1,939 research outputs found
Imaging of high-Z material for nuclear contraband detection with a minimal prototype of a Muon Tomography station based on GEM detectors
Muon Tomography based on the measurement of multiple scattering of
atmospheric cosmic ray muons in matter is a promising technique for detecting
heavily shielded high-Z radioactive materials (U, Pu) in cargo or vehicles. The
technique uses the deflection of cosmic ray muons in matter to perform
tomographic imaging of high-Z material inside a probed volume. A Muon
Tomography Station (MTS) requires position-sensitive detectors with high
spatial resolution for optimal tracking of incoming and outgoing cosmic ray
muons. Micro Pattern Gaseous Detector (MPGD) technologies such as Gas Electron
Multiplier (GEM) detectors are excellent candidates for this application. We
have built and operated a minimal MTS prototype based on 30cm \times 30cm GEM
detectors for probing targets with various Z values inside the MTS volume. We
report the first successful detection and imaging of medium-Z and high-Z
targets of small volumes (~0.03 liters) using GEM-based Muon Tomography
Event characterization of dark bosons via exotic Higgs decays with final states of displaced dimuons in high luminosity era of the LHC
We investigate the potential reach of a search for a long-lived/prompt dark
vector boson , also called dark , and a prompt dark Higgs boson
through exotic decays of the observed Higgs boson into either ,
, or with being the hypercharge gauge boson. The
production through the Higgs portal is completed via one of two mechanisms,
kinetic mixing of with and the mixing of with . All
production modes of are considered, while the branching fractions are
calculated in Monte Carlo simulation using the {\textsc{MadGraph5}}\_aMC@NLO
v2.7.2 framework. We focus on a final state of multiple dimuons, displaced up
to \mbox{7500 mm}, where the muons can be reconstructed without vertex
constraint using data from ATLAS and CMS detectors to be collected in Run~3.
Integrated luminosities of 137, 300, and 3000 fb for Run~2, Run~3, and
high luminosity run (HL-LHC), respectively, are used for estimating the
expected search sensitivity of the Large Hadron Collider to each of the decay
modes.Comment: 4 pages, 3 figures, ICHEP202
Performance of a Large-area GEM Detector Read Out with Wide Radial Zigzag Strips
A 1-meter-long trapezoidal Triple-GEM detector with wide readout strips was
tested in hadron beams at the Fermilab Test Beam Facility in October 2013. The
readout strips have a special zigzag geometry and run along the radial
direction with an azimuthal pitch of 1.37 mrad to measure the azimuthal
phi-coordinate of incident particles. The zigzag geometry of the readout
reduces the required number of electronic channels by a factor of three
compared to conventional straight readout strips while preserving good angular
resolution. The average crosstalk between zigzag strips is measured to be an
acceptable 5.5%. The detection efficiency of the detector is (98.4+-0.2)%. When
the non-linearity of the zigzag-strip response is corrected with track
information, the angular resolution is measured to be (193+-3) urad, which
corresponds to 14% of the angular strip pitch. Multiple Coulomb scattering
effects are fully taken into account in the data analysis with the help of a
stand-alone Geant4 simulation that estimates interpolated track errors.Comment: 30 pages, 28 figures, submitted to NIM
Experimental Investigation of Hadron Collisions at the Highest Center-of-Mass Energies
In this report, we summarize the research in physics of elementary particles conducted by the Florida Tech DOE supported group at the CMS experiment at CERN, during the last 3-year cycle under this grant
Low-mass GEM detector with radial zigzag readout strips for forward tracking at the EIC
We present design and construction of a large low-mass Triple-GEM detector
prototype for forward tracking at a future Electron-Ion Collider. In this
environment, multiple scattering of forward and backward tracks must be
minimized so that electron tracks can be cleanly matched to calorimeter
clusters and so that hadron tracks can efficiently seed RICH ring
reconstruction for particle identification. Consequently, the material budget
for the forward tracking detectors is critical. The construction of the
detector builds on the mechanical foil stretching and assembly technique
pioneered by CMS for the muon endcap GEM upgrade. As an innovation, this
detector implements drift and readout electrodes on thin large foils instead of
on PCBs. These foils get stretched mechanically together with three GEM foils
in a single stack. This reduces the radiation length of the total detector
material in the active area by a factor seven from over 4% to below 0.6%. It
also aims at improving the uniformity of drift and induction gap sizes across
the detector and consequently signal response uniformity. Thin outer frames
custom-made from carbon-fiber composite material take up the tension from the
stretched foil stack and provide detector rigidity while keeping the detector
mass low. The gas volume is closed with thin aluminized polyimide foils. The
trapezoidal detector covers an azimuthal angle of 30.1 degrees and a radius
from 8 cm to 90 cm. It is read out with radial zigzag strips with pitches of
1.37 mrad at the outer radius and 4.14 mrad at the inner radius that reduce the
number of required electronics channels and associated cost while maintaining
good spatial resolution. All front-end readout electronics is located away from
the active area at the outer radius of the trapezoid.Comment: 4 pages, 7 figures, submitted to conference record of 2017 IEEE
Nuclear Science Symposium, Atlanta, G
GEANT4 Simulation of a Cosmic Ray Muon Tomography System with Micro-Pattern Gas Detectors for the Detection of High-Z Materials
Muon Tomography (MT) based on the measurement of multiple scattering of
atmospheric cosmic ray muons traversing shipping containers is a promising
candidate for identifying threatening high-Z materials. Since
position-sensitive detectors with high spatial resolution should be
particularly suited for tracking muons in an MT application, we propose to use
compact micro-pattern gas detectors, such as Gas Electron Multipliers (GEMs),
for muon tomography. We present a detailed GEANT4 simulation of a GEM-based MT
station for various scenarios of threat material detection. Cosmic ray muon
tracks crossing the material are reconstructed with a Point-Of-Closest-Approach
algorithm to form 3D tomographic images of the target material. We investigate
acceptance, Z-discrimination capability, effects of placement of high-Z
material and shielding materials inside the cargo, and detector resolution
effects for such a MT station.Comment: 9 pages, 10 figures, submitted to conference proceedings of SORMA
West 08, Berkele
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