Security Classification Seen enec a TR, et oRRBae Pe? 7% 14. LINK A KEY WORDS ROLE LINK 8 wrt ROLE LINK C wT ROLE wT Radioactivity Atmosphere Measurement Radon Radioactive decay Filter collections Radon decay products Secular equilibrium INSTRUCTIONS t. ORIGINATING ACTIVITY: Enter the name and address of the contractor, subcontractor, grantee, Department of De fense activity or other organization (corporate author) issuing the report. imposed by security classification, using standard statements such as: (1) 2a. REPORT SECURITY CLASSIFICATION: Enter the over all security classification of the report. Indicate whether “Restricted Data’’ is included. Marking is to be in accord ance with appropriate security regulations. 26, GROUP: Automatic downgrading is specified in rective 5200.10 and Armed Forces Industrial Manual. the group number. Also, when applicable, show that markings have been used for Group 3 and Group 4 as ized. (2) (3) DoD DiEnter optional author- DESCRIPTIVE NOTES: ‘Foreign announcement and dissemination of this report by DDC is not authorized.” “U. 5. Government agencies may obtain copies of this report directly from DDC. Other qualified DDC users shall request through * 3. REPORT TITLE: Enter the complete report title in all capital letters. Titles in all cases should be unclassified, If a meaningful title cannot be selected without classification, show tithe classification in all capitals in parenthesis immediately following the title. 4, ‘‘Qualified requesters may obtain copies of this report from DDC.”’ (4) #+‘U. S. military agencies may obtain copies of this report directly from DDC. Other qualified users shall request through (5) ‘All distribution of this report is controlled. Qualified DDC users shall request through a a YWappropriate, enter the type of report, @.g., interim, progress, summary, annual, or final. If the report has been furnished to the Office of Technical Services, Department of Commerce, for sale to the public, indicate this fact and enter the price, if known. Give the inclusive dates when a specific reporting period is covered. 5S. AUTHOR(S): Enter the name(s) of author(s) as shown on or inthe report. Enter last name, first name, middle initial. If military, show rank and branch of service. The name of 1L. SUPPLEMENTARY NOTES: Use for additional explana- tory notes. the principal author is an ahsolute minimum requirement. 12. SPONSORING MILITARY ACTIVITY: Enter the name of the departmental project office or laboratory sponsoring (pay ing for) the research and development. Include address. 6 REPORT DATE: Enter the date of the report as day, month, year, or month, year. If more than one date appears on the report, use date of publication. 13. ABSTRACT: Enter an abstract giving a brief and factual Summary of the document indicative of the report, even though it may also appear elsewhere in the body of the technical report. If additional space is required, a continuation sheet shall be attached. 7a. TOTAL NUMBER OF PAGES: The total page count should follow normal pagination procedures, i.’e., enter the number of pages containing information. 7b. NUMBER OF REFERENCES: references cited in the report. Enter the total number of $a. CONTRACT OR GRANT NUMBER: If appropriate, enter the applicable number of the contract or grant under which It is highly desirable that the abstract of classified reports be unclassified. Each paragraph of the abstract shall ead with an indi. ation of the military security classification of the information in the paragraph, represented as (TS), ($), (C), of (UH). 8b, &, & 8d. There is no limitation on the length of the abstract. ever, the suggested length is from 150 to 225 words. the repott was written PROJECT NUMBER: Enter the appropriate military department identification, such as project number, How- i4. KEY WORDS: Key words are technically meaningful terms or short phrases that characterize a report and may be used as index entries for cataloging the report. Key words must be selected so that no security classification is required. Identifiers, such as equipment model designation, trade name, military Project code name, geographic location, may be used as key words but will be followed by an indication of technical context. The assignment of links, rales, and weights is optional. subproject number, system numbers, task number, etc. 9a. ORIGINATOR’S REPORT NUMBER(S): Enter the official report number by which the document will be identified and controlled by the originating activity. This number mpst be unique to this report. 9b. OTHER REPORT NUMBER(S): If the report has been assigned any other report numbers (either by the originator or by the sponsor), also enter this number(s). 19. AVAILABILITY/LIMITATION NOTICES: Enter any limitations on further dissemination of the report, other than those 18 Security Classification ao ~ af