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A N-doped hierarchical porous carbon nanostructure (NHPCN) was created on a carbon cloth (CC), through a templating process using self-assembled mesoporous silica spheres as the template, to fabricate high-performance flexible gel-type symmetric supercapacitors (NHPCN@CC//NHPCN@CC). The NHPCN@CC//NHPCN@CC cell exhibited outstanding capacitive performances, giving a decent energy density of 10.3 W h kg–1 at a high power density of 10 kW kg–1 and reaching a high energy density of 24.3 W h kg–1 at a power density of 0.5 kW kg–1, outperforming most carbon-based gel-type, symmetric supercapacitors. This success may be attributed to the continuous hollow, thin features of the NHPCN, with the hollow structure enabling local, fast adsorption/desorption of electrolyte ions for generation of electric double-layer capacitances and the thin carbon shells offering large amounts of exposed surface areas for accommodation of electric double-layer capacitances and pseudo-capacitances. The NHPCN@CC//NHPCN@CC cell exhibited a high specific capacitance retention rate of 85% after 8000 cycle operations at 10 A g–1, showing its good cycling stability. The mechanical robustness of the NHPCN@CC//NHPCN@CC cell was also excellent, with the energy and power densities well-maintained even under a large bending angle of 135°.

A simplified technique to measure the plasma temperature in multiwire Z-pinch experiments is reported. Experiments were carried out in a small (36 kJ) Z-pinch machine and the diagnostics employed include X-ray detection using PIN diodes fitted with different transmission filters. The comparison of the relative intensities in each filtered X-ray band allows a time-resolved measurement of the electron temperature to be obtained. The method is implemented by convoluting a simple model of the continuum spectrum with the filter-detector response and calculating signal ratios for different filters. The computed ratios are then compared to the experimental ones to obtain the time-resolved temperature. When the method was applied to shots with 1-4 wire bundles the temperature was found to be in the interval 1 to 7 keV. Characteristic radiation had to be identified beforehand as this method is not suitable for line radiation.This paper reports the conceptualization, designing and construction of a low cost table top X-pinch device. The original target was to develop a 200kV, 50kA system with 40-50 ns pulse rise time. In order to keep the cost of the device low, two major changes compared to the conventional X-pinch systems were implemented: (1) develop a low cost transformer based 200 kV pulsed high voltage power source (HVPS) instead of costly Marx generator and (2) develop an integrated pulsed forming line (PFL) with inbuilt water spark gap switch instead of a separate SF6 gas based spark gap. A 1:56 turns transformer, placed inside transformer oil container, was designed to amplify a variable voltage discharge pulse from 7.5 iF (30 kV) capacitor. The dimensions of the PFL were estimated to obtain the system impedance of 4 Q and compressed pulse of 50 ns rise time. To construct the PFL with inbuilt water spark gap switch, the breakdown potential of de-ionized water was systematically investigated. The de-ionized water was found to have the breakdown potential of about 70 kV/mm. For electrical diagnostics, a capacitive voltage probe was made for initial measurements of the HVPS. A V-dot probe and Rogowski groove were constructed and used to monitor the operation of X-pinch.The V-dot probe shows that at 12kV input voltage to HVPS, the water spark gap (with 3.5 mm gap) of PFL breakdowns at the voltages of about 200 kV. Rogowski groove has recorded the current in the range of 15-20 kA, implying the load impedance higher than the intended 4Q impedance. The time integrated optical imaging confirms the X-pinch formation. The X-ray emissions from the device are investigated using photo-conducting diamond and photodiodes. Investigations to use X-pinch device as a radiography source are undergoing at present.