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- Nuernberg, F., et al.
(author)
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Radiochromic film imaging spectroscopy of laser-accelerated proton beams
- 2009
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In: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 80:3
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Journal article (peer-reviewed)abstract
- This article reports on an experimental method to fully reconstruct laser-accelerated proton beam parameters called radiochromic film imaging spectroscopy (RIS). RIS allows for the characterization of proton beams concerning real and virtual source size, envelope- and microdivergence, normalized transverse emittance, phase space, and proton spectrum. This technique requires particular targets and a high resolution proton detector. Therefore thin gold foils with a microgrooved rear side were manufactured and characterized. Calibrated GafChromic radiochromic film (RCF) types MD-55, HS, and HD-810 in stack configuration were used as spatial and energy resolved film detectors. The principle of the RCF imaging spectroscopy was demonstrated at four different laser systems. This can be a method to characterize a laser system with respect to its proton-acceleration capability. In addition, an algorithm to calculate the spatial and energy resolved proton distribution has been developed and tested to get a better idea of laser-accelerated proton beams and their energy deposition with respect to further applications.
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2. |
- McKenna, P., et al.
(author)
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Effects of front surface plasma expansion on proton acceleration in ultraintense laser irradiation of foil targets
- 2008
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In: Laser and Particle Beams. - 0263-0346. ; 26:4, s. 591-596
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Journal article (peer-reviewed)abstract
- The properties of beams of high energy protons accelerated during ultraintense, picosecond laser-irradiation of thin foil targets are investigated as a function of preplasma expansion at the target front surface. Significant enhancement in the maximum proton energy and laser-to-proton energy conversion efficiency is observed at optimum preplasma density gradients due, to self-focusing Of the incident laser pulse. For very long preplasma expansion, the propagating laser pulse is observed to filament, resulting in highly uniform proton beams, but with reduced flux and maximum energy.
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3. |
- Edhborg, M, et al.
(author)
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"Struggling with life": narratives from women with signs of postpartum depression
- 2005
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In: Scandinavian journal of public health. - : SAGE Publications. - 1403-4948 .- 1651-1905. ; 33:4, s. 261-267
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Journal article (peer-reviewed)abstract
- Aim: The aim of this study was to explore and describe how Swedish women with signs of postpartum depression two months postpartum experience the first months with their child. Method: A grounded theory approach was chosen. Twenty-two women who showed signs of depression, i.e. scored 10 or more on the Edinburgh Postnatal Depression Scale (EPDS), were interviewed at an average of 80 days after the delivery. Results: The new mothers were struggling with life related to the self, the child, and the partner. They expressed feelings of loss of who they are, felt overwhelmed by the responsibility for the child, and were struggling with feelings of abandonment, worries, and breastfeeding problems. They often felt like ``bad mothers'' but they never blamed the child. Most mothers were reluctant to speak about their feelings and they assigned their depressed mood to personal weakness rather than illness. In relationship to the partner the mothers were struggling to keep their equality in the new situation and to get him involved in childcare. Conclusions: The findings suggest that depressed feelings postpartum may be explained in terms of losses and changes. However, postpartum depressive symptoms remain hidden and it is important to understand the complexity of postpartum depressive mood, described here as struggling with life related to three different dimensions: the self, the child, and the partner.
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6. |
- Akesson, A, et al.
(author)
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Cadmium-induced effects on bone in a population-based study of women
- 2006
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In: Environmental Health Perspectives. - : Environmental Health Perspectives. - 1552-9924 .- 0091-6765. ; 114:6, s. 830-834
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Journal article (peer-reviewed)abstract
- High cadmium exposure is known to cause bone damage, but the association between low-level cadmium exposure and osteoporosis remains to be clarified. Using a population-based women's health survey in southern Sweden [Women's Health in the Lund Area (WHILA)] with no known historical cadmium contamination, we investigated cadmium-related effects on bone in 820 women (53-64 years of age). We measured cadmium in blood and urine and lead in blood, an array of markers of bone metabolism, and forearm bone mineral density (BMD). Associations were evaluated in multiple linear regression analysis including information on the possible confounders or effect modifiers: weight, menopausal status, use of hormone replacement therapy, age at menarche, alcohol consumption, smoking history, and physical activity. Median urinary cadmium was 0.52 mu g/L adjusted to density (0.67 mu g/g creatinine). After multivariate adjustment, BMD, parathyroid hormone, and urinary deoxypyridinoline (U-DPD) were adversely associated with concentrations of urinary cadmium (p < 0.05) in all subjects. These associations persisted in the group of never-smokers, which had the lowest cadmium exposure (mainly dietary). For U-DPD, there was a significant interaction between cadmium and menopause (p = 0.022). Our results suggest negative effects of low-level cadmium exposure on bone, possibly exerted via increased bone resorption, which seemed to be intensified after menopause. Based on the prevalence of osteoporosis and the low level of exposure, the observed effects, although slight, should be considered as early signals of potentially more adverse health effects.
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7. |
- Akesson, AA, et al.
(author)
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Tubular and glomerular kidney effects in Swedish women with low environmental cadmium exposure
- 2005
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In: Environmental Health Perspectives. - : Environmental Health Perspectives. - 1552-9924 .- 0091-6765. ; 113:11, s. 1627-1631
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Journal article (peer-reviewed)abstract
- Cadmium is a well-known nephrotoxic agent in food and tobacco, but the exposure level that is critical for kidney effects in the general population is not defined. Within a population-based women's health survey in southern Sweden (Women's Health in the Lund Area, WHILA), we investigated cadmium exposure in relation to tubular and glomerular function, from 1999 through early 2000 in 820 women (71% participation rate) 53-64 years of age. Multiple linear regression showed cadmium in blood (median, 0.38 mu g/L) and urine (0.52 mu g/L; density adjusted = 0.67 mu g/g creatinine) to be significantly associated with effects on renal tubules (as indicated by increased levels of human complex-forming protein and N-acetyl-beta-D-glucosaminidase in urine), after adjusting for age, body mass index, blood lead, diabetes, hypertension, and regular use of nephrotoxic drugs. The associations remained significant even at the low exposure in women who had never smoked. We also found associations with markers of glomerular effects: glomerular filtration rate and creatinine clearance. Significant effects were seen already at a mean urinary cadmium level of 0.6 mu g/L (0.8 mu g/g creatinine). Cadmium potentiated diabetes-induced effects on kidney. In conclusion, tubular renal effects occurred at lower cadmium levels than previously demonstrated, and more important, glomerular effects were also observed. Although the effects were small, they may represent early signs of adverse effects, affecting large segments of the population. Subjects with diabetes seem to be at increased risk.
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8. |
- Carroll, DC, et al.
(author)
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Active manipulation of the spatial energy distribution of laser-accelerated proton beams
- 2007
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In: Physical Review E (Statistical, Nonlinear, and Soft Matter Physics). - 1539-3755. ; 76:065401(R), s. 1-065401
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Journal article (peer-reviewed)abstract
- The spatial energy distributions of beams of protons accelerated by ultrahigh intensity (>10^19 W/cm2) picosecond laser pulse interactions with thin foil targets are investigated. Using separate, low intensity (<10^13 W/cm2) nanosecond laser pulses, focused onto the front surface of the target foil prior to the arrival of the high intensity pulse, it is demonstrated that the proton beam profile can be actively manipulated. In particular, results obtained with an annular intensity distribution at the focus of the low intensity beam are presented, showing smooth proton beams with a sharp circular boundary at all energies, which represents a significant improvement in the beam quality compared to irradiation with the picosecond beam alone.
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9. |
- Clarke, R. J., et al.
(author)
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Detection of short lived radioisotopes as a fast diagnostic for intense laser-solid interactions
- 2006
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In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 89:14
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Journal article (peer-reviewed)abstract
- As a diagnostic of high-intensity laser interactions (> 10(19) W cm(-2)), the detection of radioactive isotopes is regularly used for the characterization of proton, neutron, ion, and photon beams. This involves sample removal from the interaction chamber and time consuming post shot analysis using NaI coincidence counting or Ge detectors. This letter describes the use of in situ detectors to measure laser-driven (p,n) reactions in Al-27 as an almost real-time diagnostic for proton acceleration. The produced Si-27 isotope decays with a 4.16 s half-life by the predominantly beta+ emission, producing a strong 511 keV annihilation peak. (c) 2006 American Institute of Physics.
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