The first measurements of the radioactive 135Cs and 134Cs isotopes were made on an accelerator mass spectrometer. The natural Ba interference was suppressed using an isobar separator for anions (ISA) in order to measure the less abundant isobaric 134Cs and 135Cs isotopes. It was found that the Ba interference could be suppressed by a factor of 2 × 10^5 while 25% of Cs was transmitted. Furthermore, through comparing the known natural abundance of Ba isotopes to the measured concentration in a sample it was shown that the ISA does not introduce significant mass dependant fractionation at the level of 0.8%. A slow sequential injection analysis technique was developed to measure 135Cs using 134Cs as a reference isotope. This technique also permitted the monitoring of Ba interference. The ionization efficiency of Cs when analyzed in the molecular anion form, CsF2^- , was on the order of 10^−7 while the total measurement efficiency was 1.7×10^−9. The abundance sensitivity of this system was found to be 135Cs/ 133Cs = (1.3 ± 1.7) × 10^−10 , corresponding to a 3σ detection limit of 132.5 pg of analyte per target. Lastly, using the developed AMS techniques, beta spectroscopy, gamma spectroscopy, and isotope production, a measurement of the half life of 135Cs was made. The two measurements of the half life of 135Cs were 0.72 ± 0.32 Ma and 0.99 ± 0.42 Ma.

Kolliderare är en typ av partikelaccelerator som används till att kollidera subatomiska partiklar och är viktiga för utförandet av experiment i partikel- och kärnfysik. Laddade partiklar accelereras och hålls i separata omloppsbanor med dipol- och kvadrupolmagneter, och deras banor korsar varandra minst en gång. De laddade partiklar som åker i en omloppsbana kan generaliseras till en laddad partikelstråle. Dessa strålar propagerar åt motsatta håll, och när dessa kolliderar rakt in i varandra, är laddningarna så tätt fördelade att dess elektriska fält påverkar partiklarna i den motgående strålen. Denna så kallade beam-beam effekt begränsar prestandan på kolliderare, och det är därför av intresse att kunna beskriva denna effekt med en såprecis modell som möjligt. I denna rapport testas en modell av beam-beam effekten som baserar sig på en modell som beskrevs av M. A. Furman, K. Y. Ng och A. W. Chao i rapporten "A Symplectic Model of Coherent Beam-Beam Quadrupole Modes"från 1988, men med en ändring på hur de elektriska fälten påverkar de laddade partiklarna. Denna modell testas därefter mot Furmans modell, och den nya modellen utvärderas. Den nya modellen ger stabilare strålningsspridningar under inverkan av beam-beam effekten jämfört med Furmans modell.

Non-linear errors in the magnetic field of the Large Hadron Collider (LHC) at CERN often lead to undesirable resonances and instabilities in the particle motion, which can negatively affect the operations of the accelerator. This project focuses on developing a new correction scheme with a response matrix approach to optimize the values of the skew sextupolar correctors of the LHC at injection, in order to mitigate the impact of resonance driving terms (RDTs). So far, no correction has been introduced to actively compensate these RDTs. In particular, we investigate the RDTs related to the 3Qy resonance, which has been proposed to be connected to emittance growth in the LHC, leading to a loss of luminosity in the detectors. Starting from a basic linear model of the LHC, we gradually introduce more complex errors and demonstrate that this correction scheme is more effective than the standard correction. The correction scheme also proves to be effective for more advanced non-linear models, also considering alignment errors.

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In many optics applications we need lenses with dynamically tunable focal lengths. One design of such a lensis developed in and it relies on the magneto-optical eect. In this design, a graphene layer is placed ina magnetic eld that varies quadratically in space. During this project I have built an experimental set-upthat can be used to make magneto-optical measurements. The graphene sample is placed in an evacuatedcryostat and it needs to be cooled to low temperatures using liquid nitrogen. The magnetic eld neededfor the measurements is generated by a permanent magnet system placed outside the cryostat. This reportpresents the theory behind the optical magnetic lens, a description of the cryostat and of the steps I tookto design and build the cooling system and the magnet system. Finally, temperature and magnetic eldmeasurements are presented and compared with the values obtained from COMSOL simulations.

In this work, we have studied the photochromic response of several oxygen containing rare-earth hydride thin films (REHO, RE = Y, Nd, Gd, and Dy). Their chemical composition was characterized by an iterative multi-method approach based on ion beams, while the photochromic effect was measured by means of optical spectrometry. We report photochromic responses for YHO, NdHO, GdHO and DyHO of several thicknesses but averaged chemical compositions described by the formula REH2-δOδ; in the range of 0.45 < δ < 1.5 (δ being the [O]/[RE] ratio). Possible side-effects of the ambient conditions on the photochromic effect in YHO thin films were investigated by comparing the optical properties (photochromic response and bleaching) of YHO films capped with two different diffusion barrier layers (Al2O3 and Si3N4) to their respective uncapped sample. The ambient atmosphere was found to play no significant role in the photochromic effect. In sequence, identical YHO thin films were prepared on three different (transparent) substrates (i.e., soda lime glass, CaF2, and Al2O3 as buffer layer). The effect of substrate induced stress in the YHO thin films was investigated in details and no significant correlation between the substrate and photochromic effect was observed. Finally, isotope labeling in double layers of YHO and YDO was done to investigate possible diffusion of hydrogen/deuterium within the REHO layers. No diffusion of hydrogen/deuterium could be observed in the double layered structure during a one-week period and one illumination/bleaching cycle.

A particle accelerator simulation which straddles the gap between multi-particle and moment codes is derived. The hybrid approach represents the beam using macro-particles which contain discrete longitudinal coordinates and transverse second moments. The discretization scheme for the macro-particles is derived using variational principles, as a natural extension of well known variational approaches. This variational discretization allows for exact transverse emittance conservation. The electrostatic self-potential is discrete in the longitudinal direction and solved semi-analytically in the transverse direction using integrated Green’s functions. The algorithm is implemented and tested against both a moment and multi-particle code. / Graduate

Replacement of the superconducting magnet used in the SPECTRAP laser spectroscopy experiment at GSI necessitates redesign of some associated components. This thesis investigates a potential new beamline for SPECTRAP using a single pulse drift tube to slow the ions down. The beamline contains three parts, a horizontal part connected to the low-energy HITRAP beamline, a vertical part which transports the ions to the pulse drift tube and the pulse drift tube itself.   Simulation and tuning of the horizontal beamline were performed using the ion optics code called COSY Infinity. The resultant beam was then continued into the vertical part in SIMION. The components were then tuned by hand. The result was approximately 19% of ions ending up within the radius of the input beam used when simulating the pulse drift tube.   Additionally, the function of a crown-shaped pulse drift tube were analysed, consisting of two interlocked serrated tubes separated by a small distance. Simulations were performed in SIMION based on reasonable input beam conditions. The effect of parameters influencing the behaviour of the ions traversing the pulse drift tube were investigated, leading to optimisation of operating voltages and design specifications.   Based on the results of the simulations performed it was determined that a beamline based on a single crown-shaped PDT could be feasible. It is however unclear if existing beamline components could operate at the voltages required for transport to the pulse drift tube.

With help from a 3D-camera Photon Sports has developed reliable and easy-to-use technology tomeasure and give feedback to athletes during performance tests. This technology makes it possibleto directly extract a number of parameters Key Performance Indicators (KPIs).In most field sports, multidirectional acceleration and deceleration are key areas to improveto become quicker as an athlete. However, it has become clear that only using the 3D-camera hassome limitations. This project aims to investigate if accelerometers can provide us with this extrainformation and thereby complement measurement technology to the measurements PhotonSports are doing today.We have done a three-part project where we first focused on time synchronization betweenclocks from the 3D-camera and the accelerometers. In the second part, we investigated how wellwe can extract the ground contact time (gct) during sprint using accelerometers attached to thefeet of the athlete. In the third and last part, we studied how we can combine both the 3D-cameraand the accelerometers to extract new KPIs that we were unable to extract before.From our developed time-synchronization algorithm, we found that the result is promisingif one looks at how the measured acceleration data from both devices are matching each othervisualy, however, it does not agree with the reference data we have extracted using a Software-Development-Kit (SDK) and Photon Sports already developed application. The gct was evaluatedto values in most cases either ranging between 100 ms and 200 ms or 300 ms and 400 ms. Whencomparing to earlier studies it seems like gct in the 100−200 ms interval are closer to the correctvalue whilst there has been some error in the calculations in the later interval. By combiningthe camera and the accelerometers we were able to extract leg stiffness and reactivity index as newKPIs. The KPIswere evaluated to a reasonable value, however, it became apparent both fromcalculationsof the newKPIs and the gct that the lowsampling rate of the camera and the accelerometersare an obstacle to reliably compute these parameters. We could therefor conclude that if PhotonSports want to introduce new tests where accelerometers are used they should be aware of the limitationsthat comes with i low sampling rate and be sure they try to compute KPIs that are possibleto evaluate with the sampling rate they have.

No description available.