Design Of Vacuum Chamber Research Articles

Elettra 2.0: The Vacuum System Design for a New Generation Storage Ring

Next-generation synchrotron facilities currently under development and construction are promising and delivering great advances in terms of machine design and research physics. At the same time, they are pushing the limits of technological solutions for various subsystems: to achieve the desired ultra-low electron beam emittance required in the next generation machines, the magnetic lattice has to adopt a compact design with reduced magnet apertures and other constraints like high heat load from synchrotron radiation, dynamic pressure inside vacuum chambers and chamber wall impedance are presenting unique challenges for the vacuum and engineering teams. At Elettra-Sincrotrone Trieste (Italy), the Elettra 2.0 project aims to develop a new-generation storage ring. Taking into consideration the above-mentioned constraints, we decided to adopt a new design of a vacuum chamber, while utilizing novel pumping solutions to overcome hugely reduced conductance compared to the current machine. Large sputter ion pumps (SIP) will be in the majority replaced by distributed non-evaporable getter (NEG) coatings and small NEG cartridges and SIP pumps. For the synchrotron radiation handling, due to the tight space constraints imposed by the compact lattice, the photon absorption will be managed jointly with discrete and distributed solutions: photon absorbers have been carefully studied for combining compact form and high power density loads, while key sections of the new storage ring will be water-cooled. Throughout the whole development phase, we were using Monte-Carlo simulation codes like SynRad and MolFlow+ as effective tools supporting the design of new vacuum chambers and photon absorbers. The current state of development for the Elettra 2.0 vacuum system, the challenges we faced and the solutions we adopted are presented here.

Concept of a miniature dipole trap system based on a simple-architecture grating chip

This research presents the theoretical demonstration of a grating chip that can facilitate a miniature dipole trap system for rubidium atoms. The innovative chip design is expected to form both a magneto-optical trap and a dipole trap with a single laser. The paper further examines the dependence of the chip’s focusing properties and diffraction efficiency on its structural parameters. Findings confirm the proposed design’s ability to effectively trap atoms. The research also proposes a compact vacuum chamber design compatible with the grating chip. This design incorporates a non-evaporable getter and dispenser, utilizing materials with minimal outgassing and helium permeation rates.

Thermal analysis of condensation-induced vacuum and its feasibility for operating a vacuum membrane distillation system

Vacuum pumps are primarily used in vacuum membrane distillation (VMD) for vacuum generation. However, vacuum pumps are characterized by low operational durability and a high energy demand. In this study, a steam condensation process was combined with the VMD process such that the vacuum created during the steam condensation process drove the VMD operation. A thermodynamic cycle comprised of three main processes: steam purging, vacuum creation, and water recovery was described. This paper presents a detailed thermal analysis of each process of the thermodynamic cycle based on heat transfer and thermodynamic models. The modeling results are compared with experimental data. The pressure in the vacuum chamber increased during the water recovery process because of the accumulation of non-condensable gases, which permeated the chamber along with the water vapors. Consequently, the mass flux of the VMD permeate decreased, and finally, the permeation ceased when the pressure in the chamber reached ~20 kPa; after this stage, the cycle restarted. For the current experimental conditions and vacuum chamber design, the durations of the purging, vacuum creation, and recovery processes were 30, 500, and 270 s. At least three linked vacuum chambers must be synchronized and operated simultaneously to realize continuous water recovery.

Design and development of vacuum chamber for superconducting undulator at IHEP

Superconducting undulators (SCUs) are crucial components for advanced photon sources and have broad applications. IHEP is currently developing SCU, which requires a vacuum chamber to provide a beam path and protect the superconducting magnets from image currents induced by the beams. However, due to the narrow magnetic gap and low temperature of the SCU, designing and processing its vacuum chamber presents challenges in terms of mechanical design, positioning, and intercepting synchrotron radiation that could damage the sensitive superconducting magnets. The SCU vacuum chamber is divided into three parts based on location and function: chamber inside the cryostat as well as upstream and downstream chambers outside it. The complex fit of the constant aperture vacuum chamber inside the cryostat with both magnets and cryostat ensures high-current operation while also safely managing dynamic heat loads imposed by beams. Using an SCU operating on HEPS as an example shows how smooth transitions between upstream/downstream and storage ring chambers effectively absorb synchrotron radiation to protect magnets and downstream equipment from damage caused by synchrotron radiation exposure. Simulations are performed to check the possible effects of synchrotron radiation on the mechanical properties, the ultimate vacuum of these chambers and to calculate the beam impedance. Finally, two solutions for using the vacuum chamber as a channel for measuring the magnetic field of the SCU in the operating state are discussed.

SLIM Tricks: Tools, Concepts, and Strategies for the Development of Planar Ion Guides.

Traveling wave ion mobility experiments using planar electrode structures (e.g., structures for lossless ion manipulation, TW-SLIM) leverage the mature manufacturing capabilities of printed circuit boards (PCBs). With routine levels of mechanical precision below 150 μm, the conceptual flexibility afforded by PCBs for use as planar ion guides is expansive. To date, the design and construction of TW-SLIM platforms require considerable legacy expertise, especially with respect to simulation and circuit layout strategies. To lower the barrier of TW-SLIM implementation, we introduce Python-based interactive tools that assist in graphical layout of the core electrode footprints for planar ion guides with minimal user inputs. These scripts also export the exact component locations and assignments for direct integration into KiCad and SIMION for PCB finalization and ion flight simulations. The design concepts embodied in the set of scripts comprising SLIM Pickins (PCB CAD generation) and pigsim (SIMION workspace generation) build upon the lessons learned in the independent development of the research-grade TW-SLIM platforms in operation at WSU. Due to the inherent flexibility of the PCB manufacturing process and the time devoted to board layouts prior to manufacturing, both scripts serve to enable rapid, iterative design considerations. Because only a few predefined parameters are necessary (i.e., the TW-SLIM monomer width, x position following a TW Turn, and y position following a TW Turn) it is possible to design the exact component layouts and accompanying simulation space in a manner of minutes. There is no known limitation to the board layout capacities of the scripts, and the size of a designed layout is ultimately constrained by the abilities of the final PCB design and simulation tools, KiCad and SIMION, to accommodate the thousands of electrodes comprising the final design (i.e., RAM and software overhead). Toward removing the barriers to exploring new SLIM tracks and the likelihood of layout errors that require considerable revision and engineering time, the SLIM Pickins and pigsim tools (included as Supporting Information) allow the user to quickly design a length of planar ion guide, simulate its abilities to confine and transmit ions, compare hypothetical board outlines to given vacuum chamber dimensions, and generate a near-production ready PCB CAD file. In addition to these tools, this report outlines a series of cost-saving strategies with respect to vacuum feedthroughs and vacuum chamber design for TW ion mobility experiments using planar ion guides.

An improved vacuum-steam pulsed blanching machine design and garlic scape blanching verified experiment

Vacuum-steam pulsed blanching (VSPB) is an emerging blanching method resulting in high efficiency and product quality. However, inconvenient loading, small loading capacity, uneven rinsing and imprecise control hinder its application in food industry. Therefore, the current work aimed to design a VSPB machine, including selection of components, building a control system and designing a steam nozzle in order to increase the load capacity and improve device control. For this purpose, a horizontal blanching chamber with internal nozzle was designed and optimized using CFD method. The vacuum chamber design required a more evenly distributed steam inlet. A water-sealing vacuum pump, a cooling device and a hardware system were developed. The distribution of steam released from the nozzle in the chamber was numerically investigated by solving the three-dimensional Reynolds-averaged Navier-Stokes equations, with a velocity uniformity index value of 0.448. The validation blanching test was conducted using garlic scape as the test material. The steam holding time and the number of cycles significantly affected (p < 0.05) the color of the garlic scapes. Peroxidase (POD) activity decreased with the increase of blanching cycles until the enzymes were completely inactivated. VSPB significantly decreased (p < 0.05) the lignin content of the garlic scapes. The findings indicate that the best results were obtained after 2 cycles of VSPB and steam holding time of 30 s. Industrial relevanceHot water and steam thermal blanching are the two most frequently used blanching methods in food processing. Generally, they are used as a pretreatment before drying, freezing or canning of different fruits and vegetables. In current work, an improved vacuum-steam pulsed blanching machine was designed and the validation blanching test with garlic scape as the material indicated that VSPB operation was effective in preventing the synthesis of lignification in garlic scapes. By considering enzyme inactivation, lignification, color, and other quality attributes, 2 cycles of VSPB and steam holding for 30 s were proposed as the optimal VSPB conditions.

Vacuum Chamber Design and Analysis of the Space Station High Temperature Material Science Experimental System

中国空间站高温材料科学实验系统能够在轨进行多种材料的微重力高温加热实验，其关键组件真空室是可实现密封的压力容器，为实验插件提供机械、真空、氮气、废气排放、供电、控制、冷却等接口，支持实验插件完成相关功能。本文依据承压范围、漏率等设计技术指标进行真空室的结构设计和力学分析。真空室采用分段式结构，由方形真空室、密封门、圆形真空室、安装支架等组件依次连接组成，连接结构处使用密封圈。通过真空室的承压分析、模态分析、随机响应分析和力学试验，校核了真空室的强度、刚度及随机振动响应特性，验证了真空室设计的安全性和可靠性，其能够满足发射及在轨工作要求。

Vacuum Chamber Design and Analysis of the Space Station High Temperature Material Science Experimental System

Vacuum Chamber Design and Analysis of the Space Station High Temperature Material Science Experimental System

Impedance modelling and collective effects in the Future Circular e+e− Collider with 4 IPs

The FCC-ee impedance model is being constantly updated closely following the vacuum chamber design and parameters evolution. In particular, at present, a thicker NEG coating of 150 nm (instead of previous 100 nm) has been suggested by the vacuum experts, and a more realistic impedance model of the bellows has been investigated. Moreover, also the transverse impedance has been updated by considering the same sources as for the longitudinal case. Therefore, the FCC-ee impedance database is getting more complete and the impedance model is being refined. In this paper we describe the presently available machine coupling impedance in both longitudinal and transverse planes, and study the impedance-driven single bunch instabilities (with and without beam-beam interaction) for the new FCC-ee parameter set with 4 interaction points (IPs). The results are compared with the previously obtained ones and a further possible mitigation of the beam-beam head-tail instability (X-Z instability) is proposed.

Ultra-high-quality two-dimensional electron systems.

Two-dimensional electrons confined to GaAs quantum wells are hallmark platforms for probing electron-electron interactions. Many key observations have been made in these systems as sample quality has improved over the years. Here, we present a breakthrough in sample quality via source-material purification and innovation in GaAs molecular beam epitaxy vacuum chamber design. Our samples display an ultra-high mobility of 44 × 106 cm2 V-1 s-1 at an electron density of 2.0 × 1011 cm-2. These results imply only 1 residual impurity for every 1010 Ga/As atoms. The impact of such low impurity concentration is manifold. Robust stripe and bubble phases are observed, and several new fractional quantum Hall states emerge. Furthermore, the activation gap (Δ) of the fractional quantum Hall state at the Landau-level filling (ν) = 5/2, which is widely believed to be non-Abelian and of potential use for topological quantum computing, reaches Δ ≈ 820 mK. We expect that our results will stimulate further research on interaction-driven physics in a two-dimensional setting and substantially advance the field.

Study on Au coating of ceramic-lined thin-wall vacuum chamber for HIAF

HIAF-BRing, the main synchrotron accelerator of the High Intensity Heavy-Ion Accelerator Facility, requires an average pressure lower than 1 × 10−9 Pa and the magnetic field increase rate no less than 12 T/s to fulfill radioactive beam physics and high energy density physics experiments. To reduce the eddy current effect and the gap size of dipoles compared to the thin-wall stainless steel vacuum chamber with reinforced ribs, a new design of ceramic-lined vacuum chamber with wall thickness 0.3 mm has been proposed by IMP. In order to effectively reduce the beam impedance and the desorption rate of ceramic materials, Au coating on ceramic (Yttria stabilized zirconia) by magnetron sputtering has been carried out. The adhesive force of Au film is 28.1 MPa measured by scratch test while the crystalline size of Au particle is in the range of 15.7–21.4 nm by X-ray diffraction (XRD). The longitudinal impedances of four types of round-ring-lined 0.6-m-long straight stainless-steel tubes and the ultimate pressure of the new designed vacuum chamber (uncoated vs Au-coated) have been measured to verify the feasibility of this method.

Species of vacuum chamber design with cryogenic cooling for strontium optical clocks

The paper briefly reviews the reasons for the optical clock resonance shift due to thermal radiation. The ways to decrease thermal radiation influence with modification of the spectroscope by introducing of the cryogenic elements as an environment of the atoms from a cryogenic nozzle to create special internal chamber with the example of 87Sr optical clocks are shown. The possibility and usefulness of using the double-circuit dual-mode cryogenic chamber to suppress thermal shift in a strontium optical clocks are considered. The selection of the each element material of the chamber is based on simulated thermal distributions and heat flows of these elements. The detailed concept of this double-circuit dual-mode chamber and calculation of the shifts from each element of this chamber are also presented.

Design of the future circular hadron collider beam vacuum chamber

The optimized vacuum chamber for a future higher-energy hadron collider minimizes electron cloud build-up, outgassing from synchrotron radiation, and heat leakage to the cold mass of the superconducting magnets, while maximizing pumping efficiency and ensuring mechanical stability during a magnet quench.

New Design of Vacuum Chambers for Radiation Shield Installation at Beam Injection Area of J-PARC RCS

One of the issues in the J-PARC 3 GeV rapid cycling synchrotron is the high residual radiation dose around the beam injection point. A radiation shield is necessary to reduce radiation exposure of workers when maintenance is performed there. A space to install the radiation shield should be secured by newly designing a structure of the vacuum chamber at the injection point and the alumina ceramics beam pipes for the shift bump magnets. To make the space for the shield, the chamber is lengthened along the beam line and the cross-sectional shape is changed from circle to rectangle. The displacement and inner stress of the vacuum chamber due to atmospheric pressure were evaluated to be enough small by the calculation. For the ceramics beam pipe’s rf-shield, the damping resistor was effective to reduce the induced modulation voltages by the pulsed magnetic field.

Methods to simplify cooling of liquid Helium cryostats

Liquid Helium is used widely, from hospitals to characterization of materials at low temperatures. Many experiments at low temperatures require liquid Helium, particularly when vibration isolation precludes the use of cryocoolers and when one needs to cool heavy equipment such as superconducting coils. Here we describe methods to simplify the operations required to use liquid Helium by eliminating the use of high pressure bottles, avoiding blockage and improving heating and cooling rates. First we show a simple and very low cost method to transfer liquid Helium from a transport container into a cryostat that uses a manual pump having pumping and pressurizing ports, giving a liquid Helium transfer rate of about 100 liters an hour. Second, we describe a closed cycle circuit of Helium gas cooled in an external liquid nitrogen bath that allows precooling a cryogenic experiment without inserting liquid nitrogen into the cryostat, eliminating problems associated to the presence of nitrogen around superconducting magnets. And third, we show a sliding seal assembly and an inner vacuum chamber design that allows inserting large experiments into liquid Helium.

Design of small thermal vacuum chamber for 125-U CubeSat satellite

The thermal vacuum chamber is a specialized chamber to test any mechanical system, which is planned to be launched to outer space. The research is about designing a new thermal vacuum chamber to accommodate a 125-U CubeSat satellite. The role is to create a space condition environment with ultra-high vacuum in high and low temperature and induced radiation. Liquid nitrogen is utilized as the thermal medium. The proposed design is simulated and tested acoording to the working parameters. The velocity result indicates a sensible output velocity of 3.841 m/s with an input velocity of 10m/s. The pressure contour provides a maximum of 13,280 Pa.

Beam dynamics studies at DAΦNE: from ideas to experimental results

DAΦNE is the electron-positron collider operating at the energy of Φ-resonance, 1 GeV in the center of mass. The presently achieved luminosity is by about two orders of magnitude higher than that obtained at other colliders ever operated at this energy. Careful beam dynamic studies such as the vacuum chamber design with low beam coupling impedance, suppression of different kinds of beam instabilities, investigation of beam-beam interaction, optimization of the beam nonlinear motion have been the key ingredients that have helped to reach this impressive result. Many novel ideas in accelerator physics have been proposed and/or tested experimentally at DAΦNE for the first time. In this paper we discuss the advanced accelerator physics studies performed at DAΦNE.

Long-life micro vacuum chamber for a micromachined cryogenic cooler

Micromachined cryogenic coolers can be used for cooling small electronic devices to improve their performance. However, for reaching cryogenic temperatures, they require a very good thermal insulation from the warm environment. This is established by a vacuum space that for adequate insulation has to be maintained at a pressure of 0.01 Pa or lower. In this paper, the challenge of maintaining a vacuum chamber with a volume of 3.6 × 10−5 m3 and an inner wall area of 8.1 × 10−3 m2 at a pressure no higher than 0.01 Pa for five years is theoretically analyzed. The possible sources of gas, the mechanisms by which these gases enter the vacuum space and their effects on the pressure in the vacuum chamber are discussed. In a long-duration experiment with four stainless steel chambers of the above dimensions and equipped with a chemical getter, the vacuum pressures were monitored for a period of two years. In that period, the measured pressure increase stayed within 0.01 Pa. This study can be used to guide the design of long-lifetime micro vacuum chambers that operate without continuous mechanical pumping.

The MAX IV storage ring project.

The MAX IV facility, currently under construction in Lund, Sweden, features two electron storage rings operated at 3 GeV and 1.5 GeV and optimized for the hard X-ray and soft X-ray/VUV spectral ranges, respectively. A 3 GeV linear accelerator serves as a full-energy injector into both rings as well as a driver for a short-pulse facility, in which undulators produce X-ray pulses as short as 100 fs. The 3 GeV ring employs a multibend achromat (MBA) lattice to achieve, in a relatively short circumference of 528 m, a bare lattice emittance of 0.33 nm rad, which reduces to 0.2 nm rad as insertion devices are added. The engineering implementation of the MBA lattice raises several technological problems. The large number of strong magnets per achromat calls for a compact design featuring small-gap combined-function magnets grouped into cells and sharing a common iron yoke. The small apertures lead to a low-conductance vacuum chamber design that relies on the chamber itself as a distributed copper absorber for the heat deposited by synchrotron radiation, while non-evaporable getter (NEG) coating provides for reduced photodesorption yields and distributed pumping. Finally, a low main frequency (100 MHz) is chosen for the RF system yielding long bunches, which are further elongated by passively operated third-harmonic Landau cavities, thus alleviating collective effects, both coherent (e.g. resistive wall instabilities) and incoherent (intrabeam scattering). In this paper, we focus on the MAX IV 3 GeV ring and present the lattice design as well as the engineering solutions to the challenges inherent to such a design. As the first realisation of a light source based on the MBA concept, the MAX IV 3 GeV ring offers an opportunity for validation of concepts that are likely to be essential ingredients of future diffraction-limited light sources.

Planetary Atmosphere and Surfaces Chamber (PASC): A Platform to Address Various Challenges in Astrobiology

The study of planetary environments of astrobiological interest has become a major challenge. Because of the obvious technical and economical limitations on in situ planetary exploration, laboratory simulations are one of the most feasible research options to make advances both in planetary science and in developing a consistent description of the origin of life. With this objective in mind, we applied vacuum technology to the design of versatile vacuum chambers devoted to the simulation of planetary atmospheres’ conditions. These vacuum chambers are able to simulate atmospheres and surface temperatures representative of the majority of planetary objects, and they are especially appropriate for studying the physical, chemical and biological changes induced in a particular sample by in situ irradiation or physical parameters in a controlled environment. Vacuum chambers are a promising potential tool in several scientific and technological fields, such as engineering, chemistry, geology and biology. They also offer the possibility of discriminating between the effects of individual physical parameters and selected combinations thereof. The implementation of our vacuum chambers in combination with analytical techniques was specifically developed to make feasible the in situ physico-chemical characterization of samples. Many wide-ranging applications in astrobiology are detailed herein to provide an understanding of the potential and flexibility of these experimental systems. Instruments and engineering technology for space applications could take advantage of our environment-simulation chambers for sensor calibration. Our systems also provide the opportunity to gain a greater understanding of the chemical reactivity of molecules on surfaces under different environments, thereby leading to a greater understanding of interface processes in prebiotic chemical reactions and facilitating studies of UV photostability and photochemistry on surfaces. Furthermore, the stability and presence of certain minerals on planetary surfaces and the potential habitability of microorganisms under various planetary environmental conditions can be studied using our apparatus. Therefore, these simulation chambers can address multiple different challenging and multidisciplinary astrobiological studies.