Zobrazeno 1 - 10
of 20
pro vyhledávání: '"Humphrey, J. A."'
Publikováno v:
Journal of Physics: Conference Series. 568:012010
We have performed calculations of the properties of bubbles in liquid helium containing small numbers of electrons. We use an iterative approach to estimate the energy of the electrons inside a bubble of given shape, and then vary the shape of the bu
Publikováno v:
Journal of Physics: Conference Series. 568:012011
We have extended our measurements of the properties of exotic negatively-charged ions in superfluid helium-4. We measured the ion mobility using the time-of-of-flight method at temperatures in the range between 1.03 and 1.16 K. Ions were generated by
Autor:
Ambarish Ghosh, Humphrey J. Maris
Publikováno v:
Journal of Physics: Conference Series. 400:012011
When an electron is injected into liquid helium, it forces open a cavity that is free of helium atoms (an electron bubble). If the electron is in the ground 1S state, this bubble is spherical. By optical pumping it is possible to excite a significant
Autor:
Humphrey J. Maris
Publikováno v:
Journal of Physics: Conference Series. 400:012041
Helium can be prepared with a purity much higher than any other element. As a consequence, it is an ideal material in which to study nucleation processes. We describe work in which liquid helium has been studied at pressures below the pressure range
Publikováno v:
Journal of Physics: Conference Series. 400:012042
The normal negative ion in liquid helium consists of an electron confined in a bubble of radius approximately 19 A. These bubbles have been studied in many experiments. Time-of-flight mobility measurements have revealed that there are other types of
Autor:
Arto V. Nurmikko, Shan Che, F Yang, George Andrew Antonelli, Humphrey J. Maris, T. J. Grimsley
Publikováno v:
Journal of Physics: Conference Series. 278:012037
The propagation of ultra-short sound pulses in water has been studied using an ultrafast opto-acoustic technique. A pulse time-of-flight technique for measuring the depths of deep channels in Si-based nanostructures was demonstrated. We report in the
Publikováno v:
Journal of Physics: Conference Series. 150:032027
We have performed numerical calculations to investigate the stability of multi-electron bubbles in liquid helium-4. In our calculations, for each bubble shape considered we find the equilibrium distribution of the electron gas on the inside surface o
Publikováno v:
Journal of Physics: Conference Series. 92:012001
We have developed an apparatus which can be used to monitor the motion of individual electrons in liquid helium. A sound wave is used to explode an electron bubble for a fraction of a microsecond. While the bubble is expanded, it is illuminated by li
Autor:
J Ma, Shan Che, Humphrey J. Maris, Arto V. Nurmikko, T. J. Grimsley, Qiang Zhang, Cuong Dang, F Yang, T. Atay
Publikováno v:
Journal of Physics: Conference Series. 92:012024
The propagation of ultra-short sound pulses in water is studied by using the picosecond ultrasonic technique. A sound pulse is generated when light is absorbed in a metal transducer film deposited onto a substrate. The sound propagates across a thin
Publikováno v:
Journal of Physics: Conference Series; 2009, Vol. 150 Issue 1, p032027-032030, 4p