This thesis is concerned with the design and realisation of components for a new state of the art 94GHz Electron Spin Resonance (ESR) spectrometer capable of operating in both pulsed and CW modes. The complete spectrometer is designed to provide phase coherent 1kW peak power sub-nanosecond π/2 pulses having variable duration and repetition rate. The mm-wave response of a paramagnetic sample to these pulses is detected with a superheterodyne detector. Such a system would offer a step change in performance, promising unprecedented resolution and sensitivity. These aims should be compared with the performance of commercial (Bruker) instruments capable of delivering 200mW 30ns π/2 pulses. For this type of system, both the long term (thermal) and short term (phase) stability of oscillators and sources employed are extremely important. Consideration of phase noise, frequency, tunability and power output shows that multiplied sources offer substantial benefits compared to fundamental sources. A delay line discriminator method of phase noise measurement, suitable for use with the low frequency oscillators is described and implemented. This is extended to 94GHz using a down convertor with a quasi-optically stabilised Gunn oscillator. These tools are used to select an optimum oscillator-multiplier combination to produce a low noise 94GHz source. Anew method of pulse generation, which has produced +23dBm peak power 250ps rectangular and 115ps Gaussian envelope phase coherent pulses, is described. These are believed to be the shortest phase coherent pulses at 94GHz available. This system will be used to provide ns pulses suitable for amplification to 1kW using a Klystron amplifier. A heterodyne detector has been constructed which employs the same oscillator/multiplier techniques identified above to produce the required local oscillator signal. It is demonstrated that by careful consideration of multiplication factors a system employing one variable and one fixed oscillator allows all the signals required in the spectrometer to maintain phase coherence. It is demonstrated that the complete demodulator responds to pulses on a ns time scale and has a noise temperature of 737K.

The performance of modern high frequency components and electronic systems are often limited by the properties of the materials from which they are made. Over the past decade, there has been an increased emphasis on the development of new, high performance dielectrics for use in high frequency systems. The development of these materials requires novel broadband characterization, instrumentation, and extraction techniques, from which models can be formulated. For this project several types of dielectric sheets were characterized at terahertz (THz) frequencies using quasi-optical (free-space) techniques. These measurement systems included a Fourier Transform Spectrometer (FTS, scalar), a Time Domain Spectrometer (TDS, vector), a Scalar Network Analyzer (SNA), and a THz Vector Network Analyzer (VNA). Using these instruments the THz spectral characteristics of dielectric samples were obtained. Polarization based anisotropy was observed in many of the materials measured using vector systems. The TDS was the most informative and flexible instrument for dielectric characterization at THz frequencies. To our knowledge, this is the first such comprehensive study to be performed. Anisotropy effects within materials that do not come into play at microwave frequencies (e.g. ~10 GHz) were found, in many cases, to increase measured losses at THz frequencies by up to an order of magnitude. The frequency dependent properties obtained during the course of this study included loss tangent, permittivity (index of refraction), and dielectric constant. The results were largely consistent between all the different systems and correlated closely to manufacturer specifications over a wide frequency range (325 GHz-1.5 THz). Anisotropic behavior was observed for some of the materials. Non-destructive evaluation and testing (NDE/NDT) techniques were used throughout. A precision test fixture was developed to accomplish these measurements. Time delay, insertion loss, and S-parameters were measured directly, from which loss tangent, index of refraction, and permittivity was extracted. The test materials were low-loss dielectric slabs ranging in thickness from 1-60 mils. The substrate sheets were PTFE, fiberglass, and epoxy-ceramic composite substrates. The other group was polyethylene plastic sheets (LDPE/HDPE/UMHW) and 3D printer Photopolymers. The results were verified by using several online THz spectral databases and compared to manufacturer data sheets. Permittivity and loss of some of the test samples varied as a function of polarization angle. 0 - 90 degrees of rotation were tested (i.e., H-V, and 45 degrees polarization). Inter-molecular scattering in the composite materials raised the loss considerably. This effect was verified. Standard, well documented, material types were selected for the project for best comparison. These techniques can also be applied to analyze newer substances such as nanodielectrics.

As part of the ExoMars space programme, the 2016 Trace Gas Orbiter mission was announced. The Martian Atmospheric Trace Molecule Occultation Spectrometer (MATMOS) was a proposed Fourier transform spectrometer and solar imager concept pair that would provide for trace gas detection and aerosol observation of the Martian atmosphere. Martian aerosols – namely CO2 crystals, water-ice crystals, and dust – have been observed during past missions; however, observations have failed to fully characterize their physical and optical properties. This thesis presents an analysis of the ability of the proposed imager to determine the pointing of the spacecraft independent of the spectrometer. Furthermore, proof of concept is presenting showing the ability to, in laboratory conditions, characterize the precision and stability of the imager. Finally, window regions in the transmittance spectrum of the Martian atmosphere are determined simulating the Martian atmosphere and viewing geometry.

Cyanobacterial toxins present a real and growing threat to humans and animals due to the projected increases in algal blooms resulting from increasing global temperature and pollution. Wild animals, livestock, pet animals and humans can be poisoned from contaminated drinking water. With the discovery of cyanobacterial toxins present in nutritional supplements, a new concern looms over consumers with threats of neurotoxin and hepatotoxin related damage from exposure to these products. To this end, work on the development of a freeze dried algal reference material was pursued for future use in environmental and nutritional supplement analysis. The first stage of the project was to prepare needed calibration standards, starting with homoanatoxin a, a homologue of the highly neurotoxic anatoxin-a compound. The resulting reference material (RM-hATX) had a homoanatoxin-a concentration of 20.2 ± 0.7 ?M, and proved to be stable while stored at temperatures of 80°C. Reference samples for dihydro and epoxy analogues of anatoxin-a and homoanatoxin-a were then prepared by semi-synthesis. The second stage of the project was the development of new analytical methods for the anatoxins. A derivatization reaction in which dansyl chloride was coupled with a novel cleanup step produced anatoxin derivatives suitable for liquid chromatography (LC) with mass spectrometry (MS) or fluorescence detection (FLD). Limits of quantitation were 60 ng L-1 and 1.6 ?g L-1 for the developed LC-MS/MS and LC-FLD methods, respectively, with the limit of quantitation significantly better than that of a previously developed method for the underivatized toxins based on HILIC MS/MS. Quantitative results for anatoxins in various algal samples using all three methods of analysis of were compared and it was found that there were no significant differences between the three methods. Unfortunately, experiments showed that the various toxin analogues did not elicit equimolar responses in either LC-MS/MS or LC FLD, thus indicating the importance of having individual calibration standards for quantitative analysis. The LC-MS/MS and LC-FLD methods were paired with a previously developed method for the analysis of hepatotoxic microcystins to screen a small number of nutritional supplement samples for cyanobacterial toxins. Microcystins were detected in all five Aphanizomenon flos-aquae samples examined. This method involved a fifteen-fold pre-concentration using a solid phase extraction cartridge, which gave a 98% recovery of microcystins. The third phase of the project was the preparation and testing of a preliminary algal matrix reference material as a feasibility study for the eventual production of a CRM. After selecting various algal cultures and samples that could be blended together, a freeze dried algal reference material was prepared and packaged. This material (RM-BGA) was then characterized using several methods including the two new dansylation-based procedures.

The Alpha Particle X-ray Spectrometer (APXS) on the Mars Exploration Rovers possesses the ability to detect carbon and oxygen within martian samples via Rutherford backscattering principles. Several consecutive measurements of the martian atmosphere by Spirit, paralleled by Monte Carlo simulations, provided an energy calibration to mitigate the absence of an alpha-mode calibration pre-flight. Data from a pre-flight thermal acceptance test agreed with this energy calibration, confirming the presence of an unexpected offset. Correcting a bug in the APXS firmware resulted in a temperature-independent energy scale. A model was developed and applied to all atmospheric data illustrating a dip in atmospheric peak areas, potentially arising from a week-long weather event on Mars. An early expansion of this model to solid samples has not yet been able to detect any hydrated minerals or carbonates. Preliminary investigations into determining martian atmospheric pressure and potential elemental layering within samples shows promise.

In this work we report on two sets of measurements involving the Hall-B photon tagging system of the Tomas Jefferson National Accelerator Facility. The relative energy calibration of the tagging counters was performed by using the PrimEx pair spectrometer and a series of high position resolution micro-strip detectors. The photon energies were determined by forming coincidence between the tagger and the e+ e- pairs for several values of the pair spectrometer magnetic field between 0.36T to 1.9T (total of 180 fields). The second set of measurements, collected in conjunction with the Fall 2004 PrimEx run, investigated inherent limitations on the photon tagging technique. We report for the first time an experimental signature for these effects.

In this thesis, the current vs. magnetic field relationships for four magnets, M1, M2, M3, and Hyperon of FNAL Experiment E781 (the charm baryon study) havel,een studied on the basis of algorithms involving sign corrections pertaining to remedying incorrect FNAL EPICURE readout system's current and magnetic field values for E78 I's 4 magnets.After analyzing previous BSU personnel's work involving re-averaging of the current and magnetic field output values for E78 1, further research was carried out in this thesis activity regarding the correction of the algebraic signs of certain current and magnetic field values in the FNAL EPICURE read out values inputted into E781' data bank.Firstly, a code was developed to merge the four files of current and magnetic fields for the four magnets of E78 1, all into one file. Then, an algorithm for a sign correction program was developed in order to both sort the merged data and correct the current and magnetic field signautomatically.In order to obtain a better understanding of the effect of the incorrect sign for a magnet's current and magnetic field on analysis results, a statistical result was summarized. Finally, some conclusions were obtained. / Department of Physics and Astronomy

名古屋大学年代測定総合研究センターシンポジウム報告

This thesis is based on experimental results from measurements on methyl halides at a photon energy corresponding to the He IIβ emission line. Double ionization processes involving the valence electrons of the molecules CH3F, CH3Cl and CH3I are studied by means of a magnetic bottle TOF-PEPECO spectrometer. Resulting double ionization data of these molecules suggest that mainly direct double photoionization is observed as a continuous energy sharing between the ejected electron pairs. As a mean to further understand the double ionization processes, a "rule of thumb", for double ionization in molecules, is applied to the data presented in the double ionization spectra. This is done in order to quantify the effective distance between the two vacancies created in the dications. It is found that the distance between the vacancies may be related to the bond distance between the carbon and halogen atoms. Further investigations call for quantum chemical calculations to scrutinize this hypothesis. / Det här examensarbetet är baserat på experimentella fotojonisations studier av metyl halider vid en fotonenergi motsvarande He IIβ emissionslinjen. Valenselektronerna i dubbeljonisations processerna för CH3F, CH3Cl och CH3I har studerats under användning av en så-kallad magnetisk flask TOF-PEPECO spektrometer. Resultaten av dessa mätningar visar att mestadels direkt dubbeljonisation processer före- kommer, där elektronerna delar kontinuerligt på energin som friges vid jonisationen. Den dubbla jonisa- tions processen är ytterligare studerad genom att tillämpa en tumregel för dubbeljonisation i molekyler, vilket ger en indikation av hur stort avståndet är mellan de två vakanserna som skapades när molekylerna joniserade. Resultaten från tumregeln visar att avståndet mellan vakanserna kan vara relaterade till bind- ningsavståndet mellan kol-atomen och halogen-atomen, i respektive metyl halogen. För att ytterligare bekräfta dubbeljonisations processerna i dessa molekyler, krävs kvantmekaniska beräkningar.

My research on the new concepts for spectrometer has been focused on the development of true multi-dimensional spectrometers, which use a multi-dimensional [two-dimensional (2D) or 3D] mapping of the spectral information into space. I showed that by combining a simple dispersive element (a volume hologram) formed in very inexpensive polymers with a basic Fabry-Perot interferometer, we can form a spectrometer with ultra-high resolution over a large spectral bandwidth, which surpasses all conventional spectrometers. I strongly believe that the extension of this mapping into three dimensions by using synthetic nanophotonic structures with engineered dispersion can further improve the performance and reduce the overall spectrometer size into the micron regime. The need for efficient modeling and simulation tools comes from the sophisticated nature of the new 3D nanophotonic structures, which makes their simple analysis using well-known simple formulas for the propagation of the electromagnetic fields in bulk materials impossible. In my Ph.D. research, I developed new approximate modeling tools for both the modeling of incoherent sources in nanophotonics, and for the propagation of such optical beams inside the 3D nanophotonic structures of interest with several orders of magnitude improvement in the simulation speed for practical size devices without sacrificing accuracy. To enable new dispersive properties using a single nanophotonic structure, I have focused in my Ph.D. research into polymer-based 3D photonic crystals, which can be engineered using their geometrical features to demonstrate unique dispersive properties in three dimensions that cannot be matched by any bulk material even with orders of magnitude larger sizes. I have demonstrated the possibilities of using a very compact structure for wavelength demultiplexing and also for spectroscopy without adding any other device.