Fermilab Research Articles

Gain stability of Hamamatsu R5912-MOD photomultipliers at low temperature

The Photon Detection System (PDS) is a crucial component of the ICARUS detector in the Short Baseline Neutrino (SBN) Program at Fermi National Accelerator Laboratory (FNAL). It consists of 360 PhotoMultiplier Tubes (PMTs) 8” Hamamatsu R5912-MOD and, since June 2020, it has been operating at the liquid Argon cryogenic temperature. During these years, the PMTs have shown gain losses as an aging effect. Using a climatic chamber at the INFN Sezione di Catania, we confirmed a stable gain for a single PMT 8” Hamamatsu R5912-MOD when operated at room temperature, and a persistent gain loss at temperatures around -70 °C, although this temperature is rather higher than that of the liquid Argon.

Search by the SENSEI Experiment for Millicharged Particles Produced in the NuMI Beam.

Millicharged particles appear in several extensions of the standard model, but have not yet been detected. These hypothetical particles could be produced by an intense proton beam striking a fixed target. We use data collected in 2020 by the SENSEI experiment in the MINOS cavern at the Fermi National Accelerator Laboratory to search for ultrarelativistic millicharged particles produced in collisions of protons in the NuMI beam with a fixed graphite target. The absence of any ionization events with 3 to 6 electrons in the SENSEI data allow us to place world-leading constraints on millicharged particles for masses between 30 to 380MeV. This work also demonstrates the potential of utilizing low-threshold detectors to investigate new particles in beam-dump experiments, and motivates a future experiment designed specifically for this purpose.

Novel indium phosphide charged particle detector characterization with a 120 GeV proton beam

Thin film detectors which incorporate semiconductor materials other than silicon have the potential to build upon their unique material properties and offer advantages such as faster response times, operation at room temperature, and radiation hardness. To explore the possibility, promising candidate materials were selected, and particle tracking detectors were fabricated. An indium phosphide detector with a metal-intrinsic-metal structure has been fabricated for particle tracking. The detector was tested using radioactive sources and a high energy proton beam at Fermi National Accelerator Laboratory. In addition to its simplistic design and fabrication process, the indium phosphide particle detector showed a very fast response time of hundreds of picoseconds for the 120 GeV protons, which are comparable to the ultra-fast silicon detectors. This fast-timing response is attributed to the high electron mobility of indium phosphide. Such material properties can be leveraged to build novel detectors with superlative performance.

Optimizing High-Throughput Inference on Graph Neural Networks at Shared Computing Facilities with the NVIDIA Triton Inference Server

With machine learning applications now spanning a variety of computational tasks, multi-user shared computing facilities are devoting a rapidly increasing proportion of their resources to such algorithms. Graph neural networks (GNNs), for example, have provided astounding improvements in extracting complex signatures from data and are now widely used in a variety of applications, such as particle jet classification in high energy physics (HEP). However, GNNs also come with an enormous computational penalty that requires the use of GPUs to maintain reasonable throughput. At shared computing facilities, such as those used by physicists at Fermi National Accelerator Laboratory (Fermilab), methodical resource allocation and high throughput at the many-user scale are key to ensuring that resources are being used as efficiently as possible. These facilities, however, primarily provide CPU-only nodes, which proves detrimental to time-to-insight and computational throughput for workflows that include machine learning inference. In this work, we describe how a shared computing facility can use the NVIDIA Triton Inference Server to optimize its resource allocation and computing structure, recovering high throughput while scaling out to multiple users by massively parallelizing their machine learning inference. To demonstrate the effectiveness of this system in a realistic multi-user environment, we use the Fermilab Elastic Analysis Facility augmented with the Triton Inference Server to provide scalable and high-throughput access to a HEP-specific GNN and report on the outcome.

Cryogenic and safety design of the future high field cable test facility at Fermilab

The HFVMTF (High Field Vertical Magnet Test Facility) is a new experimental facility under development at Fermi National Accelerator Laboratory (FNAL) to test large superconducting magnets (up to 20 tons weight and 1.3 m diameter) in a double bath superfluid helium cryostat (1.9 K and 1.2 bar). Coupled with a superconducting dipole magnet fabricated by Lawrence Berkeley National Laboratory (LBNL), this facility will be able to test future high-temperature superconductor (HTS) cables under a background magnetic field of 15 T for fusion magnets. This paper describes the design of the cryostat and its 1.4-meter diameter lambda plate, as well as the different components for a safe operation of the facility, even during critical events such a magnet quench or a vacuum breaking situation. The project is funded by US DOE Offices of Science, High Energy Physics (HEP), and Fusion Energy Sciences (FES).

Preface

The 2023 Joint Cryogenic Engineering Conference (CEC) and International Cryogenic Materials Conference (ICMC) were held from July 9 through July 13 at the Hawaii Convention Center in Honolulu, Hawaii. As at past conferences, the international scope of these meetings was strongly maintained with 19 countries being represented by 555 attendees who gathered to enjoy the joint technical programs and industrial exhibits. In total, 213 papers were submitted for publication of which 207 are published in these conference proceedings.The program for the joint conferences included a total of 494 presentations organized into 110 sessions - plenary, oral and posters, as well as awards presentations. Five plenary talks gave interesting in-depth updates and overviews on exciting topics: Amanda Simpson (Airbus Americas) discussed the Airbus hydrogen aircraft development plans in “Airbus: A Discussion About the Use of Cryogenic Hydrogen for Aviation Propulsion”, An overview of the history and recent developments in high temperature superconductors was given by Paul C. W. Chu (University of Houston) in “From High-temperature Superconductivity to Room-temperature Superconductivity: From Ambient Pressure to Very High Pressure”, Suhas Bhandarkar (Lawrence Livermore National Laboratory) presented an overview of Lawrence Livermore National Lab’s net positive energy fusion demonstration and the detailed development and operations of the hydrogen fuel in “Overview of the Fabrication of Cryogenic Hydrogen Fuel Ice Layer for Nuclear Fusion Ignition Experiments”, an overview of the developments ongoing at Robinson Research Institute for the development of electric aircraft was given by Rodney Badcock (Robinson Research Institute) in “Electric Aircraft: Solving the Key Materials and Engineering Challenges to Manufacture a Complete Electrical Propulsion System”, and a discussion on the cryogenic requirements and needs for the development of quantum computers was given by Nicholas Masluk (IBM) in “Cryogenic Infrastructure for 400 Qubits and Beyond”. The attendees also convened for two special Joint CEC-ICMC sessions organized: i) Liquid Hydrogen for Large-Scale Vehicles and ii) Superconducting Quantum Systems. Special sessions, two of them with panel discussions, were included in the programming emphasizing high-quality invited talks on seven different topics: Electromechanical Behaviors of HTS Coated Conductors for Applications, Topological Materials for Electronics, High Strength Materials, High Field Superconducting Materials for Accelerator Magnets, Low Temperature Materials Database A - Superconductors, Low Temperature Materials Database B - Functional & Structural Materials, Cryogenic Clean Energy and Mobility, and Orbital Flight Demonstrations of Cryogenic Fluid Management. A large Transportation Symposium consisting of 5 sessions and 26 talks with topics ranging from government funding perspectives, power electronics, cables, motors, and generators to system level studies was also held at CEC/ICMC’23. Contributed papers covered a wide range of topics including many aspects and advances in cryogenics and superconductors, along with their applications.Both CEC and ICMC boards are encouraging student participation, education, and career growth. It was very exciting and rewarding to have 77 students register for the conference this year. And 36 of the students received sponsorship of the registration fees. The strong session attendance was exciting and very positive and made the conference a more rewarding experience for the presenters and attendees.The CEC/ICMC Cryo Industrial Expo displayed the products and services of 31 industrial exhibitors and provided a congenial venue for a reception and refreshments throughout the week as well as for the conference poster sessions.Conference Chairs for 2023 were Wesley Johnson from the NASA Glenn Research Center for CEC and Sonja Schlachter from the Karlsruhe Institute of Technology for ICMC. The CEC Program Chair was Jacob Leachman from the Washington State University with CEC Program Vice Chair, Ram Dhuley, from the Fermi National Accelerator Laboratory and the ICMC Program co-chairs were Klaus-Peter Weiss from the Karlsruhe Institute of Technology and Judy Wu from the University of Kansas. The Exhibit Chair was Austin Capers of Scientific Instruments, Inc. who also served as Publicity and Sponsorship Chair. Finally, the Awards Chairs were Peter Kittel, Consultant, for CEC and Eric Hellstrom from the National High Magnetic Field Laboratory at Florida State University for ICMC. Michael Sumption, ICMC Board President and Peter Bradley, CEC Board President greatly participated in the conference development as part of the leadership team.

Preface

The 2023 Joint Cryogenic Engineering Conference (CEC) and International Cryogenic Materials Conference (ICMC) were held from July 9 through July 13 at the Hawaii Convention Center in Honolulu, Hawaii. As at past conferences, the international scope of these meetings was strongly maintained with 19 countries being represented by 555 attendees who gathered to enjoy the joint technical programs and industrial exhibits. In total, 213 papers were submitted for publication of which 207 are published in these conference proceedings.The program for the joint conferences included a total of 494 presentations organized into 110 sessions - plenary, oral and posters, as well as awards presentations. Five plenary talks gave interesting in-depth updates and overviews on exciting topics: Amanda Simpson (Airbus Americas) discussed the Airbus hydrogen aircraft development plans in “Airbus: A Discussion About the Use of Cryogenic Hydrogen for Aviation Propulsion”, An overview of the history and recent developments in high temperature superconductors was given by Paul C. W. Chu (University of Houston) in “From High-temperature Superconductivity to Room-temperature Superconductivity: From Ambient Pressure to Very High Pressure”, Suhas Bhandarkar (Lawrence Livermore National Laboratory) presented an overview of Lawrence Livermore National Lab’s net positive energy fusion demonstration and the detailed development and operations of the hydrogen fuel in “Overview of the Fabrication of Cryogenic Hydrogen Fuel Ice Layer for Nuclear Fusion Ignition Experiments”, an overview of the developments ongoing at Robinson Research Institute for the development of electric aircraft was given by Rodney Badcock (Robinson Research Institute) in “Electric Aircraft: Solving the Key Materials and Engineering Challenges to Manufacture a Complete Electrical Propulsion System”, and a discussion on the cryogenic requirements and needs for the development of quantum computers was given by Nicholas Masluk (IBM) in “Cryogenic Infrastructure for 400 Qubits and Beyond”. The attendees also convened for two special Joint CEC-ICMC sessions organized: i) Liquid Hydrogen for Large-Scale Vehicles and ii) Superconducting Quantum Systems. Special sessions, two of them with panel discussions, were included in the programming emphasizing high-quality invited talks on seven different topics: Electromechanical Behaviors of HTS Coated Conductors for Applications, Topological Materials for Electronics, High Strength Materials, High Field Superconducting Materials for Accelerator Magnets, Low Temperature Materials Database A - Superconductors, Low Temperature Materials Database B - Functional & Structural Materials, Cryogenic Clean Energy and Mobility, and Orbital Flight Demonstrations of Cryogenic Fluid Management. A large Transportation Symposium consisting of 5 sessions and 26 talks with topics ranging from government funding perspectives, power electronics, cables, motors, and generators to system level studies was also held at CEC/ICMC’23. Contributed papers covered a wide range of topics including many aspects and advances in cryogenics and superconductors, along with their applications.Both CEC and ICMC boards are encouraging student participation, education, and career growth. It was very exciting and rewarding to have 77 students register for the conference this year. And 36 of the students received sponsorship of the registration fees. The strong session attendance was exciting and very positive and made the conference a more rewarding experience for the presenters and attendees.The CEC/ICMC Cryo Industrial Expo displayed the products and services of 31 industrial exhibitors and provided a congenial venue for a reception and refreshments throughout the week as well as for the conference poster sessions.Conference Chairs for 2023 were Wesley Johnson from the NASA Glenn Research Center for CEC and Sonja Schlachter from the Karlsruhe Institute of Technology for ICMC. The CEC Program Chair was Jacob Leachman from the Washington State University with CEC Program Vice Chair, Ram Dhuley, from the Fermi National Accelerator Laboratory and the ICMC Program co-chairs were Klaus-Peter Weiss from the Karlsruhe Institute of Technology and Judy Wu from the University of Kansas. The Exhibit Chair was Austin Capers of Scientific Instruments, Inc. who also served as Publicity and Sponsorship Chair. Finally, the Awards Chairs were Peter Kittel, Consultant, for CEC and Eric Hellstrom from the National High Magnetic Field Laboratory at Florida State University for ICMC. Michael Sumption, ICMC Board President and Peter Bradley, CEC Board President greatly participated in the conference development as part of the leadership team.

Proton and muon beam tests for ultra-fast MCP-PMT detectors

In collaboration with the North Night Vision Science and Technology (Nanjing) Research Institute Co. Ltd, researchers at the Institute of High Energy of Physics in China have successfully developed the 20-inch micro-channel-plate photomultiplier tube (MCP-PMT) that exhibits high detection efficiency (DE) for use in the Jiangmen Underground Neutrino Observatory (JUNO). Due to the long drift path of electrons from photocathode to MCP, the 20-inch MCP-PMT has a time resolution on the order of nanoseconds. Recently, the team has made advancements in ultra-fast MCP-PMTs (FPMTs), achieving picosecond-level time resolution with both 1-inch and 2-inch types. By now, prototypes featuring single-anode, 2 × 2 anodes, 4 × 4 anodes, and 8 × 8 anodes have been successfully manufactured and tested. The 8 × 8 anode FPMT, in particular, demonstrates a transit time spread (TTS) of 36 ps (Sigma) in single photon mode, thanks to its meticulously engineered structure. To assess the FPMT’s time performance under beam conditions, two beam tests were conducted at Fermi Lab and CERN. In these tests, the 8 × 8 pixel arrays of four distinct radiators, including LYSO, BGO, Pb glass and quartz glass, were paired with the 8 × 8 anodes FPMT. This setup involved the use of two radiator-coupled FPMT detectors for particle detection. The best coincidence time resolution recorded was 64 ps (Sigma) with a 120 GeV proton beam and 56 ps (Sigma) with a 108 GeV muon beam.

The Creation and Evolution of the US ATLAS Shared Analysis Facilities

Prior to the start of the LHC Run 3, the US ATLAS Software and Computing operations program established three shared Tier 3 Analysis Facilities (AFs). The newest AF was established at the University of Chicago in the past year, joining the existing AFs at Brookhaven National Lab and SLAC National Accelerator Lab. In this paper, we will describe both the common and unique aspects of these three AFs, and the resulting distributed facility from the user’s perspective, including how we monitor and measure the AFs. The common elements include enabling easy access via Federated ID, file sharing via EOS, provisioning of similar Jupyter environments using common Jupyter kernels and containerization, and efforts to centralize documentation and user support channels. The unique components we will cover are driven in turn by the requirements, expertise and resources at each individual site. Finally, we will highlight how the US AFs are collaborating with other ATLAS and LHC wide (IRIS-HEP and HSF) user analysis support activities, evaluating tools like ServiceX and Coffea-Casa.

Sanford Underground Research Facility’s approach to school education, community activities, and public outreach

The Sanford Underground Research Facility (SURF) is the deepest underground science facility in the United States. SURF hosts world-leading experiments in neutrino, astroparticle and nuclear physics, as well as projects in biology, geology, and engineering, and is home to a major excavation project making space for Fermi National Accelerator Laboratory’s Long-Baseline Neutrino Facility (LBNF), which will power the Deep Underground Neutrino Experiment (DUNE). An emphasis on outreach and education is embedded in SURF’s mission statement: “to advance world-class science and inspire learning across generations.” To achieve this mission, SURF goes beyond established science communication methods, including operating an open-to-the-public visitor center, hosting multiple public outreach events per month, and an annual city-wide science festival. Furthermore, SURF is training K-12 science educators, developing school curriculum units, and providing classroom materials, based on science researched at the laboratory. The strategic approach, specific methods, and successful outcomes of these programs, which are based on SURF’s science, location, and community, may serve as examples for effective science education, public outreach, and community engagement.

Modular RICH detector development for the future Electron Ion Collider experiment

Excellent particle identification is an essential requirement for the future Electron Ion Collider (EIC) experiment. Particle identification (PID) of the final state hadrons in semi-inclusive deep inelastic scattering allows the measurement of flavor-dependent gluon and quark distributions inside nucleons and nuclei. The EIC PID Consortium (eRD14 Collaboration) was formed in 2015 for identifying and developing PID detectors using ring imaging Cherenkov and ultra-fast time-of-flight techniques for the EIC experiments with broad kinematics coverage. To meet the challenge of limited space in the electron end-cap of EIC experiments, a compact modular ring imaging Cherenkov (mRICH) detector has been developed that provides K/πseparation over a momentum coverage of 2 GeV/cto 10 GeV/c, and an e/πseparation up to 2.5 GeV/cor more. The mRICH detector consists of an aerogel block, a Fresnel lens, photosensor plane and flat mirrors enclosing the sides of the space between the lens and photosensors. The first prototype of this detector was successfully tested at Fermi National Accelerator laboratory in April 2016 for verifying the detector principles. This was followed by a second prototype test in 2018 at FNAL with much improved optical design and photosensor integration, which allowed adaptation of different readout options. In September 2021, the third beam-test was carried at Jefferson Laboratory (JLAB) with the goal of testing the mRICH performance with a precision tracking capability.

First Double-Differential Measurement of Kinematic Imbalance in Neutrino Interactions with the MicroBooNE Detector.

We report the first measurement of flux-integrated double-differential quasielasticlike neutrino-argon cross sections, which have been made using the Booster Neutrino Beam and the MicroBooNE detector at Fermi National Accelerator Laboratory. The data are presented as a function of kinematic imbalance variables which are sensitive to nuclear ground-state distributions and hadronic reinteraction processes. We find that the measured cross sections in different phase-space regions are sensitive to different nuclear effects. Therefore, they enable the impact of specific nuclear effects on the neutrino-nucleus interaction to be isolated more completely than was possible using previous single-differential cross section measurements. Our results provide precision data to help test and improve neutrino-nucleus interaction models. They further support ongoing neutrino-oscillation studies by establishing phase-space regions where precise reaction modeling has already been achieved.

A Glimpse in to the World of Quarks

Quarks are fundamental variety of matter, like leptons. All hadrons (baryons and mesons) are made up of these fundamental units, quarks. The Mendeleev’s periodic table of atomic elements, in 1869, pointed towards a fundamental structure of matter common to all atoms. Nearly 50 years later, the discovery that atoms consisted of electrons revolving a nucleus confirmed this. Similarly, the observation of a periodic pattern among the existing hadrons (called as the eightfold way pattern), during 1960, pointed the possibility of a more fundamental variety of matter-quarks- out of which all hadrons, including protons and neutrons , are formed. With the discovery of the 6th and the last quark –the top quark- in 1995, at Fermi Lab, confirmation about the existence of the all the quarks was proved.

Status of the High Field Cable Test Facility at Fermilab

Fermi National Accelerator Laboratory (FNAL) and Lawrence Berkeley National Laboratory (LBNL) are building a new High Field Vertical Magnet Test Facility (HFVMTF) for testing superconducting cables in high magnetic field. The background magnetic field of 15 T in the HFVMTF will be produced by a magnet provided by LBNL. The HFVMTF is jointly funded by the US DOE Offices of Science, High Energy Physics (HEP), and Fusion Energy Sciences (FES), and will serve as a superconducting cable test facility in high magnetic fields and a wide range of temperatures for HEP and FES communities. This facility will also be used to test high-field superconducting magnet models and demonstrators, including hybrid magnets, produced by the US Magnet Development Program (MDP). The paper describes the status of the facility, including construction, cryostat designs, top and lambda plates, and systems for powering, and quench protection and monitoring.

First Measurement of Quasielastic Λ Baryon Production in Muon Antineutrino Interactions in the MicroBooNE Detector.

We present the first measurement of the cross section of Cabibbo-suppressed Λ baryon production, using data collected with the MicroBooNE detector when exposed to the neutrinos from the main injector beam at the Fermi National Accelerator Laboratory. The data analyzed correspond to 2.2×10^{20} protons on target running in neutrino mode, and 4.9×10^{20} protons on target running in anti-neutrino mode. An automated selection is combined with hand scanning, with the former identifying five candidate Λ production events when the signal was unblinded, consistent with the GENIE prediction of 5.3±1.1 events. Several scanners were employed, selecting between three and five events, compared with a prediction from a blinded MonteCarlo simulation study of 3.7±1.0 events. Restricting the phase space to only include Λ baryons that decay above MicroBooNE's detection thresholds, we obtain a flux averaged cross section of 2.0_{-1.7}^{+2.2}×10^{-40} cm^{2}/Ar, where statistical and systematic uncertainties are combined.

Uncertainty aware machine-learning-based surrogate models for particle accelerators: Study at the Fermilab Booster Accelerator Complex

Standard deep learning methods, such as Ensemble Models, Bayesian Neural Networks, and Quantile Regression Models provide estimates of prediction uncertainties for data-driven deep learning models. However, they can be limited in their applications due to their heavy memory, inference cost, and ability to properly capture out-of-distribution uncertainties. Additionally, some of these models require post-training calibration that limits their ability to be used for continuous learning applications. In this paper, we present a new approach to provide prediction with calibrated uncertainties that includes out-of-distribution contributions and compare it to standard methods on the Fermi National Accelerator Laboratory (FNAL) Booster accelerator complex.

Preface

This volume of the IOP Conference Series is dedicated to scientific contributions presented at the 20th International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT 2021). In 2021, the motto guiding the scientific program was “AI Decoded: Towards Sustainable, Diverse, Performant and Effective Scientific Computing”. The workshop took place from November 29, 2021 to December 3, 2021 in Daejeon, Korea and virtually through teleconferencing.Due to the ubiquitous travel restrictions, most of the about 600 attendees participated virtually. ACAT is badged as a workshop, rather than a conference, because we believe discussions are a key ingredient. The significant fraction of virtual participation impacted this workshop atmosphere in 2021, despite the tremendous work that the Local Organizing Committee has invested in the successful workshop.To cater to virtual presentations, ACAT 2021 featured a highly focused scientific program with reduced session duration. Nonetheless, the scientific program was rich and varied, bringing together experts of all relevant fields from around the globe. It included fourteen invited presentations, both from High Energy and Nuclear Physics such as on “Normalizing Flows for LHC Theory” and “High Performance Analysis, Today and Tomorrow”, as well as from other fields such as the WHO.The parallel program consisted of three tracks, namely Computing Technology for Physics Research, Data Analysis – Algorithms and Tools, and Computations in Theoretical Physics: Techniques and Methods. These tracks featured 75 oral and 128 poster contributions. The posters were presented in a virtual environment that succeeded in engaging the audience.This was the last edition of ACAT that was unaffected by the Russian invasion of Ukraine and the subsequent statement of support from some Russian Federation Institutes.ACAT 2021 is co-organized by the Institute for Basic Science (IBS), the Korea Institute of Science and Technology Information (KISTI), and Soongsil University. IBS is supported by Grant No. IBS-R016-D1 and Soongsil University is supported by the National Research Foundation (NRF) of Korea Grant No. 2016R1D1A1B02012900. ACAT 2021 would like to thank for the support by the Asia Pacific Center for Theoretical Physics (APCTP), the Daejeon International Marketing Enterprise (DIME), the Korean Physical Society (KPS), Brookhaven National Laboratory, Fermi National Accelerator Laboratory, Thomas Jefferson National Accelerator Facility, and Micron Technology, Inc.List of Local Organizing Committee, Scientific Programming Committee, International Advisory Committee, Co-organizers, Sponsors are available in this Pdf.

Beam test results of Secondary Emission Ionization Calorimetry modules at Fermilab

Increasing the collision energy and the luminosity at particle colliders requires high radiation resistance in GigaRad levels and fast-timing detectors in picosecond levels. Secondary Emission (SE) Ionization Calorimetry, a novel technology to measure the energy of electromagnetic showers and hadronic particles in extreme radiation circumstances, is such a detector. In this study, the bias circuits of Hamamatsu single anode R7761 and multi-anode R5900-00-M16 Photomultiplier Tubes (PMTs) were modified for use as novel calorimeter sensors in different SE modules. The test beam was provided by Fermi National Accelerator Laboratory, and these new sensor modules were tested with high-energy protons and shower particles at the Fermilab Test Beam Facility (FTBF). The test results showed that the SE modules are sensitive to the electromagnetic showers and they are a promising technology. Here we discuss the design, characterization tests and the beam tests of SE sensor modules, and the projections for a full-scale calorimeter.

Status of the Muon g − 2 experiment

The Muon g−2 Experiment at Fermi National Accelerator Laboratory was designed to measure the anomalous magnetic moment of the muon, aµ, with a precision of 140 parts-per-billion; a four-fold improvement over the former BNL measurement. The Fermilab experiment was motivated by the about 3.5 standard deviation between the experiment and the Standard Model calculation of aµ which could be a hint of new physics. The experiment at Fermilab relies on the well-established storage ring technique using magic momentum muons but employs new detector systems and a higher rate of muons per injection cycle to achieve the significant improvement in precision. A first result from the Run-1 data taking period has achieved an uncertainty of 0.46 parts-per-million and confirmed the BNL discrepancy, further increasing the tension with the Standard Model to 4.2 σ. The experimental technique, key aspects of the measurement, and the data analysis of Run-1 will be summarized.

The Anomalous Magnetic Moment of Muon

Known as one of the most hopeful fields to find new physics beyond the standard model, the anomalous magnetic moment of muon has gained much attention for a long time and become even more important after the Fermi National Accelerator Laboratory’s result came out in 2018. This paper shows the general works and achievements in this exciting field. Those include experiments operated by the Brookhaven National Laboratory and Fermi National Accelerator Laboratory to measure the g-2 factor, the calculation based on the standard model, and a possible extension of the standard model that can explain the experimental results. This paper is an introduction for anyone interested in this field.