Proceedings Proceedings Proceedings ofof the the Fifth Fifth In Internationa阻 mation a1 l SymposiumSymposiu m ono n AdvAdvance岨 ced. d Nuclear Nuclear Energy Energy RResearc曲目rch h -NEUTRONS—NEUTRON S ASA S MICROSCOPICMICROSCOPI C PROBES — 1-161-1 6 NEUTRONNEUTRO N RADIOGRAPHYRADIOGRAPHY ・- STATUSSTATUS ANDAN D INTERNATIONALINTERNATIONA L PROSPECTSPROSPECT S JohnJoh n P. P. BARTONBARTO N NRENR E INCINC. 1422142 2 VueVu e DuD u BayBa y Court ,， SanSa n Diego ，, CAC A 92109 ，, USUSA A ABSTRACTABSTRAC T NeutronNeutro n radiography radiography (or (or radiology) radiology) is is a diverse diverse 罰fieleld d that that usesuse s neutronsneutrons ofof various various energies ,， subthermal ,， thermal thermal ，, epithermal epitherma l or or fast fas t in in either either steady steady state state or or pulsed pulsed modemod e to to to examineexamin e objects objects for for industrial ，, medical. medical , oror other other purposes ,， bothbot h microscopic microscopic andan d macroscopic.macroscopic . Th e applications applications include include engineering engineering design ，, biological biologica l studies ，, nondestructive nondestructive nondestructive inspection inspection andan d materials materials evaluation. evaluation. In In thethe pastpast decade ,， overove r 10010 0 di differen恥 rent t centers centers in in somesom e 303 0 countries countries havehav e publishedpublished reports reports of of pioneering pioneerin g activities activities using usingusing reactors ,， accelerators accelerator s andan d isotopic isotopic neutronneutron sources. sources. While While film film transparency transparency andan d electronic electronic electronic videovideo areare mostmos t ∞commommon n imagingimagin g methodsmethod s for fo r static static oror in in motionmotio n objects ,， respectively ,， there ther e areare other other important important data data gathering gathering techniques ,， including includin g track track etch ,， digital digital digital gauginggaugin g andan d computedcompute d tomography.tomography . A surveysurvey of of thethe world-wideworld-wide progress progress showshows s ththe e fielfield d tto o bbe e gainingaining g steadilsteadily y iin n itits s diversity,，批 its sophisticatiosophistication n anand d its its impoimportanceはance. INTRODUCTIONINTRODUCTIO N It It I t is is ana n honorhono r to to presentpresen t this this invited invited paperpape r reviewing reviewing neutron neutron radiography radiography within within this this thi s international international conferenceconferenc e entitled entitled NeutronsNeutron s asa s MicroscopicMicroscopic Probes. Probes. MostMos t ofof thethe paperspaper s in in thethe conferenceconferenc e discussdiscuss scattering scattering techniquestechniques to to studystudy microscopic microscopic details details of of of crystal crysta l structure. structure. NeutronNeutro n radiographyradiography sharesshare s a commoncommo n interest interest in in neutronneutron sourcessource s andan d neutronneutron physics ,， butbu t it it usesuse s thethe microscopically microscopically small small neutronneutron primarily primarily to toto obtain obtain macroscopicmacroscopi c information. information. TheTh e optically optically enlargedenlarged imageimag e showingshowin g individual individual boronboro n fibers fibers in in a metalmetal compositecomposit e provides provides ana n exampleexampl e of of thethe small small scale scale neutron neutron radiographyradiograph y capability. capability. A neutronneutron radiographradiograph of of a full full size size motorcyclemotorcycle hasha s beenbee n useduse d to to to iII illustrat ustrate e thethe larger larger scale scal e possibilities. possibilities. NeutronNeutro n radiographyradiography dependsdepend s ono n theth e ability ability of of neutronneutron radiation radiation to to penetrate penetrate certain certain certain materials material s (typically (typically densedens e metals) metals) moremor e readily readily thanthan enclosedenclose d elementselement s of of interest interest interes t (typically (typically thosethos e containing containing hydrogen). hydrogen). TheTh e techniquestechniques canca n sometimessometime s provide provide impoimportan同ant t information information that that cannotcanno t beb e obtainedobtained byb y conventional conventional X-radiographyX-radiography oror alternative alternative alternative inspection inspection methods.methods . In In mostmos t casescase s thethe spectrumspectru m of of predominantlypredominantly thermal thermal neutrons neutrons emergentemergen t fromfro m a moderatedmoderate d neutronneutron sourcesourc e will will provide provide thethe contrast contrast needed.needed . ofO f course ,， byb y selection selection of o f different different neutronneutron energies ，, theth e capabilities capabilities canca n beb e changedchange d significantly. significantly. SOURCESSOURCE S TheTh e neutronneutron beambea m is is usually usually 号extractextracted d throughthroug h the the sourcesourc e shielding shielding usingusing a divergent divergent divergen t collimator collimator design. design. TheTh e neutronneutron f1 fluux x incident incident ono n thethe object object is is thethe f1 fluux x at at thethe -125- collimator collimator collimator input input reducedreduce d byb y the the squaresquare of of the th e collimator collimato r ratio ratio of of length length L to to input input diameter diameter diameter D. D. Neutron Neutron Neutro sources n sources ranging ranging fromfrom very verhigh y high flux flux to to relatively relatively lowlow flux flux eacheac h havehav e a role role role to to play play in in neutron neutron radiography. radiography. At At the the enden d of o f this this conferen conferenc回e wewe shall shal l visit visit the the high high high flux flux reactor reactor JRRJRR-・3 whichwhich has has three thre e operational operational neutron neutron radiography radiography systems，, oneon e for for for nuclear nuclear fuel fuel studies ,， another anothe r for for nonno n radioactive radioactive material material studies ,， andan d a cold cold neutron neutron 回capabilitypability. 刊The reactors reactors JRRJRR-・2 (10 (10 MMW) W)， , JRRJRR-・4 (3.5 (3.5 MMWW) ) andan d NSRRNSR R (pulsed (pulsed reactor) reactor) reactor) at at JAERIJAER I havehav e also also beenbee n applied applied to to neutron neutron radiography. radiography. Saclay Saclay andan d Petten Petten are are are other other centers centers that that havehav e high high flux flux reactors reactors with wit h facilities facilities designeddesigned for for fuel ,， thermal therma l andan d cold cold neutron neutron radiography. radiography. SandiaSandia National National LaLaborator boratory y in in the the USAUS A hasha s ana n annular annular core corecore pulsed pulsed reactor reactor neutron neutron radiography radiograph y capability capability comparablecomparabl e with with NSRRNSR R (T (Tabl able e 1)1). LowLo w cost cost reactors reactors suchsuc h asa s the the 10 10 KWKW L88L8 8 solution solution type type in in the the USA ，, the th e MIRENEMIREN E reactor reactor reactor in in France ，, andan d the the 1W W reactor reacto rat at Ki Kink nki iUnive Universit陪 ity y in inJapan Japancan can also also ~eb e use!ul useful for for fo r certain certai n applications. applications. TheTh one e one watt wat t reactor reactor provides provides a neutron neutron flux flux of of 3x1033n/cm 22--s s atυoat L/ D 22. 22 . In In Taiwan Taiwan the the sos o called called zero zero powerpowe r reactor reactor hasha s beenbee n recently recently upgradedupgrade d to to 303 0 KWK W specifically specifically to to meetmee t various variou s industrial industrial neutron neutron radiography radiography demands.demands . TABLETABL E 1 ComparableComparabl e NRNR SystemsSystem s ・- ApproxlmateApproximate Flgures Figures '-i 22 NRTYPENRTYP E CENTERCENTE R REACTORREACTO R L:D L:D n/cm --s s 88 ETherma皇国E盟l JAERI JAERI JRRJRR- -3 3 170 170 2x2x1010 77 PETTENPETTE N HFRHF R 40040 0 2x2x1010 77 SACLAYSACLA Y OSIRIS OSIRIS 150 150 6x6x1010 88 SANDIA SANDIASANDIA ACPRACP R 110 110 2x2x1010 88 Cold Cold Cold JAERI JRRJRR- -3 3 GUIDE GUIDE - 2x2x1010 55 PETTENPETTE N HFR-FILTER HFR-FILTER 150 150 2x2x1010 99 SACLAYSACLA Y ORPHEE-GUIDEORPHEE-GUIDE - 1x10 Pulsed Pulsed Pulsed JAERI JAERI NSRRNSR R 30 30,00，∞ o0 MWMW approx. approx. SANDIA SANDIASANDIA ACPRACP R 30 30,00 ，000 0 MWMW approx. approx. Accelerators Accelerators Accelerators in in useus e for for neutron neutron radiography radiography include include cyclotrons ,， vanva n ded e graaff graaff machines ，, andan d sealed sealed tubetube neutron neutron generators. generators . In In JapJapan聞， , of of twenty twenty operating operating neutron neutron radiography radiography radiography systemssystem s nine nine useus e accelerators. accelerators. HighHigh yield yield 0- D-T accelerators accelerators andan d special special radio radio radio frequency frequency quadrupolequadrupol e accelerators accelerators are are being being developeddeveloped for for neutron neutron radiography radiography applications applications applications in in EuropeEurop e andan d the the USUSA A. Also Also Also isotopic isotopic neutron neutron sources ,， principally principall y Californium-252 Califomium-252,， are ar e being being appliedapplied. -126-126- ー Th e neutron neutron beambea m flux flux ofof thethe 505 0 mgmg cfCf-25・252 2 sourcesourc e in in useus e for for aircra aircraf仕t inspection inspection is is similar similar similar to to that that detailed detailed