David Neely

Current status of teaching on spirituality in UK medical schools.

Objective  To investigate the current status of teaching on spirituality in medicine in UK medical schools and to establish if and how medical schools are preparing future doctors to identify patients’ spiritual needs.

Characterisation of soft X-ray amplification observed in Ne-like germanium

Abstract Soft X-ray amplification has been observed on five 3p → 3s transitions of Ne-like germanium at 19.6, 23,2, 23.6, 24.7 and 28.6 nm using flat, massive targets irradiated in 50 and 150 μm wide line foci up to 3.2 cm long at intensities of 0.3 → 14 × 10 13 W/cm 2 by 1.06 μm laser light in 1 ns and 0.5 ns pulses. Gain lengths up to gl ≈ 12 were measured for the J =2 → 1 transition at 23.6 nm and the temporal behaviour of four of the Ne-like germanium lasing lines has been investigated for the first time. The duration of the gain was 60 → 80% of the fwhm of the laser pulse, with the gain turning off at the trailing half-maximum of the incident laser intensity. Output powers in excess of 10 kW per line have been observed.

Gain scaling relationships for Ne-like Ge slab targets

Abstract The gain coefficient of the strongest 3p→3s, J = 2→1 lasing transition at 23.6 nm in the Ne-like Ge collisional excitation scheme has been measured, using the fundamental wavelength from a Nd: glass laser (1.06 μm), for a range of incident intensities on massive stripe targets up to 2.2 cm in length. From a threshold incident laser intensity of ∼ 6 x 10 12 W/cm 2 , the gain coefficient rises to ∼ 4.5 cm -1 for an irradiation intensity of ∼ 2.5 x 10 13 W/cm 2 , tending towards still higher gain coefficients at higher incident intensities. For targets of maximum length, a gain-length product gL ≈ 10 was reached with a resultant output power at 23.6 nm estimated to be at the ∼ kW level. The beam divergence decreased with length to a minimum of ∼ 7 mrad but no significant trend in beam pointing with plasma length was observed. From the trend in the gain coefficient, it appears that for a fixed energy laser irradiating a ∼ 100 μm wide slab targets, an incident incident of I i ∼ 1.2 x 10 13 W/cm 2 represents an optimum working level, assuming that plasma length is not limited by refractive effects. In addition to the usual valence electron excited 3p→3s transitions, the gain coefficient for the core excited 1s 2 2s2p 6 3d→1s 2 2s2p 6 3p transition at 19.9 nm has been measured to be ∼ 1.5 cm -1 for an incident irradiance of ∼2.5 x 10 13 W/cm 2 .

Lasing properties of the J = 0–1 and the J = 2–1 lines of a neonlike germanium soft-x-ray laser

Lasing properties of a collisional-excitation Ne-like Ge soft-x-ray laser have been studied with exploding-foil, single-slab, and double-slab targets under identical pumping conditions. Experimental results for the angular intensity distributions and the temporal variations of the lasing intensities are examined with a hydrodynamic code and ray-trace calculations. The observed angular distributions are well reproduced by these analyses, and it is found that the effective gain regions are located on the high-density side of the expected gain regions. It is shown that the observed lasing intensity of the J = 0 to J = 1 line is strongly correlated with the temporal change of the calculated electron temperature for both the slab and the exploding-foil targets.

Suboptical x-ray imaging using the Vulcan x-ray laser

An imaging microscope, comprising a Schwarzchild condenser and a zone-plate optical arrangement, has been established on the Vulcan Nd:glass laser system at the Rutherford Appleton Laboratory. Magnified images of simple test structures have been taken in x-ray transmission in a single subnanosecond laser shot by using doublet x-ray laser radiation at 23.2 and 23.6 nm from collisionally pumped Ne-like germanium. Image resolutions of ~0.15 μm have been measured. The results are a proof of principle and demonstrate that images of potentially suboptical resolution and of specimen regions that are destroyed on passage of the x-ray beam can be taken successfully using the Vulcan x-ray laser.

Preliminary studies of radiation coupling between remote soft X-ray laser amplifiers

Coupling of a soft X-ray laser beam with a relaying concave mirror in a sequentially pumped amplifier geometry using the Ne-like Ge system has been studied experimentally. Preliminary observations indicate an increase in the spatial coherence of the amplified relayed beam. In addition, near-field imaging of one of the amplifier plasmas shows a double-lobed intensity pattern of the emergent beam indicating refractive guiding of the amplified beam with components both normal and tangential to the target surface.

Time-resolved measurements of the angular distribution of lasing at 23.6 nm in Ne-like germanium

Abstract The time dependence of the angular distribution of soft X-ray lasing at 23.6 nm in Ne-like germanium has been measured using a streak camera. Slabs of germanium have been irradiated over ≈ 22 mm length × 100 μm width with three line focussed beams of the SERC Rutherford Appleton Laboratory VULCAN laser at 1.06 μm wavelength. The laser beam sweeps in time towards the target surface plane and the divergence broadens with time. The change of the peak intensity pointing and the broadening of the profile with time are consistent with expectations of the time dependence of refraction and divergence due to density gradients in the plasma.

Nicorandil-induced rectovaginal fistula

An 82-year-old woman was admitted with feculent vaginal discharge and bleeding per vagina. Investigations revealed the presence of a rectovaginal fistula with no obvious etiology. Due to the surgical teams previous experience with nicorandil-induced ulceration, the drug was stopped. The rectovaginal fistula healed completely within 6 months.

Subnanosecond in-line soft x-ray holography using germanium laser in the 20 nm wavelength region

Near- and far-field characteristics of a germanium soft x-ray laser at the wavelengths of 23.2–23.6 nm ( J = 2-1 transitions) and 19.6 nm ( J = 0-1 transition) are given for quantitative evaluation of the germanium laser for holographic applications. In-line Gabor holography of simple structured objects, such as thin opaque fibers and a standard electron microscope test specimen, is demonstrated. The holograms were recorded on PMMA (polymethyl methacrylate) photoresists and Ilford Q-plates. The holograms recorded on PMMA were retrieved with an atomic force microscope. The object image was reconstructed by numerical reconstruction with phase retrieval algorithm, resulting in a clear, ghost-free image with sharp edges which infer sub- μ m resolution. Future directions for x-ray laser holography are briefly discussed.

Development of soft x-ray lasers at the Institute of Laser Engineering: recent results on Ge soft x-ray laser (Invited Paper)

Basic characteristics of soft x-ray lasers generated as amplified spontaneous emission are described. Experimental results on soft x-ray amplification in neon-like germanium ions, obtained recently at the Institute of Laser Engineering, are reported. By comparing the experimental results with a simplified model on amplified spontaneous emission, basic parameters such as coherence and brightness of the Ge soft x-ray laser are evaluated.