In this article we review the prospects of laser wakefield accelerators as next generation light sources for applications. This work arose as a result of discussions held at the 2013 Laser Plasma ...Accelerators Workshop. X-ray phase contrast imaging, x-ray absorption spectroscopy, and nuclear resonance fluorescence are highlighted as potential applications for laser-plasma based light sources. We discuss ongoing and future efforts to improve the properties of radiation from plasma betatron emission and Compton scattering using laser wakefield accelerators for these specific applications.
Laser-plasma technology promises a drastic reduction of the size of high-energy electron accelerators. It could make free-electron lasers available to a broad scientific community and push further ...the limits of electron accelerators for high-energy physics. Furthermore, the unique femtosecond nature of the source makes it a promising tool for the study of ultrafast phenomena. However, applications are hindered by the lack of suitable lens to transport this kind of high-current electron beams mainly due to their divergence. Here we show that this issue can be solved by using a laser-plasma lens in which the field gradients are five order of magnitude larger than in conventional optics. We demonstrate a reduction of the divergence by nearly a factor of three, which should allow for an efficient coupling of the beam with a conventional beam transport line.
Endovascular treatment of blister aneurysms is a promising approach, even though they are vascular lesions challenging to treat due to their angioarchitectural characteristics.
Our aim was to ...investigate clinical and radiologic outcomes after endovascular treatment of ruptured blister aneurysms.
PubMed, Ovid MEDLINE, Ovid EMBASE, Scopus, and the Web of Science were screened.
We performed a comprehensive review of the literature from 2010 to 2019 reporting series of patients with blister aneurysms treated with an endovascular approach.
Event rates were pooled across studies using a random effects meta-analysis.
A total of 32 studies reporting on 684 patients (707 aneurysms) were included. Stent placement, stent-assisted coiling, and flow diversion were the most commonly described treatments (282, 256, and 155 patients, respectively). The long-term complete occlusion rate was 76.9% (95% CI, 69.2%-83.9%). The perioperative complication rate was 8.9%, and clinical outcome at final follow-up was mRS <2 in 76.6% (95% CI, 68.2%-84.2%) of patients. The mortality rate was 4.7% (95% CI, 2.30%-7.80%). Among the different techniques, stent-assisted coiling is the one that had the higher rate of immediate occlusion (63.4%); however, the occlusion rate at the final follow-up was comparable among the different techniques.
Different techniques were described and data were reported in a nonhomogeneous way, possibly representing a bias in the present study.
This study suggests that endovascular treatment of blister aneurysms is associated with good long-term occlusion rates and reasonable complication and mortality rates. There is no consensus on the best endovascular techniques in blister aneurysm management.
The advent of X-ray free-electron lasers has granted researchers an unprecedented access to the ultrafast dynamics of matter on the nanometre scale. Aside from being compact, seeded plasma-based soft ...X-ray lasers (SXRLs) turn out to be enticing as photon-rich sources (up to 1015 per pulse) that display high-quality optical properties. Hitherto, the duration of these sources was limited to the picosecond range, which consequently restricts the field of applications. This bottleneck was overcome by gating the gain through ultrafast collisional ionization in a high-density plasma generated by an ultraintense infrared pulse (a few 1018 W cm-2 ) guided in an optically pre-formed plasma waveguide. For electron densities that ranged from 3 × 1018 cm-3 to 1.2 × 1020 cm-3 , the gain duration was measured to drop from 7 ps to an unprecedented value of about 450 fs, which paves the way to compact and ultrafast SXRL beams with performances previously only accessible in large-scale facilities.
Abstract Suitable instrumentation for laser-accelerated proton (ion) beams is critical for development of integrated, laser-driven ion accelerator systems. Instrumentation aimed at beam diagnostics ...and control must be applied to the driving laser pulse, the laser–plasma that forms at the target and the emergent proton (ion) bunch in a correlated way to develop these novel accelerators. This report is a brief overview of established diagnostic techniques and new developments based on material presented at the first workshop on ‘Instrumentation for Diagnostics and Control of Laser-accelerated Proton (Ion) Beams’ in Abingdon, UK. It includes radiochromic film (RCF), image plates (IP), micro-channel plates (MCP), Thomson spectrometers, prompt inline scintillators, time and space-resolved interferometry (TASRI) and nuclear activation schemes. Repetition-rated instrumentati on requirements for target metrology are also addressed.
We present results from an analysis of B(0)B(0)--> rho(+)rho(-) using 232 x 10(6) Gamma (4S) --> BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. We ...measure the longitudinal polarization fraction f(L) = 0.978 +/- 0.014(stat) + 0.021 / -0.029(syst) and the CP-violating parameters S(L)= -0.33 +/- 0.24(stat) + 0.08 / -0.14(syst) and C(L)= -0.03 +/- 0.18(stat) +/- 0.09(syst). Using an isospin analysis of B --> rhorho decays, we determine the unitarity triangle parameter alpha. The solution compatible with the standard model is alpha = (100 +/- 13) degrees.
2020 roadmap on plasma accelerators Albert, Félicie; Couprie, M E; Debus, Alexander ...
New journal of physics,
03/2021, Letnik:
23, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Abstract
Plasma-based accelerators use the strong electromagnetic fields that can be supported by plasmas to accelerate charged particles to high energies. Accelerating field structures in plasma can ...be generated by powerful laser pulses or charged particle beams. This research field has recently transitioned from involving a few small-scale efforts to the development of national and international networks of scientists supported by substantial investment in large-scale research infrastructure. In this New Journal of Physics 2020 Plasma Accelerator Roadmap, perspectives from experts in this field provide a summary overview of the field and insights into the research needs and developments for an international audience of scientists, including graduate students and researchers entering the field.
Historically, traditional laboratory experiments have been given a central and distinctive role in science education. However, virtual laboratories have received considerable attention over the past ...several years in different areas of knowledge. The main aim of this study is to analyse the impact of the use of both traditional and virtual laboratories in Basic Science Subjects (BSS) in Health Sciences university degrees. For this reason, we have described and analysed different variables such as level of satisfaction, increase in perceived motivation and increase in perceived academic performance. Throughout the academic course the pupils who took part in our study carried out laboratory experiments both traditionally and virtually in different BSS, and they completed a questionnaire to assess their satisfaction and the impact of both approaches at the end of the course. The results point to statistically significant differences in favour of traditional laboratories in all the studied variables, together with some differences between male and female students. In general, students showed more positive attitudes towards traditional experiments. These results emphasize the importance of carrying out hands-on experiments to boost student motivation and perceived performance.
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