Nuclear pumping of a neutral carbon laser

Nuclear pumped lasing on the neutral carbon line at 1.45 micron was achieved in mixtures of He-CO, He-N2-CO, He-CO2, and Ne-CO and Ne-CO2. A minimum thermal neutron flux of 2 x 10 to the 14th power sq cm-sec was sufficient for oscillation in the helium mixtures. The peak of the laser output was delayed up to 5.5 ms relative to the neutron pulse in He-CO2, He-N2-CO, Ne-CO, and Ne-CO2 mixtures while no delay was observed in He-CO mixtures. Lasing was obtained with helium pressures from 20 to 800 T, Ne pressures from 100 to 200 T, CO from 0.25 to 20 mT, N2 from 0.5 mT, and CO2 from 0.1 to 25 mT in the respective mixtures

Temperature effects on an InGaP (GaInP) (55)Fe X-ray photovoltaic cell.

This paper investigates the effects of temperature on an InGaP (GaInP) (55)Fe X-ray photovoltaic cell prototype for a radioisotope microbattery (also called a nuclear microbattery). An In0.5Ga0.5P p-i-n (5 μm i-layer) mesa photodiode was illuminated by a standard 206 MBq (55)Fe radioisotope X-ray source and characterised over the temperature range -20 °C to 100 °C. The electrical power output of the device reached its maximum value of 1.5 pW at a temperature of -20 °C. An open circuit voltage and a short circuit current of 0.82 V and 2.5 pA, respectively, were obtained at -20 °C. While the electrical power output and the open circuit voltage decreased with increasing temperature, an almost flat trend was found for the short circuit current. The cell conversion efficiency decreased from 2.1% at -20 °C to 0.7% at 100 °C

Study of impurities and color effects on gemstones [abstract]

Abstract only availableFaculty Mentor: Dr. Mark A. Prelas, Nuclear EngineeringGemstones are found in a variety of colors but, what causes it? The color of gemstones is due to different impurities that are on the surroundings of the mines. In this project, researchers at the University of Missouri Columbia are using different processes to change the atomic structure of gemstones, create impurities and cause a change of color. In order to do that, the gemstones have to be characterized. The characterization process consists in measure the mass once a day, for three days to see if it remains constant. With a Raman Spectroscopy of each sample we can measure the wavelength and intensity of the molecules when radiation passes through them in a second. The Fourier Transform InfraRed Spectroscopy (FTIR) uses an infrared source to excite the sample. These spectrums identify a compound and it composition. In addition, the UV Spectroscopy is used to identify the type of atom of an element. This analysis gives us specific information about the sample's properties. After all this data is analyzed, the samples are annealed for six hours. The annealing process is held on a Cold Wall Reactor. This reactor maintains a constant temperature gradient on the walls and works in vacuum. This is a low pressure treatment, which is 10 to 20 mmHg and the maximum temperature reached is 1200˚ C. When finished, the spectroscopy tests are repeated and compared