KHOA RQC_& PHAT TRieN_
J Mem W hao ciia khoa hoc chau Au
Cach day 60 nam, 12 ni/dc Tay Au da chinh thu'c thanh lap CERN, viet tat cua Conseil Europeen pour la Recherche Nucleaire {To chijfc Nghien ciJu Nguyen tuf chau Au), trirdc do la mpt to chufclam thdi du'OC hinh thanh tCr nam 1952 , vdi nhiem vu trd thanh motto chufc nghien cufu vat ly cua chau Au CO dang cap hang dau tren the gldi - khi do nganh vat ly ly thuyet dang tap trung tim hieu ban chat vat chat ben trong nguyen tijf, bdi vay khai niem "hat nhan" du'pc difa vao ten gpi cua to chu'c.
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gay nay, tochiic nghian cuu cd tru sd tai bien gidi Phap - Thuy ST nay dugc md rdng bao gom 21 thanh vien. Trong bdi canh tn thuc cua con ngudl ve vdt chat da khong con chi dimg lai d hat nhan, linh vuc nghien cuu md CERN chu trgng hien nay la vat ly hat, tim hieu ve nhdng thanh td ca
ban nhat cau thanh nan vat chat ciing nhu cac luc tuang tdc giiia chiing. Vi vdy, phdng thi nghiem ciia CERN cung thudng dupc ggi la Phdng thi nghiem chdu Au ve Vat ly Hat,
Tit thap ky 1970, cac nha vat ly hat da tim ra Md hinh Chuan, mpt he thdng cac phuang trinh tuyet dep giiip md ta cau tnic vdt chdt vdi nhiing thanh td can ban ggi la hat co ban, dugc van hanh bdi bdn loai luc. De kiem chung cdc du dodn va gidi ban cua Md hinh Chudn, cac nha khoa hgc tai CERN da xay dung va su dung nliiing co may gia tdc va cam bien manh nhdt tren tha gidi.
Cdng viec ciia hp qua nhiau nam thang da giiip ly giai nhieu kat qua thi nghiem va du doan chinh xac nhiau hien nrpng.
Tuy nhian, Md hinh Chudn chi mdi md ta duoc 4% cua vii trii ma chiing ta da bi6t, trong khi vdn con nhung cau hoi quan trpng dang da
Hien thj cacsU kien va cham gida proton v6i proton, ghi lai bdi LHC
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ngd, nhu lieu LHC co the giup thong nhat bon loai lire d miic nang lugng cao? Vi sao trgng luc lai yau nhir vay? Vi sao cd nhi6u v^t chdt hon phdn vat chat trong vu try? Lieu cd nhiing hien tuong vdt ly ky do dang chd dupc phat hi?n 6 muc ndng lugng cao? Li?u chung ta cd tim ra bang chung ciia thuyat sieu can doi nhd vdo LHC? Ngay ca Higgs boson md ngudi ta mdi tim ra van cdn la mpt bi dn.
Do la nhung cau hdi ma cdc nha khoa hgc tai CERN dang tim kiem ldi giai dap. Vi the, pham vi nghien cim ciia hp khdng chi la vat ly hat ma rOng hon rat nhiau, bao gdm tu vat ly hat nhan tdi v^t l^
nang lugng cao, tir nghien cuu phdn vat chat tdi nghien cuu ve kha nang xay ra tia vii tru trong nhiing dam may.
NHONG C6 MAY G I A T 6 C 6 CERN De tim hieu ve ckc hat co ban hay cau tnic vjit chat CO ban cua vu tru, cac nha khoa hpc d CERN su dung nhung thiet bj cd quy md to Idn va phitc tap nhat tran tha gidi, khien cdc hat va dap vao nhau, qua dd giiip hp hinh dung ro hon ve s\r nrong tac giira cdc hat cung nhu cac dinh ludt ca ban cil tu nhien.
Cac td hap may gia tdc d CERN la m^t chuoi
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cac cd may lam tang miic nang lugng cua cac hat. Mdi mdy CO chuc nang ldm tang nang lupng cua mgt tia cdc hat, trudc khi ban tia do vdo cac cd may tiep theo mgt each lan lugt.
Ngudn proton cua cdc tia hat la mdt ong khi hydro dan gian.
Cdc nha khoa hpc diing mpt dien trudng de tach electron khdi nguyen hi' de tao ra proton. Sau do, Linac 2, cd may dau tien trong chuoi cdc may gia tdc, se tang tdc muc nang lugng cua proton ian 50 MeV Tia hat sau dd dupc ban vao may Proton Synchrotron Booster (PSB) co nhiem vu tang mirc nang lupng ian 1,4 GeV, trudc khi dupc cd mdy Proton Syn- chrotron day len mirc 25 GeV, rdi duac mdy Super Proton Synchrotron tang ian mirc 450 GeV. Trong cd may gia toe LHC (Large Hadron Collider) - la cd may cudi ciing trong chudi cdc may gia tdc ~ cdc tia hat dupc tang tdc len mdc nang lugng ky lyc la 4 TeV/tia Da sd cdc may gia toe khac tren the gidi chi dat duac muc nang lupng thap han I'dt nhieu.
Trong CO may LHC, mpt tia hat dugc bdn di trong mgt dng dan theo chieu kim ddng hd, trong khi mdt tia khac dugc bdn trong mdt dng dan kliac theo chieu ngugc lai. Mdi dng dan cdn 4 phiit 20 giay de lap day, va can 20 phut de cac pro- ton d^t muc nang lugng tdi da 4 TeV. Cac tia nay chay vdng quanh trong cd may LHC trong nhieu gid dudi diau kien van hdnh binh thudng, sau dd dupc cho va dap vdo nhau tai bdn cdm bian cd ten gpi ALICE, ATLAS, CMS, va LHCb- noi tdng ndng lupng tai diem va dap la 8 TeV.
Ngodi cdc cd mdy gia tdc ndi tren, td hop thiet bi tai CERN cdn bao gdm cde he thdng khac nhu Antiproton De- celerator giup cung edp cdc phdn proton nang lupng thap de nghien euu phan vgt chat; Online Isotope Mass Separator (ISOLDE) giilp nghien cuu hat nhan nguyen tu va cdc img dyng trong nghien cuu co bdn thupc cdc ITnh vuc vat Iy thian vdn. v^t li?u, khoa hpc su sdng; Compact Linear Collider giiip nghien cOni ve cde thi nghipm va dap giira electron va
May gia toe Tuyen tinh (Linear Accelerator) Linac 2
N H C N G THANH TLTU KHOA HOC Ndi BAT CUA CERN
1973: Tim ra cac dong trung hoa trong cam bien Gargamelle bubble chamber;
1983; Tim ra cac W v a Z boson qua cac thi nghiem UA1 va UA2;
1989: Xac dinh so Idpng cac nhom neutron nhe trong Large Electron-Positron Collider (LEP) van hanh tai dinh Z boson;
1995: Tao ra cac nguyen t d phan hydro dau tien qua thi nghiem PS210;
1999: Phat hien ra sai lech CP trdc tiep qua thi nghiem NA;
2010: Co lap dupc 38 nguyen t d phan hydro;
2011: Duy tri ddpc phan hydro trong 15' 2012:Tim ra mot boson cd khoi Idpng khoang 125 GeV/c2 tddng dong vdi Higgs boson dupc con ngudi tim kiem lau nay.
Nam 1984, giai Nobel vat ly dupc trao cho Carlo Rubbia va Simon van der Meer nhd nhdng nghien cdu dan tdi viec tim ra cac boson W va Z. Nam 1992, giai Nobel Vat ly ddpc trao cho Georges Charpak, vai cong lao phat kien va phat trien thiet bi cam bien hat.
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phan electron; neutron time-of-flight facility (nTOF) nghien cuu cdc tuong tac giiia neutron vd hat nhan vdi nang lupng neutron tu vai meV tdi vai GeV, v.v.
VAI TR.6 C O A CdNG NGH^ T H O N G TIN 6 CERN Cu mdi giay, cac hat trong co may LHC va dap vao nhau khoang 600 trieu lan. Mdi va dap tao ra nhung hat mdi, m6i hat thudng ty tieu buy theo cac phuang thuc phiic tap de trd thdnh nhieu hat khdc.
Cac mach dien giup luu trii lai thdng tin ve su di chuyen cua mdi hat thdng qua mgt cam bian, dua tren mdt chudi cac tin hieu dien, rdi chuyan dij lieu ve Trung tam Dii lieu CERN de dupc sd hda thanh nhung "su kien va dap". Hang nam, cac nha vdt ly phai kiem tra khoang 30 petabyte du lieu de tim kiam nhiing hien tuong vat ly md hg quan tam.
CERN khdng cd du nang luc tinh toan vd ngudn luc tai chinh de xii ly tat ca du lieu nay ngay tai chd, vi vay nam 2002 hp ap dung dien toan ludi (comput- ing grid) de chia se gdnh nang vdi cac trung tam tinh toan tren khap the gidi. Mang ludi Worldwide LHC Computing Grid cho phep mot cgng d6ng khoang 8.000 nha vat ly dugc truy cap dii lieu LHC. Ludi dien toan nay duac dua tren nen tang cdng nghe in- ternet (World Wide Web), cung dupc phat minh tai CERN vao nam 1989.
Moi ngay, Trung tam Du lieu cua CERN xu ly khoang 1 petabyte, tuong duong vdi khoang 210 nghin dTa DVD. Trung tdm chira 11 nghin server vdi
100 nghin ldi xu Iy. Mdi giay khodng 6.000 Ihay ddi trong he dir lieu dupc xu ly. Moi ngdy, Liroi Dien todn thirc hien han 2 trieu lenh. Vao cao diem, mdi gidy cd khodng 10 gigabj^e dupc v^
chuyen giiia cac server.
Td hgp server ciia CERN nam trong mpt can phdng rdng 1.450 m^ tai Tnmg tam Dii li|u, la diem tuong tie giao cat dau tien giira nhung du lieu thi nghiem tu LHC vd Ludi Dien todn. Ngoai ra, nhiing server quan trpng dupc dat trong cac can phdng dac biet rieng, dupc van hanh va Iam mat bdi cac thiat bi chuyen biet. Nam 2011, CERN lap dat cdi tien he thdng tiat kiem nang lupng, giup tiet kiem 4,5 GWh moi ndm.
Dau nam 2013, CERN tang quy mo nang lupng cua trung tam tir 2,9 MW len 3,5 MW, cho phep lat dat them nhieu may tinh. Ben canh do, de dap ung yeu cdu ngay cang tang tir LHC, Trung tam Nghien cuu Vat ly Wigner dupe van hdnh tai Budapest, Hungary, nhu mpt bp phan noi dai cua Trung tam Du lieu nham tang nang luc ciia Ludi Dien toan, vd cho phep mpi hoat ddng van hanh binh thudng ngay ca khi try sd chinh cua CERN a Meynn, Thyy ST gap true trac. Trung tam Dii lieu tai Meyrin cho phep luu trii khodng 45 petabyte vd chiem da sd trong 100 nghin ldi xii ly cua CERN, trong khi trung tam Wigner tai Bu- dapest cd 20 nghin loi xu ly va luu trii dugc 5,5 petabyte dir lieu (ngudi ta ky vgng nang lire ciia
GitA khoa hoc hin hoan tiep nhan cac binq chiitig ve viec tim ra loai hat ca hin cd cic dac tinh khdp vdi dir doan cua Mo hlnti Chuan ve lliggs bosoii
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et qua khoa hpc tieu bieu nhat cua CERN gan day !a viec tim ra loai hat khdp vdi ly thuyet ve Higgs boson.Ngay 4/7/2012, cac nha khoa hpc trong thi nghiem ATLAS va CMS thuc hien vdi co may LHC tai CERN tuy§n bo d hai nhom deu tim ra mpt hat mdi co khoi Idpng khoang 126 GeV, khdp vdi mo ta ve Higgs boson cua Mo hinh Chuan Thang 3/2013, hat nay tiep tuc dupc chdng minh c6 mflt so dac tinh khac giong vdi dU doan cua Mo hinh Chuan Mac du nhan loai se phai tiep tuc nghien cifu de chiJng minh day thUc sU la Higgs boson ma Mo hinh ChuSn fi / d u doan, nhung cac ket qua thi nghiem tren day da dSn tdi viec giai Nobel Vat ly nam 2013 dupc trao cho Francois Englert va Peter Higgs do cdng hien cua hp mang lai mfit
"kham pha ly thuyet ve mpt co che vat ly dong gdp vio sU hieu biet cua con ngudi ve nguon goc ciia kh6i l u ^ g 6 nhirng hat dudi quy mo nguyen tiJf."
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_KHOA tlQC_& PHAT T R | £ N
Trung tam tin hocCERN
Wigner se gdp ddi trong vdng ba nam)
MOT D O l NGO KY SU TUYgT V d l
Dpi ngu ky su ddng mdt vai trd trpng yeu ddi vdi hoat dgng ciia CERN. Hp la tdc gia cua nhiing thiet bi may mdc tan tian nhat tran the gidi, cdng cu de cac nha nghien eiiu tao ra nhirng dot phd mdi cua vat ly thuc nghiem. Diau do ddi hdi hp phai vupt qua nhieu thach thuc khdc nhau, giai quyat cac van de cdng nghe mdi me nhdt, til quy md khong Id tdi quy mo rat nhd ciia hat nhdn. Cdc ky su xay dung vd thu nghiem cac thiet bi, he thong ldm cdng cy nghian ciiu cho cac nha vdt ly, trong khi dpi ngu ky thuat vian cd trach nhiem duy tri nhiing cd mdy nay chay on dinh, thuc hien sda ehiia vd nang cap mdi khi can thiat
Cdng viec do thudng ddi hdi ehuyen gia tir nhieu nganh khdc nhau. Vi du viec xdy dung, che tao cac may gia tdc ddi hdi cdc chuyan gia xay dung de tien hanh ddo ham va lap dat cac ket cdu ha tang Idn.
Cdc ky su vd ky thudt vien khdc phu trach ldp ddt cdc thiet bi vd cung tinh xao, ti mi, nhu cdc hoc tan sd vd tuyan phai cd kich cd hinh thu tuyet ddi chinh xac de thuc day proton ban trong may gia tdc; can hang nghin nam cham dien khdng Id dugc gia cong rieng biet da dan cdc hat chay vdng trdn trong cac may gia toe; mpt he thong lam Ianh ldn nhdt tha gidi giiip lam mat cac nam cham trong may gia tdc LHC tdi tuyet ddi khdng do, cho phep cac day dan dien cd the van hanh lien tyc trong trang thai siau dan va khdng bi mat nang lugng do dien trd.
Cac cam bien cung dat ra nhung thach thuc khac, vdl moi thiet bi vd he thdng con deu dugc thiet ke, che tao, thu nghiem rieng biet, trudc khi dugc ghep vdi nhau da van hanh mdt each hdi hoa, Nhieu km day dan va hang nghin thiel bi dien tao thanh cac cam bian, co the dugc coi la ky cong ciia cac ky su cua CERN, •
THANH XUAN tdng hap
S I ; RA Ddi COA INTERNET TCT CERN Tim Berners-Lee, mpt nha khoa hpc ngUdi Anh lam v i k tai CERN (Anh ben), da phat kien ra mang World Wide Web (WWW) vao nam 1989. Mang nay dau tien dupc xdy dung nhSm dap dng nhu cau chia se thong tin tudpng giQa cac nha khoa hpc 6 cac trddng dai hpc vd vi^n nghien cdu tren khap the gidi.
Trang web dau tien tren the gidi chinh la cua CERN, phuc vu cho du dn World Wide Web, vdi may chii la chiec mdy tinh Ne)fT cCia Berners-Lee. Trang web nay c6 nhffng chiirc nang can bSn ciia web, cho phep truy c3p tcii li^u cOa nnpi ngUdi, cho ph^p moi ngUdi t u thi^t l|p server cCia minh. Ngay nay, chiec may tinh NeXT, mtiy chd mang dau tien, van ndm tai CERN. Vao ngiy 30/4/1993. CERN dUa phan mem World Wide Web t h i n h ph5n m^m cdng cpng (public domain).
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