Frankfurt (Main), Univ., Diss., 2004. / Erscheinungsjahr an der Haupttitelstelle: 2004. Computerdatei im Fernzugriff.

Frankfurt (Main), Universiẗat, Diss., 2004. / Erscheinungsjahr an der Haupttitelstelle: 2004.

Universiẗat, Diss., 2007--Frankfurt (Main). / Zsfassung in dt. und engl. Sprache.

Universiẗat, Diss., 2001--München.

Univ., Diss., 2004--Frankfurt (Main)

Universiẗat, Diss., 2005--Frankfurt (Main).

Universiẗat, Diss., 2006--Frankfurt (Main).

Last years have become very productive for the research, construction and development of new facilities devoted to the production of beams with exotic radioisotopes (Radioactive Ion Beams, RIB). These beams are later used for experiments in fields like nuclear physics, atomic physics, astrophysics or medicine, among others. Within this kind of facilities, the ISOL facilities stand out. They are based on the on-line separation of radioactive isotopes produced in nuclear reactions between a target and a high-energy proton beam. The ISOL method was the pioneer for these facilities and it has kept up to now the leadership of RIB facilities. The main reason is ISOLDE, an ISOL facility located at CERN, the largest accelerator complex in the world, where this doctoral thesis has been carried out.The first innovation which is described is the design of an ion trap for the cooling and bunching of RIB's for ISOLDE, the so-called ISCOOL (ISOLDE COOLer). It is an Radio Frequency Quadrupole ion Cooler and Buncher (RFQCB), device based on the Paul traps. In these traps, the ions are confined in the three dimensions by electric fields. The ions are confined on the transverse plane with the pseudopotential well created by the Radio Frequency Quadrupole (RFQ) and focused on the longitudinal axis. At the same time, a gas (normally helium) fills the chamber with a pressure between 10-3 and 10-2 mbar. The collisions between the atoms or molecules of the gas and the ions. In addition, to drive the ions to the extraction of the RFQCB, an axial electric field is created by segmented electrodes. Different voltages are applied to these electrodes in order to choose the shape of the field. The shape can be chosen to create a potential well close to the extraction from the RFQCB in which the ions are accumulated and extracted as bunches, by the fast-switch of the voltages applied to the axial electrodes.The new ISCOOL will be installed as a permanent device of the ISOLDE beam lines.

University, Diss., 2004--München.

Die vorliegende Arbeit ist Teil eines Forschungsprojekts zur Entwicklung eines neuartigen Systems zur zerstörungsfreien und bildgebenden Untersuchung von Luftfracht mittels Neutronen- und Gammastrahlung. Im Rahmen dieser Arbeit wurde eine Strahlungsquelle entwickelt, die optimal auf die Anwendung angepasst ist: Ein gepulster Deuteronenstrahl wird in einer Ionenquelle erzeugt und mittels eines niederenergetischen Strahltransportsystems zum Hauptbeschleuniger geführt. Dieser besteht aus einem Radiofrequenz Quadrupol (RFQ) mit einer finalen Energie von 6 MeV. Da für die Anwendung sehr kurze Pulse der Strahlung in der Größenordnung einiger Nanosekunden unabdingbar sind, musste eine neuartige Lösung zur Pulsung des Deuteronenstrahls gefunden werden. Eine große Herausforderung bestand hierbei im Zusammenspiel der kurzen Pulsdauer und hohen Pulsladung in Kombination mit der hohen Wiederholrate. Dieses wurde erreicht, indem ein spezielles Pulsungssystem innerhalb des Strahlentransportes zwischen Ionenquelle und RFQ eingefügt wurde. Dieses System enthält neben einem strahlablenkenden auch ein strahlbündelndes Element. Der Deuteronenstrahl wird hinter dem RFQ auf ein Target geführt, welches aus Borcarbid besteht. In dieser Arbeit wird das komplette physikalische Design der Strahlungsquelle diskutiert sowie Simulationen zum Pulsungssystem bzw. dem RFQ-Beschleuniger präsentiert. Weiterhin werden Proof-of-Principle Experimente beschrieben, die mithilfe eines Prototypen-Pulsungssystems entwickelt im Rahmen dieser Arbeit und gefertigt von der RI Research Instruments GmbH an einem speziell für diesen Zweck errichteten Teststands durchgeführt wurden. Außerdem wurden mehrere Experimente sowohl an der Beschleunigeranlage der Physikalisch- Technischen Bundesanstalt (PTB) Braunschweig als auch am RFQ Beschleuniger der Nuclear Energy Corporation of South Africa (NECSA) in Pelindaba durchgeführt, um das Target zu optimieren und das erzeugte Strahlungsfeld zu charakterisieren. / This thesis is part of a research project whose goal is to develop a novel, non-destructive imaging system to be employed for air freight security. The screening will be performed employing neutron- and gamma-radiation based techniques. One of the critical issues in this project was the absence of an adequate particle source. Thus, a new type of source was developed during this work. The new source consists of four main parts: A pulsed deuteron beam is formed in an ion source (IS) and is fed, via a matching low energy beam transport system (LEBT), into the main accelerator. The latter comprises a radio frequency quadrupole (RFQ) that produces a deuteron beam with a final energy of 6 MeV. Since pulsing of this beam in the regime of several nanoseconds is mandatory for the application, a novel solution had to be found to apply the required pulsing scheme, without undershoot the required beam charge per pulse. A major challenge in doing so was the combination of pulse length, high bunch charge as well as high repetition rate. This could be achieved by adding a pulsing system in between the LEBT section and RFQ: it consists of a beam-deflection, as well as a beam-bunching element. The deuteron beam is ultimately directed to a wobbling, plasma sprayed boron carbide (B4C) target. This work focuses on an entire physical design as well as simulation work of the pulsing system and RFQ. Furthermore, proof-of-principle experiments concerning a prototype of the pulsing system developed in the framework of this thesis and manufactured by RI Research Instruments GmbH could be performed at a test bench dedicated to this project. To round up the study, the suitability of the target and target reaction was demonstrated during multiple experiments performed at Physikalisch- Technische Bundesanstalt (PTB) at Braunschweig as well as the Nuclear Energy Corporation of South Africa (NECSA) in Pelindaba.