42 research outputs found
Inelastic Neutron Scattering from the Spin Ladder Compound (VO)2P2O7
We present results from an inelastic neutron scattering experiment on the
candidate Heisenberg spin ladder vanadyl pyrophosphate, (VO)2P2O7. We find
evidence for a spin-wave excitation gap of meV, at a
band minimum near . This is consistent with expectations for
triplet spin waves in (VO)2P2O7 in the spin-ladder model, and is to our
knowledge the first confirmation in nature of a Heisenberg antiferromagnetic
spin ladder.Comment: 11 pages and 2 figures (available as hard copy or postscript files
from the authors, send request to [email protected] or
[email protected]), TEX using jnl, reforder and eqnorder, ORNL-CCIP-94-05
/ RAL-94-04
A psicologia cognitiva experimental cinqĂŒenta anos depois: a crise do paradigma do processamento de informação
Highly-parallelized simulation of a pixelated LArTPC on a GPU
The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype