radiation damage

放射線障害

WordNet

1. suffer or be susceptible to damage; "These fine china cups damage easily"
2. inflict damage upon; "The snow damaged the roof"; "She damaged the car when she hit the tree"
3. the act of damaging something or someone (同)harm, hurt, scathe
4. loss of military equipment (同)equipment casualty
5. the occurrence of a change for the worse (同)harm, impairment
6. the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay (同)radioactivity
7. energy that is radiated or transmitted in the form of rays or waves or particles
8. the act of spreading outward from a central source
9. a radial arrangement of nerve fibers connecting different parts of the brain
10. the spread of a group of organisms into new habitats
11. designed or tending to discredit, especially without positive or helpful suggestions; "negative criticism" (同)negative
12. (sometimes followed by `to' (同)detrimental, prejudicial, prejudicious
13. harmed or injured or spoiled; "I wont buy damaged goods"; "the storm left a wake of badly damaged buildings"
14. a sum of money paid in compensation for loss or injury (同)amends, indemnity, indemnification, restitution, redress

PrepTutorEJDIC

1. 〈U〉『損害』,損傷,被害 / 《複数形で》損害賠障[金] / 《the~》《単数形で》《話》飛用 / …‘に'損傷する
2. 〈U〉(光・熱・放射能などの)発散,放射 / 〈C〉放射物;放射線;輻射(ふくしゃ)熱 / 〈C〉(喜び・幸福感などの)発散《+『of』+『名』》 / =radioactivity

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/01/19 16:05:25」(JST)

wiki en

[Wiki en表示]

For the effects of radiation of living tissues, see radiation poisoning and radiation therapy.

Radiation damage is a term associated with ionizing radiation.

Causes

This radiation may take several forms:

• Cosmic rays and subsequent energetic particles caused by their collision with the atmosphere and other materials.
• Radioactive daughter products (radioisotopes) caused by the collision of cosmic rays with the atmosphere and other materials, including living tissues.
• Energetic particle beams from a particle accelerator.
• Energetic particles or electro-magnetic radiation (X rays) released from collisions of such particles with a target, as in an X ray machine or incidentally in the use of a particle accelerator.
• Particles or various types of rays released by radioactive decay of elements, which may be naturally occurring, created by accelerator collisions, or created in a nuclear reactor. They may be manufactured for therapeutic or industrial use or be released accidentally by nuclear accident, or released sententially by a dirty bomb, or released into the atmosphere, ground, or ocean incidental to the explosion of a nuclear weapon for warfare or nuclear testing.

Effects on materials and devices

Radiation may affect materials and devices in deleterious ways:

• By causing the materials to become radioactive (mainly by neutron activation, or in presence of high-energy gamma radiation by photodisintegration).
• By nuclear transmutation of the elements within the material including, for example, the production of Hydrogen and Helium which can in turn alter the mechanical properties of the materials and cause swelling and embrittlement.
• By radiolysis (breaking chemical bonds) within the material, which can weaken it, cause it to swell, polymerize, promote corrosion, cause belittlements, promote cracking or otherwise change its desirable mechanical, optical, or electronic properties.
• By formation of reactive compounds, affecting other materials (e.g. ozone cracking by ozone formed by ionization of air).
• By ionization, causing electrical breakdown, particularly in semiconductors employed in electronic equipment, with subsequent currents introducing operation errors or even permanently damaging the devices. Devices intended for high radiation environments such as the nuclear industry and extra atmospheric (space) applications may be made radiation hard to resist such effects through design, material selection, and fabrication methods.

Many of the radiation effects on materials are produced by collision cascades and covered by radiation chemistry.

Effects on gases

Exposure to radiation causes chemical changes in gases. The least susceptible to damage are noble gases, where the major concern is the nuclear transmutation with followup chemical reactions of the nuclear reaction products.

High-intensity ionizing radiation in air can produce a visible ionized air glow of telltale bluish-purplish color. The glow can be observed e.g. during criticality accidents, around mushroom clouds shortly after a nuclear explosion, or inside of a damaged nuclear reactor like during the Chernobyl disaster.

Significant amounts of ozone can be produced. Even small amounts of ozone can cause ozone cracking in many polymers over time, in addition to the damage by the radiation itself.

Gas-filled tubes

Radiation has detrimental effects on gas-filled tubes, ionizing the gas inside and increasing its electrical conductivity, interfering with the functionality of the tubes. Vacuum tubes are much less sensitive to radiation effects.

The ionization effects are exploited in gas-filled radiation detectors, e.g. the Geiger tube. The electrical discharge plasma however tends to cause aging of the gas and/or the detector electrodes.

Gas-filled radiation detectors

In gas-filled particle detectors, radiation damage to gases plays an important role in the device's aging, especially in devices exposed to high intensity radiation, e.g. detectors for the Large Hadron Collider.

Ionization processes require energy above 10 eV, while splitting covalent bonds in molecules and generating free radicals requires only 3-4 eV. The electrical discharges initiated by the ionization events by the particles result in plasma populated by large amount of free radicals. The highly reactive free radicals can recombine back to original molecules, or initiate a chain of free radical polymerization reactions with other molecules, yielding compounds with increasing molecular weight. These high molecular weight compounds then precipitate from gaseous phase, forming conductive or non-conductive deposits on the electrodes and insulating surfaces of the detector and distorting its response. Gases containing hydrocarbon quenchers, e.g. argon-methane, are typically sensitive to aging by polymerization; addition of oxygen tends to lower the aging rates. Trace amounts of silicone oils, present from outgassing of silicone elastomers and especially from traces of silicone lubricants, tend to decompose and form deposits of silicon crystals on the surfaces. Gaseous mixtures of argon (or xenon) with carbon dioxide and optionally also with 2-3% of oxygen are highly tolerant to high radiation fluxes. The oxygen is added as noble gas with carbon dioxide has too high transparency for high-energy photons; ozone formed from the oxygen is a strong absorber of ultraviolet photons. Carbon tetrafluoride can be used as a component of the gas for high-rate detectors; the fluorine radicals produced during the operation however limit the choice of materials for the chambers and electrodes (e.g. gold electrodes are required, as the fluorine radicals attack metals, forming fluorides). Addition of carbon tetrafluoride can however eliminate the silicon deposits. Presence of hydrocarbons with carbon tetrafluoride leads to polymerization. A mixture of argon, carbon tetrafluoride, and carbon dioxide shows low aging in high hadron flux.

Effects on liquids

Like gases, liquids lack fixed internal structure; the effects of radiation is therefore mainly limited to radiolysis, altering the chemical composition of the liquids. As with gases, one of the primary mechanisms is formation of free radicals.

All liquids are subject to radiation damage, with few exotic exceptions; e.g. molten sodium, where there are no chemical bonds to be disrupted, and liquid hydrogen fluoride, which produces gaseous hydrogen and fluorine, which spontaneously react back to hydrogen fluoride.

Effects on water

Water subjected to ionizing radiation forms free radicals of hydrogen and hydroxyl, which can recombine to form gaseous hydrogen, oxygen, hydrogen peroxide, hydroxyl radicals, and peroxide radicals. In living organisms, which are composed mostly of water, majority of the damage is caused by the reactive oxygen species, free radicals produced from water. The free radicals attack the biomolecules forming structures within the cells, causing oxidative stress (a cumulative damage which may be significant enough to cause the cell death, or may cause DNA damage possibly leading to cancer).

In cooling systems of nuclear reactors, the formation of free oxygen would promote corrosion and is counteracted by addition of hydrogen to the cooling water. The hydrogen is not consumed as for each molecule reacting with oxygen one molecule is liberated by radiolysis of water; the excess hydrogen just serves to shift the reaction equilibriums by providing the initial hydrogen radicals. The reducing environment in pressurized water reactors is less prone to buildup of oxidative species. The chemistry of boiling water reactor coolant is more complex, as the environment can be oxidizing. Most of the radiolytic activity occurs in the core of the reactor where the neutron flux is highest; the bulk of energy is deposited in water from fast neutrons and gamma radiation, the contribution of thermal neutrons is much lower. In air-free water, the concentration of hydrogen, oxygen, and hydrogen peroxide reaches steady state at about 200 Gy of radiation. In presence of dissolved oxygen, the reactions continue until the oxygen is consumed and the equilibrium is shifted. Neutron activation of water leads to buildup of low concentrations of nitrogen species; due to the oxidizing effects of the reactive oxygen species, these tend to be present in the form of nitrate anions. In reducing environments, ammonia may be formed. Ammonia ions may be however also subsequently oxidized to nitrates. Other species present in the coolant water are the oxidized corrosion products (e.g. chromates) and fission products (e.g. pertechnetate and periodate anions, uranyl and neptunyl cations). Absorption of neutrons in hydrogen nuclei leads to buildup of deuterium and tritium in the water. Behavior of supercritical water, important for the supercritical water reactors, differs from the radiochemical behavior of liquid water and steam and is currently under investigation.

The magnitude of the effects of radiation on water is dependent on the type and energy of the radiation, namely its linear energy transfer. A gas-free water subjected to low-LET gamma rays yields almost no radiolysis products and sustains an equilibrium with their low concentration. High-LET alpha radiation produces larger amounts of radiolysis products. In presence of dissolved oxygen, radiolysis always occurs. Dissolved hydrogen completely suppresses radiolysis by low-LET radiation while radiolysis still occurs with

The presence of reactive oxygen species has strongly disruptive effect on dissolved organic chemicals. This is exploited in groundwater remediation by electron beam treatment.

Countermeasures

Two main approaches to reduce radiation damage are reducing the amount of energy deposited in the sensitive material (e.g. by shielding, distance from the source, or spatial orientation), or modification of the material to be less sensitive to radiation damage (e.g. by adding antioxidants, stabilizers, or choosing a more suitable material). In addition to the electronic device hardening mentioned above, some degree of protection may be obtained by shielding, usually with the interposition of high density materials (particularly lead, where space is critical, or concrete where space is available) between the radiation source and areas to be protected. For biological effects of substances such as radioactive iodine the ingestion of non-radioactive isotopes may substantially reduce the biological uptake of the radioactive form, and chelation therapy may be applied to accelerate the removal of radioactive materials formed from heavy metals from the body by natural processes.

See also

• Radiation material science

References

UpToDate Contents

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• 1. 放射線誘発性線維症の臨床症状および治療 clinical manifestations and treatment of radiation induced fibrosis
• 2. 画像検査の放射線関連リスク radiation related risks of imaging studies
• 3. Adjuvant radiation therapy for high-grade gliomas
• 4. Delayed complications of cranial irradiation
• 5. 放射線療法誘発性肺障害 radiation induced lung injury

English Journal

• Alteration of the inflammatory molecule network after irradiation of soft tissue.

• Xiao Z, Yang S, Su Y, Wang W, Zhang H, Zhang M, Zhang K, Tian Y, Cao Y, Yin L, Zhang L, Okunieff P.SourceDepartment of Radiation Oncology, UF Shands Cancer Center, University of Florida, 103633, Gainesville, FL, 32610, USA.
• Advances in experimental medicine and biology.Adv Exp Med Biol.2013;765:335-41.
• Inflammatory molecules (IMs) play an important role in ionizing radiation (IR)-induced soft tissue damage. The alteration of IMs as a function of time was studied with a protein array containing 62 IMs in mouse cutaneous soft tissues exposed to 30 Gy. The results showed that: (1) 2 days after irradi
• PMID 22879053

• Fibroblast growth factor-Peptide promotes bone marrow recovery after irradiation.

• Ma J, Hou Y, Han D, Zhang M, Chen C, Zhang B, Zhang Z, Wang X, Yang S, Guo Y, Okunieff P, Zhang L.SourceInstitute of Digestive Diseases, Zhengzhou University, Henan, China.
• Advances in experimental medicine and biology.Adv Exp Med Biol.2013;765:155-61.
• Various members of the fibroblast growth factor (FGF) family mitigate radiation-induced damage. We designed and synthesized the binding domain peptide of FGF-2 (FGF-P) with a dimer form resistant to peptidase and examined its mitigatory effect on murine bone marrow cells. NIH Swiss mice were exposed
• PMID 22879028

Japanese Journal

• Energy loss process analysis for radiation degradation and immediate recovery of amorphous silicon alloy solar cells

• Sato Shin-ichiro,Beernink Kevin,Ohshima Takeshi
• Jpn. J. Appl. Phys. 54(6), 061401, 2015-04-28
• … Significant recovery is always observed independent of radiation species and temperature. … In addition, the radiation degradation mechanism is discussed by analyzing the energy loss process of incident particles (ionizing energy loss: IEL, and non-ionizing energy loss: NIEL) and their relative damage factors. …
• NAID 150000110657

• SACLA自由電子レーザーを用いた無損傷タンパク質結晶構造解析手法の開発

• 平田 邦生
• 生物物理 55(2), 84-86,103, 2015-04
• NAID 40020436016

• Sensitivity and dose dependency of radiation-induced injury in hematopoietic stem/progenitor cells in mice

• Guo Chang-Ying,Luo Lan,Urata Yoshishige,Goto Shinji,Huang Wen-Jing,Takamura Syu,Hayashi Fumiko,Doi Hanako,Kitajima Yuriko,Ono Yusuke,Ogi Tomoo,Li Tao-Sheng
• Scientific Reports 5, 8055, 2015-01-27
• … We evaluated the sensitivity and dose dependency of radiation-induced injury in hematopoietic stem/progenitor cells. … The damage of hematopoietic stem/progenitor cells in bone marrow were investigated within 2 hours (acute phase) or at 3 months (chronic phase) after the last exposure. … Our data have clearly shown the sensitivity and dose dependency of radiation-induced injury in hematopoietic stem/progenitor cells of mice with daily exposures to 2 ∼ 250 mGy γ-ray. …
• NAID 120005572529

Related Links

• Radiation damage - Wikipedia, the free encyclopedia

Radiation damage is a term associated with ionizing radiation. Contents. 1 Causes; 2 Effects on materials and devices. 2.1 Effects on gases. 2.1.1 Gas-filled tubes; 2.1.2 Gas-filled radiation detectors. 2.2 Effects on liquids. 2.2.1 Effects on water ...

• Radiation hardening - Wikipedia, the free encyclopedia

Typical sources of exposure of electronics to ionizing radiation are the Van Allen radiation belts for satellites, nuclear reactors in power plants for sensors and control circuits, particle accelerators ...

Related Pictures

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★リンクテーブル★

リンク元	「放射線障害」
関連記事	「damage」「radiation」「damaged」

「放射線障害」

　　[★]

英

radiation damage, radiation injury, radiation hazard

同

放射能症、電離放射線障害 radiolesion ionizing radiation injury、放射線の危険性 radiation risk

関

放射線、放射能、放射性核種

全身被爆の症状と予後 RNT.322

全身被爆線量	前駆症状(%)	潜伏時間	死因	症状	死亡率(%)
～2	0～50	>3 hr		無症状～軽度の血球現象	0～10
2～10	100	0.5-3 hr	骨髄死	血球現象→感染、出血	0～90
10～20	100	0.5 hr	消化管死	嘔吐・下痢・吐血・下血・脱水	90～100
50	100	several min.	中枢神経死	脳浮腫→けいれん、意識障害	100
*前駆症状：悪心、嘔吐、めまい、全身倦怠感、発熱

• 末梢の血球への影響はリンパ球＞その他の白血球＞血小板＞赤血球

SUB 449

身体的影響	早期障害	骨髄抑制、嘔吐、下痢、下血、放射線宿酔	確定的影響(閾値有り)
		皮膚紅斑・潰瘍、脱毛
		不妊、脳浮腫
	晩期影響	白内障、胎児奇形
遺伝的影響		白血病、癌	確率低影響(閾値無し)
	染色体異常など

メモ

111018

• 放射線による慢性的な障害は、ふくしまの件では微々たるものなのでは？
• 大気汚染、喫煙、飲酒による健康への障害の方が遙かに大きい。
• 問題は、放射線への知識が貧弱すぎること(いわゆる文系馬鹿のマスコミが煽る)と、放射線を積極的に回避しづらいことである。
• 例えば、大気汚染は外出を控えることで避けられるし、喫煙は吸わないこと、副流煙を吸わないことで回避できる。飲酒は飲まなければよい。
• しかし、放射線からは距離を置く、放射性同位体を含む物を摂取しないことしか回避できない。
• しかも、どれだけ体内被曝することで、どれだけ生命予後に影響を及ぼすかは不明である。
• 政府が基準値を定めているが、その値は次々と変更され、疑心暗鬼を生じる原因となってしまった。

「damage」

　　[★]

• n.

• ダメージ、障害、損傷、破損

• v.

• 破損する、損傷する

関

barrier、break、breakage、difficulty、disorder、disruption、disturbance、dysfunction、foe、hindrance、impair、impairment、impediment、injure、injury、lesion、obstacle、spoilage

　 　 　 　 　 　

「radiation」

　　[★]

• n.

• 放射、放射線
• 放射物
• 輻射、放熱

　 　 　 　 　 　

「damaged」

　　[★]

• adj.

• 傷害性の

関

affective、injurious、traumatic