Browsing by Author "Chuaqui, Hernán"
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- ItemA Miniature Capacitive Probe Array for Transient High Voltage Capillary Discharges(2001) Favre Domínguez, Mario; Chuaqui, Hernán; Wyndham, Edmund
- ItemA simple Faraday Cup with Subnanosecond Response(1989) Chuaqui, Hernán; Favre Domínguez, Mario; Wyndham, Edmund; Arroyo González, Luis Orlando
- ItemAn Observation of Energetic Electron Beams in a Low Pressure Linear Discharge(1987) Choi, P.; Chuaqui, Hernán; Favre Domínguez, Mario; Wyndham, Edmund
- ItemAnisotropy of Ion Emission from a Low Energy Plasma Focus(2006) Bhuyan, Heman; Chuaqui, Hernán; Wyndham, Edmund; Bhuyan, Heman; Chuaqui, Hernán; Wyndham, Edmund
- ItemArchival and Wide Exposure Latitude Process for Holography(1990) Aliaga R; Chuaqui, Hernán
- ItemBeam and hot-spot formation in a low impedance line driven vacuum spark discharge(1992) Chuaqui, Hernán; Favre Domínguez, Mario; Wyndham, Edmund
- ItemBreakdown Characteristics of a Laser Triggered Pseudospark Discharge(1989) Chuaqui, Hernán; Favre Domínguez, Mario; Wyndham, Edmund; Arroyo González, Luis Orlando
- ItemBreakdown Formation in a Transient Hollow Cathode Discharge-A Statistical Study(1995) Choi, P.; Chuaqui, Hernán; Favre Domínguez, Mario
- ItemCharacteristics of a small plasma focus device(IET, 1996) Favre Domínguez, Mario Benjamin; Silva, P.; Chuaqui, Hernán; Wyndham Hodder, Edmund Sydenham; Choi, P.; Dumitrescu-Zoita, C.We report on experimental observations in PFP-I, a small 3.8 kJ plasma focus, which is operated in Hydrogen-Argon mixtures to investigate the effect of parameter modifications on the overall performance of the device. An extensive array of diagnostics is been used, which includes voltage and current probes in the external circuit, a novel small magnetic probes array located along the cathode rods, filtered PIN diodes located side and end on, and multi-pinhole X-ray camera. EX1ended operated range from below 0.2 Torr upwards has been achieved with the implementation of the auxiliary discharge circuit. Despite the low voltage and low energy operation, energetic beam formation has been observed at the time of the final compression, prior to disruption. Current sheath formation and evolution has been characterised using the magnetic probes array, in correlation with beam formation and plasma emission. Time integrated visible plasma spectroscopy is performed to investigate impurity effects on focus performance and plasma dynamics at the collapse phase.
- ItemCharacteristics of electron beam formation in a hollow cathode triggered fast capillary discharge(IET, 2000) Favre Domínguez, Mario Benjamin; Choi, P.; Dumitrescu, C.; Chuaqui, Hernán; Wyndham Hodder, Edmund Sydenham; Krisch, I.; Larour, J.; Rous, J.; LeBlanc, C.; Rutkevich, I.; Mond, M.The fast pulsed capillary discharge has been shown to be an efficient source of radiation in the XUV range. Two main conditions are required to operate a pulsed capillary discharge as a fast XUV radiation source. First, initial formation of an on-axis conducting plasma column detached from the capillary wall, and second, application of a high rate of current rise to an inductive load, to heat the capillary plasma. To satisfy these requirements we have developed a pulsed capillary discharge device which combines the features of a transient hollow cathode discharge (THCD) with the inherent characteristics of the capillary discharge, to obtain XUV radiation with ns rise time. The discharge operates in the nanosecond regime with current in the kA region into a millimeter diameter capillary. The initial breakdown process is controlled by the physics of the THCD, with hollow cathode emitted electron beams, which assist the formation of an on-axis ionization channel. In this paper we present a theoretical model of breakdown formation in the capillary which is compared with experimental measurements of ionization growth. The properties of the electron beams are quantified and their influence on the subsequent breakdown formation is considered through time-resolved measurements on the plasma emission properties and VUV spectroscopy.
- ItemCharacterization of capacitively coupled radio-frequency argon plasma by electrical circuit simulation(2012) Bora, Bijit; Bhuyan, Heman; Favre Domínguez, Mario; Wyndham, Edmund; Chuaqui, Hernán
- ItemCurrent measurement by Faraday effect on GEPOPU(2012) Correa Poblete, Noemí Patricia; Chuaqui, Hernán; Wyndham, Edmund; Veloso Espinosa, Felipe Eduardo; Valenzuela Ahumada, Julio César; Favre Domínguez, Mario; Bhuyan, Heman
- ItemCurrent measurement by Faraday effect on GEPOPU(2014) Correa Poblete, Noemí Patricia; Chuaqui, Hernán; Wyndham, Edmund; Valenzuela Ahumada, Julio César; Favre Domínguez, Mario; Bhuyan, Heman; Veloso Espinosa, Felipe Eduardo; Correa, N.; Chuaqui, Hernán; Wyndham, Edmund; Valenzuela Ahumada, Julio César; Favre Domínguez, Mario; Bhuyan, Heman; Veloso Espinosa, Felipe Eduardo
- ItemCurrent Sheath Studies in a Small Plasma Focus Operating in Hydrogen- Argon Mixtures(1998) Favre Domínguez, Mario; Chuaqui, Hernán
- ItemDependence of cathode aperture in pulsed hollow‐cathode discharges(1992) Favre Domínguez, Mario; Leñero Merchant, Ana María; Chuaqui, Hernán; Wyndham, Edmund
- ItemDesign Note: Mechanical Mounts for Mirrors and Beam Splitters(2000) Soto L; Chuaqui, Hernán
- ItemElectrical characteristics of a small plasma focus device(IET, 1996) Choi, P.; Favre Domínguez, Mario Benjamin; Silva, P.; Chuaqui, Hernán; Wyndham Hodder, Edmund SydenhamEfficient plasma focus operation relies on uniform initial breakdown across the insulator surface. In this paper, we discuss basic plasma focus electric circuit, in order to highlight circuit modifications that produce high voltage oscillation at initial breakdown time. Superimposed on the main discharge voltage such oscillating voltage has been found in real systems to enhance the initial gas breakdown by localizing the initial current path across the insulator surface. PSpice circuit simulations are compared with electric signals from different operational plasma focus devices.
- ItemElectron beam measurements in a pulsed capillary discharge(IEEE, 1998) Favre Domínguez, Mario; Choi, P.; Chuaqui, Hernán; Wyndham Hodder, Edmund Sydenham; Dumitrescu-Zoita, C.; Larour, J.; Rous, J.In this work we present experimental observations of the XUV and electron beam emission properties of an ultrafast pulsed capillary discharge, which combines the features of a transient hollow cathode discharge with the inherent characteristics of the capillary discharge.
- ItemExperimental investigation of ionization growth in the pre-breakdown phase of fast pulsed capillary discharges(2003) Favre Domínguez, Mario; Chuaqui, Hernán; Mitchell, Ian H.; Wyndham, Edmund
- ItemExperimental investigations of hotspots in a low energy plasma focus operating in hydrogen-argon mixtures(IEEE, 1998) Favre Domínguez, Mario; Silva, P.; Choi, P.; Chuaqui, Hernán; Dumitrescu-Zoita, C.; Wyndham, EdmundWe present experimental results on the investigation of hotspot formation in PFP-I, a small 3.8 kJ plasma focus device operating in hydrogen-argon mixtures, at pressures from below 0.2 torr upward. A combination of multipinhole and slit-wire X-ray photography is used to measure the characteristic size and temperature of the hotspots, over a range of pressure and gas mixing ratios. Filtered p-i-n diodes and a beam-target detector are used to investigate the time evolution of the hotspots. Typical size for the hottest emitting region, at temperatures between 200 and 400 eV, is found to be around 150 /spl mu/m, with a typical duration of the high temperature phase of the order of 10 ns. In general, the temperature in the final phase of the time evolution of the hotspots reaches values which are nearly twice those of the plasma column where they are formed. Characteristic size of the hotspots is about half of that of the initial plasma column.