Gamma Rays Of Radium Research Articles

Naturally Occurring Radioactive Materials in the Soil of Near Basra Oil Company Fields

The present study aimed to determine the levels of contamination with Natural Occurring Radioactive Materials NORM in one of the south oil company fields. The external gamma absorbed dose rate Dγ measured in units of µSv/h was caused by gamma rays of Radium 222, Radium 228 (Thorium 232), and Potassium 40, respectively. The largest value is 9.220 µSv/h. It was found that the highest specific activity (concentration) for Radium 226 is 1136 Bq/kg and the lowest is 0.06 and the highest specific activity for Radium 228 is 721 Bq/kg and the lowest is 0.02 Bq/kg. As for Radium 224, its highest specific activity is 631 Bq/kg and the lowest is 0.02 Bq/kg. Radium-228 is higher than that of Radium-224 or Radium-226, as the Radium-224 is from the Uranium-232 series, and the Radium-228 and Radium-224 are from the Thorium-232 series, meaning that the percentage of the daughters of the Thorium chain is lower than the percentage of the daughters of the Thorium chain Uranium, because the half-life of Radium-226 is 1600 years, which is greater than the half-life of Radium-228, which is 5.75 years. A comparison was made between the local results with the results of soil in Amman. Methods of treating pollution with natural radioactive materials in the oil industry were also discussed.

The potential of californium-252 in radiotherapy. Preclinical measurements in physics and radiobiology.

Californium-252 is a man-made radionuclide (half-life 2-65 years) which emits a mixture of neutrons and gamma rays. It is used in radiotherapy as an alternative to radium and extends the potential benefits of neutrons to interstitial and intracavitary applications. Gamma rays account for a variable proportion of the dose (30 to 50 per cent), depending on the source filtration and the distance from the source. Dosimetry is complicated by this mixture of neutrons and gamma rays. However, measurements with paired ion-chambers, together with Monte-Carlo calculations, have produced dosimetric data that are adequate for clinical use. Many determinations of the oxygen enhancement ratio (OER) have been reported. At the low dose-rates characteristic of interstitial implants, the OER is about 1-5. This is essentially the figure for fast neutrons alone, since at very low dose-rates the contribution of the gamma rays to the biological effect is negligible. As the dose increases, there is a corresponding rise in the OER because the gamma ray contribution can no longer be ignored. The OER is likely to be about 1-8 if 252Cf is used in intracavity treatments and 2-0 if used in "acute" exposures in devices such as the Cathetron. The relative biological effectivenesss (RBE) varies with dose-rate, and with the biological system used to measure it. Radiobiological experiments indicate that 6,000 rads of radium gamma rays in seven days is equivalent to 890 rads of 252Cf neutrons delivered in approximately the same overall time. This figure was suggested some years ago as an interim guide-line until sufficient clinical experience is accumulated.

A comparison of radium and californium 252 using cultured mammalian cells. A suggested extrapolation to radiotherapy.

Chinese hamster cells were irradiated at various low-dose rates with radium gamma rays and with the mixed neutron and gamma emission from californium 252. Cell killing was unaffected by a dose-rate change from 1.14 to 21.4 rads/hour for californium. For radium there was a continuous reduction in cell-killing effect as the dose rate was reduced from 52.5 to 11.7 rads/hour. It is suggested that 890 rads of californium neutrons in a time period close to seven days is equivalent to the standard treatment of 6,000 rads of radium gamma rays in seven days.

Response of Mouse Jejunal Crypt Cells to Low Dose Rate Irradiation with Californium Neutrons or Radium Gamma-Rays

Californium-252 emits neutrons and gamma-rays and has a potential use in radiotherapy as a replacement for radium. There is no single value for the relative biological efficiency (RBE) of radiations from californium and radium. At high dose rates, the RBE for killing of mammalian cells usually varies with the degree of injury, being highest at low doses. At low dose rates, the RBE is more likely to be constant at all levels of injury but will vary with dose rate and distance from the californium. The RBE (Cf neutrons/Ra gamma rays) is ∼5 for killing of intestinal crypt cells when the dose rate from radium is 160 rads/hour. At the lower dose rates used in radium therapy (30-70 rads/hour), the RBE (for Cf neutrons only) may be greater than 5. If the total dose (neutrons + gamma rays) from californium had been used in calculating the RBE at a source distance of 2 cm, the value would have been about 3.2. However, the better way of determining radium-equivalent doses is to apply RBE values separately to the ne...

Low-dose-rate irradiation of mammalian cells with radium and californium 252. A comparison of effects on an actively proliferating cell population.

Abstract Mammalian cells were exposed to a range of low dose-rates from radium and californium 252. From the results obtained, it was possible to calculate the biological effectiveness of the mixed neutron and gamma-ray emission from 252Cf relative to radium gamma rays. It was found that this RBE increased as the dose-rate was decreased, according to the relationship RBE of 252Cf compared to radium α (californium dose-rate)−0.47. This factor, together with the already high RBE of neutrons, calls for extreme caution in the handling and clinical use of 252Cf.

Leak testing chromatographic radium sources--radon emanation technique.

LEAK TESTING CHROMATOGRAPHIC RADIUM SOURCES—RADON EMANATION TECHNIQUESAMUEL E. CROWDER, B.S.Audio Available | Share

Compton Effect: Historical Background

A review of the chain of experiments whose results were finally explained by Compton's discovery of the Compton effect shows that these experiments were not solely in the field of x rays. The studies of the scattering of high-energy gamma rays of radium had presented physicists with the puzzle that scattered gamma rays were distinctly less penetrating than were those that had not been scattered, and that the amount of this “softening” of the scattered gamma rays was dependent on both the initial “hardness” of the gamma rays and on the scattering angle. Many of the experimental facts of the Compton effect were well known from the studies of scattering of gamma rays some years before the effects were observed with x rays. Compton's interest in the problem was apparently greatly stimulated by his own experiments on the scattering of gamma rays. However, since the first detailed and convincing experimental verification of several of the consequences of Compton's hypothesis came from experiments with x rays, one may not be aware of the important role played by gamma-ray experiments in the steps leading to the discovery.

Occupational dermatoses among farmers.

Occupational dermatoses seen among farmers include fungous, viral and bacterial infections and infestations; dermatitis, including eczema; and tumors.Milker's eczema and ragweed and poison ivy dermatitis are probably the most common forms of contact dermatitis occurring in farmers. Sensitization also results from use of fertilizers, soaps, detergents, insecticides, weed killers, preparations used to treat skin infections in animals, and other materials used on the farm.Basal-cell epithelioma and squamous-cell carcinoma also may be classified as occupational diseases of farmers. The author recommends gentle but thorough curettage of such tumors, supplemented by irradiation with the gamma rays of radium.

The Relative Biological Efficiency of 8 MV X rays and Radium Gamma Rays, with Reference to Buccal Mucosa

The relative effectiveness of X radiation generated at 8 million volts and γ radiation from radium is compared in patients having treatment for cancer of the anterior part of the mouth. The onset of the mucosal reaction has been used as the indicator of biological effect. Comparison of the doses received on the mucosa on the day of onset of the reaction suggests that the RBE of 8 MV X radiation as compared with γ rays is slightly less than unity. Factors which may affect the reaction other than the energy of the radiation are discussed.

Radiogold in the treatment of cancer of the cervix.

The main objective in the use of radioactive colloidal gold for the treatment of cancer of the cervix is safe, adequate, and convenient irradiation of the pelvic lymph nodes. This is in no way different from the motive behind the use of conventional x-rays, supervoltage x-rays, or the gamma rays of radium or cobalt. The treatment of the primary lesion is no problem. Supplemental therapy is necessary, however, because some patients undoubtedly have cancer in the pelvic lymph nodes which would not be destroyed by direct irradiation of the cervix or by hysterectomy. Radiogold is only an agent for providing supplemental therapy. The properties of radiogold are nearly ideal for this purpose. The short half-life of 2.8 days limits the duration of irradiation. The radioactivity is primarily beta, so that the majority of the effect is restricted to the immediate vicinity of the interstitial injection. Radiogold, however, is especially valuable because of the manner in which the tissues absorb and “fix” the gold. ...

Antibody production in mice exposed intermittently to radium gamma rays.

SummaryExposure of groups of mice to a radium source providing 8.8 r or 2.2 r per 8 hour day for 51 days resulted in significantly lowered antibody titers. In these experiments the mice were immunized on the third day after the end of the radiation exposure and the serums were sampled on the 5th day after immunization. Antibody titers and leucocyte counts following a single exposure of the mice to an acute X-ray dose 4 days after the end of an intermittent exposure to 450 r of radium gamma rays provided no evidence that the prior exposure produced an altered radiation sensitivity to either the hematopoietic process or the process of hemolysin production. The possibility that antibody synthesis in response to sheep erythrocyte antigen and leucocyte production are independent processes during the recovery from irradiation is discussed.

A contribution to the establishment of the level scheme of radium C′

The gamma-rays of radium C′ and beta-rays of radium C have been studied by scintillator techniques. A decay scheme is proposed which is based on internal conversion coefficients, angular correlations between cascade gamma-rays, and transition probabilities derived from the alpha-particle fine structure. There is some evidence that collective effects occur in this nucleus.

THE RELATIVE biological efficiency of 4 MeV and 300 kV radiations. I. Introduction.

I. IntroductionPublished Online:28 Jan 2014https://doi.org/10.1259/0007-1285-30-355-337SectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail AboutAbstractThis report is concerned with a series of studies carried out on the 4 MeV linear accelerator to assess the biological (or chemical) effectiveness of radiations from this source in comparison with radiations from sources used in conventional “deep” therapy. It includes analysis of the physical aspects of the problem, a chemical study, several radiobiological studies, a short clinical report and a commentary.* Next article FiguresReferencesRelatedDetailsCited byAn Evaluation of Elective Irradiation of Neck Nodes in Patients with Cancer of the Supraglottic Larynx17 April 2018 | Tumori Journal, Vol. 67, No. 2The R.B.E. of 60 Co Gamma Rays with Respect to 300 kVp X-rays for the Survival of HeLa S-3 and CHO Cells, Irradiated in Different States of Proliferation3 July 2009 | International Journal of Radiation Biology and Related Studies in Physics, Chemistry and Medicine, Vol. 26, No. 4Oral cavity cancerThe effect of dose-rate and anoxia on the radiation-induced loss of macromolecules into the intestineShirley Hornsey and M. J. Hedges28 January 2014 | The British Journal of Radiology, Vol. 42, No. 496Book reviews Solitary Metastases. By RubinP. and GreenJ., pp. xv + 251, (illus.), 1968 (Illinois, Charles C. Thomas), $14.75.T. J. Deeley28 January 2014 | The British Journal of Radiology, Vol. 42, No. 496Book reviews Late Somatic Effects of Ionizing Radiation. By van CleaveC. D., pp. vii + 310, (illus.), 1968 (Springfield, National Bureau of Standards), $3.00.E. A. Wright28 January 2014 | The British Journal of Radiology, Vol. 42, No. 496Possibilities for the cure of Hodgkin's diseaseCancer, Vol. 19, No. 3Einfluß der Strahlenqualität auf die StrahlenwirkungIV. Comparisons of the Effects of X Rays and Cyclotron Neutrons on Mouse Ascites Tumours, Mouse Testis and Chick EmbryosS. Hornsey and G. Silini28 January 2014 | The British Journal of Radiology, Vol. 36, No. 422CorrespondenceD. Greene, J. B. Massey and W. J. Meredith28 January 2014 | The British Journal of Radiology, Vol. 35, No. 418The Relative Biological Efficiency of 8 MV X rays and Radium Gamma Rays, with Reference to Buccal MucosaRobert Morrison, Thomas J. Deeley and David K. Bewley28 January 2014 | The British Journal of Radiology, Vol. 34, No. 401The Relative Biological Efficiency of X Rays Generated at 220 kVp and Gamma Radiation from a Cobalt 60 Therapy UnitE. J. Hall28 January 2014 | The British Journal of Radiology, Vol. 34, No. 401 Volume 30, Issue 355July 1957Pages: 337-392 © The British Institute of Radiology History Published onlineJanuary 28,2014 Metrics Download PDF

Absorption in different tissues of cobalt 60 gamma radiation and roentgen rays with half-value layers from 1 mm. Al to 5 mm. Cu.

Various investigators have measured or calculated the absorption of x-rays and gamma rays in different kinds of tissue. In 1921, Failla (1) published half-value layers and coefficients of absorption of radium gamma rays for absorbers of different fresh tissues. Although his method of measurement differs from ours, the values are in good agreement, as shown in Table I. Quimby (2) measured the h.v.l. in air and at a depth of 10 cm. in tissue and in paraffin to determine the change in quality of the beam as it traversed material. With her associates (3), she measured also the depth doses in a cadaver for 200 kv, 700 kv, and gamma radiation and compared them with those obtained in a water phantom. It was found that the differences were not important except for the intraoral and thoracic regions, for which correction curves were given. Weatherwax (4), in 1930, measured the transmission of roentgen rays from a 200kv generator through an excised human lung which was connected to an air-pressure system and submerged in a water phantom of 20 cm. depth. The upper surface of the lung was 2 cm. from the surface of the water. Measurements were made directly under the lung when it was 3 cm. thick in the collapsed state, and when inflated to a thickness of 6 cm., 9 cm., and 13 cm. The ratio of the measurement at a depth of 15 cm. between the lung in the collapsed state and the lung inflated to 9 cm. was 1:1.8. The dose at a depth of 15 cm. was thus increased by 80 per cent, when x-rays passed through the lung rather than through water. Nahon (5, 6), using roentgen rays with a h.v.l. of 1.5 mm. Cu, found that the transmission through fresh calf's lung paralleled transmission through a plywood phantom with a density of 0.5 gm./c.c. At depths of 5, 10, and 15 cm. the dose was 25, 55, and 70 per cent higher, respectively, than the dose in a Presdwood phantom. Ordinary depth dose data, therefore, must be qualified before they can be used for dosage work on lung tumors. Kornelsen (7) estimated the tumor dose in the chest from a measurement of the exit dose and found the result to be in satisfactory agreement with measurements in a phantom with “lung” material having a specific gravity of 0.46. He used radiation of 1.3 mm. Cu h.v.l. Depth-dose and back-scatter measurements for soft roentgen rays were made in beef muscle by Trout and Gager (8). The dose for roentgen radiation of different wave lengths at an interface between bone and soft tissue and in tissue-filled cavities in the haversian canals of bone was calculated by Spiers (9–11), Wilson (13), and Meredith (14). Spiers (12) made absorption measurements on freshly excised human bones, using a wave-length region between 0.42 Å and 0.48 Å. Uniform layers of bone powder in Perspex cells and flat sections of bone were measured.

Training of residents in radioisotope techniques.

The production and availability of radioactive isotopes have presented to the medical profession many valuable agents for use in the fields of medical diagnosis, therapy, and research; however, the basic knowledge and disciplines necessary for the proper use of these substances are not familiar to the average physician. Since radioactive isotopes are potentially dangerous both to the patient and to all engaged in their preparation and administration, the problem of providing the basic knowledge, training, and experience for their safe use has been of grave concern to those charged with the responsibility of distributing the radioisotopes for medical use. Several radioisotopes are being used essentially as substitutes for x-rays and radium. Radioactive cobalt (Co 60 ) teletherapy, radioactive strontium (Sr 90 ) beta applicators, and radiogold (Au 198 ) wire are examples of these uses. The manner of use of these isotopes is similar to that of beta and gamma rays of radium

Time-intensity factor in the production of dicentric bridges with gamma rays of radium during meiosis in the grasshopper, Gesonula punctifrons.

Time-intensity factor in the production of dicentric bridges with gamma rays of radium during meiosis in the grasshopper, Gesonula punctifrons.

Observations on the ionization produced by radium gamma rays in air-walled ionization chambers at low gas pressures.

In 1940 Sievert published curves of the measured variation of γ-ray ionization with air pressure obtained with spherical elektron metal condenser chambers with smaller inter-electrode distances (0·25–0·50 mm). These showed that as the pressure was reduced, the ionization per cm of mercury, measured at atmospheric pressure, increased very rapidly instead of remaining constant at 100 per cent as it should according to the Bragg-Gray theory of cavity ionization. A calculated curve obtained by Sievert (1940) showed that ionization by collision did not entirely account for his observations. In Fig. 1 Sievert's curves have been replotted to show the relation between observed current and pressure of air, the current per cm of mercury measured at atmospheric pressure being taken as 100. The curves are straight lines which we have extrapolated back to zero pressure. In effect, some current is still present at zero pressure when theory indicates zero current, and this for very low chamber potentials. Sievert's calc...

The Status of X-Ray Standards in the United Kingdom

Recent intercomparisons between the medium voltage X-ray standards of N.P.L. and of Sweden and USA (National Bureau of Standards) are described. The results confirm the work of Kemp and indicate that the original N.P.L. and N.B.S. standard free-air chambers have inadequate dimensions for the measurement of X-rays excited above 100 kV. In the case of the N.P.L. chamber the error has been about 0.4 per cent at 100 kV and 3 per cent at 200 kV. After allowing for the errors revealed by these intercomparisons, the calibration of secondary by the three laboratories concerned was found to be in agreement to about 1 per cent.Details are given of the installation at N.P.L. of a 2 MV Van de Graaff X-ray generator and of the dose measuring equipment constructed for use with this machine. Comparisons of the calibration of Victoreen chambers when exposed to X-rays generated at 1 to 2 MV or to radium gamma rays at N.P.L. and to 60Co gamma rays at N.B.S. indicate agreement to 1 per cent provided the conditions of stem i...

BETATRON IRRADIATION OF AQUEOUS FERROUS SULPHATE SOLUTIONS

The oxidation of aerated aqueous solutions of ferrousammonium sulphate has been studied using radium gamma rays and X rays of 24.5 Mev. peak energy from a betatron. The behavior at high photon energies has been shown to be closely similar to that at lower photon energies.

Beta- and Gamma-Induced Čerenkov Radiation in Water*

The spectral energy distribution of radiation from water bombarded by radium gamma-rays or P32 beta-rays is that expected for Cerenkov radiation. A solution of P32 in water furnishes a source of Cerenkov radiation which is convenient for the determination of the spectral sensitivity of photographic emulsions.