Session SK: Mini-Symposium: Novel detector Technologies, from detectors to data analysis IV

GEM data analysis for the MUSE experiment at PSI

The Muon Scattering Experiment at the PiM1 beam line of the Paul-Scherrer Institute (PSI) will~contribute to the resolution of the proton radius puzzle by measuring the~proton charge radius with simultaneous electron and muon scattering. Both positive and negative beam polarities will be used. Precise measurements of the elastic~differential cross sections require accurate determinations of the~scattering angle. The secondary PiM1 beam has a large divergence, which necessitates measuring both the incoming and outgoing trajectories of scattered particles. High resolution Gas Electron Multiplier (GEM) detectors~are used to determine the incoming beam~particle trajectory. I will discuss recent improvements in pedestal and noise subtraction, hot/dead channel~masking, suppression of cross talk of electronics and subsequently~improved cluster finding and tracking~efficiency of the GEM detector telescope.   

Study of triple and quadruple GEM detector

Gas Electron Multipliers (GEMs) are gaseous ionization detectors operated using the principle of multistage avalanche of primary ionizing electrons, which results in the amplification of weak signals. GEMs are used in both particle and nuclear physics and medical science. The parameters associated with the performance of GEMs are effective gain, ion back flow, energy resolution, and stability over time. The choice of gas mixture for operating GEM detectors also affects their performance. The effective gain quantifies the avalanche process by the GEM while the ion back flow characterizes the fraction of Ions that drift in the opposite direction to the avalanche electrons in GEM detectors. The backwards-drifting Ions in GEM detectors are undesirable because they distort the uniform electric field in the detector gas volume. Studies done by our group involve optimizing the effective gain for different gas mixtures over various operating voltages, reducing ion back flow while enhancing the energy resolution for detected particles for both triple and quadruple gem detectors.   

Commissioning and Characterization of the GEM Based Proton Polarimeter Trackers in the Super Bigbite Spectrometer in JLAB

The electromagnetic form factors of the nucleon are essential for our understanding of the structure of the nucleon. Precision measurement of nucleon form factors is an important part of the Jefferson Lab experimental program. The 12 $GeV$ beam upgrade of the Jefferson lab accelerator and the newly designed Super BigBite Spectrometer make possible a new generation of experiments to measure nucleon form factors with high precision at high $Q^2$ values to over 10 $GeV^2/c^2$. The concept of the Super BigBite Spectrometer, which provides a large solid angle and the capability to operate at high luminosity, relies on Gas Electron Multiplier (GEM) detector based particle trackers. The SBS GEM chambers are expected to provide a good position resolution of $\sim$ 70 $\mu m$, while operating in at high rate conditions up to 1 $MHz/cm^2$. A set of 44 GEM detector modules, each with an active area of 60 x 50 $cm^2$, has been built in the GEM detector lab at UVa for the proton polarimeter trackers of SBS. This talk will report on the commissioning activities of SBS polarimeter GEM tracker layers at the Jefferson lab and plans for their use in SBS form factor experiments.   

Commissioning of the Gas Electron Multiplier System for the E12-17-004 Neutron Polarimeter

The Super Bigbite Spectrometer (SBS) at Thomas Jefferson National Laboratory was proposed to perform a series of high precision nucleon form factor experiments at large momentum transfer.The SBS will be capable of operating at very high luminosity and provide a large solid angle acceptance.A set of large Gas Electron Multiplier (GEM) detectors is being commissioned for a novel neutron polarimeter based on elastic and charge-exchange recoil proton detection.This talk will report on the commissioning activity and performance of the GEM detectors.   

Alignment of the GEM Based Beam Tracking Telescope for MUSE

The Muon Scattering Experiment (MUSE) at Paul Scherrer Institute (PSI) is designed to measure the proton charge radius with simultaneous elastic scattering of electrons and muons of either charge polarity. For an accurate determination of the lepton scattering angle, event-by-event beam particle tracking is required to reconstruct the incoming particle track. A telescope of Gas Electron Multipliers (GEM), exposed to a high flux of beam particles are used to reconstruct the incoming tracks with high spatial resolution while representing minimal material for the beam to pass through. This presentation lays out the idea of how the GEMs were surveyed and how the alignment is inferred from the survey data and accounted for in the data analysis. The goal of the alignment procedure is to limit the errors from any misalignments on tracking and scattering angle determination to be much less than the dominating uncertainties due to multiple scattering.   

Experience with GEM detectors during the PREX-2 Physics run

Proper understanding of beam optics is crucial for any measurement involving the high resolution spectrometer (HRS) in Hall A at JLab. The vertical drift chambers (VDCs), used for decades for optics calibration of the HRSs, are not designed to typically handle high event rates ($\approx$20kHz/cm$^2$) required for the PREX-2 experiment. Event rate over 10 kHz/cm$^2$ distorts the Q$^{2}$-distributions due to pileup in the VDC. New Gas Electron Multiplier (GEM) detectors were installed for PREX-2 and used along with the VDC to acquire higher rate data. Three 10cm$\times$20cm triple-GEM detectors (from Idaho State, and Stony Brook Univ.) and three 50cm$\times$60cm triple-GEM detectors (from Univ. of Virginia) are used on each arm of the HRS. A CODA (CEBAF Online Data Acquisition) based acquisition system using multipurpose digitizer (MPD) and required software for GEM based tracking analysis were developed and incorporated with the standard HallA analyzer. PREX-2 is the first experiment in Hall A at JLab where CODA is used with GEM detectors and MPDs. We will report on cosmic muon and in-beam performance of the GEM detector systems, as well as characterizations with respect to the VDC for efficiency and track reconstruction. This characterization will help planned future experiments.   

U-V GEM Design and Development for the SBS at JLab

The success of all experiments in the Super BigBite Spectrometer (SBS) program depend on large area gas electron multipliers (GEMs) which can handle extremely high particle rates. Over the last decade, our research group at the University of Virginia (UVa) has developed and constructed over 50 large GEMs for the SBS. We are developing new “U-V” GEM trackers that will ensure the success of GEn-RP and other SBS experiments by supplementing "X-Y" trackers already present. The new detectors serve as an additional (front) tracking layer which coordinates using a "U-V" basis (a modified X-Y type basis rotated by 45$^{\circ}$). These new GEMs (150 x 40 $cm^2$ active area each) will be the largest in the world. The design of these new GEM chambers is completed, and production of their components is in process. The GEM chambers will be assembled, tested, and characterized at UVa. Upon completion of this initial construction and verification phase at UVa, the GEMs will then be transported to Jefferson Lab where they will be installed and commissioned onto the SBS apparatus to ensure the success of GEn-RP and other SBS experiments.   

High Voltage Monolithic Active Pixel Sensors for High Energy Electron Beam Compton Polarimetry

Precision polarimetry for high energy electron beams is a crucial aspect of the precision physics experiments that are either under construction or planned at facilities such as Jefferson Laboratory, the EIC (electron-ion collider), or the proposed upgrade for SuperKEKB polarized beam. Compton polarimetry can be implemented as a continuous measurement during data production. The technique is well known and has been used to make the highest precision polarimetry measurements to date 1% during the Jefferson Lab QWeak experiment. In this talk we report on our design and prototyping progress, for a Compton electron detector, proposed for the Jefferson Lab MOLLER experiment, the SuperKEKB polarized beam upgrade and as a possible technology for the future EIC. The detectors will use high voltage monolithic active pixel sensors, operated under vacuum and actively cooled. We will report on the current prototype development status, including the implementation of the carrier PCB, and the cooling design.   

Noise Correlation with Acoustic Signals in CUORE

The Cryogenic Underground Observatory for Rare Events (CUORE) experiment is an ongoing search for neutrinoless double beta decay ($0\nu\beta\beta$) located at the Gran Sasso National Laboratory (LNGS) in Italy. Recent work has found that the CUORE bolometers are sensitive to acoustic and seismic events originating from outside the detector at LNGS. To measure these events, microphones and accelerometers have been installed around the cryostat. It is expected that down-mixing occurs during the conversion of acoustic energy to heat, which is ultimately measured by the bolometers. In this presentation, we show the correlation between acoustic noise and low-frequency noise in the CUORE detector. Additionally, the current thermal model for CUORE indicates a small nonlinearity in the detector response. We measure this nonlinearity in the frequency domain using bispectral analysis, a technique used in neuroscience and seismology to search for nonlinear interactions. Finally, we examine how decorrelating this noise affects the energy resolution of the CUORE detector.