Upgrade Project Research Articles

Advanced Monte Carlo simulations and benchmark of residual dose rate assessments in the ATLAS detector at CERN LHC

Background The European Organization for Nuclear Research (CERN) pushes the frontiers of physics through the Large Hadron Collider (LHC), a 27-kilometre hadron accelerator capable of producing proton-proton collisions at a center-of-mass energy of up to 13.6 TeV. Its four main detectors (ALICE, ATLAS, CMS, LHCb) are unique examples of advanced particle detection technology and complexity. Ensuring radiological safety throughout the LHC’s environments and lifecycle is a critical task managed by the CERN Radiation Protection group. In this context, assessing residual dose rates is crucial for planning exposure situations, such as maintenance and upgrade projects during LHC shutdowns. Methods This work presents advanced Monte Carlo techniques developed at CERN to predict residual dose rates in the LHC experimental caverns, focusing on the ATLAS detector. Predictions are made using the FLUKA Monte Carlo code and the SESAME toolkit for two-step simulations. The simulation results are benchmarked against experimental residual dose rate measurements collected during LHC Long Shutdown 2 at ATLAS. Additionally, forecasts for Long Shutdown 3 are also presented. Results The FLUKA benchmark for the ATLAS detector demonstrates a general agreement within a factor of 1.5. This consistency validates both the FLUKA geometry model of the ATLAS detector and the reliability of the Monte Carlo techniques used to predict residual dose rates in such complex environments. Conclusions The study highlights the predictive capabilities of the FLUKA and SESAME coupling for simulating residual dose rates in large LHC experiments. This method plays a crucial role in ensuring radiological safety, primarily for dose prediction and optimization. The reliability of this approach is significantly supported by the benchmark results obtained at ATLAS and presented in this paper.

Green upgrading of SPring-8 to produce stable, ultrabrilliant hard X-ray beams.

SPring-8-II is a major upgrade project of SPring-8 that was inaugurated in October 1997 as a third-generation synchrotron radiation light source. This upgrade project aims to achieve three goals simultaneously: achievement of excellent light source performance, refurbishment of aged systems, and significant reduction in power consumption for the entire facility. A small emittance of 50 pm rad will be achieved by (1) replacing the existing double-bend lattice structure with a five-bend achromat one, (2) lowering the stored beam energy from 8 to 6 GeV, (3) increasing the horizontal damping partition number from 1to 1.3, and (4) enhancing horizontal radiation damping by installing damping wigglers in long straight sections. The use of short-period in-vacuum undulators allows ultrabrilliant X-rays to be provided while keeping a high-energy spectral range even at the reduced electron-beam energy of 6 GeV. To reduce power consumption, the dedicated, aged injector system has been shut down and the high-performance linear accelerator of SACLA, a compact X-ray free-electron laser (XFEL) facility, is used as the injector of the ring in a time-shared manner. This allows the simultaneous operation of XFEL experiments at SACLA and full/top-up injection of the electron beam into the ring. This paper overviews the concept of the SPring-8-II project, the system design of the light source and the details of the accelerator component design.

Minimizing Business Disruption During Enterprise End-Point OS Upgrade while Maintaining a Robust Security Posture

The deployment of a major end-point operating system (OS) upgrade presents significant challenges for enterprise organizations, requiring a comprehensive strategy to minimize business disruption and maintain a robust security posture. Beyond the operational complexities of managing user productivity and application compatibility, organizations must also proactively address the critical security risks associated with such large-scale technology transitions. Cybercriminals often target organizations undergoing major IT changes, seeking to exploit vulnerabilities that may arise due to shifts in the OS architecture, user workflows, and security controls. This paper outlines practical strategies for executing successful OS upgrade projects that balance operational resilience and cyber risk management. Key focus areas include proactive management of end-point security, comprehensive contingency planning and rollback procedures, strategies to sustain productivity and business continuity, effective end-user training and communication, and valuable insights into the next- generation OS deployment. By focusing on these critical aspects, organizations can navigate major OS upgrade initiatives while preserving vigorous business operations, enhancing end-user experience, and safeguarding sensitive data and systems from costly security incidents.

Slum housing upgrading strategies: a case study of Kampaeng Ngam informal settlement along Mae Kha Canal in Chiang Mai historic city

ABSTRACT In 2011, UNESCO issued recommendations urging cities, especially those rich in historical significance, to strike a balance between preservation and growth. The goal was to better cater to the needs of present-day residents and improve their quality of life through a focus on people-centered development. This study examines informal settlements along the Mae Kha Canal in Chiang Mai, a locality adjacent to the city’s historical elements. The present study aims to formulate strategies for upgrading housing, examining the case of Kampaeng Ngam as a pilot community. The investigation is aligned with the city’s current agenda, aiming to gather insights from inhabitants for future improvement. A field study began with structured observation, followed by an investigation of sample housing and in-depth interviews with the householders. The results are presented in three facets: (1) current physical existence, (2) resident background, and (3) dwelling characteristics of the community. The influence of resident-related aspects on housing attributes is then discussed. The findings reveal that previous plans by local authorities to relocate households into one-size-fits-all family housing failed to meet the diverse living conditions of the residents. Consequently, this article concludes with alternative suggestions for the upcoming Kampaeng Ngam Housing Upgrade project.

CSNS-II multi-harmonic LLRF upgrade and commissioning

The second phase of the China Spallation Neutron Source (CSNS-II) will employ a dual-harmonic RF system to mitigate the significant space charge effects associated with 500 kW beam power. To address this, three magnetic alloy loaded cavities, characterized by their wideband and high-gradient properties, will be integrated as multi-harmonic cavities in the upgrade project. Additionally, the current LLRF control system hardware, based on the CPCI platform, is encountering issues related to discontinuation and performance limitations. This paper presents the testing and verification of hardware upgrades and multi-harmonic control system algorithms for the magnetic alloy loaded cavity LLRF control system, ensuring the effective implementation of the multi-harmonic control algorithm within the new hardware framework.

ATLAS upgrade for the HL-LHC

While the on-going Run-3 data-taking campaign will provide twice the integrated proton–proton luminosity currently available at the LHC, most of the data expected for the full LHC physics program will only be delivered during the HL-LHC phase. For this, the LHC will undergo an ambitious upgrade program to be able to deliver an instantaneous luminosity of 7.5⋅1034cm−2s−1, allowing the collection of more than 3 ab−1 of data at s=13.6(14)TeV. This unprecedented data sample will allow the ATLAS experiment to perform several precision measurements to constrain the Standard Model (SM) in yet unexplored regions of phase space, in particular in the Higgs sector, only accessible at the LHC. To benefit from such a rich data sample, it is fundamental to upgrade the detector to cope with the challenging experimental conditions that include radiation doses 10 times higher than what ATLAS experienced since its construction and increase in the number of interactions per bunch crossing from the current 50-60 to 200. The upgrade of the ATLAS detector comprises a completely new all-silicon tracker with extended rapidity coverage that will replace the current inner tracker detector; a redesigned trigger and data acquisition system for the calorimeters and muon systems, allowing the implementation of a readout system that can operate complex trigger algorithms at 40 MHz. Finally, a new subsystem called High Granularity Timing Detector will aid the track-vertex association in the forward region by providing timing information to the reconstructed tracks. An important ingredient, relevant to almost all measurements, is the precise determination of the delivered luminosity with systematic uncertainties below the percent level. This challenging task will be achieved by collecting the information from several detector systems using different and complementary techniques. This document will describe the ongoing ATLAS detector upgrade status and the main results obtained with the prototypes, giving a synthetic view of the whole upgrade project.

External costs of high-voltage overhead transmission lines: Evidence from a causal approach in rural France

In light of climatic change and global warming, electricity transmission networks need to be developed for the integration of renewable sources. In North America and Europe, to achieve renewable electricity goals, massive investments in electricity transport infrastructure are planned to connect solar and wind generation sites to the grid network. However, local opposition to new installations of high-voltage overhead transmission lines (HVOTLs) is causing delays and cost overruns. Visual nuisance is an important basis of local stakeholders' opposition to a new project. Estimations of the local economic impact of HVOTLs can help in identifying the external costs of the electricity supply industry to improve both efficiency in electricity pricing and fairness in defining provision for host community compensation. Prior research has provided evidence that existing HVOTLs have negative but not substantial effects on their immediate neighbourhoods. However, these studies have applied a correlational approach. This paper revisits the external effects of HVTOLs, exploring the case of a 225 kV line connecting two medium-size cities (Saint-Privat-d'Allier to Saint-Etienne) in France. We take advantage of the public disclosure in 2009 of undergrounding 8 km out of a total of 87 km lines as a result of a network upgrade project, to develop a difference-in-difference specification of a hedonic regression model, by comparing house sale prices at different distances from existing pylons, before and after the announcement of the decision to upgrade the line. We show that undergrounding was accompanied by an increase of about 38% in the price of treated houses located within 200 m of old pylons. The implied environmental costs of proximity to high-voltage pylons are substantial and their reduction is internalized into house prices as soon as the decision to go underground is announced.

Examining Dwelling Interior Conditions for Informal Settlement Upgrading Along the Mae Kha Canal, Chiang Mai

This article delves into the internal features of habitat in slum-like informal settlements, focusing on the challenges faced by the locale in the Mae Kha Canal informal settlements in Chiang Mai, Thailand. The study aims to clarify the dwelling characteristics as well as understand the interplay between housing and the living circumstances of the occupants. A mixed-methods approach was utilised, primarily employing field surveys, house investigation including arrangement and utilisation of space, and in-depth interviews with residents. A total of 80 households were sampled and analysed. The findings reveal that the previous relocation plans made by local authorities, which offered only a single room per family as a one-size-fits-all strategy, are not suitable for the current inhabitants' living conditions. Consequently, this article concludes with alternate suggestions for the forthcoming practical Mae Kha Canal Housing Upgrade project. It emphasises the potential of applying the idea of interiority to examine the distinctive interior conditions, thereby contributing to better dwelling design for the locals.

Feasibility Study of Cement Plant Production Facility Upgrade Project to Support Export Business

Feasibility Study of Cement Plant Production Facility Upgrade Project to Support Export Business

Performance of the CERN Proton Synchrotron internal dump: numerical simulation studies and comparison with beam measurements

In the framework of the LHC Injector Upgrade project, a new internal dump for the CERN Proton Synchrotron (PS) ring has been designed, installed, and successfully commissioned. This device is designed to move rapidly into the beam and stop charged particles over several thousand turns to provide protection to PS hardware against beam-induced damage. Due to its design, the internal dump absorbs only a fraction of the secondary particles shower produced by the beam particles that impinge on it. The performance of the dump should ensure efficient use throughout the PS energy range, i.e. from injection at 2 GeV (kinetic energy) to flat top at 26 GeV (total energy). This paper presents comprehensive numerical simulations that combine advanced beam dynamics and beam-matter interaction codes to analyse the behaviour of stopped or scattered particles. Based on the impacts computed by multi-turn beam dynamics simulations, detailed shower simulations with FLUKA were performed to assess the impact of the radiation field on downstream equipment, with a particular emphasis on the dose measured by Beam Loss Monitors. The results of these numerical simulations are compared with the data collected during the routine operation of the PS and its internal dump.

Design, assembly and testing of an upgraded aeroacoustics wind tunnel facility

The Aeroacoustics Laboratory in the Department of Aerospace Engineering at Penn State currently serves several areas of experimental research. Most notable in the laboratory is the Anechoic Chamber of which the Aeroacoustics Wind Tunnel is an integral part. In recent years the dominant areas of research have included model aircraft exhaust jets and model rotors for helicopter applications involving detailed noise experiments. In the jet noise area, the applications have included aircraft in both flyover and take-off configurations. In the flyover application the air flow surrounding the exhaust jet has a significant effect on the radiated noise and must be simulated to produce experimental results that will be most useful in preliminary design of noise suppression applications. The Aeroacoustics Wind Tunnel at Penn State serves the purpose for this simulation. During aircraft take-off, the aircraft airspeed is in a range exceeding 250 ft per second, or Mach number of over M = 0.22. In the years preceding 2022, the velocity of the free jet flow of the Penn State facility was limited to less than 200 ft/sec. This paper reports on a project to design upgrades to the existing wind tunnel to improve the test section flow velocity to values closer to the 250 ft/sec target. The approach began with a preliminary design of the return flow ducting to convert the open jet, open return wind tunnel to a closed return tunnel. The concept is to make use of the flow energy in the exhaust of the tunnel to boost the input energy to the inlet fan that drives the flow to the test section. An integral part of the preliminary design involved making use of an upgraded flow analysis computer code to predict the gain in test section velocity of the new facility. For the available horsepower of two fans in the facility, the configurations of the existing and upgraded wind tunnel were entered into this analysis code based on a quasi-one-dimensional formulation. The code included empirical data formulated to include the various shapes of the components of the tunnels. The relative flow velocities in each section used simple incompressible continuity to calculate all velocities in the component sections. The average dynamic pressure in each section is calculated from the flow (constant) density and the velocity squared. Each section had a non-dimensional pressure loss parameter calculated from empirical data (from the relevant literature). The basic code (using the Excel algorithms) was based on a predictor-corrector concept in which the calculation was initialized with the estimated velocity and pressure of the flow at the entrance to the test section. The loss in each following section is estimated to determine the loss in the total pressure and the cumulated loss compared to the gains made at the two fans in the circuit. The initial guess is adjusted based on the total pressure value at the end of the circuit. During the related experiments, measurements of the total and dynamic pressure were performed at several joints between sections and compared to the values predicted in the analysis code. Various settings of the horsepower of the drive fans were used and the results were compared to flow measurements for the tunnel configurations (predominantly for the open return and closed return tunnel setups available before and after the upgrade project.) Results of the analysis and experiments are presented and analyzed together with the remaining activities planned for the coming months.

Spallation Neutron Source Hydrogen Relief Analysis for the Cryogenic Moderator System

The Spallation Neutron Source at Oak Ridge National Laboratory operates the Cryogenic Moderator System (CMS) which provides hydrogen cooling at 20K to three neutron moderators. Each hydrogen loop is protected by multiple burst discs and reclosing relief valves. As a result of the Proton Power Upgrade project, the CMS moderator loops will hold more hydrogen and thus require piping modifications. Operational experience has demonstrated that transient pressure increases in these hydrogen loops occasionally result in the rupture of the burst discs. The causes for pressure transients in the system that might lead to hydrogen venting are varied and complex, for example loss of vacuum or cooling. Dynamic simulation and analysis of the parameters considered as the worst-case relief venting scenario were performed and will be presented.

Matched phase sweep method for the optimization of bunching factor in dual rf systems of high-intensity hadron synchrotrons

The scheme of multiturn painting beam injection in a dual harmonic rf system is widely employed in high-intensity proton or heavy ion synchrotrons to alleviate space charge effects. With a momentum offset of the injected beams, a large bunching factor can be achieved at the end of multiturn painting injection process. However, the momentum offset can increase the instantaneous beam peak current during the first 1/4 synchrotron period, causing a reduced bunching factor during the beam injection process. To address this issue, a matched phase sweep method is developed. By matching the synchrotron oscillation frequency and beam injection period, an optimal curve for phase sweeping can be directly obtained. The effectiveness of the method has been checked via simulations and machine study, which are in good agreement. The matched phase sweep method is employed for the increase of the beam power in the upcoming upgrade project of the China Spallation Neutron Source and can also be generally applied for the operation in the presence of dual harmonic rf system in high-intensity hadron synchrotrons. Published by the American Physical Society 2024

Design and early operation of a new-generation internal beam dump for CERN’s Super Proton Synchrotron

The Super Proton Synchrotron (SPS) is the last stage in the injector chain for CERN’s Large Hadron Collider, and it also provides proton and ion beams for several fixed-target experiments. The SPS has been in operation since 1976, and it has been upgraded over the years. For the SPS to operate safely, its internal beam dump must be able to repeatedly absorb the energy of the circulating beams without sustaining damage that would affect its function. The latest upgrades of the SPS led to the requirement for its beam dump to absorb proton beams with a momentum spectrum from 14 to 450 GeV/c and an average beam power of up to ∼270 kW. This paper presents the technical details of a new design of the SPS beam dump that was installed in one of the long straight sections of the SPS during the 2019–2020 shutdown of CERN’s accelerator complex within the framework of the Large Hadron Collider Injectors Upgrade Project. This new beam dump has been in the operation since May 2021, and it is foreseen that it will operate with a lifetime of 20 years. The key challenges in the design of the beam dump were linked to the high levels of thermal energy to be dissipated—to avoid overheating and damage to the beam dump itself—and high induced levels of radiation, which have implications for personnel access to monitor the beam dump and repair any problems occurring during operation. The design process, therefore, included extensive thermomechanical finite-element simulations of the beam-dump core and its cooling system’s response to normal operation and worst-case scenarios for beam dumping. To ensure high thermal conductivity between the beam-dump core and its water-cooling system, hot isostatic pressing techniques were used in its manufacturing process. A comprehensive set of instrumentation was installed in the beam dump to monitor it during operation and to cross-check the numerical models with operational feedback. The beam dump and its infrastructure design were also optimized to ensure it can be maintained, repaired, or replaced while minimizing the radiation doses received by personnel. Published by the American Physical Society 2024

Recent advances in the CERN PS impedance model and instability simulations following the LHC Injectors Upgrade project

Transverse instability growth rates in the CERN Proton Synchrotron (PS) are studied thanks to the recently updated impedance model of the machine. Using this model, macroparticle tracking simulations were performed with a new method well-suited for the slicing of short wakes, which achieves comparable performance to the originally implemented method while reducing the required number of slices by a factor of 5 to 10. Furthermore, dedicated beam-based measurement campaigns were carried out to benchmark the impedance model. Until now, beam dynamics simulations based on this model underestimated instability growth rates at injection energy. Thanks to a recent addition to the impedance model, namely the kicker magnets' connecting cables and their external circuits, the simulated instability growth rates are now comparable to the measured ones even when neglecting the impact of the space charge force. Finally, the space charge force is included in simulations and its impact on the instability growth rate and intra-bunch motion is studied.

Validation of the 65 nm TPSCo CMOS imaging technology for the ALICE ITS3

During the next Long Shutdown (LS3) of the LHC, planned for 2026, the innermost three layers of the ALICE Inner Tracking System will be replaced by a new vertex detector composed of curved ultra-thin monolithic silicon sensors. The R&D initiative on monolithic sensors of the CERN Experimental Physics Department, in cooperation with the ALICE ITS3 upgrade project, prepared the first submission of chip designs in the TPSCo 65 nm technology, called MLR1 (Multi Layer Reticle). It contains four different test structures with different process splits and pixel designs. These proceedings illustrate the first validation of the technology in terms of pixel performance and radiation hardness.

Project Risk Management for the Repair and Upgrade of Nhi Thien Duong 1 Bridge, Ho Chi Minh City, Vietnam

No project is without risks, especially in the construction industry, which harbors numerous potential pitfalls. Some risks may occur with a low probability but can have a significant impact, while others may manifest repeatedly across various projects. Negative risks, when realized, result in losses that affect the project's objectives. Meanwhile, project participants aspire to capitalize on opportunities presented by positive risks. Therefore, identifying risks, elucidating risk management methods, and formulating risk response strategies for construction projects are crucial to ensure their success. Through methods such as analysis, synthesis, comparison, and reference, this article identifies risks associated with the repair and upgrade project of the Nhi Thien Duong 1 Bridge in Ho Chi Minh City. Additionally, it proposes a set of risk response solutions from the investor's perspective in terms of construction investment management.

HGTD DC/DC converter in low temperature and magnetic field operation

The BPOL12V is a DC/DC converter designed to supply power to the High Granularity Timing Detector (HGTD) as part of the ATLAS Phase II upgrade project. The HGTD operates in an environment characterized by low temperatures and a magnetic field. Ensuring the reliable functionality of the BPOL12V under such conditions is of utmost importance. This paper outlines a series of functionality tests for the BPOL12V, including efficiency, ripple, and rise/fall edge assessments across various operational scenarios. The performance of the BPOL12V consistently meets the requirements of the HGTD, whether it operates in low temperatures down to -30 °C or in the presence of a 0.4 T magnetic field.

ЕФЕКТИВНІСТЬ КРИПТОВАЛЮТ ЯК ЗАСОБУ МІЖНАРОДНИХ ПЛАТЕЖІВ: АНАЛІЗ ВАРТОСТІ, ШВИДКОСТІ ТА БЕЗПЕКИ ТРАНЗАКЦІЙ

This article focuses on the effectiveness of using cryptocurrencies as a means for international payments, with an emphasis on the analysis of cost, speed, and security of transactions. The aim of the study is to explore the potential of blockchain technologies to optimize international financial operations. This research considers the performance of cryptocurrencies in international payments, focusing on an analysis of cost, speed, and security of transactions, utilizing data from various sources and case studies. Blockchain technologiessuch as Ripple and Solana demonstrate high throughput, capable of processing up to 65,000 transactions per second (TPS).In comparison, traditional banking systems offer significantly lower processing speeds, withBitcoin handling around 7 TPS and Ethereum up to 15 TPS. The anticipated Ethereum 2.0 network upgrade projects an increase to 100,000 TPS, significantly enhancing their potential in international payments. Traditional banking transactions can incur fees of up to $50 USD, whereas blockchain networks can reduce costs to less than $0.01 per transaction. The implementation of distributed ledger technology could save up to $27 billion by 2030 on international transactions. According to research, the average cost of an international remittance is 6.4% of a $200 transaction, indicating the potential for significantsavingsthrough the adoption of cryptocurrencies. Cryptocurrency payments are protected using cryptographic methods and decentralization, reducing the risks of fraud and attacks. By adhering to "privacy by default" principles, transaction confidentiality can be further enhanced, including generating new addresses for each transaction. Regular security audits and multi-factor authentication provide an additional layer of protection. It can be asserted that blockchain technology offers significant advantages in speed, cost, and security of transactions, which could radically transform the landscape of international trade and financial transfers. The practical significance of the research lies in identifying the potential of cryptocurrencies as a reliable, cost-effective, and secure tool for international payments, which may alter the global money transfer system.

Status and upgrades of radio frequency system at Taiwan Photon Source

In order to meet the upcoming RF power requirements of TPS, a five-year upgrade project to construct a new RF station was completed in early 2022. This new RF station mainly consists of an SRF module, a 300-kW SSPA, an analog LLRF control system, RF transmission components, and accessary cooling systems. Test results of the SRF module and 300-kW SSPA met the expected performances. Also presented are the operation statistics of the two original RF stations and the ongoing upgrades. Meantime between RF failures during TPS user time reached 600 hours in 2022, while the construction and tests on DLLRF control system, power combination of klystron and SSPA, and 2-cell 1.5-GHz SRF module have all progressed well.