The NEUT neutrino interaction simulation program library

is a neutrino–nucleus interaction simulation program library. It can be used to simulate interactions for neutrinos with between 100 MeV and a few TeV of energy. is also capable of simulating hadron interactions within a nucleus and is used to model nucleon decay and hadron–nucleus interactions for particle propagation in detector simulations. This article describes the range of interactions modelled and how each is implemented.

Investigation of Particle Steering for Different Cylindrical Permanent Magnets in Magnetic Drug Targeting

Magnetic Drug Targeting is a promising cancer treatment that offers the possibility of increasing therapeutic efficiency while reducing the patient’s side-effects. Thereby, the cancer-drug is bounded to magnetic nanoparticles, which are injected into a vessel and guided through the cardiovascular system into the tumor by an external magnetic field. However, a successful navigation depends on several multiphysical parameters including the properties of the nanoparticles, the flow characteristics of blood, and the gradient of the applied magnetic field. To investigate their impact, the propagation of particle packets within a 45∘ bifurcation vessel was modeled in COMSOL Multiphysics®. Therefore, magnets with varying radius-to-length ratios and magnetizations (radial and axial) were placed right before the bifurcation. Furthermore, different fluid velocities in addition to the influence of the gravitational force were evaluated. Overall, a strong dependency of the particle steering on the fluid velocity and the magnet’s radius-to-length ratio was observed. Moreover, a radial magnetization has a greater impact on the particle propagation, while the gravitation can be neglected for higher velocities. However, when a single permanent magnet is used, the results depict that it is a fine line between deflecting or trapping a particle at the vessel wall.

Hepatitis B Virus Exploits ERGIC-53 in Conjunction with COPII to Exit Cells

Several decades after its discovery, the hepatitis B virus (HBV) still displays one of the most successful pathogens in human populations worldwide. The identification and characterization of interactions between cellular and pathogenic components are essential for the development of antiviral treatments. Due to its small-sized genome, HBV highly depends on cellular functions to produce and export progeny particles. Deploying biochemical-silencing methods and molecular interaction studies in HBV-expressing liver cells, we herein identified the cellular ERGIC-53, a high-mannose-specific lectin, and distinct components of the endoplasmic reticulum (ER) export machinery COPII as crucial factors of viral trafficking and egress. Whereas the COPII subunits Sec24A, Sec23B and Sar1 are needed for both viral and subviral HBV particle exit, ERGIC-53 appears as an exclusive element of viral particle propagation, therefore interacting with the N146-glycan of the HBV envelope in a productive manner. Cell-imaging studies pointed to ER-derived, subcellular compartments where HBV assembly initiates. Moreover, our findings provide evidence that HBV exploits the functions of ERGIC-53 and Sec24A after the envelopment of nucleocapsids at these compartments in conjunction with endosomal sorting complexes required for transport (ESCRT) components. These data reveal novel insights into HBV assembly and trafficking, illustrating therapeutic prospects for intervening with the viral life cycle.

Halo fraction in TeV-bright pulsar wind nebulae

The discovery of extended TeV emission around the Geminga and PSR B0656+14 pulsars, with properties consistent with free particle propagation in the interstellar medium (ISM), has led to the suggestion of “TeV halos” as a separate source class, which is distinct from pulsar wind nebulae. This has sparked considerable discussion on the possible presence of such halos in other systems. In defining halos as regions where the pulsar no longer dominates the dynamics of the interstellar medium, yet where an over-density of relativistic electrons is present, we make an assessment of the current TeV source population associated with energetic pulsars in terms of size and estimated energy density. Based on two alternative estimators, we conclude that a large majority of the known TeV sources have emission originating in the zone that is energetically and dynamically dominated by the pulsar (i.e. the pulsar wind nebula), rather than from a surrounding halo of escaped particles diffusing into the ISM. Furthermore, whilst the number of established halos will surely increase in the future since there is a known large population of older, less energetic pulsars, we find that it is unlikely that such halos contribute significantly to the total TeV γ-ray luminosity from electrons accelerated in pulsar wind nebulae due to their lower intrinsic surface brightness.

Energetic particles measurements on the lunar far-side by Lunar Lander Neutron and Dosimetry(LND) experiment

<p>After Chang’E 4 successfully landed on the far side of the moon on Jan 3rd, 2019, the Lunar Lander Neutron and Dosimetry experiment has been working for 13 lunar days from January, 2019 to January, 2020, sending back the measurements of dose, linear energy transfer (LET) spectrum, neutrons, and charged particles. Here, we show observations of charged particles especially protons and Helium ions during quiet time. We also present two solar energetic particle events registered by LND in May 2019, which are also the first such measurements on the far-side surface of the moon. The temporal variations of particle fluxes on the far side of the moon detected by LND provide a new observation site in space and can be helpful to improve our understanding of particle propagation and transport in the heliosphere.</p><p> </p>

ION BEAM PROPAGATION STABILITY IN A LINAC ACCELERATING CHANNEL BASED ON COMBINED RF-FOCUSING

The issue of simultaneous longitudinal and transverse particle propagation stability in a linear ion accelerator channel based on combined RF-focusing is investigated. Values for RFQ field gradient to provide transverse propagation stability for all the particles in an acceleration mode are calculated. It is also shown that electrical strength of the electrodes influences the gradient value. Much attention is given to modeling of an accelerating-focusing channel which provides the minimal growth in beam emittance.