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We present UV/optical observations and models of supernova (SN) 2023ixf, a type II SN located in Messier 101 at 6.9 Mpc. Early-time ("flash") spectroscopy of SN 2023ixf, obtained primarily at Lick Observatory, reveals emission lines of H I, He I/II, C IV, and N III/IV/V with a narrow core and broad, symmetric wings arising from the photo-ionization of dense, close-in circumstellar material (CSM) located around the progenitor star prior to shock breakout. These electron-scattering broadened line profiles persist for $\sim$8 days with respect to first light, at which time Doppler broadened features from the fastest SN ejecta form, suggesting a reduction in CSM density at $r \gtrsim 10^{15}$ cm. The early-time light curve of SN2023ixf shows peak absolute magnitudes (e.g., $M_{u} = -18.6$ mag, $M_{g} = -18.4$ mag) that are $\gtrsim 2$ mag brighter than typical type II supernovae, this photometric boost also being consistent with the shock power supplied from CSM interaction. Comparison of SN 2023ixf to a grid of light curve and multi-epoch spectral models from the non-LTE radiative transfer code CMFGEN and the radiation-hydrodynamics code HERACLES suggests dense, solar-metallicity, CSM confined to $r = (0.5-1) \times 10^{15}$ cm and a progenitor mass-loss rate of $\dot{M} = 10^{-2}$ M$_{\odot}$yr$^{-1}$. For the assumed progenitor wind velocity of $v_w = 50$ km s$^{-1}$, this corresponds to enhanced mass-loss (i.e., ``super-wind'' phase) during the last $\sim$3-6 years before explosion., Comment: 19 pages, 8 figures. Accepted for publication in ApJL

Direct detection of gravitational waves (GW) on Aug. 17, 2017, propagating from a binary neutron star merger, opened the era of multimessenger astronomy. The ejected material from neutron star mergers, or kilonova, is a good candidate for optical and near infrared follow-up observations after the detection of GWs. The kilonova from the ejecta of GW1780817 provided the first evidence for the astrophysical site of the synthesis of heavy nuclei through the rapid neutron capture process or rprocess. Since properties of the emission are largely affected by opacities of the ejected material, enhancements in the available, but limited rprocess atomic data have been motivated recently. However, given the complexity of the electronic structure of these heavy elements, considerable efforts are still needed to converge to a reliable set of atomic structure data. The aim of this work is to alleviate this situation for low charge state elements in the Os-like isoelectronic sequence. In this regard, the general purpose relativistic atomic structure packages (GRASP0 and GRASP2K) were used to obtain energy levels and transition probabilities (E1 and M1). We provide line lists and expansion opacities for a range of r-process elements. We focus here on the Os isoelectronic sequence (Os I, Ir II, Pt III, Au IV, Hg V). The results are benchmarked against existing experimental data and prior calculations, and predictions of emission spectra relevant to kilonovae are provided. Finestructure (M1) lines in the infrared potentially observable by the James Webb Space Telescope are highlighted.

We report the first unambiguous observational evidence of Rydberg Enhanced Recombination (RER), a potentially important recombination mechanism that has hitherto been unexplored in low-temperature photoionized plasmas. RER shares similarities with dielectronic recombination, with the difference that the electron is captured into a highly excited state below the ionization threshold -- rather than above the threshold -- of the recombining ion. We predict transitions of carbon and oxygen ions that are formed via the RER process, and their relative strengths with collisional-radiative spectral models. Optical C II RER features are detected in published high-resolution spectra of eight planetary nebulae, and a C III transition has been found in the ultraviolet spectrum in a symbiotic star system. The relative intensities of these lines are consistent with their production by this recombination mechanism. Because RER has not previously been accounted for in photoionized plasmas, its inclusion in models can significantly impact the predicted ionization balance and hence abundance calculations of important astrophysical species. Calculations for C+ suggest that the enhancement in the total recombination rate can amount to a factor of 2.2 at 8100 K, increasing to 7.5 at T = 3500 K. These results demonstrate the importance of including RER in models of photoionized astrophysical plasmas and in elemental abundance determinations., Comment: 3 Figures, 2 Tables. Published in The Astrophysical Journal Letters. 2019 December 10

DIII-D research is addressing critical challenges in preparation for ITER and the next generation of fusion devices through focusing on plasma physics fundamentals that underpin key fusion goals, understanding the interaction of disparate core and boundary plasma physics, and developing integrated scenarios for achieving high performance fusion regimes. Fundamental investigations into fusion energy science find that anomalous dissipation of runaway electrons (RE) that arise following a disruption is likely due to interactions with RE-driven kinetic instabilities, some of which have been directly observed, opening a new avenue for RE energy dissipation using naturally excited waves. Dimensionless parameter scaling of intrinsic rotation and gyrokinetic simulations give a predicted ITER rotation profile with significant turbulence stabilization. Coherence imaging spectroscopy confirms near sonic flow throughout the divertor towards the target, which may account for the convection-dominated parallel heat flux. Core-boundary integration studies show that the small angle slot divertor achieves detachment at lower density and extends plasma cooling across the divertor target plate, which is essential for controlling heat flux and erosion. The Super H-mode regime has been extended to high plasma current (2.0 MA) and density to achieve very high pedestal pressures (∼30 kPa) and stored energy (3.2 MJ) with H 98y2 ≈ 1.6-2.4. In scenario work, the ITER baseline Q = 10 scenario with zero injected torque is found to have a fusion gain metric independent of current between q 95 = 2.8-3.7, and a lower limit of pedestal rotation for RMP ELM suppression has been found. In the wide pedestal QH-mode regime that exhibits improved performance and no ELMs, the start-up counter torque has been eliminated so that the entire discharge uses ≈0 injected torque and the operating space is more ITER-relevant. Finally, the high- (3.8) hybrid scenario has been extended to the high-density levels ne

We report the first unambiguous observational evidence of Rydberg Enhanced Recombination (RER), a potentially important recombination mechanism that has hitherto been unexplored in low-temperature photoionized plasmas. RER shares similarities with dielectronic recombination, with the difference that the electron is captured into a highly excited state below the ionization threshold -- rather than above the threshold -- of the recombining ion. We predict transitions of carbon and oxygen ions that are formed via the RER process, and their relative strengths with collisional-radiative spectral models. Optical C II RER features are detected in published high-resolution spectra of eight planetary nebulae, and a C III transition has been found in the ultraviolet spectrum in a symbiotic star system. The relative intensities of these lines are consistent with their production by this recombination mechanism. Because RER has not previously been accounted for in photoionized plasmas, its inclusion in models can significantly impact the predicted ionization balance and hence abundance calculations of important astrophysical species. Calculations for C+ suggest that the enhancement in the total recombination rate can amount to a factor of 2.2 at 8100 K, increasing to 7.5 at T = 3500 K. These results demonstrate the importance of including RER in models of photoionized astrophysical plasmas and in elemental abundance determinations., Comment: 3 Figures, 2 Tables. Published in The Astrophysical Journal Letters. 2019 December 10

Purpose The authors, seven women–writers–performers–artists–academics, have been working collectively for a year, storying, de-storying and re-storying the experience of our lives. The authors write to “taste life twice, in the moment and in retrospect” (Nin, 1976), to uncover and learn ourselves through writing (Richardson, 1997), to take the “risky” steps of talking to each other about our inner lives (Palmer, 1998). Cognisant of the limitations and masculinities of traditional academic discourses, in form and content, and heavily confined by neoliberal expectations to count and be counted, we write and express the stories of lives the authors did not choose or imagine – lives we are given and live through. Our expression inhabits aesthetic, contemplative and sensory ways of knowing and employs poetry, image, song and story to create a polyvocal account of women’s lives, voices, struggles and learning. The authors share here part of our collective memoir and its development. The paper aims to discuss these issues. Design/methodology/approach This paper is designed as a collective memoir. Findings The authors write and express the stories of lives we did not choose or imagine – lives we are given and live through. The expression inhabits aesthetic, contemplative and sensory ways of knowing and employs poetry, image, song and story to create a polyvocal account of women’s lives, voices, struggles and learning. The authors share here part of our collective memoir and its development. Research limitations/implications The research focuses on autoethnography and lived experience. Originality/value Auto-ethnography/lived experience offers rich insights into the personal and political actions and actors within higher education

Purpose The authors, seven women–writers–performers–artists–academics, have been working collectively for a year, storying, de-storying and re-storying the experience of our lives. The authors write to “taste life twice, in the moment and in retrospect” (Nin, 1976), to uncover and learn ourselves through writing (Richardson, 1997), to take the “risky” steps of talking to each other about our inner lives (Palmer, 1998). Cognisant of the limitations and masculinities of traditional academic discourses, in form and content, and heavily confined by neoliberal expectations to count and be counted, we write and express the stories of lives the authors did not choose or imagine – lives we are given and live through. Our expression inhabits aesthetic, contemplative and sensory ways of knowing and employs poetry, image, song and story to create a polyvocal account of women’s lives, voices, struggles and learning. The authors share here part of our collective memoir and its development. The paper aims to discuss these issues. Design/methodology/approach This paper is designed as a collective memoir. Findings The authors write and express the stories of lives we did not choose or imagine – lives we are given and live through. The expression inhabits aesthetic, contemplative and sensory ways of knowing and employs poetry, image, song and story to create a polyvocal account of women’s lives, voices, struggles and learning. The authors share here part of our collective memoir and its development. Research limitations/implications The research focuses on autoethnography and lived experience. Originality/value Auto-ethnography/lived experience offers rich insights into the personal and political actions and actors within higher education

© 2016, Western Australian Institute for Educational Research Inc. All rights reserved. In this article, we reflect on ways that young adolescents learn through embodied practice, which we define as moments when the body is ‘caught up’ in learning activities. Our observations draw from two workshops conducted as part of the IMC Sky High! program which annually involves over 150 Year 7 and 8 students from schools in low socioeconomic areas of south-west Sydney, Australia. The program is delivered on and off campus by a team at the University of Technology Sydney. In addition to building confidence and skill in curriculum areas, the program aims to introduce young high school students to a tertiary environment and motivate them to engage more actively at school. Paying close attention to a classical music encounter and a trip to a museum, we use ethnographic strategies to consider how looking, doing, listening and proximity facilitate feelings of connection and motivation towards learning. We discuss how an educators’ sensitivity to the listening and speaking body, and the learning and caring body can enhance learning design and opportunities for engagement. Greater awareness of embodiment can enable educators to facilitate rich, sensory learning encounters that are empowering and transformative.

In this chapter we experiment with ways to speak our lives in the academy as we question what counts as research and what should and could be the work of researchers. As we do this we confirm the notion that we cannot do the work of research without being who we are. Our chapter emerges from a body of shared communication which seeps deeply into our lives — our work in education, our values, identities, histories, domesticities and professional and personal experiences. In assembling our chapter we use aesthetic methodologies of story and image to explore our thinking, feeling and manoeuvring through the expectations and requirements of academic life and the everyday happenings of being human. Researchers interested in the human experience have long been attracted to inquiry approaches that possess aesthetic qualities (Dewey, 1934; Eisner, 1997). Aesthetic representations and visual methodologies support inquiry and voice, and promote personal and professional connections to ways of knowing and to internal and tacit narratives. For us, these methodologies have opened doorways to deep experiences, thinking and reflection. Acknowledging and responding to our own and each other’s ways of knowing and living has created nurturing, reciprocal spaces of disclosure/exposure which we make public and invite others to share.

In this chapter we experiment with ways to speak our lives in the academy as we question what counts as research and what should and could be the work of researchers. As we do this we confirm the notion that we cannot do the work of research without being who we are. Our chapter emerges from a body of shared communication which seeps deeply into our lives — our work in education, our values, identities, histories, domesticities and professional and personal experiences. In assembling our chapter we use aesthetic methodologies of story and image to explore our thinking, feeling and manoeuvring through the expectations and requirements of academic life and the everyday happenings of being human. Researchers interested in the human experience have long been attracted to inquiry approaches that possess aesthetic qualities (Dewey, 1934; Eisner, 1997). Aesthetic representations and visual methodologies support inquiry and voice, and promote personal and professional connections to ways of knowing and to internal and tacit narratives. For us, these methodologies have opened doorways to deep experiences, thinking and reflection. Acknowledging and responding to our own and each other’s ways of knowing and living has created nurturing, reciprocal spaces of disclosure/exposure which we make public and invite others to share.

© 2016, Western Australian Institute for Educational Research Inc. All rights reserved. In this article, we reflect on ways that young adolescents learn through embodied practice, which we define as moments when the body is ‘caught up’ in learning activities. Our observations draw from two workshops conducted as part of the IMC Sky High! program which annually involves over 150 Year 7 and 8 students from schools in low socioeconomic areas of south-west Sydney, Australia. The program is delivered on and off campus by a team at the University of Technology Sydney. In addition to building confidence and skill in curriculum areas, the program aims to introduce young high school students to a tertiary environment and motivate them to engage more actively at school. Paying close attention to a classical music encounter and a trip to a museum, we use ethnographic strategies to consider how looking, doing, listening and proximity facilitate feelings of connection and motivation towards learning. We discuss how an educators’ sensitivity to the listening and speaking body, and the learning and caring body can enhance learning design and opportunities for engagement. Greater awareness of embodiment can enable educators to facilitate rich, sensory learning encounters that are empowering and transformative.

© 2013 Taylor & Francis. This paper explores the storylines of four student ballet dancers who attend a specialist performing arts secondary school and who, in differing ways, envisage futures which ‘look straight at ballet’. When decisions about schooling intermingle with long-held imaginings of futures in ballet, thought is provoked about ways the young adolescents embody and express notions of becoming. A Deleuzian lens is employed to explore assemblages of the self through the deterritorialisation that is provoked when unforeseen images emerge and imaginings are challenged. The data discussed in this paper include interview transcripts and pictures participants have drawn of themselves. The analysis uses notions of rhizomatic becoming and positions students' decision-making in oscillation between deterritorialisation and reterritorialisation as new languages make sense of how a future in ballet is configured from different perspectives. Themes of being in love with ballet and identities of dancers/non-dancers are negotiated through the data. As talented ballet students are compelled to move away from schooling in order to move closer to their future, concepts of schooling are problematised. Understandings of rhizomatic structures offer insight into the working out of desires, particularly in the context of a specialist performing arts school.

© 2013 Taylor & Francis. This paper explores the storylines of four student ballet dancers who attend a specialist performing arts secondary school and who, in differing ways, envisage futures which ‘look straight at ballet’. When decisions about schooling intermingle with long-held imaginings of futures in ballet, thought is provoked about ways the young adolescents embody and express notions of becoming. A Deleuzian lens is employed to explore assemblages of the self through the deterritorialisation that is provoked when unforeseen images emerge and imaginings are challenged. The data discussed in this paper include interview transcripts and pictures participants have drawn of themselves. The analysis uses notions of rhizomatic becoming and positions students' decision-making in oscillation between deterritorialisation and reterritorialisation as new languages make sense of how a future in ballet is configured from different perspectives. Themes of being in love with ballet and identities of dancers/non-dancers are negotiated through the data. As talented ballet students are compelled to move away from schooling in order to move closer to their future, concepts of schooling are problematised. Understandings of rhizomatic structures offer insight into the working out of desires, particularly in the context of a specialist performing arts school.

Recombination spectra of F5+ producing F4+ have been investigated with high-energy resolution, using the CRYRING heavy-ion storage ring. The absolute recombination rate coefficients are derived in the centre-of-mass energy range of 0-25 eV. The experimental results are compared with intermediate-coupling AUTOSTRUCTURE calculations for 2s-2p (Delta n = 0) core excitation and show very good agreement in the resonance energy positions and intensities. Trielectronic recombination with 2s(2)-2p(2) transitions are clearly identified in the spectrum. Contributions from F5+ ions in an initial metastable state are also considered. The energy-dependent recombination spectra are convoluted with Maxwell-Boltzmann energy distribution in the 10(3)-10(6) K temperature range. The resulting temperature-dependent rate coefficients are compared with theoretical results from the literature. In the 10(3)-10(4) K range, the calculated data significantly underestimates the plasma recombination rate coefficients. Above 8 x 10(4) K, our AUTOSTRUCTURE results and plasma rate coefficients from elsewhere show agreement that is better than 25% with the experimental results., AuthorCount:5;Fundin agencies:Swedish Research Council VR

Recombination spectra of F5+ producing F4+ have been investigated with high-energy resolution, using the CRYRING heavy-ion storage ring. The absolute recombination rate coefficients are derived in the centre-of-mass energy range of 0-25 eV. The experimental results are compared with intermediate-coupling AUTOSTRUCTURE calculations for 2s-2p (Delta n = 0) core excitation and show very good agreement in the resonance energy positions and intensities. Trielectronic recombination with 2s(2)-2p(2) transitions are clearly identified in the spectrum. Contributions from F5+ ions in an initial metastable state are also considered. The energy-dependent recombination spectra are convoluted with Maxwell-Boltzmann energy distribution in the 10(3)-10(6) K temperature range. The resulting temperature-dependent rate coefficients are compared with theoretical results from the literature. In the 10(3)-10(4) K range, the calculated data significantly underestimates the plasma recombination rate coefficients. Above 8 x 10(4) K, our AUTOSTRUCTURE results and plasma rate coefficients from elsewhere show agreement that is better than 25% with the experimental results., AuthorCount:5;Fundin agencies:Swedish Research Council VR

Recombination spectra of F5+ producing F4+ have been investigated with high-energy resolution, using the CRYRING heavy-ion storage ring. The absolute recombination rate coefficients are derived in the centre-of-mass energy range of 0-25 eV. The experimental results are compared with intermediate-coupling AUTOSTRUCTURE calculations for 2s-2p (Delta n = 0) core excitation and show very good agreement in the resonance energy positions and intensities. Trielectronic recombination with 2s(2)-2p(2) transitions are clearly identified in the spectrum. Contributions from F5+ ions in an initial metastable state are also considered. The energy-dependent recombination spectra are convoluted with Maxwell-Boltzmann energy distribution in the 10(3)-10(6) K temperature range. The resulting temperature-dependent rate coefficients are compared with theoretical results from the literature. In the 10(3)-10(4) K range, the calculated data significantly underestimates the plasma recombination rate coefficients. Above 8 x 10(4) K, our AUTOSTRUCTURE results and plasma rate coefficients from elsewhere show agreement that is better than 25% with the experimental results., AuthorCount:5;Fundin agencies:Swedish Research Council VR

Recombination spectra of F5+ producing F4+ have been investigated with high-energy resolution, using the CRYRING heavy-ion storage ring. The absolute recombination rate coefficients are derived in the centre-of-mass energy range of 0-25 eV. The experimental results are compared with intermediate-coupling AUTOSTRUCTURE calculations for 2s-2p (Delta n = 0) core excitation and show very good agreement in the resonance energy positions and intensities. Trielectronic recombination with 2s(2)-2p(2) transitions are clearly identified in the spectrum. Contributions from F5+ ions in an initial metastable state are also considered. The energy-dependent recombination spectra are convoluted with Maxwell-Boltzmann energy distribution in the 10(3)-10(6) K temperature range. The resulting temperature-dependent rate coefficients are compared with theoretical results from the literature. In the 10(3)-10(4) K range, the calculated data significantly underestimates the plasma recombination rate coefficients. Above 8 x 10(4) K, our AUTOSTRUCTURE results and plasma rate coefficients from elsewhere show agreement that is better than 25% with the experimental results., AuthorCount:5;Fundin agencies:Swedish Research Council VR

Recombination spectra of F5+ producing F4+ have been investigated with high-energy resolution, using the CRYRING heavy-ion storage ring. The absolute recombination rate coefficients are derived in the centre-of-mass energy range of 0-25 eV. The experimental results are compared with intermediate-coupling AUTOSTRUCTURE calculations for 2s-2p (Delta n = 0) core excitation and show very good agreement in the resonance energy positions and intensities. Trielectronic recombination with 2s(2)-2p(2) transitions are clearly identified in the spectrum. Contributions from F5+ ions in an initial metastable state are also considered. The energy-dependent recombination spectra are convoluted with Maxwell-Boltzmann energy distribution in the 10(3)-10(6) K temperature range. The resulting temperature-dependent rate coefficients are compared with theoretical results from the literature. In the 10(3)-10(4) K range, the calculated data significantly underestimates the plasma recombination rate coefficients. Above 8 x 10(4) K, our AUTOSTRUCTURE results and plasma rate coefficients from elsewhere show agreement that is better than 25% with the experimental results., AuthorCount:5;Fundin agencies:Swedish Research Council VR

Recombination spectra of F5+ producing F4+ have been investigated with high-energy resolution, using the CRYRING heavy-ion storage ring. The absolute recombination rate coefficients are derived in the centre-of-mass energy range of 0-25 eV. The experimental results are compared with intermediate-coupling AUTOSTRUCTURE calculations for 2s-2p (Delta n = 0) core excitation and show very good agreement in the resonance energy positions and intensities. Trielectronic recombination with 2s(2)-2p(2) transitions are clearly identified in the spectrum. Contributions from F5+ ions in an initial metastable state are also considered. The energy-dependent recombination spectra are convoluted with Maxwell-Boltzmann energy distribution in the 10(3)-10(6) K temperature range. The resulting temperature-dependent rate coefficients are compared with theoretical results from the literature. In the 10(3)-10(4) K range, the calculated data significantly underestimates the plasma recombination rate coefficients. Above 8 x 10(4) K, our AUTOSTRUCTURE results and plasma rate coefficients from elsewhere show agreement that is better than 25% with the experimental results., AuthorCount:5;Fundin agencies:Swedish Research Council VR

Recombination through doubly excited states that can be formed only through spin-flip of the excited electrons can give very strong contributions to the recombination rate of Be-like ions. We demonstrate this, in this paper, with the electron-ion recombination spectra of Be-like Ne(6+) and Be-like Si(10+), recently measured at the CRYRING storage ring. These resonances have significant effects on the plasma rate coefficients. We show that neglect or imprecise calculation of these resonances is responsible for large spreads observed between various theoretical results from the literature., authorCount :5

The five J$\Pi$ levels within a $np^2$ or $np^4$ ground state complex provide an excellent testing ground for the comparison of theoretical line ratios with astrophysically observed values, in addition to providing valuable electron temperature and density diagnostics. The low temperature nature of the line ratios ensure that the theoretically derived values are sensitive to the underlying atomic structure and electron-impact excitation rates. Previous R-matrix calculations for the Ne$^{2+}$ O-like ion exhibit large spurious structure in the cross sections at higher electron energies, which may affect Maxwellian averaged rates even at low temperatures. Furthermore, there is an absence of comprehensive excitation data between the excited states that may provide newer diagnostics to compliment the more established lines discussed in this paper. To resolve these issues, we present both a small scale 56-level Breit-Pauli (BP) calculation and a large-scale 554 levels R-matrix Intermediate Coupling Frame Transformation (ICFT) calculation that extends the scope and validity of earlier JAJOM calculations both in terms of the atomic structure and scattering cross sections. Our results provide a comprehensive electron-impact excitation data set for all transitions to higher $n$ shells. The fundamental atomic data for this O-like ion is subsequently used within a collisional radiative framework to provide the line ratios across a range of electron temperatures and densities of interest in astrophysical observations., Comment: 17 pages, 8 figures

The five J$\Pi$ levels within a $np^2$ or $np^4$ ground state complex provide an excellent testing ground for the comparison of theoretical line ratios with astrophysically observed values, in addition to providing valuable electron temperature and density diagnostics. The low temperature nature of the line ratios ensure that the theoretically derived values are sensitive to the underlying atomic structure and electron-impact excitation rates. Previous R-matrix calculations for the Ne$^{2+}$ O-like ion exhibit large spurious structure in the cross sections at higher electron energies, which may affect Maxwellian averaged rates even at low temperatures. Furthermore, there is an absence of comprehensive excitation data between the excited states that may provide newer diagnostics to compliment the more established lines discussed in this paper. To resolve these issues, we present both a small scale 56-level Breit-Pauli (BP) calculation and a large-scale 554 levels R-matrix Intermediate Coupling Frame Transformation (ICFT) calculation that extends the scope and validity of earlier JAJOM calculations both in terms of the atomic structure and scattering cross sections. Our results provide a comprehensive electron-impact excitation data set for all transitions to higher $n$ shells. The fundamental atomic data for this O-like ion is subsequently used within a collisional radiative framework to provide the line ratios across a range of electron temperatures and densities of interest in astrophysical observations., Comment: 17 pages, 8 figures

We present recent measurements of absolute electron-impact ionization cross sections for Be-like C III, N IV, and O V forming Li- like C IV, N V, and O VI. The measurements were taken using the crossed-beams apparatus at Oak Ridge National Laboratory. A gas cell beam attenuation method was used to independently measure the metastable fractions present in the ion beams. The measured ionization cross sections were compared with calculations using the R-matrix with pseudostates and distorted-wave theoretical methods. Best agreement is found with the R-matrix with pseudostates cross sections results that account for the metastable fractions inferred from the gas attenuation measurements. We present a set of recommended rate coefficients for electron-impact single ionization from the ground state and metastable term of each ion., authorCount :12

Cytotoxic T-lymphocytes play an important role in the protection against viral infections, which they detect through the recognition of virus-derived peptides, presented in the context of MHC class I molecules at the surface of the infected cell. The transporter associated with antigen processing (TAP) plays an essential role in MHC class I-restricted antigen presentation, as TAP imports peptides into the ER, where peptide loading of MHC class I molecules takes place. In this study, the UL49.5 proteins of the varicelloviruses bovine herpesvirus 1 (BHV-1), pseudorabies virus (PRV), and equine herpesvirus 1 and 4 (EHV-1 and EHV-4) are characterized as members of a novel class of viral immune evasion proteins. These UL49.5 proteins interfere with MHC class I antigen presentation by blocking the supply of antigenic peptides through inhibition of TAP. BHV-1, PRV, and EHV- 1 recombinant viruses lacking UL49.5 no longer interfere with peptide transport. Combined with the observation that the individually expressed UL49.5 proteins block TAP as well, these data indicate that UL49.5 is the viral factor that is both necessary and sufficient to abolish TAP function during productive infection by these viruses. The mechanisms through which the UL49.5 proteins of BHV-1, PRV, EHV-1, and EHV-4 block TAP exhibit surprising diversity. BHV-1 UL49.5 targets TAP for proteasomal degradation, whereas EHV-1 and EHV-4 UL49.5 interfere with the binding of ATP to TAP. In contrast, TAP stability and ATP recruitment are not affected by PRV UL49.5, although it has the capacity to arrest the peptide transporter in a translocation-incompetent state, a property shared with the BHV-1 and EHV-1 UL49.5. Taken together, these results classify the UL49.5 gene products of BHV-1, PRV, EHV-1, and EHV-4 as members of a novel family of viral immune evasion proteins, inhibiting TAP through a variety of mechanisms.

A joint theoretical and experimental investigation is made of the influence of long-lived metastable levels on the electron-impact single ionization of C2+. It is expected that our electron cyclotron resonance ion source produces a beam with 40% of the C2+ ions in the 1s22s2 1S0 ground level and 60% in the 1s22s2p 3P0,2 excited levels. The comparison of nonperturbative close-coupling calculations with previous single-pass crossed beams and with our multiple-pass storage-ring measurements for the electron-impact ionization of C2+ is consistent with the predicted large metastable fraction. Reasonable agreement is found between the present time-dependent close-coupling, R-matrix with pseudostates, and converged-close-coupling ionization cross-section calculations for the ground and first excited configuration, and experimental measurement, assuming a 60% metastable fraction in the ion beam. Distorted-wave calculations are found to overestimate the ionization cross section from both the ground and metastable terms, compared with nonperturbative calculations, resulting in an overestimation of the resultant total cross section when compared with experiment. It is clear that collisional-radiative modeling of the evolution of atomic plasmas through the Be-like ionization stage will need to take into account the role of both ground and metastable levels.

The paper presents an integrated view of the population structure and its role in establishing the ionisation state of light elements in dynamic, finite density, laboratory and astrophysical plasmas. There are four main issues, the generalised collisional-radiative picture for metastables in dynamic plasmas with Maxwellian free electrons and its particularising to light elements, the methods of bundling and projection for manipulating the population equations, the systematic production/use of state selective fundamental collision data in the metastable resolved picture to all levels for collisonal-radiative modelling and the delivery of appropriate derived coefficients for experiment analysis. The ions of carbon, oxygen and neon are used in illustration. The practical implementation of the methods described here is part of the ADAS Project., Comment: At Press for Plasma Physics and Controlled Fusion. 33 pages, 11 figures

A joint theoretical and experimental investigation is made of the influence of long-lived metastable levels on the electron-impact single ionization of C2+. It is expected that our electron cyclotron resonance ion source produces a beam with 40% of the C2+ ions in the 1s22s2 1S0 ground level and 60% in the 1s22s2p 3P0,2 excited levels. The comparison of nonperturbative close-coupling calculations with previous single-pass crossed beams and with our multiple-pass storage-ring measurements for the electron-impact ionization of C2+ is consistent with the predicted large metastable fraction. Reasonable agreement is found between the present time-dependent close-coupling, R-matrix with pseudostates, and converged-close-coupling ionization cross-section calculations for the ground and first excited configuration, and experimental measurement, assuming a 60% metastable fraction in the ion beam. Distorted-wave calculations are found to overestimate the ionization cross section from both the ground and metastable terms, compared with nonperturbative calculations, resulting in an overestimation of the resultant total cross section when compared with experiment. It is clear that collisional-radiative modeling of the evolution of atomic plasmas through the Be-like ionization stage will need to take into account the role of both ground and metastable levels.

The paper presents an integrated view of the population structure and its role in establishing the ionisation state of light elements in dynamic, finite density, laboratory and astrophysical plasmas. There are four main issues, the generalised collisional-radiative picture for metastables in dynamic plasmas with Maxwellian free electrons and its particularising to light elements, the methods of bundling and projection for manipulating the population equations, the systematic production/use of state selective fundamental collision data in the metastable resolved picture to all levels for collisonal-radiative modelling and the delivery of appropriate derived coefficients for experiment analysis. The ions of carbon, oxygen and neon are used in illustration. The practical implementation of the methods described here is part of the ADAS Project., Comment: At Press for Plasma Physics and Controlled Fusion. 33 pages, 11 figures

The agent's annual report proving complete summary of all the work performed during the year. This would include but not limited to systematic records of notes of tasks completed, brief observations of general conditions observed, as well as detailed information regarding certain localities.

Recombination spectra of F VI forming F V have been investigated with high-energy resolution, using the CRYRING heavy-ion storage ring. The absolute recombination rate coefficients are derived in the center-of-mass energy range of 0-25 eV. The experimental results are compared with intermediate coupling AUTOSTRUCTURE calculations for 2s-2p (∆n=0) core excitation and show a very good agreement in the resonance energy positions and intensities. Trielectronic recombination with 2s2-2p2 transitions are clearly identified in the spectrum. Metastable ion contributions are considered and found negligible. The energy dependent recombination spectra are convoluted with Maxwell-Boltzmann energy distribution in the 10-106 K temperature range. The resulting temperature dependent rate coefficients are compared with theoretical results from literature. In the 103-104 K range the calculated data significantly underestimates the plasma recombination rate coefficients. Above ~105 K, our AUTOSTRUCTURE results and plasma rate coefficients from Colgan et al. (2003) show an agreement better than 20% with the experimental results.

A fully automatic pilot installation for straightening and restoring salvaged mine support segments was developed, built and tested: with the aid of a manipulator the encrusted and bent segments are passed individually into the cleansing plant where they are cleaned of dirt and paste by rotating chain assemblies. Then the segments are restored to their profile in the roller straightening machine. 'Radial alignment' or the restoration of the segment shape is performed on the progressive bending machine., A fully automatic pilot installation for straightening and restoring salvaged mine support segments was developed, built and tested: with the aid of a manipulator the encrusted and bent segments are passed individually into the cleansing plant where they are cleaned of dirt and paste by rotating chain assemblies. Then the segments are restored to their profile in the roller straightening machine. 'Radial alignment' or the restoration of the segment shape is performed on the progressive bending machine.