Mossbauer spectroscopy - a useful method for classification of meteorites?

The aim of our studies was to check the usefulness of M¨ossbauer spectroscopy for preliminary classification of ordinary chondrites. M¨ossbauer spectra of 50 samples of ordinary chondrites (type LL, L and H) obtained at room temperature were analyzed. 35 M¨ossbauer spectra were obtained in our laboratory, the other spectra were taken from the literature. The conclusion of our study was, that the most useful way for the preliminary classification of the ordinary chondrites is the application of two types of plots based on the data obtained by M¨ossbauer spectroscopy. One type of these plots is a linear plot which was used for the identification of the samples which are unrepresentative. The second type of these plots is a plot of “spectral area of the olivine” vs “spectral area of the metallic phase”. This last one was used for the identification of two unknown meteorites

Overview of progress in European medium sized tokamaks towards an integrated plasma-edge/wall solution

Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat and particle loads on the wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research on ASDEX Upgrade (AUG), MAST and TCV. This multi-machine approach within EU-MST, covering a wide parameter range, is instrumental to progress in the field, as ITER and DEMO core/pedestal and SOL parameters are not achievable simultaneously in present day devices. A two prong approach is adopted. On the one hand, scenarios with tolerable transient heat and particle loads, including active edge localised mode (ELM) control are developed. On the other hand, divertor solutions including advanced magnetic configurations are studied. Considerable progress has been made on both approaches, in particular in the fields of: ELM control with resonant magnetic perturbations (RMP), small ELM regimes, detachment onset and control, as well as filamentary scrape-off-layer transport. For example full ELM suppression has now been achieved on AUG at low collisionality with n  =  2 RMP maintaining good confinement ${{H}_{\text{H}\left(98,\text{y}2\right)}}\approx 0.95$ . Advances have been made with respect to detachment onset and control. Studies in advanced divertor configurations (Snowflake, Super-X and X-point target divertor) shed new light on SOL physics. Cross field filamentary transport has been characterised in a wide parameter regime on AUG, MAST and TCV progressing the theoretical and experimental understanding crucial for predicting first wall loads in ITER and DEMO. Conditions in the SOL also play a crucial role for ELM stability and access to small ELM regimes

Diagnosis and treatment of thyroid cancer in children in the multicenter analysis in Poland for PPGGL

Introduction: Differentiated thyroid carcinoma (DTC) in children presents different biological behavior in comparison to adults. Authors presents preliminary results of multicenter analysis concerning incidence, diagnostics and treatment of DTC in children. Material and methods: The study is a retrospective analysis of 107 pediatric patients from 14 academic centers based on the data from 2000 to 2005 obtained by questionnaire in hospitals involved in the treatment of DTC in children. Results: Papillary thyroid cancer was diagnosed in 83 children, follicular thyroid cancer in 10 children and medullary thyroid cancer in 14 children. Incidence of DTC in children was estimated between 18 and 23 cases per year. The biggest group of patients consisted of children between 11 and 15 years of age, with girls to boys ratio 3.3 : 1. Clinically DTC in children presented most often as solitary thyroid nodule. Cervical lymphadenopathy was observed in 42% of patients. Intraoperative verification indicated metastatic nodes in 50% of children. Low stage DTC predominated (T1 in 36% and T2 in 26% of children). One step surgery was performed in 65% of children with DTC, two step surgery in 25% of patients. I131 therapy was undertaken in 80% of children. Lung metastases were indicated in post therapeutic studies in 14% of children with DTC. Prophylactic thyroidectomies were performed in 79% of children in the group of patients with MTC and RET gene mutations. Conclusions: The necessity of introduction of unified therapeutic standard in children with DTC in Poland is underlined.Wstęp: Zróżnicowane raki tarczycy (DTC, differentiated thyroid carcinoma) występują u dzieci rzadko. Większość przypadków wykrywanych jest w wieku 11-17 lat. W odróżnieniu od dorosłych DTC u dzieci prezentują odmienne zachowanie biologiczne. Mała liczba przypadków DTC w poszczególnych ośrodkach oraz względnie łagodny ich przebieg utrudniają ocenę występowania i leczenia DTC u dzieci w Polsce, uzależniając ją od wysiłków włożonych w uzyskanie rzetelnych danych. Autorzy przedstawiają wstępne wyniki analizy wieloośrodkowej dotyczące występowania, diagnostyki i leczenia DTC u dzieci. Materiał i metody: Podjęte badania są retrospektywną analizą obejmującą lata 2000-2005, opartą na danych z historii chorób uzyskanych z ankiet rozesłanych do ośrodków dla dzieci i dorosłych podejmujących leczenie DTC. Do analizy zgłoszono 107 pacjentów z 14 ośrodków akademickich w Polsce. Analizie poddano wiek i płeć dzieci z DTC, wielkość i lokalizację zmian w tarczycy, sposoby rozpoznawania DTC, rodzaje i zakres wykonywanych zabiegów operacyjnych oraz leczenie uzupełniające izotopem J131. Wyniki: Raka brodawkowatego stwierdzono u 83 dzieci, pęcherzykowego u 10 dzieci, a rdzeniastego u 14 dzieci. Częstość występowania DTC u dzieci w Polsce wahała się między 18 a 23 przypadkami rocznie. W województwach: mazowieckim i połączonych wielkopolskim i lubuskim wykazano w okresie 2000-2005 wyższą (24 i 25) częstość występowania DTC, w pozostałych województwach wykazywano od 2 do 10 przypadków DTC. Największą grupę pacjentów stanowiły dzieci w wieku 11-15 lat, a stosunek dziewcząt do chłopców wynosił 3,3 : 1. Klinicznie DTC prezentowały się najczęściej jako pojedyncze guzki tarczycy. Limfadenopatię szyjną w badaniu klinicznym stwierdzono u 42% pacjentów, a śródoperacyjnie u 50% dzieci. U większości pacjentów dominowały niższe stopnie zaawansowania DTC (T1 u 36% i T2 u 26% dzieci). Operacje jednoetapowe wykonano u 65% dzieci, operacje dwuetapowe u 25% dzieci, a profilaktyczne tyreoidektomie u 79% dzieci z grupy pacjentów z rakiem rdzeniastym tarczycy (MTC, medullary thyroid cancinoma) i mutacją genu Ret. Leczenie izotopowe J131 podjęto u 80% dzieci. Przerzuty do płuc w scyntygrafii poterapeutycznej wykazano u 14% dzieci z DTC. Wnioski: We wnioskach podkreśla się konieczność wdrożenia na terenie całego kraju ujednoliconego i ocenianego na podstawie obiektywnych przesłanek sposobu postępowania z dziećmi z DTC

Overview of JET results for optimising ITER operation

The JET 2019–2020 scientific and technological programme exploited the results of years of concerted scientific and engineering work, including the ITER-like wall (ILW: Be wall and W divertor) installed in 2010, improved diagnostic capabilities now fully available, a major neutral beam injection upgrade providing record power in 2019–2020, and tested the technical and procedural preparation for safe operation with tritium. Research along three complementary axes yielded a wealth of new results. Firstly, the JET plasma programme delivered scenarios suitable for high fusion power and alpha particle (α) physics in the coming D–T campaign (DTE2), with record sustained neutron rates, as well as plasmas for clarifying the impact of isotope mass on plasma core, edge and plasma-wall interactions, and for ITER pre-fusion power operation. The efficacy of the newly installed shattered pellet injector for mitigating disruption forces and runaway electrons was demonstrated. Secondly, research on the consequences of long-term exposure to JET-ILW plasma was completed, with emphasis on wall damage and fuel retention, and with analyses of wall materials and dust particles that will help validate assumptions and codes for design and operation of ITER and DEMO. Thirdly, the nuclear technology programme aiming to deliver maximum technological return from operations in D, T and D–T benefited from the highest D–D neutron yield in years, securing results for validating radiation transport and activation codes, and nuclear data for ITER

Neutral pathways and heat flux widths in vertical- and horizontal-target EDGE2D-EIRENE simulations of JET

This paper further analyses the EDGE2D-EIRENE simulations presented by Chankin et al (2017 Nucl. Mater. Energy 12 273), of L-mode JET plasmas in vertical-vertical (VV) and Vertical-horizontal (VH) divertor configurations. As expected, the simulated outer divertor ionisation source peaks near the separatrix in VV and radially further out in VH. We identify the reflections of recycled neutrals from lower divertor tiles as the primary mechanism by which ionisation is concentrated on the outer divertor separatrix in the VV configuration. These lower tile reflection pathways (of neutrals from the outer divertor, and to an even greater extent from the inner divertor) dominate the outer divertor separatrix ionisation. In contrast, the lower-tile-reflection pathways are much weaker in the VH simulation and its outer divertor ionisation is dominated by neutrals which do not reflect from any surfaces. Interestingly, these differences in neutral pathways give rise to strong differences in the heat flux density width λq at the outer divertor entrance: λq = 3.2 mm in VH compared to λq = 11.8 mm in VV. In VH, a narrow channel exists in the near scrape-off-layer (SOL) where the convected heat flux, driven by strong Er × B flow and thermoelectric current, dominates over the conducted heat flux. The width of this channel sets λq and is determined by the radial distance between the separatrix and the ionisation peak in the outer divertor

Investigation into the formation of the scrape-off layer density shoulder in JET ITER-like wall L-mode and H-mode plasmas

The low temperature boundary layer plasma (Scrape-Off-Layer or SOL) between the hot core and the surrounding vessel determines the level of power-loading, erosion and implantation of material surfaces, and thus the viability of tokamak-based fusion as an energy source. This study explores mechanisms affecting the formation of flattened density profiles, so-called ‘density shoulders’, in the low-field side (LFS) SOL, which modify ion and neutral fluxes to surfaces – and subsequent erosion. There is evidence against local enhancement of ionization inducing shoulder formation. We find that increases in SOL parallel resistivity, Λdiv (=[L||νei Ωi ]/cs Ωe), postulated to lead to shoulder growth through changes in SOL turbulence characteristics, correlates with increases in upstream SOL shoulder amplitude, As only under a subset of conditions (D2-fuelled L-mode density scans with outer strike point on the horizontal target). Λdiv fails to correlate with As for cases of N2 seeding or during sweeping of the strike point across the horizontal target. The limited correlation of Λdiv with As was also found for H-mode discharges. Thus, while Λdiv above a threshold of ~1 may be necessary for shoulder formation and/or growth, another shoulder mechanism is required. More significantly we find that in contrast to parallel resistivity, outer divertor recycling as quantified by the total outer divertor Balmer Dα emission, I-Dα, does scale with shoulder amplitude where Λdiv does and even where Λdiv fails. Divertor recycling could lead to SOL density shoulder formation through: a) reducing the parallel to the field flow (loss) of ions out of the SOL to the divertor; and b) changes in radial electric fields which lead to ExB poloidal flows as well as potentially affecting the SOL turbulence birth characteristics. Thus changes in divertor recycling may be the sole process in bringing about SOL density shoulders or in tandem with parallel resistivity

Observations and modelling of ion cyclotron emission observed in JET plasmas using a sub-harmonic arc detection system during ion cyclotron resonance heating

Peer reviewe

Study of Order Parameters Coupling in Uniaxial Ferroelectrics on the Basis of Pyroelectric and Dilatometric Measurements

A method is devised of extracting the explicit form of the coupling between the primary and secondary order parameters with the use of experimental data and respecting classical and non-classical values of the effective critical exponents. The corresponding equation of state stems from the Ising model on a compressible lattice treated within the mean field approximation supplemented with terms ascertaining scaling invariance in the vicinity of the critical point. The theory is exemplified by the molecular ferroelectric crystals ($CH_{3}NH_{3})_{5}Bi_{2}Cl_{11}$ (MAPCB) and ($CH_{3}NH_{3})_{5}Bi_{2}Br_{11}$ (MAPBB)