Document Details
Title:
OPERATION SUN BEAM, SHOT SMALL BOY, PROJECT OFFICERS REPORT-PROJECT 6.4: MEASUREMENT OF GAMMA DOSE RATE AS A FUNCTION OF TIME (DELETED)
Author(s):
KRONENBERG, S [UNITED STATES ARMY - DEPARTMENT OF]; MARKOW, B [UNITED STATES ARMY - DEPARTMENT OF]; BALTON, I A [UNITED STATES ARMY - DEPARTMENT OF]
Subject Terms:
SUNBEAM PROJECT; DOMINIC II OPERATION; SMALL BOY EVENT; DOSE RATES; GAMMA RADIATION; MEASURING METHODS; MEASURING INSTRUMENTS
Document Location:
Location - DOE/NNSA NUCLEAR TESTING ARCHIVE Address - P.O. Box 98521 City - Las Vegas State - NV Zip - 89193-8521 Phone - (702)794-5106 Fax - (702)862-4240 Email - NTA@NV.DOE.GOV
Document Type:
REPORT
Publication Date:
1963 Oct 11
Declassification Status:
Sanitized
Document Pages:
0075
Accession Number:
NV0051052
Document Number(s):
POR2229EX
Originating Research Org.:
UNITED STATES ARMY - DEPARTMENT OF
OpenNet Entry Date:
1994 Aug 26
OpenNet Modified Date:
2003 Sep 18
Description/Abstract:
THE OBJECTIVE OF PROJECT 6.4 WAS TO MEASURE GAMMA INTENSITY AS A FUNCT ION OF TIME AT 625, 1,600, AND 4,000 FEET [ ] USING A NE WLY DEVELOPED GAMMA DETECTOR CALLED SEMIRAD. THE GAMMA INTENSITY WAS TO BE MEASURED FROM SEVERAL NANOSECONDS TO 90 SECONDS. BASICALLY, THE SEMIRAD IS A VACUUM DIODE. GAMMA PHOTONS PRODUCE COMPTON ELECTRONS I N THE WALL, WHICH, UPON LEAVING THE WALL, PRODUCE LOW-ENERGY SECONDARY ELECTRONS. WITHOUT SPECIAL WALL MATERIAL, SUCH AS PLASTIC OR FISSION ABLE MATERIAL, THE DEVICE IS ALMOST COMPLETELY INSENSITIVE TO NEUTRONS . THE REASON FOR CHOOSING THIS DEVICE RATHER THAN OTHER CONVENTIONAL GAMMA DETECTORS IS ITS EXTREMELY RAPID TIME RESPONSE, LIMITED ONLY BY THE COLLECTION TIME OF THE SECONDARY ELECTRONS, AND ITS HIGH DOSE-RATE SATURATION LIMIT. THE SEMIRAD IS SATURATED ONLY WHEN THE SECONDARY E LECTRONS ARE NUMEROUS ENOUGH TO PRODUCE SPACE CHARGE BIG ENOUGH TO CAN CEL THE COLLECTING POTENTIAL. THE SIGNALS FROM THIS DETECTOR WERE REC ORDED ON BOTH THE OSCILLOSCOPES AND MAGNETIC TAPE. FOR RECORDING ON M AGNETIC TAPE, THE SIGNAL WAS USED TO PULSE A MULTIVIBRATOR WHOSE PULSE REPETITION RATE IS DIRECTLY PROPORTIONAL TO GAMMA INTENSITY. THE GAM MA INTENSITY AT TIMES LATER THAN .001 TO 100 SECONDS WAS MEASURED WITH ION CHAMBERS WHOSE OUTPUT WAS RECORDED ON MAGNETIC TAPE USING CONRAD INSTRUMENTATION. RESULTS OF THE GAMMA-DOSE-RATE MEASUREMENT AS A FUNC TION OF TIME ARE FRAGMENTARY, AND REPRESENT AN UNDISTORTED MEASUREMENT IN ONLY A FEW INTERVALS. FAILURES OF EQUIPMENT AND/OR HUMAN FACTORS ACCOUNTED FOR MISSING DATA. THE DATA COULD BE IMPROVED IN A FUTURE EX PERIMENT IF SPECIFIC CHANGES ARE MADE IN THE INSTRUMENTATION, VIZ: BET TER EM SHIELDING, IMPROVED TAPE RECORDERS, AND GENERALLY HIGHER QUALIT Y ELECTRONICS.