New test beam results of 3D and pad detectors constructed with poly-crystalline CVD diamond

Chemical Vapour Deposition (CVD) diamond is being considered as a material for particle detectors in a harsh radiation environment. This article presents beam test results of 3D pixel detectors fabricated with poly-crystalline CVD diamonds. The cells of the devices had a size of 50 µm50 µm with columns 2.6 µm in diameter. The cells were ganged in a 32 and 51 pattern to match the layouts of the pixel read-out electronics currently used in the CMS and ATLAS experiments at the Large Hadron Collider, respectively. In beam tests, using tracks reconstructed with a high precision tracking telescope, a tracking efficiency of 99.3 % was achieved. The efficiency of both devices plateaus at a bias voltage of 30 V. Also irradiated poly-crystalline CVD diamond pad detectors were investigated. In high rate beam tests with particle fluxes up to 20 MHz/cm2 and irradiations up to 8 1015 n/cm2 it was shown that the pulse height of irradiated poly-crystalline CVD diamonds does not depend on flux to the

Optimal SVM Switching for a Multilevel Multi-Phase Machine using Modified Discrete PSO

This paper searches for the best possible switching sequence in a multilevel multi-phase inverter that gives the lowest amount of voltage harmonics. A modified discrete particle swarm (MDPSO) algorithm is used in an attempt to find the optimal space vector modulation switching sequence that results in the lowest voltage THD. As with typical PSO cognitive and social parameters are used to guide the search, but an additional mutation term is added to broaden the amount of area searched. The search space is the feasible solutions for the predetermined vectors at a given modulation index. Comparison of the MDPSO algorithm to an integer particle swarm optimization (IPSO) is presented for all three modulation indices tested. The resulting switching sequences found show that the MDPSO algorithm is capable of finding a minimal THD solution for all modulations indices tested. The MDPSO algorithm performed better overall than the IPSO in terms of converging to the best solution with significantly lower iterations

Extending Voltage Range and Reducing Torque Ripple of Five-Phase Motor Drives with Added Voltage Harmonics

As multi-phase (defined as greater than three-phase) drives become more popular and practical, new research in this area investigates potential advantages including lower torque ripple and better power density. The added dimensions of a multi-phase machine leads to a completely different operating nature than standard three-phase machines. It can be shown physically and mathematically that certain harmonics do not contribute to torque production and therefore the torque is not directly tied to the current wave-shape. This paper utilizes this property to demonstrate a substantial increase in voltage range and a reduction in torque ripple through the use of added voltage harmonics. An analysis of a five-phase motor is presented followed by a range of modulation techniques. It is shown that by proper selection of third, fifth, and seventh harmonics, the required dc voltage can be reduced by eighteen percent and the torque ripple can be reduced by nearly sixty percent over traditional methods at the expense of higher current THD; which may not be a disadvantage in certain applications. Further investigation is then carried out in applying a unique space-vector modulation patter to the five-phase motor drive. This further reduces the torque ripple. Detailed simulation and laboratory tests are used to demonstrate this concept

Fostering Durable Skills Development: Leveraging Student Worker Programs

The past half century has witnessed exponential increases in the cost of a college degree paralleled by an increase of undergraduate students who are employed during matriculation. While the impact on learning outcomes due to off-campus employment continues to receive much attention, there has been little attention paid to students employed on-campus through student worker programs and their benefits, especially in developing durable skills and improving retention. Research has demonstrated that engagement in oncampus activities improves retention and persistence in students. Additionally, employers desire power or durable skills (formerly known as “soft skills”), and that student worker programs are suited to meet this demand. This study proposes to investigate the way student worker programs across institutions support the development of durable skills, how these can be leveraged to improve persistence and completion rates in undergraduates, and how those differ by program. Results indicate that library services represent a model for other functional areas to adopt for student workers in order to improve retention and graduation rates, along with employable skills

The South West Nuclear Hub:Supporting Nuclear Through Education and STEM Activities

The uptake of study and careers in Science, Technology, Engineering, and Mathematics (STEM) is of paramount importance in fostering innovation to drive the economy sustainably. This paper aims to provide an exploration of the multifaceted initiatives coordinated by the South West Nuclear Hub—an alliance comprising prominent industry partners, academic institutions, and dynamic small-medium enterprises. Together, our collaborative efforts are geared towards bolstering the enduring vitality of the UK's civil nuclear industry.Our strategic focus lies in advancing research, promoting innovation, and nurturing skill sets that significantly contribute to the evolution of the nuclear sector. Recognizing the imperative to cultivate the next generation of scientists and engineers, we are aligned with the overarching Net Zero goal of the UK government. A pivotal aspect of our mission is to address the substantial workforce shortage hindering the realization of these objectives.We recognize the need to develop the next generation of scientists and engineers in support of our industry: it is estimated that the sector needs to grow by up to 150,000 people to achieve the UK government’s target for nuclear power generation (as well as decommissioning) [1]. This paper will discuss the skills gap faced by the UK and how this directly affects the ability for the UK to realize its ambition to achieve net zero, and how the South West Nuclear Hub is contributing to closing the gap.<br/