Slow Extraction Research Articles

Slow Extraction Spill Characterization From Micro to Milli-Second Scale

This contribution deals with the topic of slow extraction spill quality characterization based on the measurements performed at GSI SIS-18. The sensitivity of the spill to power supply ripples are studied by introducing external ripples. An estimate of sources of inherent power supply ripples along with ripple magnitude are thus obtained. Spill characterization in time and frequency domain are discussed and exemplified by a typical spill and the differences from an ideal or Poisson spill. An appropriate spill characterization aims to provide a suitable abstraction for communication about the spill quality requirements between accelerator operations and users.

Positive features of crystal extraction of protons and carbon ions from the U-70 on basis of long-term experience

Works on the steering of particle beams using channeling in aligned bent crystals have been carried out at IHEP over a number of years. Comprehensive theoretical and experimental studies have led to the creation of actually operating systems on the U-70 accelerator. In particular, a slow proton beam extraction with unprecedentedly high parameters, an extraction efficiency of about 85% at a beam intensity of 10[Formula: see text] particles per cycle, has been realized on U-70 using particle channeling in short bent crystals. In recent years, successful experiments on the extraction of carbon ions were performed. At present, crystal elements are used in regular U-70 runs and provide half of the particle beams for physical experiments. Here, we summarize the results of this unique experience in the world practice of accelerators and outline its prospects.

Application of Crystal Elements for Charged Particle Beam Steering and Radiation Beam Generation on the U-70 Synchrotron

Works on the formation of particle and radiation beams using particle channeling and reflection in oriented crystals have been carried out at IHEP over a number of years. Comprehensive theoretical and experimental studies have led to the creation of actually operating systems on the U-70 accelerator. In particular, a slow proton beam extraction with unprecedentedly high parameters, an extraction efficiency of about 85% at a beam intensity of 1012 particles per cycle, has been realized on U-70 using particle channeling in short bent crystals. Experiments to implement the method of particle reflection in crystals for beam extraction and collimation have been carried out on U-70. At present, crystal elements are used in regular U-70 runs and provide half of the particle beams for physical experiments. We summarize the results of this unique experience in the world practice of accelerators and outline its prospects.

Embedded EPICS Control System of Hight Voltage Power Supply for Extraction Deflector on HIRFL-CSR

Control system of HIRFL-CSR accelerator is now upgrading to new architecture based on Experimental Physics and Industrial Control System (EPICS), a control sub-system of High Voltage (HV) for slow extraction on CSRm must be redesigned with the new architecture. The hardware of the new system based on a high-performance FPGA controller. Researched on embedded EPICS technology and implemented core function of the sub-system based on the technology. This paper describes the design and implementation of the new control system.

Carbon coated MoS2 nanosheets vertically grown on carbon cloth as efficient anode for high-performance sodium ion hybrid capacitors

Sodium-ion hybrid capacitors (NIHC) with sodium ion battery type anodes and supercapacitor type cathodes are emerging as an attractive energy storage device due to the integration of high energy, high power and long lifetime. However, the battery type electrodes usually exhibit sluggish reaction kinetics than capacitor type cathodes due to slow Na ion insertion and extraction, which greatly hinders the rate performance. In this paper, carbon coated MoS2 nanosheets are vertically grown on carbon cloth (CC) substrate using a hydrothermal reaction followed by calcination. The expanded interlayer distance of the MoS2 ensures high ionic mobility while the highly conductive CC not only provides a self-supporting structure without the addition of insulative binder and additional conductive additive, but also effectively prevents the restacking of the MoS2 sheets during cycling. Thus the architecture delivers a high area capacity of 0.511 mAh cm−2 at a current density of 0.2 mA cm−2 and a stable capacity retention of 83.3% after 200 cycles at 1 mA cm−2. Furthermore, NIHC constructed with above anode delivers a high areal energy density of 1.22 mWh cm−2 at a power of 0.76 mW cm−2, demonstrating an excellent energy-power delivery.

Slow extraction from the J-PARC main ring using a dynamic bump

A dynamic bump under the achromatic condition has been applied for third integer slow extraction from the Japan Proton Accelerator Research Complex main ring. This dynamic bump scheme has drastically reduced beam loss rate for slow extraction compared to that for a fixed bump mode. The low beam loss rate for slow extraction has been retained for high power operations. A beam power of 41−44.4 kW was achieved for physics runs using the slow extraction by applying the dynamic bump scheme. The beam profile measured just upstream of the target indicates that the beam spot at the target does not travel over the entire extraction time. This behavior is advantageous for experimental data acquisition.

Investigating Beam Loss Reduction with Octupoles During Slow Extraction in the CERN SPS

Investigating Beam Loss Reduction with Octupoles During Slow Extraction in the CERN SPS

Progress Toward a Dynamic Extraction Bump for Slow Extraction in the CERN SPS

Progress Toward a Dynamic Extraction Bump for Slow Extraction in the CERN SPS

Inter-occlusal appliance for implant site augmentation and optimal implant positioning: a ten-year follow-up case report

Aim: Orthodontic implant site augmentation was proposed for exodontia of a hopeless tooth to improve bone architecture before implant installation. However, the use of orthodontic appliances to perform slow vertical movements and tooth extraction demands an interdisciplinary approach, increasing time and costs. The aim of this study is to present a technique of orthodontic implant site augmentation by the use of an inter-occlusal appliance. Case report: A 48-year-old patient presented cervical external resorption and root fracture at the upper left central incisor. A slow orthodontic extraction of the tooth was performed by the use of an inter-occlusal appliance. After extrusion, the tooth was extracted and the implant was immediately placed. Tooth was extruded 6 mm in 8 months, at a slow rate of extrusion (0.75 mm/month) along the tooth long axis, resulting in the formation of new bone at the apex and alveolar crest, leveling its height with neighboring teeth. Results: An increase in keratinized gingiva was observed. Final restoration was installed one year later, with adequate subgingival contour. No complications were observed after 10 years of follow-up. Conclusions: The use of an inter-occlusal appliance provided a simple method for orthodontic extraction and implant site development, allowing optimal implant positioning with no surgical augmentation procedures.

Highly Efficient Recovery of Uranium from Seawater Using an Electrochemical Approach

Uranium recovery from seawater offers a promising route for producing scalable and sustainable nuclear energy because the world’s oceans contain hundreds of times more uranium than lands. A current adsorption method presents limitations including low extraction capacity and slow extraction kinetics, making realistic implementation impractical. Here we develop an electrochemical extraction approach that demonstrates high extraction capacity and fast extraction kinetics in uranium recovery. In the electrochemical approach, chitosan-functionalized electrodes were used to offer surface specific binding to uranyl ions; voltages were then supplied to attract the ions to the electrode and induce electrodeposition of uranyl ions to form charge-neutral uranium species. The electrodeposition approach demonstrated nearly 8 times higher uranium extraction capacities and 3 times faster extraction rates than the current adsorption method in uranium-spiked seawater. Because of the excellent uranium extraction performanc...

The acidic ferric sulfate leaching of primary copper sulfides under recycle solution conditions observed in heap leaching. Part 1. Effect of standard conditions

Understanding the dissolution of copper from chalcopyrite is important as chalcopyrite is the most abundant copper mineral in the earth's crust. The main method for extraction of copper from chalcopyrite is by flotation concentration before being smelted and electro-refined. However, this process is not suitable for the treatment of the vast reserves of low grade chalcopyrite ores, where hydrometallurgical extraction through heap leaching is a better option. While pressure or high temperature leaching with the addition of sodium chloride or HCl have been proposed to extract copper from chalcopyrite concentrates, this process is too expensive to treat low grade copper ores. Currently the research focus to develop a treatment process involves the use of bacteria to oxidise the sulfide minerals and produce sulfuric acid. Given the slow extraction rates of this process it requires decades to extract all the copper from the mineral which would mean the leach solution would therefore be recycled during the process once the copper had been removed. While previous studies have reported the effect of leach temperature, pH (acid concentration) and Eh on copper extraction, these have only considered initial leaching conditions. Studies using recycle leach solution conditions have not been undertaken, and this is the focus of the study reported here. The recycle solution conditions were based on a simulated long term solution composition. This article is part of a series of papers that has investigated the effect on copper and iron extraction from chalcopyrite which has evaluated conditions, major species and additives under recycle leach concentrations. This article examines the effect of the conditions, specifically temperature, pH, Eh and solids density. It was determined that the temperature had the most significant effect on the copper and iron extraction while the pH, Eh or solids density had no appreciable effect on the extraction of either copper or iron under the recycle leach conditions tested. While the effect of temperature on chalcopyrite dissolution is known, the activation energy, the rate of dissolution and the degree of copper extraction is lower under these high solute or recycle concentrations. Similar observations were found when studying pyrite but this study attributed the lowering of these parameters under recycle conditions to the sulfate concentration causing a diffusion layer around the mineral particles which alters or slows the response of pH, Eh or temperature on the dissolution reaction.

Magnetic Septa for the SIS100 Accelerator at FAIR

The future heavy ion synchrotron SIS100 will have a series of two dc magnetic septa for the injection and three dc septa on the extraction line. The extraction line will allow for two different extraction schemes for vertical fast extraction and initially horizontal slow extraction. The latter requires, among other components, two additional Lambertson-type septa. The design of the magnets had to account not only for creating a high field with a narrow septum width, but also had to find way of providing bakeout jackets while limiting the technicians’ exposure to radiation. Another issue was to minimize the chance of failure, e.g., by limiting the number of soldered joints with contact to the cooling channels and by reducing the current density with help of wedge-shaped conductors. The injection septa are under construction while some design work is still in progress for the extraction septa. We will present some of our solutions and concepts.

Design of extraction system in BRing at HIAF

The Booster Ring (BRing), which is the key part of HIAF (High Intensity heavy ion Accelerator Facility) complex at IMP (Institute of Modern Physics, Chinese Academy of Sciences), can provide uranium (A∕q=7) beam with a wide extraction energy range of 200–800 MeV/u. To fulfill a flexible beam extraction for multi-purpose experiments, both fast and slow extraction systems will be accommodated in the BRing. The fast extraction system is used for extracting short bunched beam horizontally in single-turn. The slow extraction system is used to provide quasi-continuous beam by the third order resonance and RF-knockout scheme. To achieve a compact structure, the two extraction systems are designed to share the same extraction channel. The general design of the fast and slow extraction systems and simulation results are discussed in this paper.

Development of stereotactic radiosurgery using carbon beams (carbon-knife)

The aim of this research is to develop a stereotactic-radiosurgery (SRS) technique using carbon beams to treat small intracranial lesions; we call this device the carbon knife. A 2D-scanning method is adapted to broaden a pencil beam to an appropriate size for an irradiation field. A Mitsubishi slow extraction using third order resonance through a rf acceleration system stabilized by a feed-forward scanning beam using steering magnets with a 290 MeV/u initial beam energy was used for this purpose. Ridge filters for spread-out Bragg peaks (SOBPs) with widths of 5 mm, 7.5 mm, and 10 mm were designed to include fluence-attenuation effects. The collimator, which defines field shape, was used to reduce the lateral penumbra. The lateral-penumbra width at the SOBP region was less than 2 mm for the carbon knife. The penumbras behaved almost the same when changing the air gap, but on the other hand, increasing the range-shifter thickness mostly broadened the lateral penumbra. The physical-dose rates were approximate 6 Gy s−1 and 4.5 Gy s−1 for the 10 × 10 mm2 and 5 × 5 mm2 collimators, respectively.

Polarimetry concept based on heavy crystal hadron calorimeter

In the ongoing JEDI (Jülich Electric Dipole moment Investigations) project, the essential point will be to measure a tiny beam polarization change over an extended period of time. The particle scarcity in the polarized deuteron or proton beams and the required slow extraction rate puts tough experimental constrains on the polarimetry. For the EDM measurements, a dedicated high precision polarimeter is required. To fulfill specifications, a fast, dense, high resolution (energy and time), and radioactive hard novel crystal scintillating material is required. LYSO crystals are supposed to be used as an ideal scintillating material for this kind of detector. The LYSO crystal PMT and SiPM readout, with a FADC based system is under development. The first proton and deuteron beam test of the prototypes are presented here. In this paper, the new polarimetry concept and preliminary results from first proton and deuteron beam time are presented.

Quantum-Enhanced Capture of Photons Using Optical Ratchet States

Natural and artificial light harvesting systems often operate in a regime where the flux of photons is relatively low. Besides absorbing as many photons as possible it is therefore paramount to prevent excitons from annihilation via photon re-emission until they have undergone an irreversible energy conversion process. Taking inspiration from photosynthetic antenna structures, we here consider ring-like systems and introduce a class of states we call ratchets: excited states capable of absorbing but not emitting light. This allows our antennae to absorb further photons whilst retaining the excitations from those that have already been captured. Simulations for a ring of four sites reveal a peak power enhancement by up to a factor of 35 under ambient conditions owing to a combination of ratcheting and the prevention of emission through dark-state population. In the slow extraction limit the achievable power enhancement due to ratcheting alone exceeds 20%.

Design study of beam transport lines for BioLEIR facility at CERN

The biomedical community has asked CERN to investigate the possibility to transform the Low Energy Ion Ring (LEIR) accelerator into a multidisciplinary, biomedical research facility (BioLEIR) that could provide ample, high-quality beams of a range of light ions suitable for clinically oriented, fundamental research on cell cultures and for radiation instrumentation development. The present LEIR machine uses fast beam extraction to the next accelerator in the chain, eventually leading to the Large Hadron Collider (LHC) . To provide beam for a biomedical research facility, a new slow extraction system must be installed. Two horizontal and one vertical experimental beamlines were designed for transporting the extracted beam to three experimental end-stations. The vertical beamline (pencil beam) was designed for a maximum energy of 75 MeV/u for low-energy radiobiological research, while the two horizontal beamlines could deliver up to 440 MeV/u. One horizontal beamline shall be used preferentially for biomedical experiments and shall provide pencil beam and a homogeneous broad beam, covering an area of 5 × 5 cm2 with a beam homogeneity of ±5%. The second horizontal beamline will have pencil beam only and is intended for hardware developments in the fields of (micro-)dosimetry and detector development. The minimum full aperture of the beamlines is approximately 100 mm at all magnetic elements, to accommodate the expected beam envelopes. Seven dipoles and twenty quadrupoles are needed for a total of 65 m of beamlines to provide the specified beams. In this paper we present the optical design for the three beamlines.

Investigation of the Extraction of the Casing for Large Diameter Cast-in-Place Piles by Vibratory Hammers in Clays

The Benoto cast-in-place piles are widely used in civil engineering for having the advantage of producing low vibration and noise. Therefore, more researches are needed to fully understand its mechanism. However, the researches on the mechanism of Benoto piles are only limited to the driving stage, the study of extraction stage of the steel casing is not comprehensive. In this paper, a three-dimensional numerical model was developed by Coupled Eulerian–Lagrangian method. The mechanism of high-frequency vibratory extraction of casing was studied in detail. The result indicates that the vibratory casing extraction process can be divided into two stages, namely the slow and fast extraction stage. During the vibratory casing extraction process, the soil displacement, stresses, void ratio and excess pore water pressure abruptly change in the soils around the casing bottom. Furthermore, the influence of vibratory hammers on vibratory casing extraction was investigated. The change in the excitation frequency and excitation force has effect on casing extraction speed and soil particle velocity, but hardly has any influence on soil displacement and stresses.

Simulation study of slow extraction for the Shanghai Advanced Proton Therapy facility

The Shanghai Advanced Proton Therapy facility employs third-integer slow extraction. In order to achieve accurate treatment, high-quality spill is needed. Therefore, parameters that may affect slow extraction should be investigated by simulation. A computer model of the synchrotron operation slow extraction was constructed with MATLAB®. By simulating the motion of the circulating protons, we could quantify the influence of machine and initial beam parameters on properties of the extracted beam, such as ripple, uniformity, stability, on- and off-time of the spill and spill width in the synchrotron. Suitable design parameters including the horizontal tunes, power supply ripple, longitudinal RF cavity voltage, RF-KO and the chromaticities were determined.

Electron cloud simulations for the main ring of J-PARC

The simulation of beam instabilities is a helpful tool to evaluate potential threats against the machine protection of the high intensity beams. At Main Ring (MR) of J-PARC, signals related to the electron cloud have been observed during the slow beam extraction mode. Hence, several studies were conducted to investigate the mechanism that produces it, the results confirmed a strong dependence on the beam intensity and the bunch structure in the formation of the electron cloud, however, the precise explanation of its trigger conditions remains incomplete. To shed light on the problem, electron cloud simulations were done using an updated version of the computational model developed from previous works at KEK. The code employed the signals of the measurements to reproduce the events seen during the surveys.