. The Bell System technical journal . rves of the sort which I defined above, exceptthat the ordinate is not the actual number of protons observed, but thequotient of this number by that of the alpha-particles expressed in2 This is Poses convention, to which I conform in the following pages; the rangeof alpha-rays from polonium is cm. in air at 15° C. and atmospheric pressure; theother ranges mentioned in what follows should be increased m the same proportion ifthe reader wishes to hold to Rutherfords convention. 644 BELL SYSTEM TECHNICAL JOURNAL hundreds of millions—the number of protons
. The Bell System technical journal . rves of the sort which I defined above, exceptthat the ordinate is not the actual number of protons observed, but thequotient of this number by that of the alpha-particles expressed in2 This is Poses convention, to which I conform in the following pages; the rangeof alpha-rays from polonium is cm. in air at 15° C. and atmospheric pressure; theother ranges mentioned in what follows should be increased m the same proportion ifthe reader wishes to hold to Rutherfords convention. 644 BELL SYSTEM TECHNICAL JOURNAL hundreds of millions—the number of protons received and detectedin the conical chamber behind the absorption-foils of mica, per hundredmillion alpha-corpuscles impinging on the sheet of aluminium. Thissheet was so thick that all of the impinging corpuscles were swallowedup in it. Thus, the uppermost of the curves relates to aluminiumsubjected to alpha-rays of all ranges from centimeters down to nil;and the numbers attached to the others likewise stand for the maximum. 20 25 30 35 40 45 AIR-EQUIVALENT IN CENTIMETERS Fig. 6—Integral distribution-in-range curves for protons emitted from disruptednuclei of aluminium atoms (H. Pose). ranges represented among the particles as they approached the differentiating these curves one would get distribution-in-rangecurves for the protons. I will therefore refer to them, and to those ofFigs. 2, 7 and 8, as integral distribution-in-range curves. Ignoring for the moment the left-hand half of the diagram, considerthe other. The two lowest of the curves do not reach it: hence, alpha-particles of range or less do not have the power of ex-pelling protons with 30-centimeter range or greater. The other three CONTEMPORARY ADVANCES IN PHYSICS 645 curves do enter it, and there is a very important feature of their trend:all are horizontal from 30 to 45, then all drop sharply to the axis at thesame abscissa. Thus the piling-up of obstruction in the way of thep
Size: 1397px × 1789px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
