%MurNBbeta041451; ]> Memorandum from Arthur Waltner to Clifford K. Beck [a machine-readable transcription] Waltner, Arthur Creation of machine-readable version: Russell S. Koonts Creation of digital images: Russell S. Koonts Conversion to TEI.2-conformant markup: NCSU Science and Technology Electronic Text Center. ca. 9 kilobytes NCSU Libraries. Raleigh, NC. Modern English, MurNBbeta041451

Available from: NC State University Archives

Publicly-accessible

URL: http://www.lib.ncsu.edu/archives/etext/engineering/reactor/murray/

 2000

Nuclear Reactor Digitization Project

Raymond L. Murray Reactor Project Notebook

 Illustrations have been included from the print version. Scanned by Russell Koonts with Photoshop 5.0 software. Memorandum from Arthur Waltner to Clifford K. Beck <author>Arthur Waltner</author> <respStmt> <resp/> <name/> </respStmt> </titleStmt> <editionStmt> <p></p> </editionStmt> <extent>1 p.</extent> <publicationStmt> <publisher></publisher> <pubPlace></pubPlace> <date></date> <idno>Manuscript copy consulted: NCSU Libraries call number UA105.16</idno> </publicationStmt> <seriesStmt> <p/> </seriesStmt> <notesStmt> <note></note> </notesStmt> </biblFull> </sourceDesc> </fileDesc> <encodingDesc> <projectDesc> <p>Prepared for the NCSU Libraries Science and Technology Electronic Text Project.</p> </projectDesc> <editorialDecl> <p>Spell-check and verification made against printed text using Notetab spell checker.</p> <p>The lineation of the manuscript has been maintained and all end-of-line hyphens have been preserved.</p> <p>The images exist as archived TIFF images, one or more JPEG versions for general use, and thumbnails.</p> <p id="ETC">Keywords in the header are a local Electronic Text Center scheme to aid in establishing analytical groupings.</p> </editorialDecl> <refsDecl> <p>ID elements are given for each page element and are composed of the text's unique cryptogram and the given page number, as in NEprop033050a for the title page of Clifford K. Beck's Proposal.</p> </refsDecl> <classDecl> <taxonomy id="LCSH"> <bibl> <title>Library of Congress Subject Headings April 14, 1951 English non-fiction; prose LCSH 24-bit color; 400 dpi Memorandum from Arthur Waltner to Clifford K. Beck Typescript 1 p. April 14, 1951 MurNBbeta041451

NCSC-17 April 14, 1951 TO: Clifford K. Beck FROM: Arthur Waltner SUBJECT: Beta Particle Transmission for Aluminum Windows

The range-energy relation for beta particles up to 3 Mev is given by the relations (a.) below 0.8 Mev R = 0.407 E1.38 (b.) above 0.8 Mev R - 0.542 E - 0.133

In the above relations, R is expressed in gm/cm2 and E in Mev. The calculated end-point range of a 1 Mev beta spectrum is thus 0.41 gm/cm2 which is equivalent to 0.15 cm of Al.

The percent transmission of the beta particles of Bi210 through a series of Al absorbers as obtained in our laboratories is tabulated below. (Maximum energy of Bi210 Β particles - 1.17 Mev.)

TABLE IAbsorbermg/cm2Thickness (Al)mm% Transmission00100200.0774300.1163400.1453600.2240800.29291000.37221200.44161400.52121500.567.21800.676.42000.744.72400.892.52801.031.43201.19.86

Thin wall GM tubes are produced commercially with wall thicknesses of 30 mg/cm2 in Al, glass, or stainless steel, some of which are designed as dipping counters. For the RaE (Bi210) spectrum this represents about 63% transmission. It thus seems feasible to design stack and coolant monitors which will be sufficiently sensitive to beta particles, regardless of the choice of the detecting element.

CC: Reactor Committee

data gathered by W. T. Withers