Nuclear chemistry at Rensselaer Polytechnic Institute - ACS Publications

NUCLEAR CHEMISTRY AT RENSSELAER. POLYTECHNIC INSTITUTE. A sequence of two* courses in nuclear chemistry is offered at Rensselaer Polytechnic ...
2 downloads 0 Views 4MB Size
JOURNAL OF CHEMICAL EDUCATION

NUCLEAR CHEMISTRY AT RENSSELAER POLYTECHNIC INSTITUTE RERBERT M. CLARK Rensselaer Polytechnic Institute,Troy, New York

A s E w E x c E of two1 courses in nuclear chemistry is somewhat each time the course is given. TWOfactors offered a t Rensselaer Polytechnic Institute. The first which affect these variations are: (1) the publication of course consists of one term of lectures, fifteen mcks in texthooks in nuclrar physics and chemistry in which duration, while the second consist^ of one term of lnbora- rending and problem a4gnments can be made, and (2) tory work nith supporting lectures. Thr coursrs are an increasing tendency for undergraduates to learn offered by the Department of Chemistry ns electives mom of the 1)ackgmundmaterial through outside rendfor p d u a t e studmta in any tlrpnrtmmt. One year of ing and by elrcting new courses in othrr departments. Ilomew~rkprol)lems are nsqiwml and a tmm rrport is elementary physicnl chemistry is prerequisite, however. Qualified seniors may elect the courscs. Students must m u i m l sl~ortlvI~eforcthe end of the term. ' I l r rcnort con~pletcthe one-tern lecture course or a course in m i y be a reridw of some topic related to the student's nuclcnr physics before electing the Inborntory course. major field or it may be a discussion of a recent technical The majority of the students take both coumes. Dur- paper dealing with any of the topics covered in the ing onc academic year, for example, fourteen students course. A report of the first type might deal with the enrolled for the lecture course and eleven for the laborn- applications of radioactive tracers to analytical chemistry, for example. In any case, the student is encourtory course. aged to rend the literature and to hecomc familiar nith the work which is being reported currently, where the There are three lectures (fifty minutes each) per week. work is being done, and by whom. Both the syllabus and time alloted to each topic vary Two or three quizzes and a final examination are given. The final examination is the "open-book" type ' Binca the prmentation of thin paper, a t h i i mum, I n b with the questions designed to encourage the student duction ta Nuclear &ienca and Enginewing, hhss been added to the list of courses offered by the Depnrtment of Chemistry. to apply what he has learned to the solution of problems Although related to the cnunres under considenition, this lcrtunr which are typical of those which might arise in research involving rndioactivc materials. course is not in Roquenw with them.

~.

~~~

JANUARY. lssl

The following is an outline of the topics covered in the lectures.

I

.

I . His(mim1 rem'ew of the d d o p m r n l a aj domic and nuclmr theory

IT. A'ac1mrt)uwy A.

Properties of nucleons

B. Suclpnr binding pnerm C. Surlenr f o r m 1). Ihrrgy ?.levelsin nu&

15. Stn1ilit.v rules F. .\ttninmcnt of stnlrili1.y by means of the various r:alionrtivc decay proepwpa

111. Partirk and mrlinlio~tphyrier A.

B.

C.

D. E.

F. IV.

Alphnparticlrs . 1. Interaction with matter 2. Ilnnrwnar~rvddrlcrmination 3. A101111n~rli~Ies1xctn~ 4 ~deny'srhcmcsior rlphaemitlrm Betapnrticln I. lntcrnetian with matter 2. R m g e - e n r r ~determination 3. I+ta partirlr nperlrn 4. Ferrni thpory 5. Decur ~ r h c r n fnr a lrtacmitters GN~,,,,, 1. Intrrnrlion with matter 2. Iht~rminntionof meray 3. Conversion X-rnys 1. Inlcrnction with matter 2. Ikt~rminationof energy Pmitrons 1. Interaction with matter 2. 1)rtcrminntion of e n e w 3. Lh-cny rrhemrs for jwitron emitters 4 Conqrtition from K-capture Xeutrona I. Inlcraction with matter 2. Detcrminatinn of energy

my$

Deledim ofnudmr mdiorim

ilrlijcinl rdimcliuily A. Ccnerd considcrntions 1. Conncmntion of energy and momontum 2. Cnuloml, Imrrier 3. Iknction thmahdd 4. Compound nueleua 5. Crwvmet,ion and exeitation function B. Examplra of common reactions C. S p e r i ~reactions l 1. O ~ ~ p n l ~ e i t n r r - P h i l l i p 2. Fiiion 3. Sp:tll:~tion D. Sourn.* rind smlerntion of projectiles E. Equrttion for rate of prnduetion

VJlI. H ~ m l i o c l c ~ A. B.

Nsturnl wries Artificial serips C. Thc trnnsurnnies IX.

Rodialia prdwfim

A. B.

Ilnzards a.miated with vnrinus typca of nulistion Shielding C. Dasnm D. instrumentation E. 13iolopicnl eliectsof radintion X . Rodimbmiml aqmmlion prwmrr A. Precipitation methods I. Isotopic carrying 2. h'onisotopir mrrying B. ICIectmltpxitian C. Ion crrhnnm D. Solvent erlr;,ctinn E. Adwrption F. Volatilirntinn G . Szilartl-C'hnlmers p-

X1.

Applimtim of rdimdimmbaInm8

A.

Annlytirnl chemistry

B. I'lnysind rhrmirtry C. Orrrnic ehrmistry D. Iliwhcmistry l i >Ictnllure?, F. Inclustry :md engineering

A. Typm of detection equipment

B. C.

D. E.

F. V.

1. Principle of oprrntion 2. hpplimtions ~ i ~ r - > l i i lt ln~ kr 1. T y p 2. Char:tcteristica %linr rirruits Ilate rnctrrs Cnlilmtion of muntingequipment Alwolutc lrta-ray counting

Enma in m d i d i o i l y mmaurcmmb

A.

Rerice ofdistrihution laas

B. Rnclionctivcclurny nq a rnndornpC. C~leulntionof tho atnndard deviation in counting m alone dnln due to the radianetive p D. Cnlrulntion of total errors in counting data VI.

Equdirmaf m d a y and growth of d i m d i m mblonccs

A.

Single radionuclide 1. Dirintcgrntion m n m t 2. Ilnlf-life 3. A V P T Rlife ~V 4. I'nitr uirndioactivity B. Two or nwre independent radionudidas C. Pk~elirnllymla,tnl rrulionuclida I. Grncr:d rquntions 2. Secul:~ret~uilil,ri~~m 3. Trnrlaientr,loilibrium D. Erperimmtnl n ~ ~ t h for c d the ~ debtmination of hdflives

In certain w s , topics which can be treated more effectively in conjunct,ion n-ith the experiments performed in the lnhorntory course are not considered in great detail in the lecture course. Perhaps it is in order, therefore, to offer a few ~cnernlcomments concerning the material covered f& some of the topics listed above. For the presentation of nuclear theory the analogy between the concept3 of atomic theory and nuclenr theory is s t r e d . At this point the students are introduced to the various charts and compilations of nuclenr and atomic data. -4 large portion of the term is devoted to particle and radiation physics. This is considered to be one of the most importnnt topics, since experimentation with rndioactivc mnterials depends upon the detection of the nurlenr radintion emitted and on the interaction of this rndintion with matter. The properties of particles such na protons and deuterons are considered under the subject of the production of artificial radionctivity. Among the types of detection equipment discussed are ionization chambers, proportional counters, scintillation counters, photogrnpllic plntr*, and so forth. The principlm of quenching and scnling circuits are

6

JOURNAL OF CHEMICAL EDUCATION

eonsideml. The prnhlems of relative nnd nbsolutc single day. Such an arrangement can often be made for the graduate studentn, a t Irn.st. rndiation measrmmrnts are compared. The experiment* are conducted in n l ~ m o d d e dr w m In dealing with the errors of radioactivity mensuree building. As part of the ments it has been found ndvisnhle to review the suhject in the I n s t i t ~ ~ tchemistry of rxperimrntnl errors in genernl. Few students hine remwlding, n l~oodwith g o d airflow was instnllcvl and n nn sdcqontc hackground in the analysis of cxprrimental heavy rubbcr covering, turned up on thr edges and data, and, in fact, in some caws the hrief formnl error spnled to the wnlls and laborntory benches, may placed treatment given in this course has hwn thr s t ~ ~ d e n t ' son the floor. All chemical processing of rndioartive materials in this r w m is carried out in stainless fitrrl first rxpmtre to the suhject. The prohlem n.ssipmrnts are relntivrly henvy for t,rnys which are uwd on the stone brnch tops and in thr that portinn of the course denling with the quntions howl. The counting equipment is in the Rame rnnm and is for the drcny and pron.tI1 of rndionctive s~~bstnncrs. Tlw studcnts nre given nn opportunity to prwtice kept completely covered when not in u . ~ . I t is lm-ntml writing equntions for the production of rndion~rrli(lm. ss fnr a s possihle from the proceasing area. In lnrgrr In ndclition, attention is paid t,o contnminnnt.~w l ~ i r la~ nuclear chemistry qunrtrrs which are to be occupied chemist is likely to find in nn irrndintrd tnrgrt.. ( h r r r n t shortly, the counting equipment will be in n wparnte iilen.. nhout the fision prncesq nlr prrwnted, nlthnugh room near the lnhorntory. The equipment in the laboratory includes the followrnthrr briefly. The hmvy rndioelemcnts are not studied in grent ing: iletnil: rntlw, their occurrence, production, and genernl T h m sealers ehrmistry nre summarized. Amorled end-aindow and thin-rdl Geiger-N(lller tubes with In considrring the prohlem of rndiation protcrtion an shields, ete. Aluminum nnd lead abenrben nttrmpt is made to impress upon the student the need Ono ionimtion type mrvey meter for careful handling of rndionrt.ive suhstanres. At the Onc Goipcr-1lOllcr-type survey meter snmr time, however, n certain amount of popular One I.noritnen dcetmscopc misconrcption and henitancy townnl working with radioPwket ionization rhnml~rsand o h n r g i n ~unit active mnterinls hns to he climinnted. Thrre clinicnl rrntrifu~ra One annlytirnl I m l r n ~ ~ The disrussion of eepnrntion processes is confined OIK pl1 rncter mainly to exnmples and npplications. The principles Onn drying oven arc rensonnhly fnmilinr to the chemist from his hackSt:mdnrd rhemieal illmare ground in nnnlytirnl nnd physicnl chemistry. A more Sprri:d micro g111~lffai-a Stninlrw stml trnys cletnilnl trentment for some of the prncesqrs is given in I ' i p r t t i n ~dcviwa the lnhoratory course. Tonp of various ahaped md a i m I t is felt thnt little is to be gained by presenting more 1101 p l n h and heater lampa thnn n hrief grnrrnl survey of the uses of radionuclide$, Lrnrl lrricka find storage containon ~~~~~~~r alovrs with n few exnmples. A 9 pointed out enrlirr, the st.11(1rnt.s are rncourngcvl to rend the journals. With the present facilities, n mnximum of nix students With rcqpect to the time allo\ved for the vnrious may bc n s i p e d to a given lahorntory eection. The.% topirs, about five w r k a are devoted to topics I through 111. Similnrly, about five weeks nre tnkcn for topics students thrn work in pnirs. The three pairs may or IY through \'I. The remaining topics are covrrrd, may not do the mme rxprriment on n given clny. Ihring thr term rndionrtire waste material gradually then, in the lnst thinl of the term. a c c ~ ~ m ~ ~ l n Xo t r s .railionrtive wnstc is nllowed to enter NUCLEAR CHEMISTRY LABORATORY COURBE the disposnl p l ~ ~ m h i nofg thc chemistry 1)uilding. This The laborntory course consists of six hours of lahorn- rule is rigidly enforred. Except for urnnium, radium tory work nnd one hour of lecture per week. T h r D, and rnlcium 45, the rndionctive suhstnnces used in ; the lrcture period is u d for n discusion of the experiments the c o u m are m m n a b l y s h ~ r t ~ l i v e dtherefore, with lrspeet to hoth throry nnd lnhorntory technique. wnste ~olutionsare s t o l d in glms contninrrs until t,he Mnny of the exprrimrnts are of the "re.wnrrh" typr. activity lrvrl reaches hnrkgrnund. A burial grnund is The ohjretire of thr experiment is clefin~land onr or availnble for disposnl of long-lived wnstc materials more prnrnlulrs nre outlinrrl in somr detnil. The whenever this is necreenry. Certain rndint,ion-protection m e m r e s are taken by students arc r n ( ? o ~ ~ r n m to lpropnse, for discus4on and npprovnl, mnrlificnt~ionsin the detnils of proredure and all personnel working in the radiochemistry lahorntory. technique. To do so, of roume, thrv ncwl to rrcnll and A portnhle G-3I survey instnrment is u.sed t o examine apply the inorgnnir, nnnlytirnl. and physicnl rhrmintry glaswnre, benrh tops, etc., for contamination. An ionization-type survey meter is used when shipments of of their u n d e ~ r n d u n t etraining. rndionctive matcrinls from Oak Ridge are handled Since Inhorntory time is nn important consideration, and \'hen experiments are performed with a rndiumesprcinlly in nuclear chemical experiments, it has been beryllium neutron source. Each student wears two found rulvantn*.o~~sto schrrlule the lnhoratory periods so thnt the s t ~ ~ d r ncan t s take the six hours during a pocket-type ionization chambcrs at all times. These

chambem are checked a t the end of each laboratory period. Complete blood counts are taken at the local hospital once earh mont.h. The experiments performel during the term are an follon9: Determination of the operating curve, effective geometry, and resolving time for n C l I t u b . Investigation of tho errors in rndioaetivity meanurements. Invclitiaation of the frtrtom a l k t i n p the bsekncuttering of tcta n~diation.

Use of rndiation survey equipment; shieldingatudy. h p n r n t i o n ol a fmther nnnlyser based on IlaE. Rnnm nrlrl encmv drtcnnirmtion for the heta radiation fr&nI"*, ~ o q ' : h