Forschungszentrum Julich Gmbh

Kernforschungsanlage Julich Gesellschaft MIT Beschrankter Haftung

Forschungszentrum J&uuml;lich Gmbh

Other

Kernforschungsanlage Julich

Jakob Schelten

Richard Reinartz

Rainer Kurz

Ralf Engels

Ulrich Kurz

Ralf Lehmann

Andreas Scholz

Heinz Rongen

Uwe Clemens

Stefan Widdau

Karl Sobotta

Christian MÜLLER

Method for analyzing a primary neutron beam of a neutron source, a neutron source having a beam monitor, and a beam monitor. Fission chambers which are arranged in the primary neutron beam are known as beam monitors. Fission processes initiated by the neutrons produce in the fission chambers free charge carriers which, given an applied electric voltage, effect an ionization current pulse by means of which the neutron is counted. Produced as by-product during fission are undesired fast neutrons and high-energy gamma radiation. In addition, the flux of slow neutrons can be substantially attenuated by the gas filling of the fission chambers. These disadvantages can be avoided in the case of the novel method, the novel neutron source and the novel beam monitor. Neutrons are scattered incoherently out of the primary neutron beam ( ) by means of a scattering foil ( ). A portion of the scattered neutrons ( ) strike a detector device ( ) which is arranged outside the primary neutron beam ( ). The beam monitor ( ) can be constructed straight away such that the spatial distribution and, in the case of pulsed neutron sources, the spectral distribution of the neutrons in the primary neutron beam ( ) can be determined. Analysis of a primary neutron beam of a neutron source, in particular a pulsed spallation neutron source.

Method for analyzing a primary neutron beam of a neutron source, a neutron source having a beam monitor, and a beam monitor

Evaluation unit to evaluate detector events

The invention relates to a sensor for measuring a magnetic field. The inventive sensor has a high level of measuring sensitivity compared to a Hall probe, comprising several electrically semiconductive layers. The layers are arranged in the form of a power diode connected in the reverse direction, consisting of an anodelayer, a cathode layer and an intrinsically conductive layer enclosed between the two. The anode layer is subdivided by insulation sections into several anode layer areas, these areas being insulated from each other. The cathode layer has an injector area on the areas opposite the insulation sections which is oppositely doped. An electron beam is formed between the injector area and the anode by applying an injection voltage to the injector area. The electron beam is distributed across the areas of the earthed anode layer areas in the form of uniform partial currents. The electron beam is diverted by a magnetic field which forms in the intrinsically conductive layer, resulting in partial currents of different strengths on the earthed anode layer areas. The magnetic field can then be evaluated by measuring these differences in strength between the partial currents.

Sensor for measuring a magnetic field

In a neutron detector for the detection of thermal neutrons .sub.6 LiF layers are provided for the conversion of the neutrons to ionizing radiation and the .sub.6 LiF layers are surrounded by layers for detecting the ionizing radiation generated by the neutrons in the .sup.6 LiF layers.

Neutron detector

A process for determining the density distribution of positrons in human tissue in which the amount of position data stored in the computer memory from two parallel photomultiplier local position .gamma.-detectors is limited by a random-event generator connected to the computer.

Method of determining a density distribution of positrons in human tissue

A circuit arrangement for dividing an input signal A by a signal B, for eple for use in localizing radiation detection, has a dividing analog-to-digital converter receiving an addition signal A+q.times.B as well as the divisor signal B to form the quotient (A+q.times.B)/B from which a digital random value r is subtracted, where r corresponds to q. The ADC can be a Flash ADC and the resulting circuit has good differential linearity and is fast.

Divider circuit using analog-digital converter

A target rotated about an axis is subjected to large surface irradiation by ons which spread in the direction of the target from a focus and in which peripheral ions are reflected inwardly, preferably by an array of electrode elements of alternatingly opposite polarity so that the reflecting electrostatic field is located only at the periphery of the beam and immediately adjacent the interior of the ion reflector.

Method of and apparatus for irradiating large surfaces with ions

A device for the reflection of low-energy ions defines an ion guide with an array of electrode elements elongated transversely to the direction of the ion beam and in closely spaced relationship with the alternating electrode elements having the same potential but opposite polarity.

Growing community of inventors

Julich, Germany

Jakob Schelten