He āhuatanga ā-tinana te mahi irahiko e puta ana i te wā e pirau ai ngā karihi ngota kore pumau, ka tukuna ai ngā matūriki, ngā hihi rānei. I kitea tēnei āhuatanga i te mutunga o te rautau 19, ā, kua whakarārangihia te ara mō ngā mahi auaha maha i roto i te pūtaiao, te hangarau, me te rongoā. Ka tūhuratia e tēnei tuhinga ngā mātāpono taketake o te mahi irahiko, ngā momo pirau irahiko, ōna whakamahinga i roto i ngā momo mara, me ōna pānga ki te oranga o ia rā.
Hītori o te Kitea o te Irahiko
I tīmata te kitenga o te irahiko i te tau 1896 e te kaipūtaiao Wīwī a Henri Becquerel. I kitea e Becquerel ka tukuna e ngā tote uranium te irahiko ka taea te whakakore i te tae o ngā pereti whakaahua, ahakoa te kore o te māramatanga. I aro atu ētahi atu kaipūtaiao ki tēnei kitenga, tae atu ki a Marie rāua ko Pierre Curie, ā, i muri mai ka kitea, ka akohia hoki e rāua ētahi atu huānga irahiko pērā i te polonium me te radium.
Ko Marie Curie, inā koa, i tino whai wāhi ki te whakawhanake i tō tātou māramatanga ki te mahi irahiko. Ko ia te kaipūtaiao tuatahi ki te whakamahi i te kupu "mahi irahiko" ā, i whiwhi ia i ngā Tohu Nobel e rua i roto i te ahupūngao me te matū mō āna mahi i tēnei mara.
Ngā Mātāpono Taketake o te Mahi Irahiko
Ka puta te mahi irahiko ina pirau ngā karihi ngota kore pumau kia eke ki tētahi āhua pumau ake. Kei roto i tēnei tukanga pirau ngā huringa o te hanganga karihi me te tukunga o te pūngao i roto i te ahua o ngā matūriki, o te irahiko hikohiko rānei. E toru ngā momo matua o te pirau irahiko:
- Te Pirau o te Ārapa (α)Ka puta tēnei pirau ina tukuna e te karihi he matūriki ārepa, e rua ngā porotana me ngā niutorone e rua (he karihi hēriuma-4). Hei tauira, ka pirau te uranium-238 ki te thorium-234 mā te pirau ārepa. He nui te pūngao o ngā matūriki ārepa engari he iti te kaha uru, ā, ka taea te aukati mā te pepa, mā te kiri tangata rānei.
- Te Pirau Beta (β)Ko tēnei pirau ko te hurihanga o te niutorone ki te porotona, te hurihanga rānei i roto i te karihi, me te tukunga o te matūriki beta (irahiko, positron rānei). Hei tauira, ka pirau te waro-14 ki te hauota-14 mā te tukunga o te irahiko (beta-minus). He nui ake te kaha o te werohanga o ngā matūriki beta i ngā matūriki alpha, ā, ka taea te aukati mā te pepa konumohe.
- Pirau o te Gamma (γ)Ka puta tēnei pirau ina tukuna te pūngao e te karihi whakahihiri i roto i te ahua o te hihi gamma, arā, he photon pūngao teitei. He tino teitei te kaha o te uru o te hihi gamma, ā, me whakamahi i ngā rauemi matotoru ake hei mimiti, pērā i te mata, i te raima rānei, hei aukati.
Ngā Whakamahinga o te Irahiko
He maha ngā whakamahinga nui o te irahiko i roto i te pūtaiao, te hangarau, me te rongoā, tae atu ki:
- Te Whare Mana KarihiKa whakamahia e ngā tauhohenga karihi te tauhohenga wehenga o ngā wahie irahiko pērā i te uranium-235, te plutonium-239 rānei hei whakaputa wera. Kātahi ka whakamahia tēnei wera hei whakaputa mamaoa e taraiwa ana i ngā tāpine me te whakaputa hiko. He puna pūngao whai hua, pono hoki ngā tipu hiko karihi, ahakoa he wero anō hoki kei roto i te whakahaere para me te haumaru.
- Rongoā karihiE whakamahia ana ngā isotope irahiko hei tātaritanga me te maimoatanga hauora. Hei tauira, e whakamahia ana te technium-99m hei whakaahua i ngā wheua me ngā okana, ko te iodine-131 ia e whakamahia ana hei rongoā i te mate pukupuku tairoi. Ko ngā tikanga pēnei i te PET (Positron Emission Tomography) me te SPECT (Single Photon Emission Computed Tomography) e whakamahi ana i te irahiko hei whakaputa whakaahua taipitopito o ngā tukanga ā-tinana i roto i te tinana.
- Te Whakamātautau IrahikoKo ngā tikanga whakatau ine irahiko, pērā i te whakatau i te waro-14, e whakamahia ana hei whakatau i te pakeketanga o ngā kōiwi tawhito, ngā taonga whaipara tangata, me ngā tauira whenua. E hangai ana ēnei tikanga ki te tere pirau o ētahi isotope irahiko, e puta ana i te tere pumau.
- Ahumahi me te AhuwhenuaE whakamahia ana te irahiko i roto i ngā momo mahi ahumahi me te ahuwhenua, tae atu ki te ine i te matotoru o ngā rauemi, te kimi turuturu, te whakamate hua, me te whakahaere pepeke. E whakamahia ana ngā isotopes pēnei i te cesium-137 me te cobalt-60 i roto i ēnei tikanga.
Ngā Pānga me ngā Wero o te Mahi Irahiko
Ahakoa he maha ngā painga o te irahiko, tera anō ētahi pānga me ngā wero hei whakaaroaro:
- Haumarutanga IrahikoKa taea e te pānga o te irahiko te whakakino i ngā pūtau me ngā kiko, te whakanui ake i te mōrearea o te mate pukupuku, me te whakaputa i ētahi atu pānga hauora. Nō reira, he mea nui kia whakahaerea te pānga o te irahiko me te whakatinana i ngā tikanga haumaru pakari ina whakamahia ngā rauemi irahiko.
- Para IrahikoHe wero nui te whakahaere i ngā para irahiko, inā koa mai i ngā tauhohenga karihi. Me rongoa mō te wā roa ēnei para i roto i ngā whare haumaru hei ārai i te poke o te taiao me ngā tūponotanga hauora.
- Te horapa haere o ngā patu karihiKa taea te whakamahi i te hangarau kotahi e whakamahia ana mō te whakaputa hiko karihi hei hanga patu karihi. Me mahi ngā mahi a te ao whānui hei ārai i te horapa o ngā patu karihi, hei whakarite hoki i te whakamahinga rangimārie o te hangarau karihi.
- Te Tirohanga a te IwiHe maha ngā wā e hono ana te mahi irahiko ki ngā mōrearea me ngā tūponotanga, ka pā kino pea ki te whakaae a te marea ki te hangarau karihi. Me whai mātauranga me te whakawhitiwhiti kōrero whai hua hei whakapiki i te māramatanga me te tautoko a te marea mō ngā painga o te hangarau karihi.
Te Anamata o te Mahi Irahiko
Kei te haere tonu te rangahau me te whanaketanga i roto i te ao o te irahiko, me te tumanako ka taea e ngā auahatanga maha te aro atu ki ngā wero o nāianei me te whakamahi i te pūmanawa katoa o tēnei āhuatanga. Ko ētahi o ngā wāhanga rangahau me te whanaketanga whai hua ko:
- Ngā Pūrere Whakaoho Karihi o te Reanga HouKei te whakawhanakehia ngā tauhohenga karihi o te whakatupuranga tuawhā hei whakapai ake i te whai huatanga, te haumaru, me te whakahaere para. Kua hangaia ēnei tauhohenga hei whakaiti i te mōrearea o ngā aituā, hei whakaiti hoki i te para irahiko e puta mai ana.
- Te Hanumitanga KarihiKo te whāinga o te rangahau hanumi karihi he waihanga i tētahi pūtake pūngao ma, haumaru ake hoki i te wehenga karihi. Ahakoa kei te mau tonu ngā wero hangarau nui, mā te angitu i tēnei mara ka taea te whakarato i ngā otinga pūngao pumau mō ngā rā kei te heke mai.
- Hangarau Hauora HouKei te haere tonu te auahatanga i roto i te rongoā karihi, me te whanaketanga o ngā isotope irahiko hou me ngā tikanga whakaahua matatau ake. E matapaetia ana ka pai ake te tautuhi me te maimoatanga o te whānuitanga o ngā mate.
- Te Whakahaere Para Pai AkeKo te whāinga o te rangahau mō te hangarau whakawhiti para he huri i te para irahiko hei isotope pumau ake, iti ake te mōrearea. Ka taea e tēnei hangarau te whakaiti i te nui me te mōrearea o te para karihi.
Whakamutunga
He āhuatanga uaua te irahiko, he pānga nui ki ngā āhuatanga maha o te ora. Mai i ngā tipu hiko karihi ki ngā tono hauora me ngā tono ahumahi, he nui ngā painga o te irahiko, engari he wero me ngā mōrearea anō hoki me whakahaere marie. Mā te rangahau tonu me te auahatanga, ka taea e tātou te whakamahi i te pūmanawa katoa o te irahiko me te whakaiti i ōna mōrearea me ōna pānga kino, ka arahi ki tētahi heke mai haumaru ake, pumau ake hoki.
