The cylindrical drift chamber is the most innovative part of the MEG II detector, the upgraded version of the MEG experiment. The MEG II chamber differs from the MEG one because it is a single volume ...cylindrical structure, instead of a segmented one, chosen to improve its resolutions and efficiency in detecting low energy positrons from muon decays at rest. In this paper, we show the characteristics and performances of this fundamental part of the MEG II apparatus and we discuss the impact of its higher resolution and efficiency on the sensitivity of the MEG II experiment. Because of its innovative structure and high quality resolution and efficiency the MEG II cylindrical drift chamber will be a cornerstone in the development of an ideal tracking detector for future positron-electron collider machines.
This report describes the physics case, the resulting detector requirements, and the evolving detector concepts for the experimental program at the Electron-Ion Collider (EIC). The EIC will be a ...powerful new high-luminosity facility in the United States with the capability to collide high-energy electron beams with high-energy proton and ion beams, providing access to those regions in the nucleon and nuclei where their structure is dominated by gluons. Moreover, polarized beams in the EIC will give unprecedented access to the spatial and spin structure of the proton, neutron, and light ions. The studies leading to this document were commissioned and organized by the EIC User Group with the objective of advancing the state and detail of the physics program and developing detector concepts that meet the emerging requirements in preparation for the realization of the EIC. The effort aims to provide the basis for further development of concepts for experimental equipment best suited for the science needs, including the importance of two complementary detectors and interaction regions. This report consists of three volumes. Volume I is an executive summary of our findings and developed concepts. In Volume II we describe studies of a wide range of physics measurements and the emerging requirements on detector acceptance and performance. Volume III discusses general-purpose detector concepts and the underlying technologies to meet the physics requirements. These considerations will form the basis for a world-class experimental program that aims to increase our understanding of the fundamental structure of all visible matter
This report describes the physics case, the resulting detector requirements, and the evolving detector concepts for the experimental program at the Electron-Ion Collider (EIC). The EIC will be a ...powerful new high-luminosity facility in the United States with the capability to collide high-energy electron beams with high-energy proton and ion beams, providing access to those regions in the nucleon and nuclei where their structure is dominated by gluons. Moreover, polarized beams in the EIC will give unprecedented access to the spatial and spin structure of the proton, neutron, and light ions. The studies leading to this document were commissioned and organized by the EIC User Group with the objective of advancing the state and detail of the physics program and developing detector concepts that meet the emerging requirements in preparation for the realization of the EIC. The effort aims to provide the basis for further development of concepts for experimental equipment best suited for the science needs, including the importance of two complementary detectors and interaction regions.
This report consists of three volumes. Volume I is an executive summary of our findings and developed concepts. In Volume II we describe studies of a wide range of physics measurements and the emerging requirements on detector acceptance and performance. Volume III discusses general-purpose detector concepts and the underlying technologies to meet the physics requirements. These considerations will form the basis for a world-class experimental program that aims to increase our understanding of the fundamental structure of all visible matter.
IDEA (Innovative Detector for Electron–positron Accelerators) is a detector concept designed for a future leptonic collider operating as a Higgs factory. It is based on innovative detector ...technologies developed over years of R&D. In September 2018, prototypes of the proposed sub-detectors have been tested for the first time on a beam line at CERN. The preliminary results from this test of a full slice of the IDEA detector and standalone measurements of dual read-out calorimeter prototypes are presented.
The Cylindrical Drift Chamber of the MEG II experiment Chiappini, M.; Baldini, A.M.; Benmansour, H. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2023, Letnik:
1047
Journal Article
Recenzirano
The MEG experiment at the Paul Scherrer Institut (PSI) represents the state of the art in the search for the charged Lepton Flavor Violating μ+→e+γ decay, setting the most stringent upper limit on ...the BR (μ+→e+γ)≤4.2×10−13 (90% C.L.). An upgrade of MEG, MEG II, was designed, commissioned and recently started the physics data taking. Its goal is to reach a sensitivity level of 6×10−14. In order to reconstruct the positron momentum vector a Cylindrical Drift CHamber (CDCH) with unprecedented peculiarities was built, featuring angular and momentum resolutions at the 6.5 mrad and 100 keV/c level. The CDCH is a 2-meter long, 60 cm in diameter, low-mass, single volume detector with high granularity: 9 layers of 192 drift cells, few mm wide, defined by ∼12000 wires in a stereo configuration for longitudinal hit localization. The filling gas mixture is Helium:Isobutane 90:10. The total radiation length is 1.5×10−3 X0, thus minimizing the Multiple Coulomb Scattering and allowing for a single-hit resolution <120μm. After the assembly at INFN Pisa, the CDCH was transported to PSI and integrated into the MEG II experimental apparatus since 2018. The commissioning phase lasted for the past three years until the operational stability was reached in 2020. The analysis software is continuously developing and the tuning of the reconstruction algorithms is one of the main activities. The latest updates on the positron momentum vector resolutions and tracking efficiency are presented.
Commissioning and preliminary performance of the MEG II drift chamber Chiappini, M.; Chiarello, G.; Baldini, A.M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2022, Letnik:
1041
Journal Article
Recenzirano
In the quest for Lepton Flavor Violation (LFV) the MEG experiment at the Paul Scherrer Institut (PSI) represents the state of the art in the search for the charged LFV decay μ+→e+γ, setting the most ...stringent upper limit on the BR(μ+→e+γ)≤4.2×10−13 (90% C.L.). An upgrade of MEG, MEG II, was designed and it recently started the physics data taking, with the aim to reach a sensitivity level of 6×10−14. The Cylindrical Drift CHamber (CDCH) is a key detector in order to improve the e+ angular and momentum resolutions at the 6.5 mrad and 100 keV/c level. The CDCH is a low-mass single volume detector with high granularity: 9 layers of 192 drift cells each, few mm wide, defined by 12000 wires in a stereo configuration for longitudinal hit localization. After the assembly, the CDCH was transported to PSI for the commissioning phase and it has been integrated into the MEG II experimental apparatus since 2018. The operational stability was reached in 2020 and the complete readout electronics was tested for the first time in 2021. A preliminary analysis of 2020–2021 data is presented.
The ultra light Drift Chamber of the MEG II experiment Baldini, A.M.; Cavoto, G.; Cei, F. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2020, Letnik:
958
Journal Article
Recenzirano
Odprti dostop
The MEG experiment at the Paul Scherrer Institute searches for the charged Lepton Flavor Violating μ+→e+γ decay. MEG has already determined in a first data taking phase the world best upper limit on ...the branching ratio: BR(μ+→e+γ)<4.2×10−13 An upgrade of the whole detector has been approved to obtain a substantial increase in sensitivity. Currently MEG is in upgrade phases, this phase involves all the detectors. The new positron tracker is a high transparency single volume, fully stereo cylindrical Drift Chamber (CDCH), immersed in a non uniform longitudinal B-field, with length of 1.93 m, internal radius of 17 cm and external radius of 30 cm. It is composed of 9 concentric layers, divided into 12 identical sector of 16 drift cells. The single drift cell is approximately square, with a 20 μm gold plated W sense wire surrounded by 40 μm silver plated Al field wires in a ratio of 5:1. The total number of wires amounts to 11904 for an equivalent radiation length per track turn of about 1.5x10−3 X0 when the chamber is filled with a gas mixture of helium and iso-butane. Due to the high wire density (12wires∕cm2), the use of the classical feed-through technique as wire anchoring system could hardly be implemented and therefore it was necessary to develop new wiring strategies. The number of wires and the stringent requirements impose the use of an automatic system (wiring robot) to operate the wiring procedures. Several tests have been performed in different prototypes of the drift chamber, exposed to cosmic rays, test beams and radioactive sources, to fulfill the requirement on the spatial resolution to be less than 110 μm. In this paper we describe the CDCH construction and the first tests during the 2018 Engineering Run.
PDF
