACTIVITY CALCULATIONN = N0e(-lt)A = A0e(-l t )ECERCISE : Hitung sisa aktifitas Tritium setela tersimpan 26 tahun dari aktifitas semula 15 Ci, t1/2 tritium = 12,34 thUNTUK HALF LIFE2,303 Log 0,5/1 = - t

    = 0,693/t

  • A sample of C14, whose half life is 5730 years, has a decay rate of 14 disintegration per minute (dpm) per gram of natural C. An artifact is found to have radioactivity of 4 dpm per gram of its present C, how old is the artifact?Using the above equation, we have:

    Where: years

    years

  • Kinetics of Radioactive Decay[N] = [N]0exp(-lt)ln[N] = ln[N]0 - lt23.3

  • Arithmetically, melalui term half life kemudian dapat dihitung perubahan jumlah/aktivitas zat radioaktive selama waktu tertentuGraphycally, Mengunakan grafik semilog antara Aktivita radioaktiv Vs waktu Radioactive Equilibrium - Ratio Nomor atom pada proses reaksi decay zat radioaktive seperti dibawah ini, 238U u 234Th Th 234Pa NTh / NU = U / Th N Th / N U = t Th / t U

    - Hal yang sama untuk atome decay dengan nomor atom yang kostan , Ratio Massa ebanding dengan ratio half life nya,

    Massa X / Massa Y = t X . A X / t Y . A Y Dari perhitungan ratio nomor atom dan massa ada decay reaction maka dapat dihitung ratio dari ratio nomor atom dan mass dari hasil decay tersebut

  • Nuclear Reaction

  • Balancing Nuclear EquationsConserve mass number (A). The sum of protons plus neutrons in the products must equal the sum of protons plus neutrons in the reactants.235 + 1 = 138 + 96 + 2x1Conserve atomic number (Z) or nuclear charge. The sum of nuclear charges in the products must equal the sum of nuclear charges in the reactants.92 + 0 = 55 + 37 + 2x023.1

  • Alpha emissionNote that mass number (A) goes down by 4 and atomic number (Z) goes down by 2.Nucleons (nuclear particles protons and neutrons) are rearranged but conserved

  • Beta emissionNote that mass number (A) is unchanged and atomic number (Z) goes up by 1.

  • Positron (0+1b): a positive electronElectron capture: the capture of an electron

  • New elements or new isotopes of known elements are produced by bombarding an atom with a subatomic particle such as a proton or neutron -- or even a much heavier particle such as 4He and 11B.Reactions using neutrons are called g reactions because a g ray is usually emitted.Radioisotopes used in medicine are often made by g reactions.

  • Nuclear reactorCyclotron or accelerator

  • Is the probability that a bombarding particle (neutron) will produce a nuclear reactionCross section Unit is Barn (1 barn = 1024 cm-2)Formula ; N = x x nXWhere, N = Total number of reaction = Flux neutron = nuclear cross section n = number of nuclei in Cm3 X = is thickness of target in Cm

  • Example of a g reaction is production of radioactive 31P for use in studies of P uptake in the body.3115P + 10n ---> 3215P + g

  • Elements beyond 92 (transuranium) made starting with an g reaction 23892U + 10n ---> 23992U + g23992U ---> 23993Np + 0-1b 23993Np ---> 23994Pu + 0-1b

  • Fission is the splitting of atomsThese are usually very large, so that they are not as stableFission chain has three general steps:1. Initiation. Reaction of a single atom starts the chain (e.g., 235U + neutron)2. Propagation. 236U fission releases neutrons that initiate other fissions3. ___________ . EXCERCISE , REACTION FISSION RANTAI URANIUM

  • Nuclear Fission23.5Energy = [mass 235U + mass n (mass 90Sr + mass 143Xe + 3 x mass n )] x c2Energy = 3.3 x 10-11J per 235U= 2.0 x 1013 J per mole 235UCombustion of 1 ton of coal = 5 x 107 J

  • Nuclear Fission23.5Nuclear chain reaction is a self-sustaining sequence of nuclear fission reactions.The minimum mass of fissionable material required to generate a self-sustaining nuclear chain reaction is the critical mass.

  • a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235.

  • A control rod is a rod made of chemical elements capable of absorbing many neutrons without fissioning themselves. They are used in nuclear reactors to control the rate of fission of uranium and plutonium. Because these elements have different capture cross sections for neutrons of varying energies, the compositions of the control rods must be designed for the neutron spectrum of the reactor it is supposed to control. Light water reactors (BWR, PWR) and heavy water reactors (HWR) operate with "thermal" neutrons, whereas breeder reactors operate with "fast" neutrons.Silver-indium-cadmium alloys, generally 80% Ag, 15% In, and 5% Cd, are a common control rod material for pressurized water reactors. The somewhat different energy absorption regions of the materials make the alloy an excellent neutron absorber. It has good mechanical strength and can be easily fabricated. It has to be encased in stainless steel to prevent corrosion in hot water.A coolant is a fluid which flows through a device to prevent its overheating, transferring the heat produced by the device to other devices that use or dissipate it. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, and chemically inert, neither causing nor promoting corrosion of the cooling system. Some applications also require the coolant to be an electrical insulator.

  • Currently about 103 nuclear power plants in the U.S. and about 435 worldwide.17% of the worlds energy comes from nuclear.

  • Fusion small nuclei combine

    2H + 3H 4He + 1n + 1 1 2 0

    Occurs in the sun and other stars

    Energy

  • 23.6Nuclear FusionFusion ReactionEnergy Released6.3 x 10-13 J2.8 x 10-12 J3.6 x 10-12 JTokamak magnetic plasma confinement

  • Fusion Excessive heat can not be containedAttempts at cold fusion have FAILED.Hot fusion is difficult to contain

  • Mempelajari efek kimia yang di timbulkan oleh radiasi pengion bila ia diserap oleh materiRADIASI : Emisi dan propagasi energi dalam udara dan suatu materi

    RADIASI PENGION : Dapat mengionkan dan mengeksitasi target(Partikel bermuatan/ion /elektron, Gel elektromagnetik/gamma and sinar x, neutron)IONISASI : Pelepasan elektron dari orbital suatu atom/molekul netral - elektron yang terikan paling lemah - terbentuk ion positif dan elektron bebas - hanya bisa ditimbulkan oleh radiasi pengionEKSITASI : Perpindahan elektron ke orbital lebih tinggi dalam suatu atom/molekul netral menjadi atom/molekul mempunyai energi berlebih - kembali ke tingkat semula dengan disertai emisi cahaya atau - terjadi pemutusan ikatan yang lemah menghasilkan radikal bebasIRADIASI : Paparan terhadap radiasi pengion (berdaya tembus)

  • Spektrum elektromagnetikRadiasi pengionRadiasi non-pengionMatahari/radio isotopTabung sinar XMatahari/lampu UVMatahari/bola pijarMatahari/pemanasPemancar/microwave ovenPemancar

  • RADIOISOTOPE ALAM DAN BUATAN--------- FOTON DAN PARTIKELMESIN PEMERCEPAT (ACCELERATOR) PATIKEL----- BERKAS ELEKTRON, BERKAS IONREAKTOR NUKLIR --------- BERKAS NETRONKARAKTERISASI RADIASI PENGION : DAYA TEMBUS DAN LET

    Radiation pengion mempunyai daya tembus, tergantung pada jenis radiasi, energi foton/partikel dan kerapatan targetLET = Linier Energy Transer defined as the linier (distance) rate at which energy is lost by radiation traversing a material medium in unit kev/

  • DNA Sel Mikroba Patogenterkena radiasi menjadi tidak mampuberreplikasi dan mati Radiasi Sinar Gamma terhadap Materi

  • Sinar gamma > sinar x > partikel beta > partikel alpha Daya tembusPartikel alpha > partikel beta > sinar x > sinar gammaL E T

  • Linear energy transfer (LET) is a measure of the energy transferred to material as an ionizing particle travels through it. Typically, this measure is used to quantify the effects of ionizing radiation on biological specimens or electronic devices.Linear energy transfer is closely related to stopping power. Whereas stopping power, the energy loss per unit distance, dE / dx

  • ENERGY RANGETYPE OF RADIATIONSLET VALUE IN WATER (kev/)4 MeV 9 MeV

    0,5 MeV 2 MeV

    0,1 MeV - 2 MeV

    -Alpha 5 MeV

    Beta 2 MeV

    Gamma 1,25 MeV

    X- Rays 200 KeV140

    0,2

    0,3

    3

  • PARTIKEL ALPHA - Daya tembus di udara antara 2,5 9 cm sedangkan untuk aluminium antara 0,02 mm 0,006mm - Electrostatic interaction dgn orbital electron menghasilkan ionisasi dan ion pair (ion positive dan ejected electron)PARTIKEL BETA - Daya tembus 500 kali partikel alpha pada energi yang sama - Production of ion pair - Interaction of fast moving of beta particle produced electromagnetic radiation (X-ray and gamma ray) near positive field of nucleus disertai efect bremsstrahlung (slowing down radiation)

  • e-e-e-e-Partikel pengionelektronIONISASIe-e-e-e-ionisasiPartikel pengeksitasiEKSITASIREAKSI INTI4Be9 + 2He4 ------------ 6C13 + 1H1e-

  • e-e-e-e-e-e-Elektron dg energi Berkurang /BremsstraslungSinar xIonisasiEksitasiBremstrahlung

  • Gamma Rays -Photoelectric absorption, gamma photon expends all of its energy to eject an orbital electron from inner shell (beta particle), energi foton < 1MeV seluruhnya diserap oleh target -Comfton effect, only part of the original gamma energy is used to eject a bound electron, and partly as gamma scattered (energy gamma about 1 - 5 MeV) -Pair Production, interaksi menghasilkan pasangan elektron-positron (energy gamma about 5 MeV), konversi foton oleh medan magnet inti menjadi elektron dan positron--- akan mengionisasi. Elektron dan positron akan berannihilasi menghasilkan sinar gamma lemah (0,51 MeV) yanh diserap target.

  • K-shell: 69.5 keVL-shell: 12 keVM-shell: 3 keVN-shell: 1 keVO-shell: 0.1 keVDenise Moore, Sinclair Community College

  • The projectile electron interacts with the nuclear force field of the target tungsten atomThe electron (-) is attracted to the nucleus (+)The electron DOES NOT interact with the orbital shell electrons of the atomAlways produced = 100% of timehttp://www.internaldosimetry.com/courses/introdosimetry/images/ParticlesBrem.JPG

  • As the electron gets close to the nucleus, it slows down (brems = braking) and changes directionThe loss of kinetic energy (from slowing down) appears in the form of an x-rayThe closer the electron gets to the nucleus the more it slows down, changes direction, and the greater the energy of the resultant x-ray The energy of the x-ray can be anywhere from almost 0 (zero) to the level of the kVp

  • Rayleigh scatteringCompton scatteringPhotoelectric absorptionPair production

  • Incident photon interacts with and excites the total atom as opposed to individual electronsOccurs mainly with very low energy diagnostic x-rays, as used in mammography (15 to 30 keV)Less than 5% of interactions in soft tissue above 70 keV; at most only 12% at ~30 keV

  • Predominant interaction in the diagnostic energy range with soft tissueMost likely to occur between photons and outer (valence) shell electronsElectron ejected from the atom; photon scattered with reduction in energyBinding energy comparatively small and can be ignored

  • Dowd, S.B. Practical Radiation Protection and Applied Radiobiology

  • As incident photon energy increases, scattered photons and electrons are scattered more toward the forward directionThese photons are much more likely to be detected by the image receptor, reducing image contrastProbability of interaction increases as incident photon energy increases; probability also depends on electron densityNumber of electrons/gram fairly constant in tissue; probability of Compton scatter/unit mass independent of Z

  • Laws of conservation of energy and momentum place limits on both scattering angle and energy transferMaximal energy transfer to the Compton electron occurs with a 180-degree photon backscatterScattering angle for ejected electron cannot exceed 90 degreesEnergy of the scattered electron is usually absorbed near the scattering site

  • Incident photon energy must be substantially greater than the electrons binding energy before a Compton interaction is likely to take placeProbability of a Compton interaction increases with increasing incident photon energyProbability also depends on electron density (number of electrons/g density)With exception of hydrogen, total number of electrons/g fairly constant in tissueProbability of Compton scatter per unit mass nearly independent of Z

  • All of the incident photon energy is transferred to an electron, which is ejected from the atomKinetic energy of ejected photoelectron (Ec) is equal to incident photon energy (E0) minus the binding energy of the orbital electron (Eb) Ec = Eo - Eb

  • Dowd, S.B. Practical Radiation Protection and Applied Radiobiology

  • Incident photon energy must be greater than or equal to the binding energy of the ejected photonAtom is ionized, with an inner shell vacancyElectron cascade from outer to inner shellsCharacteristic x-rays or Auger electronsProbability of characteristic x-ray emission decreases as Z decreasesDoes not occur frequently for diagnostic energy photon interactions in soft tissue

  • Probability of photoelectric absorption per unit mass is approximately proportional to

    No additional nonprimary photons to degrade the imageEnergy dependence explains, in part, why image contrast decreases with higher x-ray energies

  • Although probability of photoelectric effect decreases with increasing photon energy, there is an exceptionGraph of probability of photoelectric effect, as a function of photon energy, exhibits sharp discontinuities called absorption edgesPhoton energy corresponding to an absorption edge is the binding energy of electrons in a particular shell or subshell

  • At photon energies below 50 keV, photoelectric effect plays an important role in imaging soft tissueProcess can be used to amplify differences in attenuation between tissues with slightly different atomic numbers, improving image contrastPhotoelectric process predominates when lower energy photons interact with high Z materials (screen phosphors, radiographic constrast agents, bone)

  • Can only occur when the energy of the photon exceeds 1.02 MeVPhoton interacts with electric field of the nucleus; energy transformed into an electron-positron pairOf no consequence in diagnostic x-ray imaging because of high energies required

  • Attenuation of gamma rays in a material is exponential, I = Io e-x

    Io adalah Intensitas awalI adalah intensitas gamma setelah melalui material adalah koefisien absorptionX adalah ketebalan material

    X1/2 = 0.693/

  • Counts per minute Curie (unit) , BqGray (unit) Rad (unit) Rem (unit) rntgen (unit) Sverdrup (unit) (a unit of volume transport with the same symbol Sv as Sievert) Background radiation Relative Biological Effectiveness Radiation poisoning Linear Energy Transfer

  • Counts per minute (cpm) is a measure of radioactivity. It is the number of atoms in a given quantity of radioactive material that are detected to have decayed in one minute. Disintegrations per minute (dpm) is also a measure of radioactivity. It is the number of atoms in a given quantity of radioactive material that decay in one minute. Dpm is similar to cpm, however the efficiency of the radiation detectorCPM ~ DPMDPM = Ef Det x CPM

  • One Bq is activity of a quantity of radioactive material in which one nucleus decay per secondSI unit untuk Radioactivity is, Bacquerel = Bq adalah unit terkecil 1 Bq = 1 radioactive decay per second (S-1)= dis/s 1 Bq = 60 dpm Satuan Lama adalah Curie = Ci , 1 Ci = 3.7 x 1010 Bq = 37 GBqBq dapat dalam bentuk sbb - kBq , MBq, GBq, TBq and PBq Hitung : 0,25 Ci = dpm ?

  • Pada pengukuran zat radioaktive dgn alat ukur akan terukur unit cps (count per second) or cpm (count per minute) dalam bentuk digital. Konversi cps ke absolute activity (Bq) adalah : Bq = cps x detektor effesiensiUnit of absorbed radiation dose (SI) due to ionization radiation (X-ray) is called Gray (Gy)

  • Absorbed dose (also known as total ionizing dose, TID) is a measure of the energy deposited in a medium by ionizing radiation. It is equal to the energy deposited per unit mass of medium, and so has the unit J/kg, which is given the special name Gray (Gy).1 Gy of alpha radiation would be much more biologically damaging than 1 Gy of photon radiation

  • Absorbed dose ; SI , Gray (Gy, kGy, etc)Definition : One gray is the absorption of one joule of energy, in the form of ionizing radiation, by one kilogram of matter

    1 Gy = 1 J/kg

    Absorbed dose = Gray (Gy), mengukur deposit energi radiasi 100 rad = 1 Gy

  • Absorbed dose is the amount of energy absorbed into matter. The working SI unit is a gray (Gy), while the traditional unit is rad (rad)1 rad = 62.4 x 106 MeV per gram 1 gray = 100 erg per gram1 rad = 0.01 gray 1 gray (Gy) = 100 radIn the United States, radiation absorbed dose, dose equivalent, and exposure are often measured and stated in the older units called rad, rem, or roentgen (R)

  • Rongent as radiation exposure equal to the ionization radiation will produce one esu of electricity in one cc of dry air at oC and standard atmosfer 1 Gy 115 RThe rntgen was occasionally used to measure exposure to radiation in other forms than X-rays or gamma rays1 R = 2.58104 C/kg (from 1 esu 3.335641010 C and the standard atmosphere air density of ~1.293 kg/m)

  • The rad (radiation absorbed dose) is a unit of absorbed radiation doseA dose of 1 rad means the absorption of 100 ergs of radiation energy per gram of absorbing material 1 Gy = 100 rad1 roentgen (R) = 258 microcoulomb/kg (C/kg)

  • When ionising radiation is used to treat cancer, the doctor will usually prescribe the radiotherapy treatment in Gy. When risk from ionising radiation is being discussed, a related unit, the sievert is used.

  • The equivalent dose (HT) is a measure of the radiation dose to tissue where an attempt has been made to allow for the different relative biological effects of different types of ionizing radiationEquivalent dose adalah absorbed dose + biology effect = Rongent Equivalent Man (REM)Equivalent dose (HTR) = Absorbed dose (Gy) x radiation weighting factor (Wr)Equivalent dose (SI) ---- Sievert (Sv) unit Sievert (sv) (biasanya untuk X-ray) 100 REM = 1 Sv1 Sv = 1 J/kg = Gy

  • Dose equivalent is the absorbed dose into biological matter taking into account the interaction of the type of radiation and its associated linear energy transfer through specific tissues. The working SI unit is the sievert (Sv), while the traditional unit is roentgen equivalent man (rem). 1Sv = 1 rads x quality factor x any other modifying factors 1rem = 1 gray x quality factor x any other modifying factors1 Sv =100 roentgen equivalent man (rem) 1 rem = 0.01Sv = 10mSv

  • The dose equivalent is a measure of biological effect for whole body irradiation. The dose equivalent is equal to the product of the absorbed dose and the Quality FactorThe millisievert is commonly used to measure the effective dose in diagnostic medical procedures (e.g., X-rays, nuclear medicine, positron emission tomography, and computed tomography). The natural background effective dose rate varies considerably from place to place, but typically is around 2.4 mSv/year that quantity of X rays which when absorbed will cause the destruction of the [malignant mammalian] cell

  • This variation in effect is attributed to the Linear Energy Transfer [LET] of the type of radiation, creating a different relative biological effectiveness for each type of radiation under considerationthe RBE [Q] for electron and photon radiation is 1, for neutron radiation it is 10, and for alpha radiation it is 20unit of the equivalent dose is the rem (Rntgen equivalent man); 1 Sv is equal to 100 rem, for a quality factor Q=1

  • Here are some quality factor values:[Photons, all energies: Q = 1 Electrons all energies: Q = 1 Neutrons, energy < 10 keV: Q = 5 10 keV < energy < 100 keV: Q = 10 100 keV < energy < 2 MeV: Q = 20 2 MeV < energy < 20 MeV: Q = 10 energy > 20 MeV: Q = 5 Protons, energy > 2 MeV: Q = 5 Alpha particles and other atomic nuclei: Q = 20

  • Dose rate criteria (outside storage area):2.5 Sv/hr = 0.25mrem/hrCNSC Dose Limits (non-Nuclear Energy Worker):Whole body = 1mSv/yr = 100 mrem/yr Skin, Hands, Feet = 50 mSv/yr = 5 rem/yr

  • Here are some N values for organs and tissues:[2]Gonads: N = 0.20 Bone marrow, colon, lung, stomach: N = 0.12 Bladder, brain, breast, kidney, liver, muscles, oesophagus, pancreas, small intestine, spleen, thyroid, uterus: N = 0.05 Bone surface, skin: N = 0.01

  • And for other organisms, relative to humans:Viruses, bacteria, protozoans: N 0.03 0.0003 Insects: N 0.1 0.002 Molluscs: N 0.06 0.006 Plants: N 2 0.02 Fish: N 0.75 0.03 Amphibians: N 0.4 0.14 Reptiles: N 1 0.075 Birds: N 0.6 0.15 Humans: N = 1

  • Radiation sourceCommentsmSv/yrmrem/yrNatural sourcesindoor radon due to seepage of 222Rn from ground2.0200radionuclides in body primarily 40K and 238U progeny0.3939terrestrial radiation due to gamma-ray emitters in ground0.2828cosmic rays roughly doubles for 2000 m gain in elevation0.2727cosmogenic especially 14C0.011total (rounded) 3.0300

  • Medical sourcesDiagnostic x-rays excludes dental examinations 0.3939Medical treatments radionuclides used in diagnosis (only)0.1414total 0.5353Otherconsumer products primarily drinking water, building materials0.110occupational averaged over entire US population0.011nuclear fuel cycle does not include potential reactor accidents0.00050.05TOTAL (rounded)3.6360

  • Proses Big bang dan pembentukan alamRadioaktive decay untuk dating (penanggalan) umur batuan (C-14 dan K/Ar)Irradiasi gamma untuk sterilisasi produk kesehatan dan makananReaktor nuklir untuk PLTNTeknik radiotracer untuk IndustriTeknik radiasi untuk pertanianLaser dan pemanfaatannya untuk kesehatan

  • Proses pemisahan (enrichment) bahan bakar U235 dan U238

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