Abstract: An accelerator mass spectrometry system for measuring an isotopic ratio of a chemical element in a sample. The system includes an ion source generating a beam of negative ions of the chemical element containing ions of first and second isotopes of the chemical element, a first analyzer section, comprising a first mass analyzer; a tandem accelerator comprising a first accelerating section, a charge stripping section for converting the negative ions into positive ions, and a second accelerating section behind the charge stripping section. A second analyzer section includes a second mass analyzer and an electrostatic analyzer; a particle detector; and a controller system configured to control the first mass analyzer section and the second analyzer section such that the ions of the first and second isotopes traverse the tandem accelerator and ions of only one of the first and second isotopes enter the particle detector.

Abstract: An accelerator mass spectrometry system for measuring an isotopic ratio of a chemical element in a sample. The system includes an ion source generating a beam of negative ions of the chemical element containing ions of first and second isotopes of the chemical element, a first analyzer section, comprising a first mass analyzer; a tandem accelerator comprising a first accelerating section, a charge stripping section for converting the negative ions into positive ions, and a second accelerating section behind the charge stripping section. A second analyzer section includes a second mass analyzer and an electrostatic analyzer; a particle detector; and a controller system configured to control the first mass analyzer section and the second analyzer section such that the ions of the first and second isotopes traverse the tandem accelerator and ions of only one of the first and second isotopes enter the particle detector.

Abstract: A single-ended DC linear accelerator for the generation of high-current, high-energy ion beams of H, D or He includes an ion source located in a high-voltage terminal for the creation of the ion beam, an analyzing magnet to purify the ion beam, an accelerating tube and DC high-voltage power supply for accelerating the ions of interest to high energies and a separate pumping tube that transports the vast majority of the neutral gas from the ion source at high-voltage towards a vacuum pump at ground potential, thereby preventing the adverse influence of increased vacuum pressure inside the accelerating tube to facilitate stable acceleration of high-current beams to high energies in single-ended DC linear accelerators. The resulting high-current accelerator for H, D or He has diverse applications, including ion beam cancer therapy, cyclotron injection, silicon cleaving, ion implantation in semiconductor devices and NRA.

Abstract: Pulsed MeV ion beam techniques are broadly applied in time-of-flight experiments for direct measurements of neutron velocities and energies. They are also used to achieve a neutron monochromater by allowing the selection of neutrons having a well defined velocity. The sequence of components needed for creation of sub-nanosecond pulsed MeV ion beam systems usually consist of a suitable DC ion source, a chopper module for production of beam pulses, a klystron buncher for introducing time compression to individual pulses and a final ion-acceleration stage. It is pointed out that the achievable pulse compression is limited by the energy spread within the pulses that are directed into the klystron buncher. Furthermore, that this energy spread may be dominated by the energy spread created within the preceding chopper system.

Abstract: A DC high voltage generator includes an AC power supply, an AC-DC rectifier and means to stabilize the DC high voltage generator against load variations. The stabilizer means uses at least two electro-magnetically coupled resonant circuits, which compensate the load variations at an operating frequency in such a way that the output voltage is essentially constant.

Abstract: The disclosure relates to a particle accelerator which comprises two accelerating tubes as well as a charge-exchange channel, whereby the vacuum pump for evacuating from said charge-exchange channel gas particles injected therein is not connected to the high-voltage side but, via a vacuum tube, to the low-voltage side of the particle accelerator. This means a substantial simplification of the maintenance of the vacuum pump. In addition to that a motor and a generator are no longer required. By providing the vacuum pump with equipotential plates, which comprise pump holes arranged eccentrically round the center of the vacuum tube, the gas particles are in this configuration are accelerated while retaining the high breakdown strength.

Abstract: A particle accelerator includes one or more accelerating tubes (1) which accelerating tube (1) includes spatially separated electrodes (2), each electrode (2) surrounded by a corona ring (4). The electrode (2) includes at least one spark gap (6) having a connection for connecting one side of a resistor (7).

Abstract: Accelerator mass spectrometry (AMS) demonstrates more than a million times greater sensitivity for .sup.14 C atoms and a thousand times greater sensitivity for tritium atoms than is possible using classical beta particle detection. This improved sensitivity can be used to help understand the role that chemical pollutants at ambient concentrations play in metabolic processes and in initiating mutations. Such measurements are critical to understanding many biomedical processes and establishing relevant environmental regulations. The present invention comprehends a device that can be used for the direct detection of either carbon-14 or tritium atoms. Unique features are that the highest acceleration voltage needed is only about 200 kilovolts and that vacuum insulation can be used to provide the necessary electrical insulation, rather than the high pressure sulfur hexafluoride gas, that is a characteristic of most electrostatic accelerators.

Abstract: This invention relates to the detection of the radioisiotope carbon-14 using Accelerator Mass Spectrometry (AMS). This invention has particular relevance to the fields of attomole level (10.sup.-18 molar) tracking of chemicals in biomedicine and the environment, the testing of new classes of medical drugs, the whereabouts of chemotherapy agents within cancer patients, the elimination of the need to store and dispose of low-level carbon-14 nuclear waste and neutron exposure monitoring around nuclear reactors.

Abstract: Samples are directed into a liquid or gas chromatograph, and the output from the liquid or gas chromatograph is directed into the ion source of an accelerator mass spectrometry system so as to provide an ultra-sensitive identifier of molecules in the samples.

Abstract: Compact and economical apparatus for use in accelerator mass spectrometry for mass selection and attenuation of each isotope by a predetermined fraction that is necessary to permit isotope sequencing through the accelerator stage, by a rotating shutter whose attenuation characteristics are defined by its mechanical shape.

Abstract: A compact ion beam injection apparatus for tandem accelerators wherein the outputs from two independent ion sources, that may be operated continuously, can be selectively chosen and mass analyzed so that the output from any one of the sources can be rapidly selected and efficiently directed to the input point of a tandem accelerator.

Abstract: An injection system for a tandem accelerator with equal transmission efficiency over a broad energy range includes means for shielding the injected ion beam from the electric field within the grounded end of the low-energy acceleration tube and injecting the ion beam into the low-energy acceleration tube sequentially through a narrow acceleration gap and the shielded region.

Abstract: The capability of an existing AMS system is expanded to provide capability for identification of .sup.36 Cl atoms to the exclusion of .sup.36 S atoms by adding to such a system a booster accelerator having an ionization detector in its high-voltage terminal capable of measuring dE/dx as a function of penetration depth. The voltage of the direct-voltage accelerators employed need not exceed voltages of the order of 3 million volts, even though the ions detected have energies in excess of 36 million electron volts.

Abstract: Backgrounds of AMS measurements are reduced by eliminating unwanted charged particles which undergo charge change during the acceleration process. This reduction is accomplished by a configuration of inclined electric fields throughout the acceleration region.

Abstract: Apparatus for the exchange of emission sources of a particle accelerator located in an accelerator vessel filled with a gaseous insulating medium, comprising a gastight source-exchange chamber (3) which is connected by means of a line (26) that can be closed by an exchange valve (8) to the accelerator vessel (17), the said chamber (3) being provided on the inside with a movable exchange member (4 and 5, respectively) having at least one hole (41 and 51, respectively) and at least two holders (43, 44 and 53, 54, respectively) for the emission sources (6a, 6b) to be exchanged, one or more lead-through rods (1) for the transfer of an emission source from the accelerator vessel (17) to the exchange chamber (3) or from the exchange chamber (3) to the accelerator vessel (17), as well as means for placing the movable exchange member (4 and 5, respectively) in the desired position relative to the exchange valve (8).