Light Facility Research Articles

Analisis Komitmen Organisasi dan Kompensasi Terhadap Produktivitas Kerja : Survei pada PT Ideal Sarana Cahaya Sukabumi

The aim of this research is to determine organizational commitment and compensation on the work productivity of PT employees. Ideal Sukabumi Light Facility. This research uses associative descriptive research methods with a quantitative approach. The sampling technique uses a saturated sampling technique, namely the entire population is sampled, so that there are 74 PT employees. Ideal Sarana Cahaya Sukabumi was used as a respondent. The data analysis techniques used are validity, reliability, then classical assumption tests, multiple correlation coefficients, correlation coefficients of determination, multiple linear regression, and hypothesis testing consisting of simultaneous hypothesis testing (F test) and partial hypothesis testing (T test). The results of this research are, the F test shows that organizational commitment and compensation together have a significant effect on work productivity with an F value of 18,948 > F table 3,126. Then, the T test results of organizational commitment on work productivity with a calculated T value of 2,269 > T table 1,993 show that organizational commitment has an effect on work productivity, and the results of the compensation T test on work productivity with a calculated T value of 3,309 > T table 1,993 show that there is an influence from compensation to work productivity

Thermal analysis of a reflection mirror by fluid and solid heat transfer method.

High-repetition-rate free-electron lasers impose stringent requirements on the thermal deformation of beamline optics. The Shanghai HIgh-repetition-rate XFEL aNd Extreme light facility (SHINE) experiences high average thermal power and demands wavefront preservation. To deeply study the thermal field of the first reflection mirror M1 at the FEL-II beamline of SHINE, thermal analysis under a photon energy of 400 eV was executed by fluid and solid heat transfer method. According to the thermal analysis results and the reference cooling water temperature of 30 °C, the temperature of the cooling water at the flow outlet is raised by 0.05 °C, and the wall temperature of the cooling tube increases by a maximum of 0.5 °C. The maximum temperature position of the footprint centerline in the meridian direction deviates away from the central position, and this asymmetrical temperature distribution will directly affect the thermal deformation of the mirror and indirectly affect the focus spot of the beam at the sample.

Design and tuning of S-band traveling wave accelerating structures for Hefei Advanced Light Facility.

The Hefei Advanced Light Facility (HALF) injector comprises 40 S-band 3-m traveling wave accelerating structures, capable of delivering electrons with a full energy of 2.2 GeV into the storage ring. To mitigate emittance degradation caused by field asymmetry in the coupler cavity, the coupler design incorporates a racetrack and a short-circuit waveguide. This paper introduces the microwave design and provides the parameters of the HALF accelerating structure. Two design methods for couplers were compared, and the effectiveness of using the undercoupling (for which the coupling coefficient β calculated by Kyhl's method is less than 1) to match the output coupler was experimentally demonstrated. The nodal-shift method and bead-pull method were used to test and tune the structures of different output coupler designs during the cold test, demonstrating the tuning results under actual conditions. Experiments were conducted under different load conditions to calculate the local reflection coefficient of the output coupler. The results show that both the accelerating structure design and the tuning results meet the HALF requirements.

High Q and high gradient performance of the first medium-temperature baking 1.3 GHz cryomodule

The world’s first 1.3 GHz cryomodule containing eight 9-cell superconducting radio-frequency (rf) cavities treated by medium-temperature furnace baking (mid-T bake) was developed at the Institute of High Energy Physics, Chinese Academy of Sciences. The 9-cell cavities in the cryomodule achieved an unprecedented high average intrinsic quality factor (Q0) of 3.8×1010 at 16 MV/m and 3.6×1010 at 21 MV/m in the horizontal test. The cryomodule can operate stably up to a total continuous wave rf voltage greater than 193 MV, with an average cavity usable accelerating gradient of more than 23 MV/m. The results significantly exceed the specifications of Circular Electron Positron Collider and Dalian advanced light source and the other high repetition rate free electron laser facilities [Linac Coherent Light Source II (LCLS-II), LCLS-II-high energy, Shanghai High Repetition Rate X-ray FEL and Extreme Light Facility, Shenzhen Superconducting Soft X-Ray Free Electron Laser, etc.]. There is evidence that the mid-T bake cavity may not require fast cooldown or long processing time in the cryomodule. This paper reviews the cryomodule performance and discusses some important issues in cryomodule assembly and testing. Published by the American Physical Society 2024

An MTCA-based LLRF prototype system of LINAC in Hefei Advanced light facility

The linear accelerator (LINAC) system currently under construction at the Hefei Advanced Light Facility (HALF) employs acceleration tubes to accelerate the electron beam to 2.2 GeV. The RF field within the acceleration tube is controlled by an MTCA.4-based low-level radio frequency (LLRF) prototype system to meet stringent phase stability requirements. This paper introduces the structure of the LLRF system, encompassing both its hardware and software components. The LLRF system uses the non-IQ-sampling method to suppress odd harmonics through digital filters, achieving a signal-to-noise ratio (SNR) of approximately 73 dB. Given that the power sources of most acceleration tubes operate in a saturated state, the radio-frequency (RF) control algorithm within the software is based on a separate amplitude open-loop and phase close-loop to maintain stable phase control during amplitude disturbances. The design of the RF control logic, including digital filters, the REF phase tracking method, the close-loop feedback controller, and the output pulse mode control algorithm, is detailed. Offline pulse-to-pulse test results demonstrate that it achieves a phase stability of 0.0176° rms with a solid-state amplifier, meeting the facility's requirements.

Investigation of outgassing properties of CuZr alloy for vacuum chamber structural materials

CuZr alloy is considered for the structural material of the vacuum chamber of the Hefei Advanced Light Facility (HALF) storage ring. In order to test the outgassing properties of CuZr alloy, we designed and constructed a vacuum gauge calibration device and an outgassing rate test system. The outgassing rates of CuZr alloy and Stainless Steel (SS) were tested and compared at different temperatures after a rigorous ultra-high vacuum cleaning process. It can be seen that the outgassing rate of CuZr alloy can be reduced to 3.85 × 10−11 Pa L/s·cm2 after baking at 120 °C for 48h, which is lower than that of SS after baking at 180 °C. The outgassing rate of CuZr alloy can reach 2.69 × 10−11 Pa L/s·cm2 after baking at 180 °C for 48h, which is more than one order of magnitude lower than that of SS. These results indicate that CuZr alloy is easier to degas by baking at lower temperatures and is a material with very low outgassing rates. Moreover, it is a highly competitive structural material for future accelerator vacuum chamber based on its good electrical conductivity, high strength and hardness.

Vibration stability of an ultra-high-resolution plane grating monochromator at HALF

The global requirement for grating monochromators with high precision and exceptional vibrational stability is crucial for diffraction-limited synchrotron radiation sources (DLSR). An ultra-high-spectral resolution plane grating monochromator (PGM) based on the stroke bearing shaft has been developed for Hefei Advanced Light Facility (HALF) at the National Synchrotron Radiation Laboratory (NSRL). A comprehensive performance evaluation of PGM is crucial prior to its online installation during the commissioning phase. Various vibration measurement tools were employed to meticulously characterize PGM stability. A magneto-electric velocity sensor is used to measure the vibration amplitude of the PGM components, and an optical encoder and laser interferometer are used to quantify the angular stability. The measured data are analyzed to determine the vibration source. Angular vibrations with different water-cooling conditions are compared. The PGM exhibited angular vibrations of approximately 30 nrad RMS (1–500 Hz, pitch direction), thereby satisfying the beamline requirements.

Status of Multipole Magnets for Hefei Advanced Light Facility

Status of Multipole Magnets for Hefei Advanced Light Facility

Thermal optimization of a high heat load liquid-metal-bath cooled mirror at the Hefei Advanced Light Facility.

Within the beamlines of diffraction-limited storage rings, the liquid-metal-bath cooling scheme is a prevalent choice for the cooling of high-heat load mirrors. This study employs the finite element analysis method to evaluate the thermal deformations of liquid-metal-bath horizontally deflecting mirrors in the Hefei Advanced Light Facility. In particular, we introduce a novel optimization strategy to obtain the optimal thermal deformation scenario, which also satisfies mechanical design requirements. Moreover, a concurrent optimization approach across multiple structural parameters of mirrors is adopted to attain globally optimal thermal deformation. Following the optimization of the mirror's structural parameters, the curvature radius increases to 227 km, while the residual slope error decreases to 36.3 nrad at 6eV in the meridian direction. The ray tracing analysis of the beam demonstrates a considerable reduction in the influence of thermal deformation on the beam's focal point. This work proposes an optimization method for designing cooling schemes under mechanical constraints.

ANALYSIS OF THE IMPLEMENTATION OF ISAK 16 - SERVICE CONCESSION AGREEMENTS AND ITS IMPLICATIONS FOR THE COMPANY'S FINANCIAL STATEMENTS

This research is qualitative research with data collection techniques through literature studies and field studies. Literature studies were obtained from scientific journals, accounting standards, government regulations, agreements and business studies related to the implementation of light rail/Light Rail Transit, while field studies were carried out through interviews with informants who understand the implementation of light rail/LRT. The company that is the object of research is PT Jakarta Propertindo (Perseroda) which is a company assigned by the DKI Jakarta Provincial Government to provide infrastructure and facilities for Light Rail Transit Corridor 1 Phase 1 (Kelapa Gading Velodrome). The aim of the research is to analyze appropriate accounting policies for companies related to the Light Rail Transit Infrastructure and Facilities Agreement for Corridor 1 Phase 1 (Kelapa Gading Velodrome) which is the scope of ISAK -16 Services Concession Agreement, implementation of ISAK 16 and implications of implementing ISAK 16 to the financial statements. The results of the research conclude that accounting policies related to the Implementation of Light Rail Transit Infrastructure are within the scope of ISAK 16: Service Concession Agreements so that the implications for financial statements are that companies must record LRT Infrastructure Assets as Intangible Assets, while for the Operation of Light Rail Transit Facilities Rail Transit is within the scope of PSAK 16: Fixed Assets so companies must record LRT Facilities Assets as Fixed Assets.

Research on the optimization methods of common points layout for survey and alignment of particle accelerators

As a fourth-generation synchrotron light source based on a diffraction-limited storage ring, Hefei Advanced Light Facility (HALF) puts forward higher requirements for the alignment accuracy of the main components. Aggregated common points result in a loss of accuracy during the coordinate transformation required by accelerator alignment. To address this challenge, we proposed two methods: “aggregated points centralization (APC)" and “uniformity-weighted algorithm (UWA)" according to different usage scenarios. APC combines uniformity with the K-means algorithm to enhance the accuracy of coordinate transformation while reducing the number of common points. UWA calculates the uniformity in different directions and assigns weights to common points, reducing the accuracy loss. Simulations demonstrate that these two methods have strong superiority and stability with significantly improved accuracy. Applications of these 2 methods in the magnet unit pre-alignment experiment and tunnel network measurement show promising results. APC in pre-alignment can reduce the cost of building common points by 26% while maintaining the coordinate conversion accuracy. In tunnel network measurement, accuracy can be increased by 28% using UWA. The methods proposed offer broad applicability in the field of particle accelerator alignment and guiding alignment solutions for HALF.

Design of RIXS beamline at Shenzhen innovation light facility

An optical design of the RIXS beamline for the Shenzhen Innovation Light Facility (SILF) was reported. The beamline will cover an energy range from 200 to 1500 eV, with three endstations: a Q-RIXS for momentum-dependent high-resolution resonant inelastic x-ray scattering, an e-RIXS for high-throughput resonant inelastic x-ray scattering and an APXPS. All endstations share the same undulator, front end optics and the main branch of beamline until the deflecting mirrors after the monochromator. The Q-RIXS and e-RIXS will be located in two separate branches, while the APXPS endstation is mounted on a free port located right between the exit slit and the refocusing optics for the e-RIXS endstation. This design allows for the mounting of different techniques and the preparation of sample environments without disrupting the operation of the other branch, thus maximizing the utilization of beamtime. The combined energy resolution is expected to be better than 50 meV for Q-RIXS and better than 100 meV for e-RIXS. Once available, it will provide in-demand, versatile and high-quality soft x-ray spectroscopy techniques to users in fields of quantum, energy and surface science.

Setting up a light microscopy core facility: Facility design.

The successful operation of a light microscopy core facility depends also on the initial setup of its infrastructure. This article covers the aspects of location selection and room planning and what environmental factors need to be considered. These include light, temperature, vibrations as well as the basic installations needed for microscope operation.

Development of undulator motion control system with redundant protections

The undulator is a key luminous component of the Shanghai high repetition rate x-ray free electron laser and extreme light facility, and the motion control system is an important part of the undulator. The main task of the motion control system is to complete the high precision adjustment of the gap and taper between the upper magnetic pole girder and lower magnetic pole girder, so as to adjust the wavelength of the radiation light. According to the development requirements of the motion control system for the U26 undulator, which is a conventional permanent magnet, this paper proposes a new motion control system with double position feedback closed-loop control, including programmable logic controller (PLC) closed-loop control based on position feedback by a linear absolute encoder (LAE) and driver closed-loop control based on position feedback by a rotary absolute encoder (RAE) of a servo motor. Multiple motion tests of the U26 undulator have shown that the repeatability accuracy of the gap is ±50 nm and the gap drive can reach 0.1 µm step size, the error of which is about ±20 nm according to the feedback of the LAE. The conclusion can be drawn that the motion step size and repeatability accuracy of the motion control system for the U26 undulator are improved by one order of magnitude on the basis of meeting all technical requirements. At the same time, motor torque protection, motor temperature protection, and redundant position protection with RAE can further improve the reliability and safety of the motion control system for the U26 undulator.

Development of beamline control system for Hefei Advanced Light Facility

The design and the control scheme of beamline control system for Hefei Advanced Light Facility (HALF;Hefei, People's Republic of China) which is under construction is described in this paper.It mainly includes, equipment protection safety, personal protection safety,fast signal interlock and status monitoring and fault diagnosis system. In this control system ,the human presence perception function has been added to the personal protection safety system. Multi-parameter status monitoring of key equipment on beamline station can automatically alarm equipment failures and send relevant personnel timely notifications. At the same time, it can also provide early warning on the health status of key equipment on the beamline. The system not only improves the safety and reliability of beamline control, but also increases the degree of automation and intelligence, reduces the workload of operation and maintenance personnel, and improves operation and maintenance efficiency.

Research on fusion and deformation analysis of decade' HLS-II control network surveying data

To ensure the long-term stability of the beam and further construction needs, it is necessary to re-measure the particle accelerator regularly. Since 2013, we have been measuring the HLS-II control network with laser trackers and the level for 10 years. Taking HLS-II as the object of study, we introduced the data acquisition strategy for the period of 2013–2023. We analyzed the horizontal and vertical deformation trends of each control point. In the vertical direction, we fused the geometric level and elevation data of the laser tracker network by using MC-GMM (a Gauss-Markov model which considers the uncertainty of Monte Carlo simulation). The analysis results show that, after the HLS upgrade, the annual average settlement of the ground control network tends to be stable. The settlement and horizontal variation of the device are all within a reasonable and controllable range. To ensure stability, accuracy, and efficiency in the measurement, we recommend employing the laser tracker for the re-measurement of the HLS-II storage ring. The data processing flow and methods mentioned in the article can provide a reference for deformation analysis of the upcoming construction of the Hefei Advanced Light Facility (HALF) and other large-scale metrology projects.

A 5.12-Gbps serializer circuit for front-end fast readout electronics of silicon pixelated detectors

Advanced synchrotron radiation sources are major facilities for analyzing the formation and evolution of material structure in multidisciplinary research, owing to their high luminosity, low emittance, wide energy bandwidth and other characteristics. In China, several advanced synchrotron radiation sources are under construction, including the HEPS (High Energy Photon Source) and SHINE (Shanghai high repetition rate X-ray Free Electron Laser and extreme light facility). These facilities are poised to become major multidisciplinary research platforms in China. To meet the requirements of pixel detectors in these facilities, dedicated pixel readout chips are being developed, including HEPS-BPIX and HYLITE. This paper presents a high-speed serializer circuit developed in a commercial 130-nm CMOS technology for the full-scale (128 × 128) pixel readout chip of HYLITE, which requires a data rate of 4 Gbps currently. The serializer consists of a 16-to-1 binary-tree multiplexer, a ring-oscillating-based phase-locked loop (RO-PLL) and a current-mode logic driving stage with a multi-stage pre-amplifier. Test results demonstrate its expected functionality within a wide operating range from 0.52 Gbps to 5.5 Gbps. At 5.12 Gbps, the measured jitter values are about 2 ps for random jitter, 20 ps for deterministic jitter, and 47 ps for total jitter with a 10−12 bit error rate. Additionally, the horizontal and vertical eye openings are 0.84 UI and 72%, respectively. These positive results indicate that the serializer meets the requirements of HYLITE.

Optimized design and characterization of HYLITE, a charge-integration readout chip of XFEL

HYLITE (High dYnamic range free electron Laser Imaging deTEctor) is a charge-integration pixel readout chip designed for SHINE (Shanghai HIgh repetition rate XFEL aNd Extreme light facility). The target specifications for the full-size HYLITE chip include a pixel matrix of 128 × 128 pixels and a frame rate of 10 kHz. In order to meet these specifications, two small-scale chips, designated HYLITE0.1 and HYLITE0.2, were fabricated and underwent comprehensive testing. Some issues were discovered during tests including the noise performance and the error of output ADU (Analog Digital Units) codes.The HYLITE200S represents the third prototype chip developed to address the above issues. The CDS (Correlated Double Sampling) circuits and glitch-clear clock structures are integrated in pixels. Furthermore, to meet the data output rate requirements of the full-size chip, a high-speed data interface has been designed. Test results show that the signal-to-noise ratio is improved to 9.31 for a 12 keV single photon, and the ADU error is fixed. By integrating a phase-locked loop and a balanced encoding logic, the data interface can work steadily at a speed of 3.125 Gbps.

RF direct sampling and processing electronics for SHINE cavity BPM system

Cavity BPMs are crucial for achieving submicron beam alignment in X-ray Free-Electron Lasers (XFEL), particularly in undulator sections. These monitors typically generate RF signals in the S, C, or X band regions. Due to the limitations of analog-to-digital converter's (ADC) bandwidth and sampling rates, and digital signal processing capabilities, heterodyne and homodyne receivers are often employed to down-convert the RF signal to an intermediate frequency (IF) or baseband (Zero IF) respectively before digital sampling. The digitized signal is then processed by Field Programmable Gate Array (FPGA) to get the beam position and phase information. An RF direct-sampling beam signal processor has been developed using ADCs with a bandwidth of 9 GHz and a sampling rate of 2.6 GSPS, and a powerful system-on-chip FPGA. In addition, a prototype RF module without complex down conversion devices has been designed for the SHINE (Shanghai High Repetition Rate XFEL and Extreme Light Facility) cavity BPM. The processor and the RF module make a novel RF direct sampling and processing cavity BPM electronics for SHINE. This is the first attempt to use direct sampling electronics in the C band cavity BPM system. The analog signal processing chain is greatly simplified compared to the down-conversion structure. The performance of this electronics has been analyzed and evaluated in laboratory. The amplitude relative error is 2.0 × 10-4, surpassing the required accuracy of 1 × 10-3 for cavity BPM systems. The phase error is 14 femtoseconds (fs), which also meets the requirements for an RF Beam Arrival Time Monitor (BAM) system. Additionally, the paper introduces the cavity BPM signal processing algorithms and their implementation in FPGA. The processor can deliver pulse-to-pulse beam position measurement above 1 MHz. The RF direct-sampling electronics represents significant advancements in cavity BPM system, large-scale application can be carried out in accelerator facilities like SHINE.

Development of a special kicker for HALF injection systems

A modified local bump injection scheme using a novel dual-channel kicker is proposed for beam injection into a diffraction-limited storage ring (DLSR) at the Hefei Advanced Light Facility (HALF). The dual-channel kicker combines the functions of a standard kicker and a special septum magnet, which deflects the stored beam while remaining transparent to the injected beam. Compared to those of traditional local bump schemes, this scheme can reduce the dynamic aperture requirements and is expected to be promising for 4th generation storage rings. This paper presents a detailed discussion of the dual-channel kicker, its underlying principles, magnetic field and mechanical design, simulations, field measurements, and future optimizations.