Electron Multiplier Research Articles

A neutron beam monitor based on ceramic gas electron multiplier with high spatial resolution for low flux measurements.

Neutron scattering instruments play an important role in studying the inner structure of materials. A neutron beam monitor is a detector commonly used in a neutron scattering instrument. The detection efficiency for most neutron beam monitors is quite low (10-4-10-6). However, in some experiments with a low neutron flux, such as small angle neutron scattering (SANS) and inelastic neutron scattering experiments, a neutron beam monitor with a higher detection efficiency (∼1% for thermal neutrons) is required to reduce the duration of the experiment. To meet this requirement, a ceramic gas electron multiplier-based neutron beam monitor equipped with a 1 µm 10B4C neutron converter was developed in this study. Its performance was determined both experimentally and in simulations. The detection efficiency in the wavelength range of 1.8-5.5 Å was measured experimentally and was confirmed by the simulation results. An algorithm based on event selection and position reconstruction was developed to improve the spatial resolution to about 1mm full-width-half-maximum. The wavelength spectrum was measured in beamline 20 (BL20) and agreed well with the results obtained using a commercial monitor. The maximum counting rate was 1.3MHz. The non-uniformity over the whole 100 × 100mm2 active area was determined to be 1.4%. Due to the excellent performance of this monitor, it has been used in several neutron instruments, such as the SANS and the High-Energy Direct-Geometry Inelastic Spectrometer instruments in the China spallation neutron source.

Production and validation of industrially produced large-sized GEM foils for the Phase-2 upgrade of the CMS muon spectrometer

The upgrade of the CMS detector for the high luminosity LHC (HL-LHC) will include gas electron multiplier (GEM) detectors in the end-cap muon spectrometer. Due to the limited supply of large area GEM detectors, the Korean CMS (KCMS) collaboration had formed a consortium with Mecaro Co., Ltd. to serve as a supplier of GEM foils with area of approximately 0.6m2. The consortium has developed a double-mask etching technique for production of these large-sized GEM foils. This article describes the production, quality control, and quality assessment (QA/QC) procedures and the mass production status for the GEM foils. Validation procedures indicate that the structure of the Korean foils are in the designed range. Detectors employing the Korean foils satisfy the requirements of the HL-LHC in terms of the effective gain, response uniformity, rate capability, discharge probability, and hardness against discharges. No aging phenomena were observed with a charge collection of 82mCcm−2. Mass production of KCMS GEM foils is currently in progress.

A Segmental 2D Readout Board Manufactured in Printed Circuit Board Technology for Gas Electron Multiplier Detectors.

The Gas Electron Multiplier (GEM) was introduced by Fabio Sauli in 1997. This technology is broadly used in current and planned High-Energy Physics (HEP) experiments. One of the key components of these detectors is a readout board, which collects charges amplified by GEM foils and transfers them to readout electronics. The commonly used Cartesian XY readout boards are manufactured from the same type of polyamide film used to produce the GEM foils. The manufacturing process utilizes a deep polyimide etching, similar to the Micro Chemical Vias (MCV) etching process, which is protected by patent. The material prepared in this way is glued onto a rigid substrate and mounted in a detector. The production process was developed at CERN, and the technology has been commercialized to a small extent. Consequently, only a few research centers have the ability to make dedicated readout strips readouts. GEM detectors are characterized by a segmented structure that allows the separation of an electron-multiplying structure from a readout. This feature enables the implementation of a new type of charge reading system without the need to interfere with the GEM foil system. A new approach is proposed to simplify production and reduce the costs of GEM detector readout boards. It is based on the concept of segmental readout structures that are manufactured in standard Printed Circuit Board (PCB) technology. The interconnectors and mountings are located on the back of the bottom, so it is possible to place the readout electronics behind the readout plate. The boards are designed in such a way that they can be panelized into a readout with a more extensive active area. The margin between PCBs is minimalized to approximately 200 µm, which is less than 1% of the 70 × 70 mm2 board area, so the active area is as big as possible. Therefore, this solution gives us the ability to further increase the size of a readout by adding additional segments, which reduces the cost of scaling up the detector size. A few research groups have suggested similar solutions that utilize PCB technology, but currently, only detectors with 1D zigzag readouts have been validated and used. The measurement results of other 2D (XY) redouts using PCB technology have not been presented. The measurements shown and discussed in this paper validated the proposed technology. X-ray radiographs were obtained, validating the ability to use this technology to manufacture readout boards for GEM detectors. In opposition to state-of-the-art readouts, the proposed solution can be manufactured by any PCB manufacturer without using MCV-patented technology. This gives the users flexibility in designing and ordering low-cost custom readouts.

Performance of the new hadron blind HADES RICH in heavy ion collisions

The High Acceptance Dielectron Spectrometer (HADES) situated at GSI Darmstadt, Germany, has recently upgraded its gaseous ring imaging Cherenkov (RICH) detector. Studying the properties of the hot and dense fireballs produced in heavy ion collisions the RICH is the key component to efficiently identify electrons and positrons emitted therein. The new photon detection plane is comprised of 428 multianode photo electron multipliers (MAPMT)(Hamamatsu H12700) partly coated with p-Terphenyl as a wavelength shifter. It is operated with a gaseous C4H10 (isobutane) radiator making it essentially hadron blind for particle momenta up to approximately 2.5GeV/c. All 27392 MAPMT channels are read out by an FPGA based readout electronic scheme called DIRICH, which will also be used in other future Cherenkov detectors. The DIRICH readout allows to measure leading and trailing edges for each pixel pulse and hence time over threshold and hit arrival time down to sub-nanosecond precision. This article will discuss the key features of the upgraded HADES RICH and its performance based on a Ag+Ag run at E=1.58AGeV incident energy within the FAIR Phase-0 research program.

Noise assessment of CMOS active pixel sensors for the CYGNO Experiment

Active Pixel sensors play a crucial role in enabling successful low-light scientific experiments due to their inherent advantages and capabilities. Such devices not only offer high spatial resolution but also feature individual pixels with integrated amplifiers, allowing for direct signal amplification at the pixel level. This results in reduced readout noise and improved signal-to-noise ratio (SNR), which are particularly vital when dealing with limited photon counts in low-light environments. This holds particularly true for scientific CMOS (sCMOS) sensors, acknowledged as an advanced evolution of Active Pixel sensors. However, despite their advantages, such sensors can still exhibit limitations such as higher cost and presence of noise artifacts that should be closely investigated. In particular, CYGNO project fits in a global effort aimed at direct detection of Dark Matter particles. CYGNO collaboration intends to build a detector based on a Time Projection Chamber making use of Gas Electron Multipliers for the amplification of ionization electrons. The GEM multiplication process produces photons that can be readout by a high-resolution sCMOS sensor. Such detection system is being designed to have enough sensitivity to detect low-energy particles and to measure released energy with enough granularity so to reconstruct direction and energy profile along their trajectories. The image sensor has an important role in the detector performance, having a direct impact on the SNR of the experiment. This work proposes a study on the performance of three different sCMOS sensors with respect to their sensitivity to low-energy particles and their intrinsic noise, which are of the utmost importance for various scientific experiments.

Hybrid Garfield++ simulations of GEM detectors for tokamak plasma radiation monitoring

This work presents recent efforts in optimization of Gas Electron Multiplier (GEM) detector simulations developed so far. The mentioned triple-GEM based measurement systems were already tested at the WEST project and other devices recording soft X-ray (SXR) plasma radiation in the target range of 2-15 keV. Long term plans may envisage usage of gaseous detector based SXR diagnostics in DEMO reactor for real time plasma monitoring and control, as high neutron fluxes preclude application of semiconductor-based technologies. Conditions in fusion reactors as well as in currently operating devices necessitate simulating the interactions of high-energy photons and neutrons with the detector parts, including proper handling of primary ionization electrons paths, gas mixture fluorescence and collisions with detector materials. For this use case a full-detector simulation software was created based on the already existing interface and previous results obtained so far within the group. It combines Geant4 package for interactions with solid parts of the detector, Garfield++ for electron avalanching, Heed for X-ray interaction with gas, Gmsh and Elmer for meshing and electrostatics and introduces hybrid approach to the simulation of electron drift in different manner depending on the electron position with respect to multiplication stage. To optimize the computation time software employs precomputation algorithms in later stages of the electron cascades. The expected response profiles of the triple-GEM detector, exposed to 55Fe calibration source radiation, were simulated and verified by comparing them with experimental data.

GEM Parçacık Dedektörlerinde Lignoselülozik Malzeme Kullanım Potansiyeli

This study investigates the potential use of lignocellulosic material for Gas Electron Multiplier (GEM) foils in high-energy physics experiments. A 50 µm thick lignocellulosic film was created using a scattering method, and both surfaces were coated with a 2 µm thick copper electrode layer. Electrical characterization studies were conducted to assess the suitability of lignocellulosic material in GEM detectors. To ensure consistent atmospheric conditions during measurements, a special chamber was designed to monitor temperature and humidity values over time using an SHT3x sensor module and Rense Temperature/Humidity Meter. Electrical measurements were performed using a Keithley 4200 semiconductor characterization system, and I-V curves showing the current-voltage relationship under different atmospheric conditions were plotted. The results demonstrate the potential for developing sustainable and efficient detectors for various high-energy physics experiments using GEM detectors with lignocellulosic foils. This study comprehensively presents the advantages and disadvantages of using lignocellulosic material in GEM foils and contributes to the development of more environmentally friendly alternatives for GEM detector manufacturing.

Microstructure and texture analysis of 304 austenitic stainless steel using Bragg edge transmission imaging

Bragg edge imaging using pulsed neutrons is a non-destructive technique for studying microstructure and texture of materials. It provides two-dimensional visualization of crystallographic information using a pixelated gas electron multiplier detector and a time-of-flight method. In this work, the properties of type 304 austenitic stainless steel samples were studied via Bragg edge imaging. The samples included hot-rolled, cold-rolled and heat-treated specimens, which were characterized to investigate texture, phase fraction and grain growth. The results showed that the crystallite size increased with increasing annealing temperature. The cold-rolled and annealed samples exhibited strong textures, while the hot-rolled sample showed no preferred orientation. The phase volume fraction of induced martensite in the cold-rolled sample was also obtained. Two-dimensional maps of microstructures and textures were obtained without destructive processes. The results were validated by electron backscatter diffraction and found to be consistent. This work provides valuable information for non-destructive characterization of bulk materials by performing Bragg edge imaging using the Hokkaido University compact accelerator neutron source.

Secondary scintillation properties of multi-layer THGEMs operated in low-pressure CF4 and Ar/5%Xe

We present a measurement of the secondary scintillation yield produced by two-layer Thick Gas Electron Multipliers (M-THGEMs) in pure Tetrafluoromethane (CF4) gas and in Ar mixed with 5% Xe in low-pressures down to 20 Torr. The detector was irradiated with 5.49 MeV alpha particles from a low-rate 241-Am source. The secondary scintillation light generated during the gas avalanche process was read out by a Hamamatsu photomultiplier tube (model R8520-406), sensitive to a broad wavelength range (160–650 nm). The avalanche charge was collected on the bottom electrode of M-THGEM and correlated to the scintillation light on an event-by-event basis. We observed that, for both gas types, the value of the photon to electron production ratio (0.4 ph/el in CF4 and 0.1 ph/el in Ar/5%Xe) increases with the thickness of the M-THGEM electrodes and varies significantly with the pressure, being higher at lower values. The decrease in electroluminescence yield at higher pressures is much more pronounced in the Ar/Xe mixture. In addition, because of a larger gas avalanche volume, the electroluminescence light yield is larger in thicker M-THGEM structures. Presented results are particularly useful for designing the next generation of Optical-readout Time Projection Chambers (O-TPCs) operated at low-pressure CF4; applications include experimental nuclear physics with rare isotope beams, dark matter detection with directional sensitivity and observation of the Migdal effect in a low-pressure Optical TPC.

Directional dark matter readout with a novel multi-mesh ThGEM for SF6 negative ion operation

Abstract Direct searches for Weakly Interacting Massive Particle (WIMP) dark matter could greatly benefit from directional measurement of the expected induced nuclear recoils. Gas-based Time Projection Chambers (TPCs) offer potential for this, opening the possibility of measuring WIMP signals below the so-called neutrino floor but also of directional measurement of recoils induced by neutrinos from the Sun, for instance as proposed by the CYGNUS collaboration. Presented here for the first time are results from a Multi-Mesh Thick Gas Electron Multiplier (MM-ThGEM) using negative ion gases for operation with such a directional dark matter TPC. Negative ion drift gases are favoured for directionality due to their low diffusion characteristics. The multiple internal mesh structure is designed to provide a high gain amplification stage when coupled to future large area Micromegas, strip or pixel charge readout planes. Experimental results and simulations are presented of MM-ThGEM gain and functionality using low pressure pure CF4, SF6 and SF6:CF4 mixtures irradiated with alpha particles and 55Fe x-rays. The concept is found to work well, providing stable operation with gains over 103 in pure SF6.

Performance of prototype dual gain multilayer thick gas electron multiplier with high-intensity heavy-ion beam injections in low-pressure hydrogen gas

Abstract A prototype Dual Gain Multilayer Thick Gas Electron Multiplier (DG-M-THGEM) with an active area of 10 cm × 10 cm was manufactured aiming at the production of a large-volume active-target time projection chamber which can work under the condition of high-intensity heavy-ion beam injections. The DG-M-THGEM has an alternating structure of electrodes and insulators. Effective gas gains of two regions, which are called beam and recoil regions, are separately controlled. Performance of the prototype DG-M-THGEM in hydrogen gas at a pressure of 40 kPa was evaluated. Irradiating a 132Xe beam, an effective gas gain lower than 100 with a charge resolution of 3% was achieved in the beam region while an effective gas gain of 2000 was maintained in the recoil region. Position distributions of measured charges along the beam axis were investigated in order to evaluate gain uniformity in the high-intensity beam injection. The gain shift was estimated by simulations considering space charges in the drift region. The gain shift was suppressed within 3% even at the beam intensity of 2.5 × 106 particles per second.

GEM detectors for the CMS endcap muon system: status of three new detector stations

The High-Luminosity LHC (HL-LHC, or Phase-2 LHC) will deliver proton-proton collisions at 5–7.5 times the nominal LHC luminosity, with an expected number of 140–200 pp-interactions per bunch crossing (Pile-up or PU). To maintain the performance of muon triggering and reconstruction under high background, the forward part of the Muon Spectrometer of the CMS experiment will be upgraded with Gas Electron Multipliers (GEM) and improved Resistive Plate Chambers (iRPC) detectors [1,2]. A first GEM station (GE1/1) was installed during Long Shutdown 2 (LS2, 2019–2021), a 2nd station (GE2/1) of Triple-GEM detectors will be installed in winter 2023–24 and 2024–25, while a new 6-layer station (ME0) will be installed in the third Long Shutdown (LS3, 2026–2028). GE11 is considered an early Phase-2 upgrade as it will reduce the pT threshold by combining GEM and Cathode Strip Chamber (CSC) hits in the forward muon system at twice the LHC design luminosity (ℒ = 2 · 1034 cm-2 s-1, 50 PU). After a successful start of Run-3 in 2022, with almost 40 fb-1 collected, the commissioning of the GE1/1 detector is nearly complete. Most chambers are operated stably with an efficiency in excess of 95%, next being the demonstration of the combined CSC-GEM trigger in 2023. The lessons learnt with the first large-area GEM station have lead to improvements in detector and electronics design for the Phase 2 detectors GE2/1 and ME0. This proceeding will discuss the progress made since last MPGD Conference (MPGD 2019) [3], discussing the commissioning and early performance of GE1/1; the design improvements and start of construction of GE2/1; and the R&D currently ongoing for ME0.

Design and studies of thick Gas Electron Multipliers fabricated in India

THick Gas Electron Multipliers (THGEMs) are robust and high gain Micro Pattern Gaseous Detectors which are economically manufactured by standard drilling and etching of thin printed circuit boards. In this paper, we present our recent simulation as well as experimental studies on THGEMs which have been fabricated in India using local expertise. Two types of THGEMs have been fabricated; one set has holes without any external rim and another set has holes with rims. These detectors have been characterized using argon-carbon dioxide and argon-isobutane gas mixtures. Electron transmission, effective gain, energy resolution, optimized working range and charging up studies have been presented for both the sets of THGEMs.

Effect of multiple discharges on accumulated damage to the DLC anode layer of a resistive Well Electron Multiplier

A prototype of the WEM (Well Electron Multiplier) detector with an active area of 10 × 10 mm2 and a resistive DLC anode was tested in terms of robustness to electrical discharges induced by highly ionizing particles (241Am alpha source). The perforated structure of the WEM detector was produced from a 500 μm thick FR4 with drilled holes of 200 μm in diameter and 500 μm in pitch. The resistive anode was made of 100 nm thick DLC layer with 30 MOhm/square sheet resistance deposited on the anode grid electrode. The anode grid electrode is used to distribute voltage to the resistive layer and provide fast charge evacuation. The detector was operated in Ar:CO2 (90:10) gas mixture at gas gain of 3,500. The alpha source was placed in the drift gap. The WEM detector with intrinsic capacitance of 34 pF did not show visible damage and changes in performance after 1 million accumulated discharges. To simulate a large area detector, we added a capacitance up to 1 nF in parallel with the test device. The results of the experiments with an additional capacitance revealed that a small WEM prototype can't be directly scaled to the dimensions more than 60 × 60 mm2 without losing the robustness to discharges. We assume that the observed damage could be caused by the design features of the prototype. The grid anode electrode with a thickness of 35 μm results in a gap between the perforated FR4 board and the resistive anode board. Simulations of the electric field distribution with Comsol Multiphysics software revealed a significant electric field strength in this gap. This could lead to electric discharge path bypassing the protective resistive DLC layer. A possible solution to this problem could be additional insulation of the anode grid electrode with a coverlay similar to that used in bulk MicroMegas production.

Novel resistive charge-multipliers for dual-phase LAr-TPCs: towards stable operation at higher gains

Cryogenic versions of Resistive WELL (RWELL) and Resistive Plate WELL (RPWELL) detectors have been developed, aimed at stable avalanche multiplication of ionization electrons in the vapor phase of LAr (dual-phase TPC). In the RWELL, a thin resistive DLC layer deposited on top of an insulator is inserted in between the electron multiplier (THGEM) and the readout anode; in the RPWELL, a resistive ferrite plate is directly coupled to the THGEM. Radiation-induced ionization electrons in the liquid are extracted into the gaseous phase. They drift into the THGEM's holes where they undergo charge multiplication. Embedding resistive materials into the multiplier proved to enhance operation stability due to the mitigation of electrical discharges — thus allowing operation at higher charge gain compared to standard THGEM (a.k.a. LEM) multipliers. We present the detector concepts and report on the main preliminary results.

Gas selection for Xe-based LCP-GEM detectors onboard the CubeSat X-ray observatory NinjaSat

We present a gas selection for Xe-based gas electron multiplier (GEM) detectors, Gas Multiplier Counters (GMCs) onboard the CubeSat X-ray observatory NinjaSat. To achieve an energy bandpass of 2–50 keV, we decided to use a Xe-based gas mixture at a pressure of 1.2 atm that is sensitive to high-energy X-rays. In addition, an effective gain of over 300 is required for a single GEM so that the 2 keV X-ray signal can be sufficiently larger than the electrical noise. At first, we measured the effective gains of GEM in nine Xe-based gas mixtures (combinations of Xe, Ar, CO2, CH4, and dimethyl ether; DME) at 1.0 atm. The highest gains were obtained with Xe/Ar/DME mixtures, while relatively lower gains were obtained with Xe/Ar/CO2, Xe/Ar/CH4, and Xe+quencher mixtures. Based on these results, we selected the Xe/Ar/DME (75%/24%/1%) mixture at 1.2 atm as the sealed gas for GMC. Then we investigated the dependence of an effective gain on the electric fields in the drift and induction gaps ranging from 100–650 V cm-1 and 500–5000 V cm-1, respectively, in the selected gas mixture. The effective gain weakly depended on the drift field while it was almost linearly proportional to the induction field: 2.4 times higher at 5000 V cm-1 than at 1000 V cm-1. With the optimal induction and drift fields, the flight model GMC achieves an effective gain of 460 with an applied GEM voltage of 590 V.

The construction and characterization of MgO transmission dynodes

In this work we demonstrate that ultra-thin (5 and 15 nm) MgO transmission dynodes with sufficient high transmission electron yield (TEY) can be constructed. These transmission dynodes act as electron amplification stages in a novel vacuum electron multiplier: the Timed Photon Counter. The ultra-thin membranes with a diameter of 30 μm are arranged in a square 64-by-64-array. The TEY was determined with a scanning electron microscope using primary electrons with primary energies of 0.75–5 keV. The method allows a TEY map of the surface to be made while simultaneously imaging the surface. The TEY of individual membranes can be extracted from the TEY map. An averaged maximum TEY of 4.6±0.2 was achieved by using 1.35 keV primary electrons on a TiN/MgO bi-layer membrane with a layer thickness of 2 and 5 nm, respectively. The TiN/MgO membrane with a layer thickness of 2 and 15 nm, respectively, has a maximum TEY of 3.3±0.1 (2.35 keV). Furthermore, the effect of the electric field strength on transmission (secondary) electron emission was investigated by placing the emission surface of a transmission dynode in close proximity to a planar collector. By increasing the electric potential between the transmission dynode and the collector, from -50 V to -100 V, the averaged maximum TEY improved from 4.6±0.2 to 5.0±0.3 at a primary energy of 1.35 keV with an upper limit of 5.5 on one of the membranes.

Integration of CVD graphene in gaseous electron multipliers for high energy physics experiments

To enhance the performance of micro-patterned gaseous detectors (MPGDs) to meet the challenging requirements of future high energy physics (HEP) experiments, two-dimensional (2D) materials are attractive candidates to address the back flow of positive ions, which affects detector performance by distorting electric field lines. In this context, graphene is promising to work as selective filter for ion back flow suppression, being transparent to electrons while at the same time blocking ions. Also, graphene membranes can physically separate drift and amplification regions of the detectors, offering additional flexibility in the choice of gas mixtures and allowing independent optimizations of detector sensitivity and electron multiplication processes. Here we present an approach to integrate graphene grown via chemical vapor deposition (CVD) on gaseous electron multiplier (GEM) prototypes via a wet transfer procedure in order to suspend graphene over thousands of holes with 60 μm diameter and overcome the challenges encountered due to process steps involving liquids, mostly related with the capillary effects during drying and evaporation of them. In order to overcome the risk of damaging the membrane and decreasing the yield of suspended 2D material membranes, critical point dryer (CPD) and inverted floating method (IFM) procedures are investigated. In addition to the necessity to cover the full holes in the active area, polymeric residuals have to be minimized in order to evaluate the graphene transparency at the electron energies (i.e., < 15 eV) typically obtained in the operating conditions, measurements in these energy ranges are still not deeply investigated.

Design of a Thick Gas Electron Multiplier based photon pre-amplifier

In this paper we present the design of a photon pre-amplifier based on a photo-cathode coated Thick Gas Electron Multiplier (THGEM). Such device is crucial in application where a weak light signal produced in a radiation detector must be amplified so that it can be carried to a photo-detector by means of optical fibres. An example of a device where a light signal must be amplified is a gamma-ray Cherenkov detector for fusion power measurements in magnetic confinement devices. In such application the active part of the detector must be located very close the plasma, typically in a harsh radiation environment where standard photodetectors cannot operate. The photon pre-amplifier allows to increase the signal generated in the active part of the detector so that it can be easily detected by the photodetector located outside the harsh environment. We present the conceptual design of a THGEM based photon pre-amplifier supported by Garfield++ simulations. The device working principle is the following: primary photons impinge on the photo-cathode and extract electrons that are accelerated by the THGEM electric field. Upon collisions with the accelerated electrons, the gas molecules in the pre-amplifier are brought to excited states and de-excite emitting scintillation photons. Since each electron excites multiple gas molecules, the scintillation photons outnumber the primary photons, leading to the amplification. In addition, we present the first observation of measurements of Nitrogen gas scintillation in a THGEM device. We devised an experimental setup consisting of a vacuum chamber containing a THGEM and an alpha particle source. The vacuum chamber is filled with pure nitrogen and is coupled to a photomultiplier tube via a view-port to detect the scintillation photons generated in the THGEM. For sake of simplicity the electrons that induce the scintillation are generated by the ionization track of an alpha particle rather than by the THGEM photo-cathode coating. A good qualitative agreement between simulations and experiment has been found, however no quantitative conclusions can be made due to the lack of N2 excitation cross sections in the Garfield++ code.

Study of discharges in the CMS GEM GE1/1 station with LHC beam

The Large Hadron Collider (LHC) and the experiments installed there are being upgraded for the High Luminosity LHC project that will provide a greatly enlarged data sample in the search for physics beyond the Standard Model. During Long Shutdown 2, from 2018 to the first months of 2022, some of these upgrades were completed. In particular, the muon spectrometer of the CMS experiment was upgraded with installation of the GE1/1 detector station, based on Gas Electron Multiplier (GEM) technology. This station is positioned in the endcap region of the CMS muon system and covers the pseudorapidity range 1.55 < |η| < 2.18. On the 5th of July, 2022, Run 3 of the LHC began with collision energy of 13.6 TeV. The newly installed GEM detectors experienced high-voltage discharges when the beams were colliding inside CMS. To monitor these events and to understand how to safely operate the detectors, a study of these phenomena became necessary. The intensity of discharge current and the discharge rate were recorded in different detectors as a function of luminosity and time. It was observed that some chambers have a significantly higher discharge rate than the modal value of rate over the entire chamber population. The reasons responsible for this behavior are currently under investigation. In this contribution, an analysis of discharges will be presented, illustrating the dependence of discharge rate on different LHC beam configurations and the high voltage working point of the chambers.