Thin Plastic Substrates Research Articles

One-dimensional time resolved soft x-ray imaging of colliding plasmas in a laser heated cavity

We describe x-ray streak camera measurements of wall motion and plasma filling in hohlraum targets heated by the AWE HELEN laser. An x-ray streak camera using a transmission mode photocathode on a thin plastic substrate (1000 Å Parylene-N) was coupled to a 15° incidence gold mirror to define a spectral channel response of width 45 eV full width at half-maximum centered around 120 eV. A 20 μm diam pinhole was used to image the hohlraum interior onto the photocathode slit of the streak camera, via the gold reflector. Plasma expansion from the laser hot spots, and the indirectly heated wall, was recorded. The experimental data are compared with simulations using the AWE Lagrangian hydrocode NYM.

Recent progress in neutron optical polarises and spin-echo spectrometry

Magnetised materials have a spin-dependent neutron refractive index. This provides the basis for a variety of cold neutron polarisers which overcome the problem of the small divergence available from a single mirror reflection. Evaporated thin-film technology is used to produce easily magnetised reflecting surfaces of appropriate composition on thin glass or plastic substrates. Such polarisers have opened the way to polarisation analysis, and hence neutron spin-echo, at long wavelength. This paper will discuss the setting-up, execution and data-analysis of a typical neutron spin-echo experiment to observe small angle coherent inelastic scattering, with the presently available energy resolution of several tens of neV.

Capacitor-shunted Josephson junction for improved coupling with microwave fields

We report the fabrication of a capacitor-shunted Josephson junction and its use as a microwave device with improved coupling to microwave fields. The junction was evaporated on a thin plastic substrate which was subsequently folded like a flat-spring clip in order to make a circular coupling loop terminated by a parallel-plate capacitor. The capacitor short-circuits the loop for high-frequency currents but keeps it open for dc currents, rendering possible the application of dc bias to the junction. The folded junction was observed at X band to couple 20 dB better to rf power than the same junction extended flat.

Theory and Practice of Steady-State Evaporation of Alloys

InSb films have been grown by steady-state evaporation, a technique that produces a vapor with the same composition as the starting liquid. Films deposited on glass substrates at room temperature typically have Hall coefficients of 10–50 cm3/C, resistivities of 0.05 and 0.5 Ω cm, and Hall mobilities of the order of 200 cm2/V sec. X-Ray fluorescence analyses of films deposited on thin plastic substrates at room temperature indicate random departure from stoichiometry of as much as 1%. Comments are made on source design and conditions that may cause deviations from stoichiometry. The theory of steady-state evaporation is briefly discussed.