Download or read book Operation GREENHOUSE Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 Annex 1 2 Delayed Gamma Ray Measurements Part 2 Measurement of Total Gamma Ray Intensity Vs Time After One Millisecond written by Harold F. Gibson and published by . This book was released on 1985 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: The gamma-ray dosage rate was determined in Operation Greenhouse to provide data for computing the bomb efficiencies; to provide an absolute calibration for the shorter-recording-time instruments; to provide absolute calibration for the total-gamma-dosage measurements; and to investigate the feasibility of evasive action by personnel.
Download or read book OPERATION GREENHOUSE Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 Annex 1 1 Prompt Gamma Ray Measurements Part 1 The Measurement of Alpha by Prompt Gamma Rays written by Wayne C. Hall and published by . This book was released on 1987 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Operation GREENHOUSE Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 Annex 1 1 Prompt Gamma Ray Measurements Part 2 Prompt Gamma Ray Intensity as a Function of Time written by Wayne C. Hall and published by . This book was released on 1985 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the procedure followed and the results obtained in measuring, as a function of time, the prompt-gamma radiation emitted within 1,000 seconds after the explosion of the atomic weapons studies in Operation Greenhouse. The design of the experiment and a description of the equipment are given. The fast coaxial scintillation detectors for the Greenhouse test were used without collimators at a distance of several mean free paths from the source. Numerous factors complicated the interpretation of the data obtained, thus reducing the accuracy that may be ascribed to the results. The probable peak gamma-ray intensity, the time of occurrence of the peak, and the prompt-gamma decay curves as a function of time were obtained for each shot. A composite decay curve fitting all the shots was obtained, and from this, a scaling factor was deduced which related the shot energy to the gamma-ray intensity.
Download or read book Operation Greenhouse Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 Annex 1 2 Delayed Gamma Ray Measurements Part 1 Gamma Ray Spectrum Measurements Abridged written by H. F. Gibson and published by . This book was released on 1985 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: The measurement of bomb efficiencies from the number of gamma-rays requires fundamentally two separate experiments. The average number of gamma-rays emitted from the fission fragments (delayed gamma-rays) per fission must be determined. This experiment can be carried out in the laboratory, A second experiment, the absolute determination of the number of gamma-rays from the bomb are also attempted. Because gamma-rays are not directly observable but are measured only through their secondary effects, and because the probability of occurrence of the secondary effects depends upon the gamma-ray energy, it is not usually possible to count directly the number of gamma-rays in a heterochromatic spectrum. A spectral distribution must be first obtained from which the actual total number of gamma-rays may be computed. This volume discusses the planning for the experiment and the spectral distribution of collimated gamma-rays determined from the Greenhouse tests on two shots. A discussion of measurement of build-up factor which is needed to estimate the effect of collimation is also given.
Download or read book OPERATION GREENHOUSE Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 Annex 1 2 Delayed Gamma Ray Measurements Part 4 Measurements Uuner Collimated Conditions written by Philips J. Cavanagh and published by . This book was released on 1952 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary purpose of the spatial measurements was to gain data from which the distribution of fission fragments as a function of time could be computed. Since it was considered that the previous Sandstone tests did not include enough sample points in space to provide more than a very rough idea of the distribution of fission fragments with time, it was decided, to provide more collimators, detectors with a faster response, a recorder with better time resolution, and more protection for the detectors. The radial motion of the fission fragments was expected to be available directly from the measured times of arrival of the source at the field of view of each detector.
Download or read book Operation GREENHOUSE Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 Annex 1 5 Neutron Measurements Part 2 External Neutron and Gamma Flux Measurements by Sample Activation written by Wendell A. Biggers and published by . This book was released on 1985 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Greenhouse operation consisted of a series of four shots conducted at Eniwetok during the Spring of 1951. The external neutron threshold measurements consisted of the use of good samples to measure integrated thermal neutron fluxes and sulfur, iodine, and zirconium samples to measure fluxes of higher energy neutrons. The iodine also measured high-energy gamma-ray intensity. Measurements were also made on slow- and fast-neutron intensities as a function of time.
Download or read book Operation GREENHOUSE Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 Annex 1 1 Prompt Gamma Ray Measurements Part 3 The Measurement of Transit Time written by W. C. Hall and published by . This book was released on 1985 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: This eport describes the procedures followed in measuring the transit time of the atomic explosions evaluated in Operation Greenhouse. It includes a description of the equipment used, the installations made, and the results obtained. Transmit time measurements were obtainded for the Easy, George and Item Shots; and on the whole, the transit-time recording equipment performed well. (Author).
Download or read book Operation GREENHOUSE Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 Annex 1 5 Neutron Measurements Part 1 Diagnostic Neutron Experiments written by E. H. Krause and published by . This book was released on 1985 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of radiation on the passage of an electromagnetic wave along a cable are too complicated to predict accurately from theory alone. Also, near the bomb, the intensity during the shot is so high that the results of laboratory measurements must be extrapolated by too many orders of magnitude to be applied with much confidence to the test conditions. Therefore a number of cables were installed near the bomb for the sole purpose of study the radiation effects, both to help correct the data obtained in the present tests and to help predict shielding requirements in future tests. The two types of effects looked for were (1) a simple attenuation of a voltage across the line due to the shunt conductance set up when Compton recoil electrons from the gamma rays ionize the gas between the inner and outer conductors; and (2) an induced signal due to the Compton electrons being knocked out of the inner and outer conductors in unequal amounts. On the basis of the results, a discussion is given of the adequacy of the coral shielding actually used to protect the horizontal cable runs.
Download or read book OPERATION GREENHOUSE Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 Annex 6 5 Interpretation of Survey Meter Data written by E. Tochilin and published by . This book was released on 1951 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the Scientific Director's Report of Atomic Weapon Test at Enuivetok, 1951. Under laboratory conditions a study of survey-instrument response to fission-product activity was made. This study involved a knowledge of beta-ray energy, gamma-ray energy, and beta-ray and gamma-ray dose rates associated with fission-product radiation fields. Fission-product activity was collected on aluminum plaques which were flown through the radioactive cloud following each of four bursts. These plaques were flown to the Laboratory for the work done. Beta-ray dose rates were determined with specially constructed beta-ray surface chambers previously calibrated with beta-ray isotopes. Using aluminum absorbers, beta-ray absorption curves were run and compared with similar absorption measurements obtained using known beta-ray isotopes. Gamma-ray dose rates were obtained by shielding out the beta-ray contribution. The response of various types of commercially available G-M counters and ion-chamber counters to fission-product beta-ray and gamma-ray was studied. Changes in beta-ray energy were studied for the period from 44.6 to 215.7 hr. It was found that the beta-ray absorption curve could be reproduced by a high-energy and low-energy component of beta radiation. Laboratory determination of effective gamma-ray energies using half-value-layer measurements by means of aluminum, copper and lead filters showed the energy to be dependent upon the absorber used.
Download or read book OPERATION GREENHOUSE Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 Volume 2 Part 2 Evaluation of Program written by and published by . This book was released on 1951 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: The biomedical program of the 1951 tests of nuclear weapons at Eniwetok is described in some detail. The purpose of the experimentation was to obtain information that could be used in planning adequate medical care for victims of atomic warfare. To accomplish this purpose experiments were designed: (a) to measure biologically the dose of gamma radiation and neutrons as functions of distance; (b) to determine the relative biological efficiency of gamma radiation; (c) to determine the median lethal dose of gamma radiation for large animals; (d) to specify the quality of the gamma ray; (e) to define the characteristics of flash burns; (f) to estimate the nature of the radiation hazard to personnel in aircraft traversing an atomic cloud; and (g) to examine the protection afforded by a foxhole. The predicted values for the field variables (nuclear radiation, thermal radiation, and blast) are discussed summarily, and the design of the experiments is described. For the benefit of those who may plan other biomedical tests, a synopsis of the procedures employed is presented with critical comments.
Download or read book OPERATION GREENHOUSE Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 Annex 1 9 Air Drop Instrumentation Part 2 Teller Alpha written by Herbert E. Grier and published by . This book was released on 1985 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: It was the purpose of the Teller-Alpha experiment to measure the coefficient alpha by means of detectors placed a long distance from the bomb. The detectors are photoelectric devices which respond to visible light produced in the air surrounding the bomb by the absorbed gamma rays, A measurement of this sort was proposed by Edward Teller prior to the Sandstone Operation. The main components of the Teller-Alpha equipment were the photohead, the 200-Mc timing oscillator, and the high-speed-sensitivity recoding oscilloscope. A complete discussion of the experiment is provided.
Download or read book Operation GREENHOUSE Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 Annex 1 3 Thermal Radiation Measurements Part 1 Atmospheric Transmission Part 2 Total Thermal Radiation Part 3 Radiant Power as a Function of Time Photoelectric Measurements Appendix A and Appendix B written by and published by . This book was released on 1985 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric transmission measurements were most important to the thermal program since they gave the information which was necessary to compute and cancel out the effects of intervening air paths on measurements of total thermal energy, radiant energy, radiant power with respect to time, and spectral emission of the bombs. The brightness temperature of each of the Operation Greenhouse firebals was measured in two wavelength regions as a function of time. The measurements were made with high-speed filtered photoelectric systems located at Parry Island. The Teller Light phenomena is also covered. The Thermal Radiation Project included specific objectives of recording the spectra of the release of visible and ultraviolet radiation by an exploding nuclear weapon in three stages: Teller Light, first maximum, and second maximum.
Download or read book Operation Greenhouse Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 written by Joseph Knopow and published by . This book was released on 1951 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: It was necessary to evaluate, as fully as possible, the developmental prototypes under conditions made possible only by an atomic bomb detonation. To carry out this evaluation program, a joint project was initiated in which a Navy P2V-2 type aircraft were, in general, identically instrumented with radiac equipment developed by both services. In general, the types of air-borne radiac equipment evaluated can be classified under the following operational functions: 1) Radioactive-cloud tracking, 2) Air-borne surface-radioactivity mapping, 3) Ground-to-air gamma-radiation-data telemetering, 4) Air-borne radiation detection and measurment. As a result of tests made on the radioactive cloud itself, the surface area within and surrounding the crater, and the air above the crater and surrounding area, the shortcomings as well as the advantages of the equipment and techniques were demonstrated.
Download or read book OPERATION GREENHOUSE Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 Annex 1 6 Blast Measurements Part 2 Free Air Peak Pressure Measurements Section 2 Telemetering from Moored Balloons written by A. J. Frolich and published by . This book was released on 1985 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this experiment was to determine the free-air peak-pressure as a function of distance from an atomic explosion. In this report, 'free-air peak-pressure' is defined as the pressure at the head of the blast wave in regions where it has not been reinforced by a reflected wave. Operation in the test area was more difficult than anticipated. Heavy winds made balloon handling very difficult. On the whole, the radio link performed satisfactorily on all occasions and appears to be a reliable method. For some unknown reason, blast switches closer than 1,500 feet failed to give satisfactory signals. Pressures were computed using the Rankine-Hugoniot relation, which is based on the shock wave being a definite discontinuity in pressure. Since the pressures measured on the ground showed relatively long times, there has been some speculation that a true shock wave may not exist in free air. If a true shock wave does not exist in the free-air region, pressures as computed are not correct, and the method of this experiment cannot be used.
Download or read book OPERATION SANDSTONE Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1948 Annex 8 Gamma Ray Measurements Parts 1 2 3 4 and 5 written by F. R. Shonka and published by . This book was released on 1985 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: Curves of absorption of gamma rays in boron carbide and a few points on the absorption curve in lead were obtained during the three atomic explosions of Operation Sandstone. Radiation was detected by integrating ionization chambers and by photographic emulsions. A few recording-type ionization chambers were used to give intensities as a function of time. Radiation detectors were located inside of shelters which protected them from blast and shielded them from scattered radiation. Because of geometry, scattered radiation was negligible and the analysis of absorption curves yields the true total absorption coefficient for the radiation.
Download or read book Operation Greenhouse Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 Annex 1 9 Air Drop Instrumentation Part 3 Disc Camera written by EDGERTON GERMESHAUSEN AND GRIER INC BOSTON MA. and published by . This book was released on 1985 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: The disc camera was designed for use to determine the growth characteristic of the fireball and so the yield. The instrument has three separate optical systems and can record three separate streak images of the fireball on a rotating glass photographic plate. The angular velocity of the photoplate at the time of exposure s determined by marker pips recorded on the photoplate. The marker generator is gated by a phototube and is turned off by a time delay. Time to minimum can be determined directly from the streaks and by the use of the scaling laws. Bhangmeter yield can also be determined. For Operation Greenhouse, two cameras were operated in phototowers. Good records were obtained on the first two shots. On the George Shot, which was a daylight test, the photocell in the fiducial marker did not function and no records were attained. The cameras were not operated on the Item Shot. The yields derived compare favorably with those from other fireball determinations.
Download or read book Operation Greenhouse Scientific Director s Report of Atomic Weapon Tests at Eniwetok 1951 written by George V. Leroy and published by . This book was released on 1951 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Glomerella, corn, and Vycor glass were used in an attempt to measure the dose of mixed nuclear radiation from an atomic bomb. Samples were placed in steel pipe stations located 300 to 800 yd from the tower on Easy Shot. Reasonable and consistent estimates of dose were obtained, but it is not possible to consider them more than approximations. Activated potassium bromide crystals and photoluminescent glass were exposed in unit-density phantoms at Easy Shot. These materials have been proposed for use as personnel dosimeters. Both were energy-dependent, but with this limitation, they were satisfactory dosimeters. (Author).
