Abstract: A method and device for taking non-invasive on-site soil carbon content and distribution measurements at the surface of the soil utilizing a neutron generator positioned on the surface of the soil to generate neutrons that penetrate the soil. The neutrons cause inelastic neutron scattering (INS) from carbon and subsequent emission of gamma rays from the first carbon excited level. The gamma rays are measured by a number of suitable on-site gamma ray detectors situated near the neutron generator. A nuclear spectroscopy system is utilized to generate an energy spectrum of the detected emitted gamma rays and a net number of gamma rays is determined by subtracting a background count from a total count at a predetermined energy level. The net count is then compared to a predetermined calibration plot to determine the weight percentage of carbon within the measured soil.

Abstract: An assembly is provided which is capable of the multiple functions that are necessary for the quality control of teleradiotherapy machines such a high energy medical accelerators, cobalt 60 machines, and low energy x-ray machines. The assembly includes a detector which is isocentrically rotatable about a pair of horizontal axes. Photodetectors or a luminescent screen are provided within the detector for detecting light and/or radiation. Tests which may be performed with the assembly include determining the position and size of a light field, the mechanical isocentricity of the gantry and of the collimator, positioning of the lasers in the treatment room, the optical distance indicator, and coincidence, symmetry, flatness and uniformity of the radiation and light fields. The multifunctionality of the assembly is based upon the isocentricity of the detector, this invariant point in space being positioned to coincide with that of the treatment machine.

Abstract: Improved methods and apparatus for in vivo measurement of the skeletal lead burden of a patient and for diagnosis of lead toxicity are disclosed. The apparatus comprises an x-ray tube emitting soft low energy x-rays from a silver anode, a polarizer for polarizing the emitted x-rays, and a detector for detecting photons fluoresced from atoms in the patient's tibia upon irradiation by the polarized x-rays. The fluoresced photons are spectrally analyzed to determine their energy distribution. Peaks indicating the presence of lead are identified if the patient has relatively high bone lead content. The data may be compared to data recorded with respect to a similar test performed on patients having also had the conventional EDTA chelation tests performed thereon in order to correlate the test results with respect to a particular patient to the conventionally accepted EDTA chelation test.

Abstract: The lithium used clinically and distributed in organs such as the brain or idney of humans and other exhaling animals is determined in-vivo by means of neutron radiation and measuring in the exhaled air elemental tritiated hydrogen released from the tritium reaction by the reaction .sup.6 Li(n,.alpha.)T. The tritium atoms so released are transformed in part in the surrounding aqueous solution to form gaseous tritiated hydrogen which has a small solubility in body tissues and liquids and thus appears quickly in the breath. After a recipient fasts and is irradiated with neutrons, the air exhaled in the breath for a given time after irradiation is captured and processed to remove water, isolate hydrogen and measure the tritiated hydrogen with a gaseous organ-methane counter.