at ASSIFIFD SECURITY CLASSIFICATION OF THIS PA REPORT DOCUMENTATION PAGE Ta REPORT SECURITY CLASSIFICATION UNCLASSIFIED 2a, SECURITY CLASSIFICATION AUTHORITY Th RESTRICTIVE MARKINGS . 3 DISTRIBUTION/ AVAILABILITY OF REPORT /A since Unclassified Approved for public release; distribution 2b. DECLASSIFICATION / DOWNGRADING SCHEDULE is unlimited. N/A since Unclassified 3. PERFORMING ORGANIZATION REPORT NUMBER(S) 5. MONITORING ORGANIZATION REPORT NUMBER(S) ITR-1624 (EX) 6a NAME OF PERFORMING ORGANIZATION 6b OFFICE SYMBOL Cf applicable) U.S. Naval Research Laboratory 6c. ADDRESS (City, State, and ZIP Code) 7a. NAME OF MONITORING ORGANIZATION . Defense Atomic Support Agency 7b. ADDRESS(City, State, and ZIP Code) Washington, I Washington, DC a. NAME OF FUNDING / SPONSORING @b. OFFICE SYMBOL ORGANIZATION (if applicable) 8c. ADDRESS(City, State, and ZIP Code) 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER 10_ SOURCE OF FUNDING NUMBERS PROGRAM ELEMENT NO. PROJECT |}NO. TASK NO. WORK UNIT ACCESSION NO. 1T TITLE include Security Classification) peRATION HARDTACK—PROJECT 2.7; Nuclear Radiation from a Detonation at Very-High Altitude, Extracted Version 12. PERSONAL AUTHOR(S) Caldwell, P.A.; Alers, P.; Drachman, R.J.; Hanscome, T.D.; et al. 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Year, Month, Day) [1S. PAGE COUNT FROM To 580718 39 a — 7 16 SUPPLEMENTARY NOTATION This report has had sensitive military information removed in order to provide an unclassified version for unlimited distribution. The work was performed by the Defense Nuclear Agency in support of the DoD Nuclear Test Personnel Review Proaram. 17 COSATI COOES ‘TS 20 FIELO GROUP 30 8 18. SUBJECT TERMS (Continue on reverse if necessary and identify by biock number) SUB-GROUP Hardtack Instrumentation Radiation Measurement 19 ABSTRACT (Continue on reverse if necessary and identify by block number} The objective of this project was to measure the neutron spectrum and total prompt-gamma-ray flux produced by the detonation of a nuclear device of low yield at an altitude of about 90,000 feet. This information was to be obtained by suitable detectors in the vicinity of the nuclear device and telemetered to the ground to be recorded and subsequently analyzed. The theory and ‘instrumentation for measurement of neutron spectrum and total prompt-gammaray flux from a nuclear device detonated at an altitude of 85,000 feet is described. The balloon system left nothing to be desired in ease of launching and getting instrumenta- tion of this type to altitude. The difficulties encountered with the command and telemeter- ing systems could certainly be corrected by adequate testing in an environment including tests in the 100,000 ft. altitude range, and if repeated with thoroughly tested systems, should offer an excellent chance of success. 20 OSTRIBUTION, AVAILABILITY OF ABSTRACT RXuncLassificovunuimireo (CJ) same as RPT 2a NAME OF RESPONSIBLE INDIVIDUAL Mark D. Flohr OD FORM 1473, 34 Mar CJ omic users 21 ABSTRACT SECURITY CLASSIFICATION UNCLASSIFIED 22b TELEPHONE (Include Area Code) 22¢. OFFICE SYMBOL (202) 325-7559 ONA/ISCM BJ APR edition may be used until exhausted All other editians are dosalete j SECURITY CLASSIFICATION OF THIS PAGE UNCLASSIFIED