AN ISOTOPE FILE ON PUNCHED CARDS GEORGE M. MURPHY Yale University, New Haven, Connecticut L ~ s mOF known isotopes and their properties are 5 X 8-inch "Rocket" cards, obtainable from the often useful to workers in nuclear chemistry and phys- Charles R. Hadley Co., Los Angeles, California. One ics. Tables, such as those of Seaborg,' are convenient card is used for each isotope and, where isomeric but corrections and new data are not readily added. states occur, each of these is placed on a separate card. Charts2, are preferable for some purposes but they The main part of the card contains as much of the also are difficult to revise and, moreover, become following information as is available or applicable: quite complex when all pertinent information is in- (1) atomic number, symbol, and mass number; (2) cluded. Punched cards 4. s, of the Keysort type exact mass on the physical scale; (3) relative abunappear to be adaptable for an isotope file and seem to dance; (4) half life; (5) nuclear spin; (6) magnetic offer certain advantages over other methods for this moment; (7) mode of decay with energy of radiation or particles emitted in m.e.v.; (8) nuclear reactions purpose. The one about to be described is kept on standard producing the isotope; (9) immediate precursor and descendant. The cards are large enough to contain all of this information without being overcrowded. To ' SEABORG, G. T.,Rev. Modern Phys., 16, 1 (1944). simplify the typing, no Greek letters are used (i. e . , b "UNDU, D. N., AND M. L. POOL, Phys. Rm., 72,101 (1947). for betas, g for gammas, etc.). A typical card, which SPENCER, H. M., J. CAEM.EDUC.,24,19 (1947). Cox, G. J., C. F. BAILEY, AND R. S. CASEY, Chem. Eng. News, should be self-explanatory, is shown in Figure 1. Letter23, 1623 (1945). number combinations on it refer to papers in the literaCASEY,R. S., C . F.BAILBY, AND G. J. COX, J. CREM. EDUC., ture. 23, 495 (1946). The file was started by typing the preceding inCox, G. J., R. S. CASEY,AND C. F. BAILEY, ibid., 24, 65 formation from Seaborg's table' and from the fission (1947).
13.00988+0.00004(~4)
b+:
0.92
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g : 0.28(92)*; none(Ll);
prec C-13
riwn 1. 556
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9.93min(S2)
NOVEMBER, 1947
product report of the Plutonium Project.' Subsequent data were added from the journals since 1944 with the corresponding references. It was also found convenient to make a separate card for the neutron and for each of the 96 known chemical elements. These contain the latest chemical atomic weight and the relative abundance of the naturally occurring isotopes. A simple method of coding the cards is used. Mass and atomic numbers are indicated by punching out the requisite number of holes: 12 and 8, respectively, being allotted for this purpose. One hole each is assigned to the properties listed as items (I), (2), (3), (5), and (6) of a preceding paragraph. One hole each is also used to designate the element card, a stable isotope, a naturally radioactive one, an artifically radioactive isotoue, occurrence in fission and fission vield. Thus it is aArelativelysimple matter to withdraw-from the file the cards showing all isotopes for which the nuclear spin has been determined or for the other properties mentioned. The half life of the isotope is indicated by punching one of seven holes representing times less than 1 sec., 1 min., 1 hour, 1 day, 1 year; more than 1 year; more than 10 years. The type of decay requires nine holes for: alphas, betas, positrons, internal conversion electrons, gammas, isomeric transitions, K capture, neutrons, and X-rays. The nuclear reactions producing the isotope are coded in two parts: one for the bombarding projectile and one for the particles ejected. The former now requires seven holes for alphas, deuterons, electrons, gammas, neutrons, protons, and tritons. For the latter, in addition to these seven, one further hole is needed for HeS, recently detected.= Since two or more particles are often released in a given reaction, it is well to provide holes for two neutrons, two protons, etc. This enables one to distinguish, for example, between (&p), (d-2p) and (d-p,2n) reactions although more than one sorting is required to withdraw the appropriate cards from the file. Reference to Figure 1 will show how the coded information appears on a card. Startingrwith the upper right-hand corner and going around in a counterclockwise direction, the numbered punches indicate the following: (1) exact mass known; (11) life time less than an hour; (17, 18, 21) mass number; (29) artificially radioactive; (32) positron emitter; (34) gamma rays emitteds; (55, 59,60, 67) particles ejected gammas, one neutron, two neutrons, tritons; (7G80) produced by bombardment with alp has^ gammas, neutrons or protons; (87) atomic number. The file in its presentstate contains 950 cards, Plutonium Project, J. Am. Chem. Soe., 68,2411 (1946). the most recent results that gammas are emitted in this particular case, the corwonding hole has been punched because of the earlier data. Corrections like this, as well as athen, will certainly have to be made from time to time.
557
The simplest way of keeping it up to date seems to be with Chemical Abstracts from which the necessary entries can be made in about an hour, twice a month, unless original papers must be consulted. For the uses intended, the file has been found to be highly satisfactory. Those who are interested in other nuclear properties omitted here, cross sections for example, could readily add such information to the cards. More complex types of coding might also be desired by some and these could be devised with no difficulty. One of the main advantages of the file is that it can be modified easily for application to special needs in nuclear studies.
GI=_ Blowing Becomes a Sci.noe Essential to Modern Research
Reaohin~ new heiahts of oornnl~rity,glass hiowing has become an engineering science without which today's huge research laboratories could scarcely operate. ~ ~ ~ vin iehea~sst d i ~and ~ most quickly fabricated forms the multi-varied shape8 required for meienti" experimentation, glass today can do things metal cannot. Its ndaptability enables it to be formed into bellows, d r a m with vacuums of one-ten-millionth of an atmorohere, welded to metal, and fitted with Dumpsand moving parts as elaborateas meehsniosl devices. To become an soeamplished modern glass teehnieisn requires uperienoe. , - ~ fhe.* t ~blown ~ hia firet ton 01 a heginner a m t ~ to get the ides," m. E. B.,,, ,hop superintendent the G L , I ~ Research 6: Development Company.
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