Related papers: On the Mechanism of Townsend Avalanche for Negativ…
Gas-based time projection chambers (TPCs) have been shown to be highly sensitive X-ray polarimeters having excellent quantum efficiency while at the same time achieving large modulation factors. To observe polarization of the prompt X-ray…
We report on the existence of temperature induced negative differential conductivity (NDC) for electrons in gaseous nitrogen. The important role of superelastic rotational collisional processes in this phenomenon is highlighted. A model…
Drift velocity and longitudinal diffusion measurements are reported for a Negative Ion TPC (NITPC) operating with Helium + carbon disulfide gas mixtures at total pressures from 160 to 700 torr. Longitudinal diffusion at the thermal-limit…
Tracking capabilities in Time Projection Chambers (TPCs) are strongly dictated by the homogeneity of the drift field. Ion back-flow in various gas detectors, mainly induced by the secondary ionization processes during amplification, has…
We have identified nitromethane (CH$_3$NO$_2$) as an effective electron capture agent for negative ion TPCs (NITPCs). We present drift velocity and longitudinal diffusion measurements for negative ion gas mixtures using nitromethane as the…
We investigate discharge inception in air, in uniform background electric fields above and below the breakdown threshold. We perform 3D particle simulations that include a natural level of background ionization in the form of positive and…
Negative-ion time projection chambers(TPCs) have been studied for low-rate and high-resolution applications such as dark matter search experiments. Recently, a full volume fiducialization in a self-triggering TPC was realized. This…
A shape of the signals in proportional chamber with preamplification gap and electron component extraction from proportional discharge has been investigated. It was shown for Penning mixtures that in proportional discharge besides the…
We present measurements of drift velocities and mobilities of some innovative negative ion gas mixtures at nearly atmospheric pressure based on SF$_{6}$ as electronegative capture agent and of pure SF$_{6}$ at various pressures, performed…
A Negative Ion Time Projection Chamber was used to measure the field dependence of lateral and longitudinal diffusion for CS$_2$ anions drifting in mixtures of CS$_2$ and Ar at 40 Torr. Ion drift velocities and limits on the capture…
The use of negative ions in TPCs has several advantages for high-resolution rare- event detection experiments. The DRIFT experiment, for example, has taken full advantage of this technique over the past decade in a directional search for…
In this article it is shown analytically that the charge spectrum generated by ionizing particles in Resistive Plate Chambers under Townsend avalanche conditions, that is, for sufficiently small avalanches not affected by space-charge and…
We report the first observation of Negative Ion Drift (NID) at surface pressure of $900 \pm 7$ mbar at Laboratori Nazionali del Gran Sasso in a He:CF$_4$:SF$_6$ mixture using an optically read out Time Projection Chamber (TPC) within the…
Time Projection Chamber (TPC) is one of the main tracking systems for many current and future collider experiments at RHIC and LHC. It has a capability to measure the space points of charged tracks for good momentum resolution as well as…
The magnetization of the prototypical molecular magnet Mn12-acetate exhibits a series of sharp steps at low temperatures due to quantum tunneling at specific resonant values of magnetic field applied along the easy c-axis. An abrupt…
Streamers, thin, ionized plasma channels, form the early stages of lightning discharges. Here we approach the study of extraterrestrial lightning by studying the formation and propagation of streamer discharges in various nitrogen-methane…
We report about a nuclear track imaging system which is designed to study in detail the ionization topology of charged particle tracks in a low-pressure gas. The detection method is based on a time projection chamber (TPC) filled with…
Electrical space thrusters show important advantages for applications in outer space compared to chemical thrusters, as they allow a longer mission lifetime with lower weight and propellant consumption. Mature technologies on the market…
The dynamics of positive and negative streamers is numerically simulated in atmospheric pressure air. It is shown that positive and negative streamers behave in radically different ways when decelerating and stopping. When the head…
A simulation model for second mode positive streamers in dielectric liquids is presented. Initiation and propagation is modeled by an electron-avalanche mechanism and the Townsend--Meek criterion. The electric breakdown is simulated in a…