scholarly journals LOW-MASS RADIATION-HARD BEAM PROFILE MONITORS FOR HIGH ENERGY PROTONS USING MICROFABRICATED METALTHIN-FILMS

2021 ◽  
Author(s):  
Didier Bouvet ◽  
Jacopo Bronuzzi ◽  
Blerina Gkotse ◽  
Georgi Gorine ◽  
Alessandro Mapell ◽  
...  
Keyword(s):  
High Energy ◽  
Beam Profile ◽  
Low Mass ◽  
Radiation Hard

scholarly journals Exploring Flaring Behaviour on Low Mass Stars, Solar-type Stars and the Sun

2019 ◽  
Vol 15 (S354) ◽  
pp. 384-391
Author(s):  
L. Doyle ◽  
G. Ramsay ◽  
J. G. Doyle ◽  
P. F. Wyper ◽  
E. Scullion ◽  
...  
Keyword(s):  
High Energy ◽  
The Sun ◽  
Low Mass Stars ◽  
Highly Active ◽  
Rotation Phase ◽  
Solar Type ◽  
Low Mass ◽  
Insight Into ◽  
Reconnection Model ◽  
High Cadence

AbstractWe report on our project to study the activity in both the Sun and low mass stars. Utilising high cadence, Hα observations of a filament eruption made using the CRISP spectropolarimeter mounted on the Swedish Solar Telescope has allowed us to determine 3D velocity maps of the event. To gain insight into the physical mechanism which drives the event we have qualitatively compared our observation to a 3D MHD reconnection model. Solar-type and low mass stars can be highly active producing flares with energies exceeding erg. Using K2 and TESS data we find no correlation between the number of flares and the rotation phase which is surprising. Our solar flare model can be used to aid our understanding of the origin of flares in other stars. By scaling up our solar model to replicate observed stellar flare energies, we investigate the conditions needed for such high energy flares.

Radiation hard amorphous silicon particle sensors

2005 ◽  
Vol 862 ◽  
Author(s):  
N. Wyrsch ◽  
C. Miazza ◽  
S. Dunand ◽  
C. Ballif ◽  
A. Shah ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Proton Beam ◽  
Thermal Annealing ◽  
Silicon Particle ◽  
Hydrogenated Amorphous Silicon ◽  
High Energy ◽  
Significant Drop ◽  
Radiation Hard ◽  
Hydrogenated Amorphous ◽  
Subsequent Thermal Annealing

AbstractRadiation tests of 32 μm thick hydrogenated amorphous silicon n-i-p diodes have been performed using a high energy 24 GeV proton beam up to fluences in excess of 1016 protons/cm2. The results are compared to irradiation of similar 1 μm and 32 μm thick n-i-p diodes using a proton beam of 280 keV at a fluence of 3x1013 protons/cm2. Even though both types of irradiation cause a significant drop in photoconductivity of thin or thick diodes, all samples survived the experiment and recover almost fully after a subsequent thermal annealing.

scholarly journals Photo-evaporation of close-in gas giants orbiting around G and M stars

2019 ◽  
Vol 624 ◽  
pp. A101 ◽  
Author(s):  
Daniele Locci ◽  
Cesare Cecchi-Pestellini ◽  
Giuseppina Micela
Keyword(s):  
Extreme Ultraviolet ◽  
Dynamical Evolution ◽  
High Energy ◽  
Electron Content ◽  
Mass Star ◽  
X Rays ◽  
Atmospheric Escape ◽  
Low Mass ◽  
M Stars ◽  
The Stability

Context. X-rays and extreme ultraviolet radiation impacting a gas produce a variety of effects that, depending on the electron content, may provide significant heating of the illuminated region. In a planetary atmosphere of solar composition, stellar high energy radiation can heat the gas to very high temperatures and this could affect the stability of planetary atmospheres, in particular for close-in planets. Aims. We investigate the variations with stellar age in the occurring frequency of gas giant planets orbiting G and M stars, taking into account that the high energy luminosity of a low mass star evolves in time, both in intensity and hardness. Methods. Using the energy-limited escape approach we investigated the effects induced by the atmospheric mass loss on giant exoplanet distribution that is initially flat, at several distances from the parent star. We followed the dynamical evolution of the planet atmosphere, tracking the departures from the initial profile due to the atmospheric escape, until it reaches the final mass-radius configuration. Results. We find that a significant fraction of low mass Jupiter-like planets orbiting with periods lower than ~3.5 days either vaporize during the first billion years or lose a relevant part of their atmospheres. The planetary initial mass profile is significantly distorted; in particular, the frequency of occurrence of gas giants, less massive than 2 MJ, around young stars can be considerably greater than their occurrence around older stellar counterparts.

DMILL, a mixed analog-digital radiation-hard BICMOS technology for high energy physics electronics

1996 ◽  
Vol 43 (3) ◽  
pp. 1763-1767 ◽  
Author(s):  
M. Dentan ◽  
P. Abbon ◽  
E. Delagnes ◽  
N. Fourches ◽  
D. Lachartre ◽  
...  
Keyword(s):  
High Energy Physics ◽  
High Energy ◽  
Bicmos Technology ◽  
Radiation Hard ◽  
Energy Physics

scholarly journals INVESTIGATION OF DENSE GAS TOWARDS RELATIVISTIC OUTFLOW SOURCES

2014 ◽  
Vol 28 ◽  
pp. 1460198
Author(s):  
J. HAWKES ◽  
G. ROWELL ◽  
B. DAWSON ◽  
F. AHARONIAN ◽  
M. BURTON ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Line Emission ◽  
High Energy ◽  
Dense Gas ◽  
Relativistic Jets ◽  
Hii Region ◽  
X Ray ◽  
Stellar Cluster ◽  
Radio Recombination Line ◽  
Low Mass

We probe the interstellar medium towards the objects Circinus X-1, a low-mass X-ray binary with relativistic jets; and the highly energetic Westerlund 2 stellar cluster, which is located towards TeV gamma-ray emission and interesting arc- and jet-like features seen in Nanten 12CO data. We have mapped both regions with the Mopra radio telescope, in 7 mm and 12 mm wavebands, looking for evidence of disrupted/dense gas caused by the interaction between high energy outflows and the ISM. Towards Westerlund 2, peaks in CS(J=1-0) emission indicate high density gas towards the middle of the arc and the endpoint of the jet; and radio recombination line emission is seen overlapping the coincident HII region RCW49. Towards Circinus X-1, 12CO(J = 1-0) Nanten data reveals three molecular clouds that lie in the region of Cir X-1. Gas parameters for each cloud are presented here.

Excitation of High-Energy Protons into Low-Mass States inp−dInteractions

1975 ◽  
Vol 35 (12) ◽  
pp. 763-766 ◽  
Author(s):  
Y. Akimov ◽  
R. Cool ◽  
L. Golovanov ◽  
K. Goulianos ◽  
D. Gross ◽  
...  
Keyword(s):  
High Energy ◽  
Low Mass

scholarly journals Environmental effects on the ionisation of brown dwarf atmospheres

2018 ◽  
Vol 618 ◽  
pp. A107 ◽  
Author(s):  
M. I. Rodríguez-Barrera ◽  
Ch. Helling ◽  
K. Wood
Keyword(s):  
White Dwarf ◽  
Binary Systems ◽  
Brown Dwarfs ◽  
High Energy ◽  
Radiation Environment ◽  
Brown Dwarf ◽  
Star Forming ◽  
Star Forming Regions ◽  
Lyman Continuum ◽  
Low Mass

Context. Brown dwarfs emit bursts of Hα, white-light flares, and show radio flares and quiescent radio emission. They are suggested to form aurorae, similar to planets in the solar system, but much more energetic. All these processes require a source gas with an appropriate degree of ionisation, which, so far, is mostly postulated to be sufficient. Aims. We aim to demonstrate that the Galactic environment influences atmospheric ionisation, and that it hence amplifies or enables the magnetic coupling of the atmospheres of ultra-cool objects, like brown dwarfs and free-floating planets. Methods. We build on our previous work on thermal ionisation of ultra-cool atmospheres and explore the effect of environmental high-energy radiation on the degree of ionisation in the atmosphere. We consider the effect of photoionisation by Lyman-continuum radiation in three different environments: in the interstellar radiation field (ISRF), O and B stars in star-forming regions, and in white dwarf companions in binary systems. We apply our Monte Carlo radiation transfer code to investigate the effect of Lyman-continuum photoionisation for prescribed atmosphere structures for very low-mass objects. Results. The external radiation environment plays an important role for the atmospheric ionisation of very low-mass, ultra-cool objects. Lyman-continuum irradiation greatly increases the level of ionisation in the uppermost atmospheric regions. Our results suggest that a shell of an almost fully ionised atmospheric gas emerges for brown dwarfs in star-forming regions and brown dwarfs in white dwarf binary systems. As a consequence, brown dwarf atmospheres can be magnetically coupled, which is the presumption for chromospheric heating to occur and for aurorae to emerge. First tests for assumed chromosphere-like temperature values suggest that the resulting free-free X-ray luminosities are comparable with those observed from non-accreting brown dwarfs in star-forming regions.

scholarly journals ALMA observations of the young protostellar system Barnard 1b: Signatures of an incipient hot corino in B1b-S

2018 ◽  
Vol 620 ◽  
pp. A80 ◽  
Author(s):  
N. Marcelino ◽  
M. Gerin ◽  
J. Cernicharo ◽  
A. Fuente ◽  
H. A. Wootten ◽  
...  
Keyword(s):  
Ethyl Formate ◽  
High Energy ◽  
Source Model ◽  
Mass Star ◽  
Line Profiles ◽  
Stellar Objects ◽  
Star Forming ◽  
Compact Component ◽  
Prestellar Cores ◽  
Low Mass

The Barnard 1b core shows signatures of being at the earliest stages of low-mass star formation, with two extremely young and deeply embedded proto-stellar objects. Hence, this core is an ideal target to study the structure and chemistry of the first objects formed in the collapse of prestellar cores. We present ALMA Band 6 spectral line observations at ~0.6″ of angular resolution towards Barnard 1b. We have extracted the spectra towards both protostars, and used a local thermodynamic equilibrium (LTE) model to reproduce the observed line profiles. B1b-S shows rich and complex spectra, with emission from high energy transitions of complex molecules, such as CH3OCOH and CH3CHO, including vibrational level transitions. We have tentatively detected for the first time in this source emission from NH2CN, NH2CHO, CH3CH2OH, CH2OHCHO, CH3CH2OCOH and both aGg′ and gGg′ conformers of (CH2OH)2. This is the first detection of ethyl formate (CH3CH2OCOH) towards a low-mass star forming region. On the other hand, the spectra of the FHSC candidate B1b-N are free of COMs emission. In order to fit the observed line profiles in B1b-S, we used a source model with two components: an inner hot and compact component (200 K, 0.35″) and an outer and colder one (60 K, 0.6″). The resulting COM abundances in B1b-S range from 10−13 for NH2CN and NH2CHO, up to 10−9 for CH3OCOH. Our ALMA Band 6 observations reveal the presence of a compact and hot component in B1b-S, with moderate abundances of complex organics. These results indicate that a hot corino is being formed in this very young Class 0 source.

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