This master's thesis presents the development of a collision handling function for Motoman industrial robots and investigates further use of the developed software. When a collision occurs the arm is to be retracted to a safe home location and the job is to be restarted to resume the production. The retraction can be done manually, which demands that the operator has to have good knowledge in robot handling and it might be a time consuming task. To minimise the time for restarting the job after a collision and allowing employees that have limited knowledge in robot handling to retract and restart the job, Motoman provides an automatical retraction function. However, the retraction function may cause further collisions when used and therefor a new function for retracting the arm is needed. The new function is based on that the motion of the robot is recorded by sampling the servo values, which are then stored in a buffer. A job file is automatically created and loaded into the control system, and the position variables of the job file are updated using the contents of the buffer. This will ensure a safe retraction of the arm as long as the environment surrounding the robot remains the same. The developed software made it possible to control the robot in real-time by changing the buffer information, which has lead to a cognitive system called the Pathfinder. By initiating the Pathfinder function with at least a start and an end point, the function generates a collision free path between the start point and the end point. A pilot-study has also been made concerning integration of a vision system with the Pathfinder to increase the decision handling for the function.

No description available.

Under the title 'Angle Resolved Photoelectron Spectroscopy Study of Small Molecules', the thesis discussed the following aspects: Processes after the interaction of photons with atoms or molecules, including photoscattering, photoexcitation and fluorescence, photoabsorption, photodissociation and photoionization; Concepts of photoionization and photoelectron spectroscopy, including ionization potentials, photoionization cross sections, photoelectron angular distributions, shape resonances and autoionization; Theory of photoionization and photoelectron angular distributions, including central field approximation, Hartree-Fock calculations and multichannnel quantum defect theory; Apparatus for an angle resolved high resolution photoelectron experiment, including the synchrotron radiation source at Daresbury Laboratory, UK and an angle resolved electron spectrometer system from NIST/ANL, USA; The experiment on <i>CO</i>₂ at Daresbury Laboratory, including electron spectrometer calibrations, experimental procedures and data processing; Results and discussion, including results for the photoionization cross sections of the <i>CO</i>^+₂<i>X</i>^{2 Π_h} state, vibrational branching ratios and asymmetry parameters for the synmmetric stretch vibrations (000) to (500) in the <i>CO</i>^+₂<i>X</i>^{2 Π_h} state in the photon wavelength region of 687 - 790AA with a resolution of about 0.1AA, analysis of photoelectron spectra taken at the Tanaka-Ogawa resonances and result for the Franck-Condon factors for transitions from the autoionizing states to different vibrational levels of the molecule.

This research work focused on studying the emission spectroscopy produced from the high energy ion-molecule collision processes in mass spectrometry. The collision experiments are described and divided into 4 chapters (Chapter 3, 4, 5, 6).N2O+● is an ion of atmospheric importance. In chapter 3 the investigation of the collision between high translational energy (4-8 keV range) N2O+● ions and Helium target gas in mass spectrometry using collision induced emission (CIE) spectroscopy is described.In chapter 4, the collision-induced emission (CIE) spectra from 4-8 keV collisions between projectile He+● ions and CO2 target gas (He+●/CO2) were obtained. In Chapter 5, to probe the validity of this hypothesis, CIE experiments were carried out to observe the photon emissions from keV collisions of a selection of projectile ions with O2 target gas. By studying the resulting CIE spectra, a second potential mechanism came to light, one that involves the nearly isoenergetic O2+. A → X state transition. In chapter 6, neutral hydroxymethylene and formaldehyde were generated by charge exchange neutralization of their respective ionic counterparts and then were reionized and detected as recovery signals in neutralization-reionization mass spectrometry in the modified VG-ZAB mass spectrometer.

This thesis is concerned with the use of L-squared or square integrable functions in electron atom scattering at intermediate energies, and tests the success of various L-squared approximations in model problems of electron hydrogen atom scattering. The representation of part or all of the wave and Green's functions by a set of L-squared pseudostates, and the associated occurrence of unphysical pseudoresonances at the pseudostate thresholds is discussed. The original work of this thesis is in two parts. In the first, a model coupled channel problem is considered in which an L-squared optical potential is used to represent the effect of additional (Q space) channels on the first (P space) channel. A method of Bransden and Stelbovics used successfully for a two channel problem is extended to the case of several channels. Numerical results are presented for the cases of two and three channels and the success of the procedure is assessed. The rest of the research presented here concerns the use of the Schwinger variational method in a restricted model of electron hydrogen atom scattering in which all states are assumed to be spherically symmetric. The method is used successfully to solve coupled channel problems using L-squared pseudostates to represent the s-wave continuum. The origins of the pseudoresonances that occur in these problems are investigated and a method of removing pseudoresonances before T matrix elements are calculated is considered. The limitations and instabilities of the Schwinger method when applied to the full model problem with different representations of hydrogen states in the trial and Green’s functions are investigated, and various modifications are considered in attempts to stabilise results where necessary in these more general cases.

No description available.

This research work focused on studying the emission spectroscopy produced from the high energy ion-molecule collision processes in mass spectrometry. The collision experiments are described and divided into 4 chapters (Chapter 3, 4, 5, 6).N2O+● is an ion of atmospheric importance. In chapter 3 the investigation of the collision between high translational energy (4-8 keV range) N2O+● ions and Helium target gas in mass spectrometry using collision induced emission (CIE) spectroscopy is described.In chapter 4, the collision-induced emission (CIE) spectra from 4-8 keV collisions between projectile He+● ions and CO2 target gas (He+●/CO2) were obtained. In Chapter 5, to probe the validity of this hypothesis, CIE experiments were carried out to observe the photon emissions from keV collisions of a selection of projectile ions with O2 target gas. By studying the resulting CIE spectra, a second potential mechanism came to light, one that involves the nearly isoenergetic O2+. A → X state transition. In chapter 6, neutral hydroxymethylene and formaldehyde were generated by charge exchange neutralization of their respective ionic counterparts and then were reionized and detected as recovery signals in neutralization-reionization mass spectrometry in the modified VG-ZAB mass spectrometer.

The proposed CLIC accelerator is designed to collide electrons and positrons at a centre of mass energy of 3 TeV, and a luminosity of 5.9 x 10^(34) cm^(−2) s^(−1) at the interaction point (IP). Being a single-pass machine, luminosity must be maximised by minimising the beam spot size to the order of a few nanometres. The effects of the final focussing and the intense beam-beam effects lead to a high production cross section of beamstrahlung photons, and highly divergent outgoing beams, both spatially and in energy. Pair-production of the beamstrahlung photons leads to coherent pairs. The proposed CLIC post-collision line must transport electrons, positrons and photons from the IP to their respective dumps with minimal losses and background contribution. It is favourable to separate the particle species for diagnostic purposes, and thus the proposed post-collision line contains vertically bending magnets to separate based on charge. This process introduces dispersion to the energetically divergent beam, requiring the vertical apertures of the accelerator components to increase with distance from the IP. Particles in the low energy extreme of the beam cannot realistically pass through the components, which must therefore be protected by carbon-based absorbers. Losses in these absorbers and in the various dumps of the accelerator lead to electromagnetic showering within the material, some of which may be directed onto the IP. Optimisation of the apertures and positions of these components is presented as original research in this thesis. It is the purpose of this thesis to study the CLIC post-collision line, beam transport and the production and effects of secondary particles at the IP. Primarily, the backscattered photons are evaluated, with an introduction to the effect of neutrons. Photonsincident on silicon detectors have the potential to produce false hits, and neutrons to degrade the detectors. The effect of losses on the accelerator components is studied and the survivability of these components discussed.

No description available.

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