Annealing characteristics of neutron irradiated silicon transistors

When a transistor is subjected to neutron irradiation, a component of base current proportional to neutron fluence is induced. From the effects of annealing on the base and collector currents, the conclusion was drawn that there is an apparent difference in the annealing characteristics between the neutral and the space-charge regions of the semiconductor device. This study of the anomalous annealing indicates that the neutron-induced component of base current is a result of one, or a combination, of the following mechanisms: a quasi-tunneling recombination phenomena in the emitter-base space-charge region, or an influence of the p-n junction electric field on the formation, annealing, and electronic behavior of the neutron-induced defect centers. A field dependence of the formation and annealing of the neutron-induced defects appears to be present both during the introduction and annealing of the neutron-induced defect centers. It could not be finally determined whether or not the quasi-tunneling phenomena occurred although it can be shown on theoretical grounds that it is possible for such phenomena to occur. The annealing characteristics of the defects, as represented by changes in the collector and base currents, have been obtained. Three sets of devices were irradiated and then annealed, with one set having a forward bias during annealing, one set having no bias, and one set having a reverse bias. The dependence of the field on annealing is present but appears quite complex. The presence of the externally applied electric field during annealing appears to influence the annealing of neutron-induced defects similarly, regardless of whether the junction is forward or reverse biased --Abstract, page i-ii

Rare Event Searches With CUORE Style TeO2 Bolometers

In this dissertation we report on the first search for solar axions from atomic transitions in the solar core. A search for the 14.4 keV axion from the ground state transition in 57Fe in the sun was also performed, via the axioelectric effect in TeO2 bolometers, in the CUORE-0 experiment. Both axion searches are performed in the scope of the DSFZ invisible axion model. An upper bound on the axion-electron coupling constant of gae ≤ 3.1 x 10-11 (95% CL) is obtained with 62.7 kg days of TeO2 exposure from the CUORICINO experiment. The CUORE-0 data results in a upper bound on the product of the axion-electro and effective axion-nucleon of |gae x geff aN | ≤ 1.33 x 10-17 (95% CL). Data from CUORE-0 was also used to place a bound on the half live for zero and two neutrino double beta decay of 130Te. For CUORE-0 the zero neutrino double beta decay half life bound is T0v ßß(130Te) \u3e 2.7 x 1024 yr When combined with the data from the earlier CUORICINO experiment the bound is T0v ßß (130Te) \u3e 4.0 x 1024 yr The two neutrino double beta decay half life of CUORE-0 was measured to be T2vßß (130Te) = 8.2 ± 0.2 (stat) ± 0.6 (syst) x 1020 yr

Radon Emanation Techniques and Measurements for LZ

Radon emanation was projected to account for $>50$% of the electron recoil background in the WIMP region of interest for the LUX-ZEPLIN (LZ) experiment. To mitigate the amount of radon inside the detector volume, materials with inherently low radioactivity content were selected for LZ construction through an extensive screening campaign. The SD Mines radon emanation system was one of four emanation facilities utilized to screen materials during construction of LZ. SD Mines also employed a portable radon collection system for equipment too large or delicate to move to a radon emanation facility. This portable system was used to assay the Inner Cryostat Vessel in-situ at various stages of detector construction, resulting in the inference that the titanium cryostat is the source of significant radon emanation. Assays of a $^{228}$Th source confirmed that its $^{222}$Rn emanation is low enough for it to be used, and that 14% of the $^{220}$Rn emanates from the source at room temperature.Comment: 6 pages, 4 figures, submitted to LRT 2022 Conference Proceeding

Classical-quantum correspondence in electron-positron pair creation

We examine the creation of electron-positron pairs in a very strong force field. Using numerical solutions to quantum field theory we calculate the spatial and momentum probability distributions for the created particles. A comparison with classical mechanical phase space calculations suggests that despite the fully relativistic and quantum mechanical nature of the matter creation process, most aspects can be reproduced accurately in terms of classical mechanics

Survey of UAVs (Drones) in the field of electronic communications

Tato bakalářská práce se zaměřuje na přehled bezpilotních letadel, často označovaných jako drony, a jejich technologický pokrok a vliv v oblasti elektronických komunikací. Vysvětluje základní definici bezpilotních letounů a ukazuje příklady některých současných typů letounů. Poté práce analyzuje kulturní a sociální vzhled při jejich každodenním používání. Mimoto, práce pojednává o dalších krocích v oblasti bezpilotních letounů a jejich ustálenou pozici v životě.This bachelor thesis focuses on the survey of unmanned aerial vehicles, often referred as drones, and its impact and technological progress in the field of electronic communications. It explains a basic definition of unmanned aerial vehicles (UAVs) and presents some examples of current types of vehicles. Moreover, this thesis analyzes the cultural and social appearance of using UAVs in everyday life. Furthermore, it discusses future steps in the field of UAVs and its stable position in life.

The CUORE Cryostat: A 1-Ton Scale Setup for Bolometric Detectors

The cryogenic underground observatory for rare events (CUORE) is a 1-ton scale bolometric experiment whose detector consists of an array of 988 TeO2 crystals arranged in a cylindrical compact structure of 19 towers. This will be the largest bolometric mass ever operated. The experiment will work at a temperature around or below 10 mK. CUORE cryostat consists of a cryogen-free system based on pulse tubes and a custom high power dilution refrigerator, designed to match these specifications. The cryostat has been commissioned in 2014 at the Gran Sasso National Laboratories and reached a record temperature of 6 mK on a cubic meter scale. In this paper, we present results of CUORE commissioning runs. Details on the thermal characteristics and cryogenic performances of the system will be also given.Comment: 7 pages, 2 figures, LTD16 conference proceedin

Marginal zone lymphomas in children and the young adult population; characterization of genetic aberrations by FISH and RT-PCR

Marginal zone lymphomas present rarely in children and young adults as either primary nodal or extranodal disease and have an excellent prognosis. To date, chromosomal aberrations have not been analyzed in the pediatric and young adult population. We undertook a study to analyze genetic alterations in nodal and extranodal marginal zone lymphomas in children and young adults using fluorescence in situ hybridization (FISH) and RT-PCR. These findings were correlated with clinical features at presentation and immunophenotype. Forty-one cases were identified meeting these criteria. The age range was 1.5-29 years old with 49% of the cases <18 years of age. 73% of the marginal zone lymphoma cases showed evidence of light chain restriction by immunohistochemistry or flow cytometry. CD43 was coexpressed in 83%. 85% of the marginal zone lymphoma cases tested showed evidence of immunoglobulin heavy chain gene rearrangement. Fifty-nine percent of the cases were nodal marginal zone lymphomas with a median age at presentation of 16 years and an M/F ratio of 7:1. Twenty-one percent of the nodal marginal zone lymphoma cases contained genetic aberrations. Seventeen percent contained trisomy 18 with one case containing an additional trisomy 3. A translocation of the immunoglobulin heavy chain gene to an unknown partner gene was present in one case. Forty-one percent of the cases were extranodal marginal zone lymphomas with a median age of 24 years and a M/F ratio of 1.4:1. Eighteen percent of the extranodal marginal zone lymphoma cases contained genetic aberrations. The t(14;18) involving the IGH and MALT1 genes was present in one case, tetraploidy was present in one case, and another case contained trisomy 3. Overall the incidence of genetic aberrations in marginal zone lymphomas in the pediatric and young adult population is low, but the aberrations seen are similar to those seen in the adult population

Commitment to glycolysis sustains survival of NO-producing inflammatory dendritic cells

TLR agonists initiate a rapid activation program in dendritic cells (DCs) that requires support from metabolic and bioenergetic resources. We found previously that TLR signaling promotes aerobic glycolysis and a decline in oxidative phosphorylation (OXHPOS) and that glucose restriction prevents activation and leads to premature cell death. However, it remained unclear why the decrease in OXPHOS occurs under these circumstances. Using real-time metabolic flux analysis, in the present study, we show that mitochondrial activity is lost progressively after activation by TLR agonists in inflammatory blood monocyte–derived DCs that express inducible NO synthase. We found that this is because of inhibition of OXPHOS by NO and that the switch to glycolysis is a survival response that serves to maintain ATP levels when OXPHOS is inhibited. Our data identify NO as a profound metabolic regulator in inflammatory monocyte–derived DCs