Luis Walter Alvarez

Luis Walter Alvarez (13 ga Yuni, 1911 - 1 ga Satumba, 1988) ƙwararren masanin kimiyyar lissafi ne na Amurka, mai ƙirƙira, kuma farfesa wanda aka ba shi kyautar Nobel a fannin kimiyyar lissafi a 1968 saboda gano yanayin resonance a fannin kimiyyar lissafi ta amfani da ɗakin hydrogen kumfa .  A cikin 2007, Jaridar Amurka ta Physics ta yi sharhi, "Luis Alvarez ya kasance ɗaya daga cikin ƙwararrun masana kimiyyar lissafi mafi hazaka da kuma amfani a ƙarni na ashirin." 

Bayan ya sami digirin digirgir (PhD) daga Jami'ar Chicago a shekarar 1936, Alvarez ya tafi aiki da Ernest Lawrence a Dakin Gwaji na Radiation a Jami'ar California, Berkeley . Alvarez ya ƙirƙiro wasu gwaje-gwaje don lura da kamawar K-electron a cikin ƙwayoyin rediyoaktif, waɗanda aka annabta ta hanyar ka'idar lalata beta amma ba a taɓa gani ba. Ya samar da tritium ta amfani da cyclotron kuma ya auna tsawon rayuwarsa. Tare da haɗin gwiwar Felix Bloch, ya auna lokacin maganadisu na neutron .

A shekarar 1940, Alvarez ya shiga dakin gwaje-gwaje na MIT Radiation Laboratory, inda ya ba da gudummawa ga wasu ayyukan radar na yakin duniya na biyu, tun daga gyare-gyaren farko zuwa na'urorin radar aboki ko maƙiyi (Identification friend or friend (IFF), waɗanda yanzu ake kira transponders, zuwa tsarin da aka sani da VIXEN don hana jiragen ruwa na ƙarƙashin ruwa na abokan gaba su fahimci cewa an same su ta hanyar sabbin na'urorin radar na microwave na iska. Tsarin radar wanda aka fi sani da Alvarez kuma wanda ya taka rawa sosai a fannin sufurin jiragen sama, musamman a cikin jirgin sama na Berlin bayan yaƙin, shine Ground Controlled Approach (GCA). Alvarez ya yi watanni da yawa a Jami'ar Chicago yana aiki akan na'urorin radar na nukiliya don Enrico Fermi kafin ya zo Los Alamos don yin aiki tare da Robert Oppenheimer akan Aikin Manhattan . Alvarez ya yi aiki akan ƙirar ruwan tabarau masu fashewa, da haɓaka fashewar bridgewire masu fashewa . A matsayinsa na memba na Project Alberta, ya lura da gwajin nukiliya na Trinity daga B-29 Superfortress, kuma daga baya ya jefa bam a Hiroshima daga B-29 The Great Artiste .

Bayan yaƙin, Alvarez ya shiga cikin ƙirar ɗakin kumfa mai hydrogen wanda ya ba wa tawagarsa damar ɗaukar hotunan miliyoyin hulɗar barbashi, haɓaka tsarin kwamfuta mai rikitarwa don aunawa da nazarin waɗannan hulɗar, da kuma gano dukkan iyalai na sabbin barbashi da yanayin rawar jiki. Wannan aikin ya haifar da ba shi kyautar Nobel a shekarar 1968. Ya shiga cikin wani aiki na X-ray na dala na Masar don neman ɗakunan da ba a sani ba. Tare da ɗansa, masanin ilimin ƙasa Walter Alvarez, ya ƙirƙiro hasashen Alvarez wanda ke nuna cewa abin da ya faru na ɓacewa wanda ya share dinosaurs waɗanda ba tsuntsaye ba sakamakon tasirin taurari ne.

 Rayuwar farko 
An haifi Luis Walter Alvarez a cikin dangin Roman Katolika a San Francisco a ranar 13 ga Yuni, 1911, ɗansa na biyu kuma babban ɗa ga Walter C. Alvarez, likita, da matarsa Harriet née Smyth. Kakansa, Luis F. Álvarez, likita ne da aka haifa a Asturias, Spain, wanda ya zauna na ɗan lokaci a Cuba, ya zauna a Amurka, kuma ya gano wata hanya mafi kyau don gano cutar kuturta . Yana da babbar 'yar'uwa, Gladys, ƙanensa, Bob, da ƙanwarsa, Bernice.  Goggonsa, Mabel Alvarez, ƙwararren mai zane ne a California wanda ya ƙware a fannin zane mai . 

Ya halarci Makarantar Madison da ke San Francisco daga 1918 zuwa 1924, sannan ya halarci Makarantar Sakandare ta Fasaha ta San Francisco .  A shekarar 1926, mahaifinsa ya zama mai bincike a Asibitin Mayo, kuma iyalinsa suka ƙaura zuwa Rochester, Minnesota, inda Alvarez ya halarci Makarantar Sakandare ta Rochester. Ya daɗe yana tsammanin zai halarci Jami'ar California, Berkeley, amma bisa ga sha'awar malamansa a Rochester, sai ya tafi Jami'ar Chicago,  inda ya sami digirinsa na farko a 1932, digirinsa na biyu a 1934, da digirinsa na uku a 1936.  A matsayinsa na dalibi na farko, ya kasance cikin ƙungiyar Phi Gamma Delta . A matsayinsa na dalibi na digiri na biyu ya koma Gamma Alpha . 

A shekarar 1932, a matsayinsa na ɗalibi mai digiri na biyu a Chicago, ya gano fannin kimiyyar lissafi kuma ya sami damar da ba kasafai ake samu ba na amfani da kayan aikin masanin kimiyyar lissafi Albert A. Michelson . Alfred B. Bortz. Physics: Decade by Decade. Facts On File, Incorporated; 2007. . p. 168. Alvarez ya kuma gina na'urar bututun Geiger da aka tsara a matsayin na'urar hangen nesa ta hasken duniya, kuma a ƙarƙashin jagorancin mai ba shi shawara kan fanninsa Arthur Compton, ya gudanar da wani gwaji a birnin Mexico don auna abin da ake kira tasirin gabas-yamma na hasken duniya . Ganin ƙarin hasken da ke shigowa daga yamma, Alvarez ya kammala da cewa hasken duniya na farko yana da caji mai kyau. Compton ya gabatar da takardar da aka samu ga Physical Review, tare da sunan Alvarez a sama. 

Alvarez mutum ne mai shakkar Allah duk da cewa mahaifinsa diakoni ne a cocin Congregational.  

 Aikin farko 
'Yar'uwar Alvarez, Gladys, ta yi aiki a matsayin sakatare na ɗan lokaci ga masanin kimiyyar lissafi na Berkeley Ernest Lawrence, kuma ta ambaci Alvarez ga Lawrence. Daga nan Lawrence ta gayyaci Alvarez don ya ziyarci baje kolin Century of Progress a Chicago tare da shi.  Bayan ya kammala jarrabawarsa ta baki a 1936, Alvarez, wanda yanzu aka yi masa alkawarin aure da Geraldine Smithwick, ya nemi 'yar'uwarsa ta duba ko Lawrence yana da wasu ayyuka a dakin gwaje-gwajen Radiation . Ba da daɗewa ba aka sami wani saƙo daga Gladys tare da tayin aiki daga Lawrence. Wannan ya fara dogon dangantaka da Jami'ar California, Berkeley . Alvarez da Smithwick sun yi aure a ɗaya daga cikin majami'un da ke Jami'ar Chicago sannan suka nufi California.  Suna da 'ya'ya biyu, Walter da Jean.  Sun sake a 1957. A ranar 28 ga Disamba, 1958, ya auri Janet L. Landis, kuma ya haifi wasu 'ya'ya biyu, Donald da Helen. 

A dakin gwaje-gwajen Radiation ya yi aiki tare da ƙungiyar gwaji ta Lawrence, wacce ƙungiyar masana kimiyyar lissafi karkashin jagorancin Robert Oppenheimer suka tallafa mata.  Alvarez ya ƙirƙiro wasu gwaje-gwaje don lura da kamawar K-electron a cikin ƙwayoyin rediyoaktif, waɗanda aka annabta ta hanyar ka'idar lalata beta amma ba a taɓa gani ba. Ta amfani da maganadisu don share positrons da electrons da ke fitowa daga tushen rediyoaktif ɗinsa, ya tsara wani takamaiman dabarar Geiger don gano X-rays masu "laushi" kawai da ke fitowa daga kamawar K. Ya buga sakamakonsa a cikin Physical Review a 1937.  

Idan aka jefa deuterium (hydrogen-2) a cikin ruwan da ke kewaye da deuterium, haɗin haɗin yana samar da tritium (hydrogen-3) tare da proton ko helium-3 tare da neutron (  ). Wannan yana ɗaya daga cikin halayen haɗuwa mafi mahimmanci, kuma tushen makamin thermonuclear da binciken da ake gudanarwa a yanzu kan haɗakar nukiliya mai sarrafawa ba a san shi ba. A wancan lokacin, ba a san daidaiton waɗannan samfuran amsawa guda biyu ba, amma bisa ga ka'idojin da ake da su Hans Bethe ya yi tunanin cewa tritium zai kasance mai karko kuma helium-3 ba shi da karko. Alvarez ya tabbatar da akasin haka ta hanyar amfani da iliminsa game da cikakkun bayanai game da aikin cyclotron mai inci 60. Ya daidaita injin don hanzarta nuclei na helium-3 mai ionized sau biyu kuma ya sami damar samun hasken ions mai sauri, don haka yana amfani da cyclotron a matsayin nau'in spectrometer mai yawa. Yayin da helium mai sauri ya fito daga rijiyoyin iskar gas masu zurfi inda yake tsawon shekaru miliyoyin, dole ne bangaren helium-3 ya kasance mai karko. Bayan haka Alvarez ya samar da tritium mai rediyoaktif ta amfani da cyclotron da  martanin kuma ya auna tsawon rayuwarsa.   

A shekarar 1938, ya sake amfani da iliminsa na cyclotron da kuma ƙirƙiro abin da yanzu aka sani da dabarun lokacin tashi, Alvarez ya ƙirƙiri wani haske mai ƙarfi na neutrons na thermal mai ƙarfi . Da wannan ya fara dogon jerin gwaje-gwaje, tare da haɗin gwiwa da Felix Bloch, don auna lokacin maganadisu na neutron . Sakamakon su na , wanda aka buga a shekarar 1940, babban ci gaba ne akan ayyukan da suka gabata. 

 Yaƙin Duniya na Biyu 

 Dakin Gwaji na Radiation 
Ofishin Jakadancin Birtaniya na Tizard zuwa Amurka a shekarar 1940 ya nuna wa manyan masana kimiyya na Amurka nasarar amfani da magnetron na rami don samar da radar mai tsayin tsayi. Kwamitin Bincike na Tsaron Ƙasa, wanda Shugaba Franklin Roosevelt ya kafa watanni da suka gabata, ya ƙirƙiri dakin gwaje-gwaje na ƙasa na tsakiya a Cibiyar Fasaha ta Massachusetts (MIT) don manufar haɓaka aikace-aikacen soja na radar na microwave. Nan da nan Lawrence ya ɗauki mafi kyawun "cyclotroneers", daga cikinsu Alvarez, wanda ya shiga wannan sabon dakin gwaje-gwaje, wanda aka sani da Radiation Laboratory, a ranar 11 ga Nuwamba, 1940.  Alvarez ya ba da gudummawa ga ayyukan radar da dama, daga haɓakawa na farko zuwa alamun radar na Identification Friend or Foe (IFF), wanda yanzu ake kira transponders, zuwa tsarin da aka sani da VIXEN don hana jiragen ruwa na abokan gaba su fahimci cewa sabbin radar na microwave da ke sama sun same su.  Jiragen ruwa na maƙiyi za su jira har sai siginar radar ta yi ƙarfi sannan su nutse, su tsere wa hari. Amma VIXEN ta aika da siginar radar wacce ƙarfinta shine kubiyar nisan da ke tsakanin jirgin ƙarƙashin ruwa ta yadda yayin da suke kusantar jirgin ƙarƙashin ruwa, siginar—kamar yadda aka auna ta ƙarƙashin ruwa—ta fara raguwa a hankali, kuma jirgin ya ɗauka cewa jirgin yana ƙara nisa kuma bai nutse ba.  

Ɗaya daga cikin ayyukan farko shine gina kayan aiki don canzawa daga radar mai tsayi na Burtaniya zuwa sabon radar mai tsawon mita na microwave wanda magnetron ramin rami ya samar. A cikin aiki akan tsarin gargaɗin farko na Microwave (MEW), Alvarez ya ƙirƙiri eriya mai layi biyu wacce ba wai kawai ta danne gefen da ba a so na filin radiation ba, har ma ana iya duba ta ta hanyar lantarki ba tare da buƙatar duba na'urar ba. Wannan shine eriya ta farko ta microwave-phase-array, kuma Alvarez ya yi amfani da ita ba kawai a cikin MEW ba har ma a cikin ƙarin tsarin radar guda biyu. Eriya ta ba da damar radar fashewar Eagle daidai don tallafawa fashewar daidai a cikin mummunan yanayi ko ta cikin gajimare. An kammala ta a ƙarshen yaƙin; kodayake an sanya wa wasu B-29s kayan Eagle kuma ta yi aiki da kyau, ya yi latti don yin babban canji. 
Tsarin radar wanda aka fi sani da Alvarez kuma wanda ya taka muhimmiyar rawa a harkar sufurin jiragen sama, musamman a bayan yakin Berlin, shine Tsarin Kula da Jiragen Sama ( Ground Controlled Approach ) (GCA). Ta amfani da eriyar dipole ta Alvarez don cimma ƙuduri mai girma, GCA tana bawa masu aikin radar na ƙasa damar kallon nuni na musamman don jagorantar jirgin sama mai sauka zuwa titin jirgin sama ta hanyar aika umarni na baki ga matukin jirgi. Tsarin ya kasance mai sauƙi, kai tsaye, kuma yana aiki da kyau, koda tare da matukan jirgin da ba a horar da su ba a baya. Ya yi nasara sosai har sojoji suka ci gaba da amfani da shi tsawon shekaru da yawa bayan yakin, kuma har yanzu ana amfani da shi a wasu ƙasashe a shekarun 1980.  An ba Alvarez lambar yabo ta Collier Trophy ta Ƙungiyar Jiragen Sama ta Ƙasa a shekarar 1945 "saboda himmarsa mai ban mamaki a cikin ra'ayi da haɓaka tsarin Tsarin Kula da Jiragen Sama don sauka lafiya a ƙarƙashin duk yanayi da yanayin zirga-zirga".  

Alvarez ya yi lokacin bazara na 1943 a Ingila yana gwada GCA, yana saukar da jiragen sama daga yaƙi a cikin mummunan yanayi, sannan kuma ya horar da Birtaniya kan amfani da tsarin. A can ya haɗu da matashin Arthur C. Clarke, wanda ƙwararren ma'aikacin radar ne na RAF. Daga baya Clarke ya yi amfani da abubuwan da ya fuskanta a tashar bincike ta radar a matsayin tushen littafinsa na Glide Path, wanda ya ƙunshi sigar Alvarez mai ɓoye.  Clarke da Alvarez sun ƙulla abota ta dogon lokaci. 

 Aikin Manhattan 
A kaka ta 1943, Alvarez ya koma Amurka da tayin Robert Oppenheimer don yin aiki a Los Alamos a kan Aikin Manhattan . Duk da haka, Oppenheimer ya ba da shawarar cewa ya fara yin watanni kaɗan a Jami'ar Chicago yana aiki tare da Enrico Fermi kafin ya zo Los Alamos. A cikin waɗannan watanni, Janar Leslie Groves ya nemi Alvarez ya yi tunanin hanyar da Amurka za ta iya gano ko Jamusawa suna aiki da kowace na'urar sarrafa nukiliya, kuma, idan haka ne, inda suke. Alvarez ya ba da shawarar cewa jirgin sama zai iya ɗaukar tsarin gano iskar gas mai ƙonewa da na'urar samar da sinadarai ke samarwa, musamman xenon-133 . Kayan aikin sun yi shawagi a kan Jamus, amma ba su gano wani xenon mai ƙonewa ba saboda Jamusawa ba su gina na'urar samar da sinadarai mai iya samar da sinadarai masu guba ba. Wannan shine ra'ayin farko na sa ido kan kayayyakin fashewa don tattara bayanai . Zai zama mahimmanci bayan yaƙin. 
Sakamakon aikin radar da ya yi da Fermi, Alvarez ya isa Los Alamos a bazara ta 1944, bayan wasu daga cikin abokan aikinsa. Aikin " Ƙaramin Yaro " (bam ɗin uranium) ya yi nisa sosai don haka Alvarez ya shiga cikin ƙirar " Mai Kitse " (bam ɗin plutonium). Dabarar da aka yi amfani da ita don uranium, wato tilasta wa ƙwayoyin biyu masu ƙanƙanta tare ta amfani da wani nau'in bindiga, ba za ta yi aiki da plutonium ba saboda babban matakin neutrons na baya-bayan nan zai haifar da fashewa da zarar sassan biyu sun kusanci juna, don haka zafi da faɗaɗawa za su tilasta tsarin ya rabu kafin a saki makamashi mai yawa. An yanke shawarar amfani da wani yanki mai mahimmanci na plutonium kuma a matse shi da sauri ta hanyar fashewa zuwa cikin ƙaramin tsakiya mai yawa, ƙalubalen fasaha a lokacin. 

Don ƙirƙirar tururin da ake buƙata don matse tsakiyar plutonium zuwa yawan da ake buƙata, za a tayar da tutocin fashewa talatin da biyu a lokaci guda a kusa da tsakiyar mai siffar ƙwallo. Ta amfani da dabarun fashewa na gargajiya tare da murfi na fashewa, ci gaba zuwa cimma daidaito a lokaci guda zuwa cikin ƙaramin juzu'i na microsecond ya hana shi. Alvarez ya umurci ɗalibinsa na digiri na biyu, Lawrence H. Johnston, da ya yi amfani da babban capacitor don isar da cajin wutar lantarki mai ƙarfi kai tsaye ga kowane ruwan tabarau mai fashewa, yana maye gurbin murfi na fashewa da masu fashewa na waya mai fashewa . Wayar fashewa ta fashe tutocin talatin da biyu zuwa cikin goma na microsecond. Ƙirƙirar ta kasance mai mahimmanci ga nasarar makamin nukiliya mai nau'in implosion . Ya kuma kula da Gwaje-gwajen RaLa .  Alvarez daga baya ya rubuta cewa:

A lokacin da yake aiki tare da Johnston, aikin ƙarshe na Alvarez ga Aikin Manhattan shine ƙirƙirar saitin makirufo / masu watsawa da aka daidaita don a yi musu parachute daga jirgin sama don auna ƙarfin guguwar fashewar da ta taso daga fashewar atomic, don ba wa masana kimiyya damar ƙididdige kuzarin bam ɗin. Bayan an naɗa shi Laftanar Kanar a Rundunar Sojan Amurka, ya lura da gwajin nukiliya na Trinity daga wani jirgin sama mai suna B-29 Superfortress wanda shi ma ke ɗauke da sauran membobin Project Alberta Harold Agnew da Deak Parsons (waɗanda aka naɗa a matsayin kyaftin bi da bi). 

Tashi a cikin Babban sansanin soja na B-29 Babban mawaƙin da ke cikin ƙungiyar Enola Gay, Alvarez da Johnston sun auna tasirin fashewar bam ɗin Little Boy wanda aka jefa a kan Hiroshima .  Bayan 'yan kwanaki, Johnston ya sake tashi a cikin Babban Mawaƙin, ya yi amfani da irin wannan kayan aikin don auna ƙarfin fashewar Nagasaki . 

Bayan kammala Yaƙin Duniya na Biyu a shekarar 1945, Alvarez ya zama farfesa a fannin kimiyyar lissafi a makarantar da yake son zuwa da farko, wato Jami'ar California, Berkeley, kuma a shekarar 1978 aka ba shi mukamin farfesa mai ritaya. 

 ɗakin kumfa 
Da ya koma Jami'ar California, Berkeley a matsayin cikakken farfesa, Alvarez yana da ra'ayoyi da yawa game da yadda zai yi amfani da iliminsa na radar na lokacin yaƙi don inganta masu haɓaka barbashi . Duk da cewa wasu daga cikinsu za su yi amfani da su, "babban ra'ayin" wannan lokacin ya fito ne daga Edwin McMillan tare da ra'ayinsa na kwanciyar hankali na lokaci wanda ya haifar da synchrocyclotron . Ta hanyar gyara da faɗaɗa wannan ra'ayi, ƙungiyar Lawrence za ta gina mafi girman mai haɓaka proton a duniya a lokacin, Bevatron, wanda ya fara aiki a 1954. Duk da cewa Bevatron zai iya samar da adadi mai yawa na barbashi masu ban sha'awa, musamman a karo na biyu, waɗannan hulɗar masu rikitarwa suna da wahalar ganowa da yin nazari a lokacin. 

Da yake amfani da wani sabon ci gaba don ganin alamun barbashi, wanda Donald Glaser ya ƙirƙira kuma aka sani da ɗakin kumfa, Alvarez ya fahimci cewa na'urar ita ce kawai abin da ake buƙata, idan da za a iya sa ta yi aiki da ruwa hydrogen . Nucleus na hydrogen, waɗanda proton ne, sun zama mafi sauƙi kuma mafi kyawun manufa don hulɗa da barbashi da Bevatron ke samarwa. Ya fara shirin haɓakawa don gina jerin ƙananan ɗakuna, kuma ya tallata na'urar ga Ernest Lawrence.

Na'urar Glaser ƙaramin silinda ce ta gilashi ( 1 cm × 2 cm ) da aka cika da ether . Ta hanyar rage matsin lamba a cikin na'urar ba zato ba tsammani, za a iya sanya ruwan a cikin yanayi mai zafi na ɗan lokaci, wanda zai tafasa a kan hanyar da ke cike da barbashi da ke wucewa. Glaser ya sami damar kula da yanayin zafi na ɗan lokaci na ɗan lokaci kafin a fara tafasa ba zato ba tsammani. Ƙungiyar Alvarez ta gina ɗakuna na 1.5 a cikin, 2.5 a cikin, 4 a cikin, 10 a cikin, da kuma 15 wajen amfani da ruwa mai hydrogen, kuma an gina shi da ƙarfe mai tagogi na gilashi, don a iya ɗaukar hotunan hanyoyin. Ana iya yin keken ɗakin a daidai gwargwado tare da hasken hanzari, a ɗauki hoto, sannan a sake matse ɗakin a kan lokaci don zagayowar haske na gaba.

Wannan shirin ya gina ɗakin kumfa mai ruwa-ruwa mai tsawon , ya ɗauki ma'aikata da dama na fannin kimiyyar lissafi da ɗaliban digiri tare da ɗaruruwan injiniyoyi da masu fasaha, ya ɗauki miliyoyin hotunan hulɗar barbashi, ya ƙirƙiri tsarin kwamfuta don aunawa da nazarin hulɗar, sannan ya gano iyalai na sabbin barbashi da yanayin magana . Wannan aikin ya haifar da kyautar Nobel a fannin kimiyyar lissafi ga Alvarez a shekarar 1968,  "Saboda gudummawar da ya bayar ga kimiyyar lissafi ta farko, musamman gano adadi mai yawa na yanayin magana, wanda ya yiwu ta hanyar haɓaka dabarar amfani da ɗakunan kumfa na hydrogen da nazarin bayanai." 

 Manazarta 

Rukuni:Mutuwan 1988
Rukuni:Haifaffun 1911
Rukuni:Shafuka masu fassarorin da ba'a duba ba