The Pandora Software Development Kit and algorithm libraries perform reconstruction of neutrino interactions in liquid argon time projection chamber detectors. Pandora is the primary event reconstruction software used at the Deep Underground Neutrino Experiment, which will operate four large-scale liquid argon time projection chambers at the far detector site in South Dakota, producing high-resolution images of charged particles emerging from neutrino interactions. While these high-resolution images provide excellent opportunities for physics, the complex topologies require sophisticated pattern recognition capabilities to interpret signals from the detectors as physically meaningful objects that form the inputs to physics analyses. A critical component is the identification of the neutrino interaction vertex. Subsequent reconstruction algorithms use this location to identify the individual primary particles and ensure they each result in a separate reconstructed particle. A new vertex-finding procedure described in this article integrates a U-ResNet neural network performing hit-level classification into the multi-algorithm approach used by Pandora to identify the neutrino interaction vertex. The machine learning solution is seamlessly integrated into a chain of pattern-recognition algorithms. The technique substantially outperforms the previous BDT-based solution, with a more than 20% increase in the efficiency of sub-1 cm vertex reconstruction across all neutrino flavours.

This paper introduces a novel track-length extension fitting algorithm for measuring the kinetic energies of inelastically interacting particles in liquid argon time projection chambers (LArTPCs). The algorithm finds the most probable offset in track length for a track-like object by comparing the measured ionization density as a function of position with a theoretical prediction of the energy loss as a function of the energy, including models of electron recombination and detector response. The algorithm can be used to measure the energies of particles that interact before they stop, such as charged pions that are absorbed by argon nuclei. The algorithm's energy measurement resolutions and fractional biases are presented as functions of particle kinetic energy and number of track hits using samples of stopping secondary charged pions in data collected by the ProtoDUNE-SP detector, and also in a detailed simulation. Additional studies describe the impact of the dE/dx model on energy measurement performance. The method described in this paper to characterize the energy measurement performance can be repeated in any LArTPC experiment using stopping secondary charged pions.

The Module-0 Demonstrator is a single-phase 600 kg liquid argon time projection chamber operated as a prototype for the DUNE liquid argon near detector. Based on the ArgonCube design concept, Module-0 features a novel 80k-channel pixelated charge readout and advanced high-coverage photon detection system. In this paper, we present an analysis of an eight-day data set consisting of 25 million cosmic ray events collected in the spring of 2021. We use this sample to demonstrate the imaging performance of the charge and light readout systems as well as the signal correlations between the two. We also report argon purity and detector uniformity measurements, and provide comparisons to detector simulations.

Power-over-Fiber (PoF) technology has been used extensively in settings where high voltages require isolation from ground. In a novel application of PoF, power is provided to photon detector modules located on a surface at $\sim$ 300 kV with respect to ground in the planned DUNE experiment. In cryogenic environments, PoF offers a reliable means of power transmission, leveraging optical fibers to transfer power with minimal system degradation. PoF technology excels in maintaining low noise levels when delivering power to sensitive electronic systems operating in extreme temperatures and high voltage environments. This paper presents the R$\&$D effort of PoF in extreme conditions and underscores its capacity to revolutionize power delivery and management in critical applications, offering a dependable solution with low noise, optimal efficiency, and superior isolation.

ProtoDUNE Single-Phase (ProtoDUNE-SP) is a 770-ton liquid argon time projection chamber that operated in a hadron test beam at the CERN Neutrino Platform in 2018. We present a measurement of the total inelastic cross section of charged kaons on argon as a function of kaon energy using 6 and 7 GeV/$c$ beam momentum settings. The flux-weighted average of the extracted inelastic cross section at each beam momentum setting was measured to be 380$\pm$26 mbarns for the 6 GeV/$c$ setting and 379$\pm$35 mbarns for the 7 GeV/$c$ setting.

Power-over-Fiber (PoF) technology has been used extensively in settings where high voltages require isolation from ground and electromagnetic isolation is critical. In cryogenic environments, PoF offers a reliable power transmission technology, leveraging optical fibers to transfer power with minimal system degradation. PoF technology excels in maintaining low noise levels and isolation when delivering power to sensitive electronic systems operating in extreme temperature ranges and high voltage environments. In a novel application of PoF for a HEP detector, power is provided to photon detector modules located on a surface at similar to 300 kV with respect to ground in the planned DUNE experiment. This summary paper of the PoF talk at the 16th PISA Meeting on Advanced Detectors highlights the R&D effort of PoF in extreme conditions and underscores its capacity to revolutionize power delivery and management in critical applications offering a dependable solution with low noise, optimal efficiency, and superior isolation. The DUNE (Abi et al., 2020) experiment will soon deploy large liquid argon (LAr) time projection chambers (TPC) to detect neutrino interactions and other particle physics phenomena. In addition to the particle tracking provided by the TPC, photon detectors, powered by a first ever PoF system, in the cryostat will leverage the high scintillation light yield of LAr to provide crucial timing and additional calorimetric information.

DUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals.

The international collaboration designing and constructing the Deep Underground Neutrino Experiment (DUNE) at the Long-Baseline Neutrino Facility (LBNF) has developed a two-phase strategy toward the implementation of this leading-edge, large-scale science project. The 2023 report of the US Particle Physics Project Prioritization Panel (P5) reaffirmed this vision and strongly endorsed DUNE Phase I and Phase II, as did the European Strategy for Particle Physics. While the construction of the DUNE Phase I is well underway, this White Paper focuses on DUNE Phase II planning. DUNE Phase-II consists of a third and fourth far detector (FD) module, an upgraded near detector complex, and an enhanced 2.1 MW beam. The fourth FD module is conceived as a "Module of Opportunity", aimed at expanding the physics opportunities, in addition to supporting the core DUNE science program, with more advanced technologies. This document highlights the increased science opportunities offered by the DUNE Phase II near and far detectors, including long-baseline neutrino oscillation physics, neutrino astrophysics, and physics beyond the standard model. It describes the DUNE Phase II near and far detector technologies and detector design concepts that are currently under consideration. A summary of key R&D goals and prototyping phases needed to realize the Phase II detector technical designs is also provided. DUNE's Phase II detectors, along with the increased beam power, will complete the full scope of DUNE, enabling a multi-decadal program of groundbreaking science with neutrinos.

The Fermilab Proton-Improvement-Plan-II (PIP-II) is being implemented in order to support the precision neutrino oscillation measurements at the Deep Underground Neutrino Experiment, the U.S. flagship neutrino experiment. The PIP-II LINAC is presently under construction and is expected to provide 800 MeV protons with 2 mA current. This white paper summarizes the outcome of the first workshop on May 10 through 13, 2023, to exploit this capability for new physics opportunities in the kinematic regime that are unavailable to other facilities, in particular a potential beam dump facility implemented at the end of the LINAC. Various new physics opportunities have been discussed in a wide range of kinematic regime, from eV scale to keV and MeV. We also emphasize that the timely establishment of the beam dump facility at Fermilab is essential to exploit these new physics opportunities.

The controls system at FNAL records data asynchronously from several thousand Linac devices at their respective ca-dences, ranging from 15 Hz down to once per minute. In case of downtimes, current operations are mostly reactive, investigating the cause of an outage and labeling it after the fact. However, as one of the most upstream systems at the FNAL accelerator complex, the Linac’s foreknowledge of an impending downtime as well as its duration could prompt downstream systems to go into standby, potentially leading to energy savings. The goals of the Linac Condition Anomaly Prediction of Emergence (L-CAPE) project that started in late 2020 are (1) to apply data-analytic methods to improve the information that is available to operators in the control room, and (2) to use machine learning to auto-mate the labeling of outage types as they occur and discover patterns in the data that could lead to the prediction of out-ages. We present an overview of the challenges in dealing with time-series data from 2000+ devices, our approach to developing an ML-based automated outage labeling system, and the status of augmenting operations by identifying the most likely devices predicting an outage.

DUNE/LBNF constitutes an international multi-decadal physics program for leading-edge neutrino science and proton decay studies [1] and is expected to serve as the flagship particle experiment based at Fermilab.

Fermilab and the HEP community invest significant resources into liquid argon detectors. The largest and most expensive of these detectors will be located in the Deep Underground Neutrino Experiment (DUNE). However, recent experiences have shown that there are limited avenues of monitoring, intervention, and interaction in the internal liquid environment. This proposal shows a technological path that could provide a valuable tool to ensure or at least improve management of these HEP detectors. The development of a robotic system named Argonaut will demonstrate several technologies including: 1. demonstration of suitable mobility of a small robotic device at liquid argon temperatures, 2. demonstration of wireless communication, 3. demonstration of improved diagnostics capabilities, such as tunable optics with motion control, 4. demonstration of interconnectivity of a robotic system with hardware residing within the detector. This initial research will be a seed for extended development in cold robotics and associated technologies. This work will allow FNAL to contribute a significant technology capability to recent efforts to cryogenic detector operations.

The Fermilab Booster uses multi-turn beam injection with all its cavities phased such that beam sees a net zero RF voltage even when each station is at the same maxi-mum voltage. During beam capture the RF voltage is increased slowly by using its paraphase system. At the end of the capture the feedback is turned on for beam acceleration. It is vital for present operations as well as during the PIP-II era that both the HLRF and LLRF systems provide the proper intended phase and RF voltage to preserve the longitudinal emittance from injection to extraction. In this paper, we describe the original architecture of the cavity phase distribution, our recent beam-based RF phase measurements, observed significant deviation in the relative phases between cavities and correction effort. Results from the improved capture for high intensity beam are also presented.

A second harmonic RF cavity which uses perpendicularly biased garnet for frequency tuning is currently being constructed for use in the Fermilab Booster. The cavity will operate at twice the fundamental RF frequency, from ~76 106 MHz, and will be turned on only during injection, and transition or extraction. Its main purpose is to reduce beam loss as required by Fermilab’s Proton Improvement Plan (PIP). After three years of optimization and study, the cavity design has been finalized and all constituent parts have been received. We discuss the design aspects of the cavity and its associated systems, component testing, and status of the cavity construction.

A second harmonic tunable RF cavity is being developed for the Fermilab Booster. This device, which promises reduction of the particle beam loss at the injection, transition, and extraction stages, employs perpendicularly biased garnet material for frequency tuning. The required range of the tuning is significantly wider than in previously built and tested tunable RF devices. As a result, the magnetic field in the garnet comes fairly close to the gyromagnetic resonance line at the lower end of the frequency range. The chosen design concept of a tuner for the cavity cannot ensure uniform magnetic field in the garnet material; thus, it is important to know the static magnetic properties of the material to avoid significant increase in the local RF loss power density. This report summarizes studies performed at Fermilab to understand variations in the magnetic properties of the AL800 garnet material used to build the tuner of the cavity.

improvements to achieve multi-MW capabilities at Fermilab. PIP-II is based on three major thrusts. They are (1) the recently completed upgrades to the Recycler and Main Injector (MI) for the NOvA experiment, (2) the Proton Improvement Plan [3] currently underway, and (3) the Project X Reference Design [4]. Note that: The Proton Improvement Plan (PIP) consolidates a set of improvements to the existing Linac, Booster, and Main Injector (MI) aimed at supporting 15 Hz Booster beam operation. In combination, the NOvA upgrades and PIP create a capability of delivering 700 kW beam power from the Main Injector at 120 GeV; The scope of the Project X Reference Design Report was aimed well beyond PIP. It described a complete concept for a multi-MW proton facility that could support a broad particle physics program based on neutrino, kaon, muon, and nucleon experiments [5,6]. The Project X conceptual design has evolved over a number of years, incorporating continuous input on physics research goals and advances in the underlying technology development programs [7,8,9]. PIP-II, to high degree, inherits these goals as the goals for future developments and upgrades. This document (PIP-II Reference Design Report) describes an initial step in the development of the Fermilab accelerating complex. The plan described in this Report balances the far-term goals of the Laboratory's long baseline neutrino mission with the near- and mid-term goals identified at the Snowmass workshop [10] and endorsed by the P5 report [1].

The extraction bucket position in the Fermilab Booster is controlled with a cogging process that involves the comparison of the Booster RF count and the Recycler Ring revolution marker. A one RF bucket jitter in the extraction bucket position results from the variability of the process that phase matches the Booster to the Recycler. However, the new slow phase lock process used to lock the frequency and phase of the Booster RF to the Recycler RF has been made digital and programmable and has been modified to correct the extraction notch position. The beam loss at the Recycler injection has been reduced by 20%. Beam studies and the phase lock system will be discussed in this paper.

A perpendicularly biased 2nd harmonic cavity is being designed and built for the Fermilab Booster. Its purpose is to flatten the bucket at injection and thus change the longitudinal beam distribution to decrease space charge effects. It can also help at extraction. The cavity frequency range is 76 - 106 MHz. The power amplifier will be built using the Y567B tetrode, which is also used for the fundamental mode cavities in the Fermilab Booster. We discuss recent progress on the cavity, the biasing solenoid design and plans for testing the tuner's garnet material.

The Booster Beam Notch is a beam gap needed to allow extraction kickers to reach full field strength for a single turn extraction scheme. The Notch is created at injection energy by kicking 3 out of the 84 bunches to a dedicated absorber. The kicker voltage, pulse length and geometry of the absorber must be optimized to minimize the beam loss due to the notch creation. Beam studies, simulation and implementation as well as the optimization and improvement of the notch system will be discussed in this paper. PROTON IMPROVEMENT PLAN (PIP) The notch system task was one of 35 PIP tasks identified for the Proton Source to address the need to increase proton beam flux. A more than doubling of proton per hour rate is required to meet the Fermilab HEP program. A significant effort to increase the flux went to increase Booster beam cycles from 7Hz to 15 Hz. The doubling of Booster beam cycles consequently would incur increased integrated beam loss at various phases of beam operations, including notch formation and extraction time. Reduction in extraction losses and better managed notch formation losses need to be optimized [1]. THE SWITCH FROM VERTICAL TO HORIZONTAL NOTCH SYSTEMS A dedicated absorber was designed and then installed in the Booster ring, in the 2012/13 upgrade maintenance period, to contain the notched beam (Fig. 1). The kicking plane was changed to the horizontal plane as there is more aperture to separate notched beam [2]. Previously, notching was achieved with 2 kicker magnets in two different regions of the Booster ring. The kick was in the vertical plane. The kicked beam was deposited into the collimation region and 2 small mask absorbing elements 6 cells away to clean up the tails of the notched bunches. Simulation is seen in Fig. 2a. This change would reduce the activation levels in the circulating beam collimation region significantly (see on Fig. 2a.) and allow for a more controlled deposition of the removed bunches to create the three-bucket notch in the new absorber (Fig. 2b). Fig. 3 depicts this this new layout. Initially, the same notching equipment was relocated to the new physical locations in the Booster ring and equipment galleries with the addition of a third old kicker system until the new equipment could be built. Simulations indicated that a third kicker would be needed for the horizontal kick scheme to work at 400-700MeV. The new consolidated power supply system and faster filling magnets where implemented in phases. This Fermilab RR/NOVA style pulser would drive 6 half meter long kickers with two CX2610 thyratrons [3]. This would provide faster fill time than the previous 1.08 meter long kickers and power supply. Our rise time improved by about 10 nsec, giving a flatter notch pulse. Figure 1: Hor. Notching kickers and absorber. Figure 2: Loss sim. vert. (a) and hor. (b) notching. Figure 3: Notched beam region. 700MEV TO 400MeV NOTCH Beam notching was initially implemented in the horizontal plane at two energies, 400MeV (Booster injection) and 700MeV. The later energy was required to establish notch synchronization when utilizing the RF cogging method, required for MI/RR batches 2-12, which could not be initiated earlier than approximately 600-700MeV [4]. With the advent of a new magnetic cogging technique, horizontal dipole corrector magnets are used to achieve this goal thus enabling an earlier notch creation time for the cogged cycles to Fermilab’s Main Injector and Recycler Ring [5]. The notch time has been optimized to occur just after recapture of the Linac beam via paraphrase method in Booster. Now all 12 notched beam events are fixed to 400MeV. For a 12 batch MI/ RR injection, this helped reduce the notch losses on the later cogged 11 batches. ___________________________________________ *Operated by Fermi Research Alliance, LLC under Contract No.DeAC02-07CH11359 with the United States Department of Energy. † chaurize@fnal.gov TUPIK117 Proceedings of IPAC2017, Copenhagen, Denmark ISBN 978-3-95450-182-3 2002 Co py rig ht © 20 17 CC -B Y3. 0 an d by th er es pe ct iv ea ut ho rs 04 Hadron Accelerators A17 High Intensity Accelerators Notching beam early highlighted the fact that the separation between the circulating beam and notched beam was less, due to lower energy and larger emittance beam. There where losses due to broader tails on the bunches. Losses were still lower overall due to the reduced notch beam energy. This required more work on beam orbits to find an ideal operating point. Beam size and orbit trajectories were simulated. Beam measurements were also made looking at beam position and losses through the notch region and ring wide. We took measurements looking at the kicked bunches using raw BPM data. We could see the effective aperture and relative beam positions of the two beams (Fig. 4). Figure 4 : Notched/circulating beam orbit.