SiC detectors: A review on the use of silicon carbide as radiation detection material

Silicon Carbide (SiC) is a wide bandgap semiconductor with many excellent properties that make it one of the most promising and well-studied materials for radiation particle detection. This review provides an overview of the main advantages in the use of SiC detectors and the current state of research in this field. Key aspects related to material properties, growth techniques, doping, defects, electrical contacts, and characterization methods are summarized, with particular emphasis on how these can be related to detector performance. The most recent and significant experimental results on the use of SiC diodes for the detection of electrons, protons, alpha, ions, UV radiation, x/γ-rays, and neutrons are discussed. The effects of high temperature operation and radiation damage on detector performance are outlined

Validation of Geant4 nuclear reaction models for hadrontherapy and preliminary results with SMF and BLOB

Reliable nuclear fragmentation models are of utmost importance in hadrontherapy, where Monte Carlo (MC) simulations are used to compute the input parameters of the treatment planning software, to validate the deposited dose calculation, to evaluate the biological effectiveness of the radiation, to correlate the bþ emitters production in the patient body with the delivered dose, and to allow a non- invasive treatment verification. Despite of its large use, the models implemented in Geant4 have shown severe limitations in reproducing the measured secondaries yields in ions interaction below 100 MeV/A, in term of production rates, angular and energy distributions [1–3]. We will present a benchmark of the Geant4 models with double-differential cross sec- tion and angular distributions of the secondary fragments produced in the 12C fragmentation at 62 MeV/A on thin carbon target, such a benchmark includes the recently implemented model INCL++ [4,5]. Moreover, we will present the preliminary results, obtained in simulating the same interaction, with SMF [6] and BLOB [7]. Both, SMF and BLOB are semiclassical one-body approaches to solve the Boltzmann-Langevin equation. They include an identical treatment of the mean-field propagation, on the basis of the same effective interaction, but they differ in the way fluctuations are included. In particular, while SMF employs a Uehling-Uhlenbeck collision term and introduces fluctuations as projected on the density space, BLOB introduces fluctuations in full phase space through a modified collision term where nucleon-nucleon correlations are explicitly involved. Both of them, SMF and BLOB, have been developed to sim- ulate the heavy ion interactions in the Fermi-energy regime. We will show their capabilities in describing 12C fragmentation foreseen their implementation in Geant4

Alpha Cluster Structure in16O

The main purpose of the present work is the investigation of the α-cluster phenomenon in 16 O. The 12 C( 6 Li,d) 16 O reaction was measured at a bombarding energy of 25.5 MeV employing the Sao Paulo Pelletron-Enge-Spectrograph facility and the nuclear emulsion detection technique. Resonant states around 4α threshold were measured and an energy resolution of 15 keV allows to define states previously unresolved. The angular distributions of the absolute cross sections were determined in a range of 4-40 degree in the center of mass system. The upper limit for the resonance widths was obtained, indicating that the α cluster structure information in this region should be revised

Thick-target inverse kinematic method in order to investigate alpha-clustering in212Po

The inverse-kinematic thick-target method has been used in order to investigate 212Po alpha-structure by the elastic scattering of 208Pb on 4He target. A 208Pb beam, accelerated by the Superconducting Cyclotron (CS) of Laboratori Nazionali del Sud - INFN, at the incident energy of 10.1 A MeV was impinging onto a specifically designed 4He gas cell, two meter long. The gas cell wasacting both as target and as beam degrader, stopping the beam before reaching the alpha-particle detection system placed at 0° with respect to the beam axis. In order to disentangle the elastic contribution from other reaction channels (e.g. inelastic scattering) a microchannel plate was used to measure the Time of Flight(ToF) of both the 208Pb beam particles and the ejectiles along the gas cell. The 208Pbstopping power in the 4He gas target was also measured, as a key ingredient in order to establish theinteraction point inside the gas cell, in turn determining the solid angle covered by the detector. In the following, the experimental technique will be described, and the results of a preliminary data analysis will be shown

Dark sectors 2016 Workshop: community report

This report, based on the Dark Sectors workshop at SLAC in April 2016, summarizes the scientific importance of searches for dark sector dark matter and forces at masses beneath the weak-scale, the status of this broad international field, the important milestones motivating future exploration, and promising experimental opportunities to reach these milestones over the next 5-10 years

US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference

The Heavy Photon Search experiment at Jefferson Laboratory

Many beyond Standard Model theories predict a new massive gauge boson, aka “dark” or “heavy photon”, directly coupling to hidden sector particles with dark charge. The heavy photon is expected to mix with the Standard Model photon through kinetic mixing and therefore couple weakly to normal charge. The Heavy Photon Search (HPS) experiment will search for the heavy photon at the Thomas Jefferson National Accelerator Facility (JLab), in the mass range 20-1000 MeV/c2 and coupling to electric charge ϵ2 = α′/α in the range 10−5 to 10−10. HPS will look for the e+e− decay channel of heavy photons radiated by electron Bremsstrahlung, employing both invariant mass search and detached vertexing techniques. The experiment employs a compact forward spectrometer comprising silicon microstrip detectors for vertexing and tracking and an electromagnetic calorimeter for particle identification and triggering

Production and Detection of Light Dark Matter at Jefferson Lab: The BDX Experiment

The Beam Dump eXperiment (BDX) is a an electron-beam thick-target experiment aimed to investigate the existence of light Dark Matter particles in the MeV-GeV mass region at Jefferson Lab. The experiment will make use of a 10.6 GeV high-intensity electron-beam impinging on the Hall-A beam-dump to produce the Dark Matter particles ( χ ) through the Dark Photon portal. The BDX detector located at ∼20 m from the dump consists of two main components: an electromagnetic calorimeter to detect the signals produced by the χ -electron scattering and a veto system to reject background. The expected signature of the DM (Dark Matter) interaction in the Ecal (Electromagnetic calorimeter) is a ∼GeV electromagnetic shower paired with a null activity in the surrounding active veto counters. Collecting 10 22 electrons on target in 285 days of parasitic run at 65 μ A of beam current, and with an expected background of O(5) counts, in the case of a null discovery, BDX will be able to lower the exclusion limits by one to two orders of magnitude in the parameter space of dark-matter coupling versus mass. This paper describes the experiment and presents a summary of the most significant results achieved thus far, which led to the recent approval of the experiment by JLab-PAC46