N\u00fckleer enerjinin deh\u015fet verici as-kerf uygulamalar\u0131 bilinmektedir. Bu uygulamalar, n\u00fckleer fizi\u011fin 1940’h ve 1950’li y\u0131llarda \u00e7ok h\u0131zl\u0131 bir geli\u015f-me g\u00f6stermeline ve \u00abuv enerji \u00fcretimine yol a\u00e7m\u0131\u015ft\u0131r. I\u015f\u0131n\u0131m\u0131 kolayca saptanabilir radyoaktif \u00e7ekirdeklerin i\u015faret a\u00bbc\u0131 olarak kullan\u0131lmas\u0131, \u00f6p, Unm, hidroloji gibi \u00e7ok de\u011fi\u015fik alanlarda yayg\u0131n bi\u00e7imde uygulan*maktad\u0131r. A\u011f\u0131r iyonlar fizi\u011finin geli\u015fmeli, y\u00fczey fizi\u011finde s\u0131na\u00ee uygu*lama olanaktan bulmu\u015ftur.
\nN\u00f6tronlar\u0131n etkinle\u015ftirilmesiyle, kimyasal elementlerin izlerinin l milyard\u0131 l gibi oranlarda saptan-mat\u0131 da m\u00fcmk\u00fcnd\u00fcr: b\u00f6ylece, \u00dcst Kreta\u0131e ile \u00dc\u00e7\u00fcnc\u00fc Zaman aras\u0131n*daki ge\u00e7i\u015fi belirleyen tortullarda anonnal y\u00fcksek miktarlarda irid*yum izleri \u00f6l\u00e7\u00fclm\u00fc\u015ft\u00fcr. Bu anormalli\u011fin m\u00fcmk\u00fcn a\u00e7\u0131klamalar\u0131ndan biri, iridyumun, bundan 65 milyon y\u0131l \u00f6nce D\u00fcnya ile \u00e7arp\u0131\u015fan, yakla*\u015f\u0131k on kilometre \u00e7ap\u0131nda bir mete*orit taraf\u0131ndan getirilmi\u015f olmas\u0131d\u0131r (b\u00f6ylesi bir \u00e7arpi|ma, aralar\u0131nda di-\u00fcozorUnn da bulundu\u011fu pek \u00e7ok canl\u0131 t\u00fcr\u00fcn\u00fcn yok olmal\u0131yla f onu\u00e7-lanan, d\u00fcnya \u00e7ap\u0131nda bir felakete yol a\u00e7mif olabilir). N\u00f6tronlar\u0131n et*kinle\u015ftirmesi, imal edildikleri yerle*rin uza\u011f\u0131mla bulunan \u00e7\u00f6mleklerin yap\u0131ld\u0131\u011f\u0131 topra\u011f\u0131n co\u011frafi k\u00f6kenini saptayarak, yok olmu\u015f uygarl\u0131klar\u0131n ticaret a\u011flar\u0131n\u0131n saptanmas\u0131n\u0131 sa\u011flad\u0131\u011f\u0131 arkeolojide de kullan\u0131lmakta*d\u0131r. 14C (karbon 14) tarihlendirme y\u00f6ntemi, tarihsel \u00f6l\u00e7e\u011fe uymakta*d\u0131r; \u00e7\u00fcnk\u00fc bu radyoaktif \u00e7ekirde\u011fin yan \u00f6mr\u00fc 5 000 y\u0131ld\u0131r: bir varl\u0131k \u00f6l*d\u00fc\u011f\u00fcnde, \u00bbruk MC so\u011furmaz; \u00ab\u00abC\/ttC oran\u0131n\u0131 \u00f6l\u00e7erek ve \u00f6ld\u00fc\u011f\u00fc tirada atmosferde bulunan “C ora*n\u0131n\u0131n bug\u00fcnk\u00fcn\u00fcn ayn\u0131s\u0131 oldu\u011funu varsayarak, bu \u00f6l\u00fcm\u00fcn tarihi belir*lenebilir. Ayn\u0131 \u015fekilde, buzul buzla-nndaki I8O\/”O izotop oran\u0131n\u0131n \u00f6l\u00e7\u00fclmesi, son biny\u0131\u00fcarda yeryuvarla-\u011f\u0131 s\u0131cakl\u0131\u011f\u0131ndaki de\u011fi\u015fikliklerin saptanmas\u0131n\u0131 sa\u011flamaktad\u0131r.
\nSSMlR\u00dc SAYILAR
\nAtom \u00e7ekirdekleriyle ilgili en \u00e7arp\u0131c\u0131 verilerden biri, bunlar\u0131n g\u00f6reli bollu\u011fudur. Evrendeki maddenin a\u011f\u0131rl\u0131kl\u0131 b\u00f6l\u00fcm\u00fc kendini en basit \u00e7ekirdek olan (bir proton) hidrojen \u00e7ekirde\u011fi bi\u00e7iminde g\u00f6sterir (y\u00fczde 75’ten fazla); helyum (2 proton, 2 n\u00f6tron) nere*deyse y\u00fczde 100’e ula\u015fmak i\u00e7in gereken tamamlay\u0131c\u0131 par\u00e7ay\u0131 olu\u015fturur. Daha a\u011f\u0131r elementlerin tamam\u0131 toplam\u0131n sadece y\u00fczde 0,1’inden az\u0131n\u0131 olu\u015fturur. Ancak, bu bakiyenin dikkatli bir bi\u00e7imde g\u00f6zlenmesi, \u00e7ok belirgin bir yap\u0131y\u0131 ortaya koyar: N n\u00f6t*ron say\u0131s\u0131n\u0131n veya Z proton say\u0131s\u0131n\u0131n 8, 14, 20, 28, 50, 82 ve 126’ya e\u015fit oldu\u011fu (bu son durum sadece n\u00f6tronlar taraf\u0131ndan ger\u00e7ekle\u015ftirilir) baz\u0131 \u00e7ekirdekler di\u011ferlerinden daha boldur.
\nBu bolluk doruklann\u0131n, n\u00fckleer yap\u0131n\u0131n daha b\u00fcy\u00fck bir kararl\u0131l\u0131\u011f\u0131yla birle\u015fmesi do\u011fald\u0131r. Bu, n\u00fckleer fizik\u00e7ilerin 1930’lardan ba\u015fla*yarak anlad\u0131klan \u015feydir. Ve bu nedenle, bu kez laboratuvarda g\u00f6z*lenen ba\u011f enerjileri sistemati\u011fi, N veya Z yukar\u0131daki say\u0131lardan birine e\u015fit oldu\u011funda doruklar ortaya \u00e7\u0131karmaktad\u0131r (s\u00f6z konusu sa*y\u0131lara bu y\u00fczden sihirli say\u0131lar denmektedir). Bu etki nicel olarak k\u00fc*\u00e7\u00fckt\u00fcr: hafif bir \u00e7ekirdekteki onlarca megaelektronvolt, a\u011f\u0131r bir \u00e7ekirdekteki binlerce megaelektronvoltluk toplam bir ba\u011f enerjisine oranla her zaman 15 MeV’un alt\u0131ndad\u0131r. Astrofizik \u00f6l\u00e7ekte, y\u0131ld\u0131z n\u00fckleosentezleri s\u0131ras\u0131nda olu\u015fan \u00e7ekirdekler, en kararl\u0131 bi\u00e7imlen*melere b\u00fcr\u00fcnme zaman\u0131n\u0131 buldu\u011funa g\u00f6re, nite! olarak \u00f6nemlidir. Di\u011fer n\u00fckleer \u00f6zellikler, \u00f6zellikle, bir n\u00f6tronun veya bir pro*tonun ayr\u0131lma enerjileri, sihirlilik kavram\u0131n\u0131n sa\u011flaml\u0131\u011f\u0131n\u0131 do\u011frulamaktad\u0131r. Birn\u00fckleonun ortalama ayr\u0131lma enerjisi 5-10 MeV d\u00fczeyindeyken, sihirli bir \u00e7ekirde\u011fin y\u00fcksek kararl\u0131l\u0131k art\u0131\u015f\u0131, bu enearjileri megaeletronvoltlarca art\u0131rmaktad\u0131r. Demek ki, burada \u00e7ok belirgin g\u00f6reli bir etki vard\u0131r.
\nKatmanl\u0131 model
\nAtom (\u00e7ekirdek + elektronlar) \u00f6l\u00e7e\u011finde de, atom yap\u0131lar\u0131n\u0131n \u00f6zellikle kararl\u0131 oldu\u011fu sihirli elektron say\u0131lar\u0131 vard\u0131r. B\u00f6ylece, soygazlar\u0131n (helyum, neon, argon, kripton, ksenon, radon) zay\u0131f kimyasal etkinli\u011fi, bu atomlar\u0131n elektronlar\u0131n\u0131n son derece kararl\u0131 bi\u00e7imlenmeler i\u00e7inde oldu\u011funu g\u00f6sterir. Bunlar\u0131n iyonla\u015fma enerjileri, Mendeleyev’in tablosundaki kom\u015fu atomlar\u0131nkinden \u00f6zellikle daha b\u00fcy\u00fckt\u00fcr.
\nAtoma ili\u015fkin bu sihirli say\u0131lar, yap\u0131n\u0131n katmanlar halinde ya*p\u0131lanm\u0131\u015f olmas\u0131yla a\u00e7\u0131klan\u0131r. \u00c7ekirde\u011fin protonlar\u0131 elektronlar \u00fczerine, kuvantum mekar\u00fc\u011fiyle ele al\u0131nd\u0131\u011f\u0131nda elektronlar\u0131n ula\u015fabilecekleri kuvantik durumlar\u0131 ortaya \u00e7\u0131karan bir \u00e7ekim uy*gular. Bu kuvantik durumlar, katman olarak adland\u0131r\u0131lan kom\u015fu enerji paketleri halinde grupla\u015fm\u0131\u015flard\u0131r. Bir atomun elektron say\u0131s\u0131 bir katman\u0131 tamamen dolduracak d\u00fczeyde oldu\u011fu her du*rumda, ba\u011f enerjisi daha b\u00fcy\u00fckt\u00fcr. Bu g\u00f6r\u00fcnt\u00fcn\u00fcn n\u00fckleer du*ruma aktar\u0131lmas\u0131, 1930’larda telkin edilmi\u015f olmakla birlikte, an*cak, 1940’lann sonlar\u0131nda kendini kabul ettirmi\u015ftir. As\u0131l ba\u015far\u0131 (1948-1949’da), n\u00fckleonlar\u0131n y\u00f6r\u00fcngesel hareketiyle spinleri (veya \u00f6z\u00fcnl\u00fc kinetik hareket) aras\u0131ndaki bir e\u015fle\u015fmenin varl\u0131j varsayarak, sihirli n\u00fckleer say\u0131lar\u0131n ve de \u00f6zellikle, sihirli \u00e7el deklere kom\u015fu \u00e7ekirdekler i\u00e7in d\u00fc\u015f\u00fck enerjili uyar\u0131lm\u0131\u015f durun r\u0131n yap\u0131s\u0131n\u0131n a\u00e7\u0131klanabilece\u011finin saptanmas\u0131 olmu\u015ftur. Bu ram, Maria Goeppert-Mayer ve Hans Daniel Jensen’e 1963 I bel Fizik \u00d6d\u00fcl\u00fc’n\u00fc kazand\u0131rm\u0131\u015ft\u0131r.
\n\u00c7ekirde\u011fin bi\u00e7imsel bozulmas\u0131 ve ekseninde d\u00f6nmesi, birle\u015fik model
\nSihirli \u00e7ekirdekler ve bunlar\u0131n yak\u0131n kom\u015fulan k\u00fcreseldir; an acile katmanl\u0131 \u00e7ekirdekler, yani, n\u00f6tron ve proton say\u0131s\u0131 iki sil say\u0131 aras\u0131nda kalan \u00e7ekirdekler bi\u00e7imsel olarak bozulmu\u015ftur. B lann \u00e7arp\u0131kl\u0131\u011f\u0131, atomun elektronlar \u00fczerindeki etkisiyle \u00f6l\u00e7\u00fcler. B\u00f6ylece, baz\u0131 \u00e7ekirdeklerin yumurtams\u0131 (kutuplan sivrice), bas r\u0131n\u0131n k\u00fcremsi (kutuplar\u0131 yass\u0131ca) olduklar\u0131 anla\u015f\u0131lm\u0131\u015ft\u0131r. \u00d6zelli armut bi\u00e7iminde daha karma\u015f\u0131k ba\u015fka bi\u00e7imler de vard\u0131r.
\nBu n\u00fckleer \u00e7arp\u0131kl\u0131\u011f\u0131n bir ba\u015fka izi d\u00fc\u015f\u00fck enerjili uyar\u0131l durumlar tayf\u0131nda g\u00f6r\u00fclebilir. Ger\u00e7ekten de, mek\u00e2nda ayr\u0131ca l\u0131 bir y\u00f6n olmad\u0131\u011f\u0131ndan, bir \u00e7ekirdek, mesela, yumurtams\u0131 bi alm\u0131\u015fsa, zaman i\u00e7inde simetri ekseninin ucunu b\u00fct\u00fcn y\u00f6n d\u00f6nd\u00fcrecektir: \u00e7ekirdek d\u00f6nmektedir; iki g\u00f6r\u00fcn\u00fcm\u00fc birbirin ay\u0131rmak m\u00fcmk\u00fcn de\u011fildir. Demek ki, \u00e7arp\u0131k (deforme) \u00e7e deklere \u00abkuvantum topa\u00e7tan\u00bb denebilir ve bunlar\u0131n d\u00f6nme rumlan, d\u00f6nme halindeki her cisim gibi \u00e7ekirde\u011fin eylemsi momentine ba\u011f\u0131ml\u0131 olan nicelie\u015ftirilmi\u015f enerjilerle ay\u0131rt ec Kavramsal olarak, d\u00f6nme tayflannm g\u00f6zlenmesi iki zaman \u00f6 \u011finin varl\u0131\u011f\u0131n\u0131 ortaya koymaktad\u0131r: n\u00fckleonlann bireysel h ketine \u00f6zg\u00fc bir h\u0131zl\u0131 zaman \u00f6l\u00e7e\u011fi ve n\u00fckleer yap\u0131n\u0131n b\u00fct\u00fc\u0131 hareketiyle ili\u015fkili yava\u015f bir \u00f6l\u00e7ek. James Rainwater, Aage B ve Ben Mottelson, n\u00fckleer dinami\u011fin bu iki zaman \u00f6l\u00e7e\u011finde al\u0131nd\u0131\u011f\u0131 birle\u015fik denen modeli 1953’te geli\u015ftirmi\u015flerdir (bu mo sahiplerine 1975 Nobel Fizik \u00d6d\u00fcl\u00fc’n\u00fc kazand\u0131rm\u0131\u015ft\u0131r). Bum birlikte, \u00e7arp\u0131k veya bak\u0131\u015f\u0131ms\u0131z yap\u0131y\u0131 do\u011furan n\u00fckleonlar\u0131r reysel hareketi oldu\u011funa g\u00f6re, belli bir e\u015fle\u015fme vard\u0131r.
\nAtom \u00e7ekirdeklerinin eylemsizlik momentlerinin deneysel \u011ferleri, kat\u0131 bir cisminkiyle normal bir s\u0131v\u0131n\u0131nk\u0131 aras\u0131nda yer N\u00fckleer ak\u0131\u015fkan\u0131n bir b\u00f6l\u00fcm\u00fcn\u00fcn, bir s\u00fcperak\u0131\u015fkan oldu\u011fu,; d\u00f6nmeye, dolay\u0131s\u0131yla da, \u00e7ekirde\u011fin eylemsizlik momentine t\u0131lmayan yap\u0131\u015fkanl\u0131\u011f\u0131 olmayan bir ak\u0131\u015fkan olu\u015fturdu\u011fu vars l\u0131rsa, bu de\u011ferler a\u00e7\u0131klan\u0131r. Ayr\u0131nt\u0131lara girmeden, n\u00fckleonlar\u0131r kirdek i\u00e7inde birbirlerinden ba\u011f\u0131ms\u0131z olarak yer de\u011fi\u015ftirmek rine, Cooper \u00e7iftleri denen \u00e7iftler olu\u015fturma e\u011filiminde oldu! s\u00f6ylenebilir. Bu \u00e7ift olu\u015fturma veya e\u015fle\u015fme, a\u015f\u0131r\u0131 ak\u0131\u015fkan hal denen o tutarl\u0131 ortak hafin temelidir -bu hal uyar\u0131lm\u0131\u015f haller l MeV d\u00fczeyinde bir enerji gap\u0131yla (tng. aral\u0131k) ayr\u0131lm\u0131\u015ft\u0131r.
\nD\u00f6nme enerjisi gapla kar\u015f\u0131la\u015ft\u0131r\u0131labilir hale geldi\u011finde, s; d\u00f6nme baz\u0131 n\u00fckleon \u00e7iftlerini hareketin eymesizli\u011fine kat\u0131l ya yatk\u0131n hale getirerek bunlar\u0131 k\u0131nyormu\u015fcas\u0131na, eylemsi momentinde ani art\u0131\u015flar g\u00f6zlenir.<\/p>\n","protected":false},"excerpt":{"rendered":"
N\u00fckleer enerjinin deh\u015fet verici as-kerf uygulamalar\u0131 bilinmektedir. Bu uygulamalar, n\u00fckleer fizi\u011fin 1940’h ve 1950’li y\u0131llarda \u00e7ok h\u0131zl\u0131 bir geli\u015f-me g\u00f6stermeline ve \u00abuv enerji \u00fcretimine yol a\u00e7m\u0131\u015ft\u0131r. I\u015f\u0131n\u0131m\u0131 kolayca saptanabilir radyoaktif \u00e7ekirdeklerin i\u015faret a\u00bbc\u0131 olarak kullan\u0131lmas\u0131, \u00f6p, Unm, hidroloji gibi \u00e7ok de\u011fi\u015fik alanlarda yayg\u0131n bi\u00e7imde uygulan*maktad\u0131r. A\u011f\u0131r iyonlar fizi\u011finin geli\u015fmeli, y\u00fczey fizi\u011finde s\u0131na\u00ee uygu*lama olanaktan bulmu\u015ftur. …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1407,1403],"tags":[2220,4694,2218,4151,2221,2223,2219,2139,2755,6940,2222,6941],"class_list":["post-2861","post","type-post","status-publish","format-standard","hentry","category-fen-ve-teknoloji-odevleri","category-odevler","tag-argon","tag-elektronlar","tag-helyum","tag-karbon-14","tag-kripton","tag-ksenon","tag-neon","tag-notron","tag-nukleer-enerji","tag-nukleer-fizigin-uygulamalari","tag-radon","tag-uv-enerji"],"_links":{"self":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts\/2861","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/comments?post=2861"}],"version-history":[{"count":0,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts\/2861\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/media?parent=2861"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/categories?post=2861"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/tags?post=2861"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}