16 research outputs found
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Recents results and future measurements for few body problems in Hall A
I will summarize the latest results in Hall A linked to Few-Body problems and the future measurements planned after the 12 GeV upgrade
NaI (Tl) Calorimeter Calibration and Simulation for Coulomb Sum Rule Experiment in Hall-A at Jefferson Lab
A precision measurment of inclusive electron scattering cross sections was
carried out at Jefferson Lab in the quasi-elastic region for He,
C, Fe and Pb targets. Longitudinal () and
transverse () response functions of nucleon were extracted in the
momentum transfer range 0.55 GeV/c1.0 GeV/c. To achieve the
above goal, a NaI (Tl) calorimeter was used to distinguish good electrons from
background including pions and low energy electrons rescattered from walls of
the spectrometer magnets. Due to a large set of kinematics and changes in HV
settings, a number of calibrations were performed for the NaI (Tl) detector.
Corrections for a few blocks of NaI (Tl) with bad or no signal were applied.
The resolution of NaI (Tl) detector after calibration reached at E=1 GeV. The performance of NaI (Tl) detector was
compared with a simulation
The low Q
The JLAB EIC (JLEIC) design includes a chicane after the interaction point to detect electron associated with production of quasi-real photon at the interaction. This chicane layout can also be used for Compton polarimetry to measure the electron beam polarization. This proceeding will present the layout of the low Q2 chicane and the implementation and current R&D of a Compton polarimeter which would be located in the middle of this chicane
Performance of photosensors in a high-rate environment for gas Cherenkov detectors
The solenoidal large intensity device (SoLID) at Jefferson Lab will push the
boundaries of luminosity for a large-acceptance detector, which necessitates
the use of a light-gas threshold Cherenkov counter for online event selection.
Due to the high luminosity, the single-photon background rate in this counter
can exceed 160 kHz/cm at the photosensors. Therefore, it is essential to
validate the high-rate limits of the planned photosensors and readout
electronics in order to mitigate the risk of failure. We report on the design
and an early set of studies carried out using a small telescopic Cherenkov
device in a high-rate environment up to 60 kHz/cm, in Hall C at Jefferson
Lab. Commercially available multi-anode photomultipliers (MaPMT) and low-cost
large-area picosecond photodetectors (LAPPD) were tested using the JLab FADC250
modules for readout. The test beam results show that the MaPMT array and the
internal stripline LAPPD can detect and identify single-electron and
pair-production events in high-rate environments. Due to its higher quantum
efficiency, the MaPMT array provided a better separation between the
single-electron and the pair-production events compared to the internal
stripline LAPPD. A GEANT4 simulation confirms the experimental performance of
our telescopic device.Comment: 16 pages, 11 figure
The Solenoidal Large Intensity Device (SoLID) for JLab 12 GeV
The Solenoidal Large Intensity Device (SoLID) is a new experimental apparatus
planned for Hall A at the Thomas Jefferson National Accelerator Facility
(JLab). SoLID will combine large angular and momentum acceptance with the
capability to handle very high data rates at high luminosity. With a slate of
approved high-impact physics experiments, SoLID will push JLab to a new limit
at the QCD intensity frontier that will exploit the full potential of its 12
GeV electron beam. In this paper, we present an overview of the rich physics
program that can be realized with SoLID, which encompasses the tomography of
the nucleon in 3-D momentum space from Semi-Inclusive Deep Inelastic Scattering
(SIDIS), expanding the phase space in the search for new physics and novel
hadronic effects in parity-violating DIS (PVDIS), a precision measurement of
production at threshold that probes the gluon field and its
contribution to the proton mass, tomography of the nucleon in combined
coordinate and momentum space with deep exclusive reactions, and more. To meet
the challenging requirements, the design of SoLID described here takes full
advantage of recent progress in detector, data acquisition and computing
technologies. In addition, we outline potential experiments beyond the
currently approved program and discuss the physics that could be explored
should upgrades of CEBAF become a reality in the future.Comment: This white paper for the SoLID program at Jefferson Lab was prepared
in part as an input to the 2023 NSAC Long Range Planning exercise. To be
submitted to J. Phys.
Precision measurements of A1N in the deep inelastic regime
We have performed precision measurements of the double-spin virtual-photon asymmetry A1A1 on the neutron in the deep inelastic scattering regime, using an open-geometry, large-acceptance spectrometer and a longitudinally and transversely polarized 3He target. Our data cover a wide kinematic range 0.277≤x≤0.5480.277≤x≤0.548 at an average Q2Q2 value of 3.078 (GeV/c)2, doubling the available high-precision neutron data in this x range. We have combined our results with world data on proton targets to make a leading-order extraction of the ratio of polarized-to-unpolarized parton distribution functions for up quarks and for down quarks in the same kinematic range. Our data are consistent with a previous observation of anA1n zero crossing near x=0.5x=0.5. We find no evidence of a transition to a positive slope in(Δd+Δd¯)/(d+d¯) up to x=0.548x=0.548
The low
The JLAB EIC (JLEIC) design includes a chicane after the interaction point to detect electron associated with production of quasi-real photon at the interaction. This chicane layout can also be used for Compton polarimetry to measure the electron beam polarization. This proceeding will present the layout of the low Q2 chicane and the implementation and current R&D of a Compton polarimeter which would be located in the middle of this chicane