Stopping power of low-energy deuterons in 3He{^{3}He} gas

The stopping power of atomic and molecular deuterons in ${^{3}He}$ gas was measured over the range $E_{\rm d}$ = 10 to 100 keV using the ${^{3}He}$ pressure dependence of the ${^{3}He}(d,p){^{4}He}$ reaction yield. At energies above 30 keV, the observed stopping power values are in good agreement with a standard compilation. However, near 18 keV the experimental values drop by a factor 50 below the extrapolated values of the compilation. In a simple model, the behavior is due to the minimum $1s \to 2s$ electron excitation of the He target atoms (= 19.8 eV, corresponding to $E_{\rm d}$ = 18.2 keV), i.e. it is a quantum effect, by which the atoms become nearly transparent for the ions

Stopping power of low-energy deuterons in 3He gas.

The stopping power of atomic and molecular deuterons in ${^{3}He}$ gas was measured over the range $E_{\rm d}$ = 10 to 100 keV using the ${^{3}He}$ pressure dependence of the ${^{3}He}(d,p){^{4}He}$ reaction yield. At energies above 30 keV, the observed stopping power values are in good agreement with a standard compilation. However, near 18 keV the experimental values drop by a factor 50 below the extrapolated values of the compilation. In a simple model, the behavior is due to the minimum $1s \to 2s$ electron excitation of the He target atoms (= 19.8 eV, corresponding to $E_{\rm d}$ = 18.2 keV), i.e. it is a quantum effect, by which the atoms become nearly transparent for the ions

Enhanced electron screening in \mth{d(d, p)t} for deuterated Ta*

The recent observation of a large electron screening effect in the d(d, p)t reaction using a deuterated Ta target has been confirmed using somewhat different experimental approaches: for the electron screening potential energy. The high $U_{\rm e}$ value arises from the environment of the deuterons in the Ta matrix, but a quantitative explanation is missing

Enhanced electron screening in \mth{d(d, p)t} for deuterated Ta*

The recent observation of a large electron screening effect in the d(d, p)t reaction using a deuterated Ta target has been confirmed using somewhat different experimental approaches: for the electron screening potential energy. The high $U_{\rm e}$ value arises from the environment of the deuterons in the Ta matrix, but a quantitative explanation is missing

The 4MOST Survey of Young Stars (4SYS)

Interstellar matter and star formatio

MAGIC very large zenith angle observations of the Crab Nebula up to 100 TeV

Aims. We measure the Crab Nebula γ-ray spectral energy distribution in the ~100 TeV energy domain and test the validity of existing leptonic emission models at these high energies. Methods. We used the novel very large zenith angle observations with the MAGIC telescope system to increase the collection area above 10 TeV. We also developed an auxiliary procedure of monitoring atmospheric transmission in order to assure proper calibration of the accumulated data. This employs recording optical images of the stellar field next to the source position, which provides a better than 10% accuracy for the transmission measurements. Results. We demonstrate that MAGIC very large zenith angle observations yield a collection area larger than a square kilometer. In only ~ 56 h of observations, we detect the γ-ray emission from the Crab Nebula up to 100 TeV, thus providing the highest energy measurement of this source to date with Imaging Atmospheric Cherenkov Telescopes. Comparing accumulated and archival MAGIC and Fermi/LAT data with some of the existing emission models, we find that none of them provides an accurate description of the 1 GeV to 100 TeV γ-ray signal

Author Correction: Proton acceleration in thermonuclear nova explosions revealed by gamma rays (Nature Astronomy, (2022), 6, 6, (689-697), 10.1038/s41550-022-01640-z)

In the version of this article initially published, there was an error in the scale described in the right-hand y-axis label of Fig. 1. Flux density (Jy), now presented on a scale from “1, 10, 102”, was originally shown as “10, 102”. The image has been corrected in the HTML and PDF versions of the article. Further, the Source Data for Fig. 1 have now been replaced online