Title

The CLAS12 Spectrometer at Jefferson Laboratory

DOI

10.1016/j.nima.2020.163419

Authors

V. D. Burkert, Thomas Jefferson National Accelerator Facility
L. Elouadrhiri, Thomas Jefferson National Accelerator Facility
K. P. Adhikari, Mississippi State University
S. Adhikari, Florida International University
M. J. Amaryan, Old Dominion University
D. Anderson, Thomas Jefferson National Accelerator Facility
G. Angelini, The George Washington University
M. Antonioli, Thomas Jefferson National Accelerator Facility
H. Atac, Temple University
S. Aune, Universite Paris-Saclay
H. Avakian, Thomas Jefferson National Accelerator Facility
C. Ayerbe Gayoso, Mississippi State University
N. Baltzell, Thomas Jefferson National Accelerator Facility
L. Barion, Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara
M. Battaglieri, Istituto Nazionale di Fisica Nucleare, Sezione di Genova
V. Baturin, Thomas Jefferson National Accelerator Facility
I. Bedlinskiy, National Research Centre "Kurchatov Institute"
F. Benmokhtar, Duquesne University
A. Bianconi, Istituto Nazionale di Fisica Nucleare, Sezione di Pavia
A. S. Biselli, Fairfield University
P. Bonneau, Thomas Jefferson National Accelerator Facility
F. Bossù, Universite Paris-Saclay
S. Boyarinov, Thomas Jefferson National Accelerator Facility
W. J. Briscoe, The George Washington University
W. K. Brooks, Universidad Técnica Federico Santa María
K. Bruhwel, Thomas Jefferson National Accelerator Facility
D. S. Carman, Thomas Jefferson National Accelerator Facility
A. Celentano, Istituto Nazionale di Fisica Nucleare, Sezione di Genova
G. Charles, IN2P3 - Institut National de Physique Nucléaire et de Physique Des Particules
P. Chatagnon, IN2P3 - Institut National de Physique Nucléaire et de Physique Des Particules
T. Chetry, Mississippi State University

Document Type

Journal Article

Publication Date

4-11-2020

Publication Title

Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

Volume

959

ISSN

1689002

Keywords

CLAS12, Electromagnetic physics, Large acceptance, Luminosity, Magnetic spectrometer

Abstract

The CEBAF Large Acceptance Spectrometer for operation at 12 GeV beam energy (CLAS12) in Hall B at Jefferson Laboratory is used to study electro-induced nuclear and hadronic reactions. This spectrometer provides efficient detection of charged and neutral particles over a large fraction of the full solid angle. CLAS12 has been part of the energy-doubling project of Jefferson Lab's Continuous Electron Beam Accelerator Facility, funded by the United States Department of Energy. An international collaboration of 48 institutions contributed to the design and construction of detector hardware, developed the software packages for the simulation of complex event patterns, and commissioned the detector systems. CLAS12 is based on a dual-magnet system with a superconducting torus magnet that provides a largely azimuthal field distribution that covers the forward polar angle range up to 35?, and a solenoid magnet and detector covering the polar angles from 35° to 125° with full azimuthal coverage. Trajectory reconstruction in the forward direction using drift chambers and in the central direction using a vertex tracker results in momentum resolutions of <1% and <3%, respectively. Cherenkov counters, time-of-flight scintillators, and electromagnetic calorimeters provide good particle identification. Fast triggering and high data-acquisition rates allow operation at a luminosity of 1035 cm?2s?1. These capabilities are being used in a broad program to study the structure and interactions of nucleons, nuclei, and mesons, using polarized and unpolarized electron beams and targets for beam energies up to 11 GeV. This paper gives a general description of the design, construction, and performance of CLAS12.

Open Access

Green Accepted

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