National Security Letters, the USA PATRIOT Act, and the Constitution: The Tensions between National Security and Civil Rights

ERIC Educational Resources Information Center

Gorham-Oscilowski, Ursula; Jaeger, Paul T.

2008-01-01

In response to the terrorist attacks of 9/11, the USA PATRIOT Act greatly expanded the ability of the Federal Bureau of Investigation to use National Security Letters (NSLs) in investigations and the contexts in which they could be used by relaxing the standards under which NSLs could be employed. NSLs allow investigators to acquire a significant…

SERVER DEVELOPMENT FOR NSLS-II PHYSICS APPLICATIONS AND PERFORMANCE ANALYSIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, G.; Kraimer, M.

2011-03-28

The beam commissioning software framework of NSLS-II project adopts a client/server based architecture to replace the more traditional monolithic high level application approach. The server software under development is available via an open source sourceforge project named epics-pvdata, which consists of modules pvData, pvAccess, pvIOC, and pvService. Examples of two services that already exist in the pvService module are itemFinder, and gather. Each service uses pvData to store in-memory transient data, pvService to transfer data over the network, and pvIOC as the service engine. The performance benchmarking for pvAccess and both gather service and item finder service are presented inmore » this paper. The performance comparison between pvAccess and Channel Access are presented also. For an ultra low emittance synchrotron radiation light source like NSLS II, the control system requirements, especially for beam control are tight. To control and manipulate the beam effectively, a use case study has been performed to satisfy the requirement and theoretical evaluation has been performed. The analysis shows that model based control is indispensable for beam commissioning and routine operation. However, there are many challenges such as how to re-use a design model for on-line model based control, and how to combine the numerical methods for modeling of a realistic lattice with the analytical techniques for analysis of its properties. To satisfy the requirements and challenges, adequate system architecture for the software framework for beam commissioning and operation is critical. The existing traditional approaches are self-consistent, and monolithic. Some of them have adopted a concept of middle layer to separate low level hardware processing from numerical algorithm computing, physics modelling, data manipulating and plotting, and error handling. However, none of the existing approaches can satisfy the requirement. A new design has been proposed by introducing service oriented architecture technology, and client interface is undergoing. The design and implementation adopted a new EPICS implementation, namely epics-pvdata [9], which is under active development. The implementation of this project under Java is close to stable, and binding to other language such as C++ and/or Python is undergoing. In this paper, we focus on the performance benchmarking and comparison for pvAccess and Channel Access, the performance evaluation for 2 services, gather and item finder respectively.« less

National Synchrotron Light Source annual report 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hulbert, S.L.; Lazarz, N.M.

1992-04-01

This report discusses the following research conducted at NSLS: atomic and molecular science; energy dispersive diffraction; lithography, microscopy and tomography; nuclear physics; UV photoemission and surface science; x-ray absorption spectroscopy; x-ray scattering and crystallography; x-ray topography; workshop on surface structure; workshop on electronic and chemical phenomena at surfaces; workshop on imaging; UV FEL machine reviews; VUV machine operations; VUV beamline operations; VUV storage ring parameters; x-ray machine operations; x-ray beamline operations; x-ray storage ring parameters; superconducting x-ray lithography source; SXLS storage ring parameters; the accelerator test facility; proposed UV-FEL user facility at the NSLS; global orbit feedback systems; and NSLSmore » computer system.« less

National Synchrotron Light Source 2010 Activity Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rowe, M.; Snyder, K. J.

This is a very exciting period for photon sciences at Brookhaven National Laboratory. It is also a time of unprecedented growth for the Photon Sciences Directorate, which operates the National Synchrotron Light Source (NSLS) and is constructing NSLS-II, both funded by the Department of Energy's Office of Science. Reflecting the quick pace of our activities, we chose the theme 'Discovery at Light Speed' for the directorate's 2010 annual report, a fiscal year bookended by October 2009 and September 2010. The year began with the news that NSLS users Venki Ramakrishnan of Cambridge University (also a former employee in Brookhaven's biologymore » department) and Thomas A. Steitz of Yale University were sharing the 2009 Nobel Prize in Chemistry with Ada E. Yonath of the Weizmann Institute of Science. Every research project has the potential for accolades. In 2010, NSLS users and staff published close to 900 papers, with about 170 appearing in premiere journals. Those are impressive stats for a facility nearly three decades old, testament to the highly dedicated team keeping NSLS at peak performance and the high quality of its user community. Our NSLS users come from a worldwide community of scientists using photons, or light, to carry out research in energy and environmental sciences, physics, materials science, chemistry, biology and medicine. All are looking forward to the new capabilities enabled by NSLS-II, which will offer unprecedented resolution at the nanoscale. The new facility will produce x-rays more than 10,000 times brighter than the current NSLS and host a suite of sophisticated instruments for cutting-edge science. Some of the scientific discoveries we anticipate at NSLS-II will lead to major advances in alternative energy technologies, such as hydrogen and solar. These discoveries could pave the way to: (1) catalysts that split water with sunlight for hydrogen production; (2) materials that can reversibly store large quantities of electricity or hydrogen; (3) high-temperature superconducting materials that carry electricity with no loss for efficient power transmission lines; and (4) materials for solid-state lighting with half of the present power consumption. Excitement about NSLS-II is evident in many ways, most notably the extraordinary response we had to the 2010 call for beamline development proposals for the anticipated 60 or more beamlines that NSLS-II will ultimately host. A total of 54 proposals were submitted and, after extensive review, 34 were approved. Funding from both the Department of Energy and the National Institutes of Health has already been secured to support the design and construction of a number of these beamlines. FY11 is a challenging and exciting year for the NSLS-II Project as we reach the peak of our construction activity. We remain on track to complete the project by March 2014, a full 15 months ahead of schedule and with even more capabilities than originally planned. The Photon Sciences Directorate is well on its way to fulfilling our vision of being a provider of choice for world-class photon sciences and facilities.« less

NSLS 2007 Activity Report (National Synchrotron Light Source Activity Report 2007)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller ,L.; Nasta, K.

The National Synchrotron Light Source is one of the world's most productive and cost-effective user facilities. With 2,219 individual users, about 100 more than last year, and a record-high 985 publications, 2007 was no exception. In addition to producing an impressive array of science highlights, which are included in this Activity Report, many NSLS users were honored this year for their scientific accomplishments. Throughout the year, there were major strides in the development of the scientific programs by strengthening strategic partnerships with major research resources and with the Center for Functional Nanomaterials (CFN). Of particular note, the Consortium for Materialsmore » Properties Research in Earth Sciences (COMPRES) received renewed funding for the next five years through the National Science Foundation. COMPRES operates four high-pressure NSLS beamlines--X17B2, X17B3, X17C, and U2A--and serves the earth science community as well as the rapidly expanding segment of researchers using high-pressure techniques in materials, chemical, and energy-related sciences. A joint appointment was made between the NSLS and Stony Brook University to further enhance interactions with COMPRES. There was major progress on two key beamline projects outlined in the Five-Year Strategic Plan: the X25 beamline upgrade and the construction of the X9 small angle scattering (SAXS) beamline. The X25 overhaul, which began with the installation of the in-vacuum mini-gap undulator (MGU) in January 2006, is now complete. X25 is once again the brightest beamline for macromolecular crystallography at the NSLS, and in tandem with the X29 undulator beamline, it will keep the NSLS at the cutting edge in this important area of research. Upgrade work associated with the new MGU and the front end for the X9 SAXS beamline--jointly developed by the NSLS and the CFN--also was completed. Beamline X9 will host the SAXS program that currently exists at beamline X21 and will provide new microbeam SAXS capabilities and much-needed beam time for the life sciences, soft condensed matter physics, and nanoscience communities. Looking toward the future, a significant step has been made in expanding the user base and diversifying the work force by holding the first Historically Black Colleges and Universities (HBCU) Professors' Workshop. The workshop, which brought 11 professors to the NSLS to learn how to become successful synchrotron users, concluded with the formation of an HBCU User Consortium. Finally, significant contributions were made in optics and detector development to enhance the utilization of the NSLS and address the challenges of NSLS-II. In particular, x-ray detectors developed by the NSLS Detector Section have been adopted by an increasing number of research programs both at the NSLS and at light sources around the world, speeding up measurement times by orders of magnitude and making completely new experiments feasible. Significant advances in focusing and high-energy resolution optics have also been made this year.« less

NSLS 2009 Activity Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nasta K.; Mona R.

2009 was an incredibly exciting year for light sources at Brookhaven. The National Synchrotron Light Source (NSLS) hosted more than 2,200 visiting researchers, who, along with the about 50 members of our scientific staff, produced a total of 957 publications - about 20 percent of which appeared in premier journals. Covering topics ranging from Alzheimer's disease detection to ethanol-powered fuel cells, a sampling of these findings can be found in this Activity Report. We've also seen the resurfacing of some of our long-time users hard work. I was very proud to hear that two of the three recipients of themore » 2009 Nobel Prize in Chemistry have ties to the NSLS. Venki Ramakrishnan, a former employee in Brookhaven's biology department and long-time user of the NSLS, now at Cambridge University, and Thomas A. Steitz of Yale University, also a long-time NSLS user, shared the prize with Ada E. Yonath of the Weizmann Institute of Science for their work on the structure and function of the ribosome. In the late 1990s, Ramakrishnan and Steitz used protein crystallography at the NSLS to gather atomic-level images of two ribosome subunits: 30S (Ramakrishnan) and 50S (Steitz). Both laureates solved the high-resolution structures for these subunits based on this data. After struggling with a rough budget for several years, we received excellent funding, and then some, this year. In addition to NSLS operations funding, we received $3 million in funds from the American Recovery and Reinvestment Act (ARRA). We used that additional money for two exciting projects: construction of a full-field x-ray microscope and acquisition of several advanced x-ray detectors. The x-ray microscope will be able to image objects with a targeted spatial resolution of 30 nanometers. This capability will be particularly important for new initiatives in energy research and will prepare our users for the projected 1-nanometer resolution benchmark at the National Synchrotron Light Source II (NSLS-II). The detectors project is expected to increase the throughput of several high-demand beamlines by an order of magnitude as well as enable new classes of experiments. In addition, a huge chunk of ARRA money - $150 million - was put toward accelerating the construction of NSLS-II, which is now taking shape across the street. Now physically much more than just a pile of dirt, NSLS-II was granted Critical Decision 3 status by the Department of Energy (DOE) early last year, giving the official go-ahead for construction. In July, construction began, marked by a groundbreaking ceremony that attracted elected officials, media, and DOE, Battelle, and Stony Brook University representatives from across the state and the country. As progress on NSLS-II continues, we're working with Stony Brook University to identify ways to capitalize on the facility's unique capabilities through the Joint Photon Sciences Institute (JPSI). Included in this effort is a series of workshops to encourage the development and application of the photon sciences with collaborative research between industries, universities, and national laboratories. We helped host three of these workshops this year, focusing on microelectronics, energy storage, and materials in next-generation energy systems. The conversation and ideas generated at these meetings has been fresh and valuable and we hope to use this model to organize research opportunities in other scientific fields. Also this year: Brookhaven was deemed the lead institution for one of DOE's 46 Energy Frontier Research Centers, focused on understanding the underlying nature of superconductivity in complex materials by using techniques at the NSLS and CFN; DOE awarded a $100,000 supplemental grant to our detector program to continue the development of a new generation of x-ray detectors that use germanium sensors, which, at high energies, are much more efficient than equivalent ones based on silicon; and funding for one of our largest consortia, Case Western Reserve University's Center for Synchrotron Biosciences (CSB), was renewed through the National Institutes of Health. The CSB, which operates five NSLS beamlines and serves more than 550 users, will receive a five-year, $4-million grant to continue to study the structure and dynamics of proteins and nucleic acids. Finally, construction of the new X9 beamline and endstation for small angle x-ray scattering (SAXS) and wide angle x-ray scattering (WAXS) was completed this year. By July, the beamline and endstation were commissioned and serving general users. This allowed for the relocation of the SAXS and WAXS experimental programs from beamline X21 to X9, providing much-needed beam time for the soft condensed matter physics, life sciences, and nanoscience communities.« less

Rf system for the NSLS coherent infrared radiation source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Broome, W.; Biscardi, R.; Keane, J.

1995-05-01

The existing NSLS X-ray Lithography Source (XLS Phase I) is being considered for a coherent synchrotron radiation source. The existing 211 MHz warm cavity will be replaced with a 5-cell 2856 MHz superconducting RF cavity, driven by a series of 2 kW klystrons. The RF system will provide a total V{sub RF} of 1.5 MV to produce {sigma}{sub L} = 0.3 mm electron bunches at an energy of 150 MeV. Superconducting technology significantly reduces the required space and power needed to achieve the higher voltage. It is the purpose of this paper to describe the superconducting RF system and cavity,more » power requirements, and cavity design parameters such as input coupling, Quality Factor, and Higher Order Modes.« less

National Synchrotron Light Source annual report 1991. Volume 1, October 1, 1990--September 30, 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hulbert, S.L.; Lazarz, N.M.

1992-04-01

This report discusses the following research conducted at NSLS: atomic and molecular science; energy dispersive diffraction; lithography, microscopy and tomography; nuclear physics; UV photoemission and surface science; x-ray absorption spectroscopy; x-ray scattering and crystallography; x-ray topography; workshop on surface structure; workshop on electronic and chemical phenomena at surfaces; workshop on imaging; UV FEL machine reviews; VUV machine operations; VUV beamline operations; VUV storage ring parameters; x-ray machine operations; x-ray beamline operations; x-ray storage ring parameters; superconducting x-ray lithography source; SXLS storage ring parameters; the accelerator test facility; proposed UV-FEL user facility at the NSLS; global orbit feedback systems; and NSLSmore » computer system.« less

Hutch for CSX Beamlines

ScienceCinema

Haas, Ed

2018-02-06

NSLS-II will produce x-rays 10,000 times brighter than NSLS. To keep people safe from intense x-rays in the new facility, special enclosures, called hutches, will surround particular sections of beamlines.

PyXRF: Python-based X-ray fluorescence analysis package

NASA Astrophysics Data System (ADS)

Li, Li; Yan, Hanfei; Xu, Wei; Yu, Dantong; Heroux, Annie; Lee, Wah-Keat; Campbell, Stuart I.; Chu, Yong S.

2017-09-01

We developed a python-based fluorescence analysis package (PyXRF) at the National Synchrotron Light Source II (NSLS-II) for the X-ray fluorescence-microscopy beamlines, including Hard X-ray Nanoprobe (HXN), and Submicron Resolution X-ray Spectroscopy (SRX). This package contains a high-level fitting engine, a comprehensive commandline/ GUI design, rigorous physics calculations, and a visualization interface. PyXRF offers a method of automatically finding elements, so that users do not need to spend extra time selecting elements manually. Moreover, PyXRF provides a convenient and interactive way of adjusting fitting parameters with physical constraints. This will help us perform quantitative analysis, and find an appropriate initial guess for fitting. Furthermore, we also create an advanced mode for expert users to construct their own fitting strategies with a full control of each fitting parameter. PyXRF runs single-pixel fitting at a fast speed, which opens up the possibilities of viewing the results of fitting in real time during experiments. A convenient I/O interface was designed to obtain data directly from NSLS-II's experimental database. PyXRF is under open-source development and designed to be an integral part of NSLS-II's scientific computation library.

New In-Situ and Operando Facilities for Catalysis Science at NSLS-II: The Deployment of Real-Time, Chemical, and Structure-Sensitive X-ray Probes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palomino, Robert M.; Stavitski, Eli; Waluyo, Iradwikanari

The start of operations at the National Synchrotron Light Source II (NSLS-II) at Brookhaven National Laboratory heralded a new beginning for photon-science-based research capabilities in catalysis. This new facility builds on many years of pioneering work that was conducted at the NSLS synergistically by many scientists from academia, government labs, and industry. Over several decades, numerous discoveries in catalysis were driven through the emergence of an arsenal of tools at the NSLS that exploited the power of emerging X-ray methods encompassing scattering, spectroscopy, and imaging. Thus, in-situ and operando methodologies that coupled reactor environments directly with advanced analytical techniques pavedmore » a rapid path towards realizing an improved fundamental understanding at the frontiers of chemical science challenges of the day.« less

New In-Situ and Operando Facilities for Catalysis Science at NSLS-II: The Deployment of Real-Time, Chemical, and Structure-Sensitive X-ray Probes

DOE PAGES

Palomino, Robert M.; Stavitski, Eli; Waluyo, Iradwikanari; ...

2017-03-31

The start of operations at the National Synchrotron Light Source II (NSLS-II) at Brookhaven National Laboratory heralded a new beginning for photon-science-based research capabilities in catalysis. This new facility builds on many years of pioneering work that was conducted at the NSLS synergistically by many scientists from academia, government labs, and industry. Over several decades, numerous discoveries in catalysis were driven through the emergence of an arsenal of tools at the NSLS that exploited the power of emerging X-ray methods encompassing scattering, spectroscopy, and imaging. Thus, in-situ and operando methodologies that coupled reactor environments directly with advanced analytical techniques pavedmore » a rapid path towards realizing an improved fundamental understanding at the frontiers of chemical science challenges of the day.« less

NSLS-II beamline scattered gas bremsstrahlung radiation shielding calculation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popescu, Razvan; Xia, Zhenghua, E-mail: xiazhenghuacn@hotmail.com; Job, Panakkal

2016-07-27

National Synchrotron Light Source II (NSLS-II) is a new state-of-the-art 3rd generation synchrotron. The NSLS-II facility is shielded up to 3 GeV electron beam energy at 500 mA. When the gas bremsstrahlung (GB) from the storage ring is scattered by the beamline components in the first optical enclosure (FOE), the scattered radiation will pose additional radiation hazard (bypassing primary GB collimators and stops) and challenge the FOE shielding. The scattered GB radiation hazard can be mitigated by supplementary shielding or with an exclusion zone downstream of the FOE.

The Latest Status of NSLS-II Insertion Devices

NASA Astrophysics Data System (ADS)

Tanabe, Toshi; Kitegi, Charles; He, Ping; Musardo, Marco; Rank, Oleg Chubar James; Cappadoro, Peter; Fernandes, Huston; Harder, David; Corwin, Todd

2014-03-01

The National Synchrotron Light Source-II (NSLS-II) project is now in the final stage of construction. The Linac, the Booster synchrotron, and the Storage Ring magnets girder assemblies have been installed. The first damping wiggler has been delivered and its field characteristics are carefully measured. A Three Pole Wiggler (3PW) and Apple-II type elliptically polarizing undulators (EPUs) have been fabricated by the vendors. Two 3.0m long in-vacuum undulators (IVUs) and one 1.5m long IVU are almost complete and waiting for factory acceptance tests. One 3.0m long IVU for Inelastic X-ray Scattering beamline is in fabrication by a different vendor. Recently two 2.8m long IVUs for long straight sections (LSSs) have been added to the project for "future beamlines". In addition, two 1.5m long IVUs and one 2.8m long IVU for LSSs have been procured for Advanced Beamlines for Biological Investigations with X-rays (ABBIX) project funded by National Institure of Health (NIH). Further, two 3.5m long EPUs for LSSs are being designed for NSLS-II Experimental Tools (NEXT) -Major Item of Equipment (MIE) project. To succeed these conventional IVUs, PrFeB based cryo-permanent magnet undulator (CPMU) is considered as next generation device of hard X-ray sources. An In-Vacuum Magnetic Measurement System (IVMMS) for cold in-situ Hall probe mapping of CPMUs up to 1.5m in length has been developed. Summary of the current status of each project and future plans for the NSLS-II ring will be discussed.

Another First at NSLS-II Construction Site

ScienceCinema

None

2017-12-09

Workers at the NSLS-II ring building construction site recently completed the first complicated concrete pour for the approximately 19-ft.-tall walls of the Utility Tunnel. The continuous pour was the first of its kind, as previous pours have been for foo

First demonstration of the fast-to-slow corrector current shift in the NSLS-II storage ring

NASA Astrophysics Data System (ADS)

Yang, Xi; Tian, Yuke; Yu, Li Hua; Smaluk, Victor

2018-04-01

To realize the full benefits of the high brightness and ultra-small beam sizes of NSLS-II, it is essential that the photon beams are exceedingly stable. In the circumstances of implementing local bumps, changing ID gaps, and long term drifting, the fast orbit feedback (FOFB) requires shifting the fast corrector strengths to the slow correctors to prevent the fast corrector saturation and to make the beam orbit stable in the sub-micron level. As the result, a reliable and precise technique of fast-to-slow corrector strength shift has been developed and tested at NSLS-II. This technique is based on the fast corrector response to the slow corrector change when the FOFB is on. In this article, the shift technique is described and the result of proof-of-principle experiment carried out at NSLS-II is presented. The maximum fast corrector current was reduced from greater than 0.45 A to less than 0.04 A with the orbit perturbation within ±1 μm.

NATIONAL SYNCHROTRON LIGHT SOURCE ACTIVITY REPORT 2004

DOE Office of Scientific and Technical Information (OSTI.GOV)

MILLER,L.; EDITOR)

2005-05-01

The NSLS remains a viable and productive facility, as can be seen by the rich and diverse science produced in 2004. In one of these exciting research projects published in Nature, researchers detected a rare 'hole crystal' in a cuprate superconductor, which may provide insight into high-temperature superconductivity. In another Nature publication, the crystal structure of a segment of RNA was determined, opening a new window of knowledge into that crucial molecule. These are just a couple of the science highlights of 2004, and many others are displayed in the pages of this report. All told, more than 700 publicationsmore » resulted from NSLS research this year, the facility hosted 2,299 users, and the number of experiments performed rose from 1,145 in 2003 to 1,374 nuclear indications that the NSLS continues to thrive. As the NSLS accelerator complex enters its third decade of operations, it continues to perform very well. For 2004, the overall reliability of the VUV-IR ring was excellent at 99 percent. The reliability of the x-ray ring was just shy of 92 percent, primarily due to the need to replace the injection septum vacuum chamber, which developed a leak during the middle of the year. The Operations Division did a tremendous job of installing our spare chamber in minimal time, despite the complexity of the job and the inaccessibility of its location in the ring, as well as keeping downtime to a minimum throughout the rest of the year. In order to continue to meet the needs of users, several key beamline upgrades took place this year that will enrich our scientific programs, including upgrades to beamlines U12IR, X1A, X13A, and X21. We are very excited about two brand-new beamlines that were commissioned in 2004: X29 and X27A. X29 is the new mini-gap undulator beamline designed for macromolecular crystallography, and it will meet the growing demand of NSLS users who perform research in that area. The establishment of an x-ray microprobe at beamline X27A, optimized for the environmental science community, is also very important, as it will help to satisfy the large over subscription rate for this technique at the NSLS. Two other important upgrades that were initiated this past year are the replacement of the X25 wiggler with an undulator and the construction of the X9 undulator beamline for small-angle scattering, with an emphasis on nanoscience research. Another key activity that will benefit all users was the restoration of the x-ray ring lattice symmetry, which reduced the horizontal emittance and made the operational lattice more robust. Similarly, all users will benefit from the introduction of the PASS (Proposal Allocation Safety Scheduling) system this past year, which has greatly improved the process of proposal submission, review, allocation, and scheduling. This coming year we will work to add Rapid Access to the capabilities of PASS. Overall, the success of these and the many other projects that space does not permit listing is a testament to the dedication, hard work, and skill of the NSLS staff. Safety has always been an important issue at a large, complex scientific facility like the NSLS and in 2004 it received renewed attention. Safety is our highest priority and we spent a great deal of time reviewing and refining our safety practices and procedures. A new 'Safety Highlights' web page was created for safety news, and a large number of safety meetings and discussions were held. These reviews and meetings generated many ideas on how the NSLS might improve its safety practices, and we are committed to putting these in place and improving our already very good safety program. We had no lost-time accidents in 2004, which is a notable accomplishment. Our goal is to be best in class and I'm confident that by working together we can achieve that status. Several activities took place this past year to advance our proposal to replace the NSLS with a new National Synchrotron Light Source-II facility. These included a major workshop in support of the proposed facility in March, a mail review of our proposal outlinin« less

First demonstration of the fast-to-slow corrector current shift in the NSLS-II storage ring

DOE PAGES

Yang, Xi; Tian, Yuke; Yu, Li Hua; ...

2018-04-01

In order to realize the full benefits of the high brightness and ultra-small beam sizes of NSLS-II, it is essential that the photon beams are exceedingly stable. In the circumstances of implementing local bumps, changing ID gaps, and long term drifting, the fast orbit feedback (FOFB) requires shifting the fast corrector strengths to the slow correctors to prevent the fast corrector saturation and to make the beam orbit stable in the sub-micron level. As the result, a reliable and precise technique of fast-to-slow corrector strength shift has been developed and tested at NSLS-II. This technique is based on the fastmore » corrector response to the slow corrector change when the FOFB is on. In this article, the shift technique is described and the result of proof-of-principle experiment carried out at NSLS-II is presented. The maximum fast corrector current was reduced from greater than 0.45 A to less than 0.04 A with the orbit perturbation within ±1 μm.« less

First demonstration of the fast-to-slow corrector current shift in the NSLS-II storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Xi; Tian, Yuke; Yu, Li Hua

In order to realize the full benefits of the high brightness and ultra-small beam sizes of NSLS-II, it is essential that the photon beams are exceedingly stable. In the circumstances of implementing local bumps, changing ID gaps, and long term drifting, the fast orbit feedback (FOFB) requires shifting the fast corrector strengths to the slow correctors to prevent the fast corrector saturation and to make the beam orbit stable in the sub-micron level. As the result, a reliable and precise technique of fast-to-slow corrector strength shift has been developed and tested at NSLS-II. This technique is based on the fastmore » corrector response to the slow corrector change when the FOFB is on. In this article, the shift technique is described and the result of proof-of-principle experiment carried out at NSLS-II is presented. The maximum fast corrector current was reduced from greater than 0.45 A to less than 0.04 A with the orbit perturbation within ±1 μm.« less

Beam measurements using visible synchrotron light at NSLS2 storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Weixing, E-mail: chengwx@bnl.gov; Bacha, Bel; Singh, Om

2016-07-27

Visible Synchrotron Light Monitor (SLM) diagnostic beamline has been designed and constructed at NSLS2 storage ring, to characterize the electron beam profile at various machine conditions. Due to the excellent alignment, SLM beamline was able to see the first visible light when beam was circulating the ring for the first turn. The beamline has been commissioned for the past year. Besides a normal CCD camera to monitor the beam profile, streak camera and gated camera are used to measure the longitudinal and transverse profile to understand the beam dynamics. Measurement results from these cameras will be presented in this paper.more » A time correlated single photon counting system (TCSPC) has also been setup to measure the single bunch purity.« less

Beam position monitor gate functionality implementation and applications

DOE PAGES

Cheng, Weixing; Ha, Kiman; Li, Yongjun; ...

2018-06-14

We introduce a novel technique to implement gate functionality for the beam position monitors (BPM) at the National Synchrotron Light Source II (NSLS-II). The functionality, now implemented in FPGA, allows us to acquire two separated bunch-trains’ synchronized turn-by-turn (TBT) data simultaneously with the NSLS-II in-house developed BPM system. The gated position resolution is improved about 3 times by narrowing the sampling width. Experimentally we demonstrated that the machine lattice could be transparently characterized with the gated TBT data of a short diagnostic bunch-train Cheng et al., 2017; Li et al., 2017. Other applications, for example, precisely characterizing storage ring impedance/wake-fieldmore » through recording the beam positions of two separated bunch trains has been experimentally demonstrated.« less

Beam position monitor gate functionality implementation and applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Weixing; Ha, Kiman; Li, Yongjun

We introduce a novel technique to implement gate functionality for the beam position monitors (BPM) at the National Synchrotron Light Source II (NSLS-II). The functionality, now implemented in FPGA, allows us to acquire two separated bunch-trains’ synchronized turn-by-turn (TBT) data simultaneously with the NSLS-II in-house developed BPM system. The gated position resolution is improved about 3 times by narrowing the sampling width. Experimentally we demonstrated that the machine lattice could be transparently characterized with the gated TBT data of a short diagnostic bunch-train Cheng et al., 2017; Li et al., 2017. Other applications, for example, precisely characterizing storage ring impedance/wake-fieldmore » through recording the beam positions of two separated bunch trains has been experimentally demonstrated.« less

Theoretical and experimental study of the formation conditions of stepped leaders in negative flashes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Shijun, E-mail: sj-xie@163.com; State Key Laboratory of Control and Simulation of Power System and Generation Equipment, Department of Electrical Engineering, Tsinghua University, Beijing 100084; Zeng, Rong

2015-08-15

Natural lightning flashes are stochastic and uncontrollable, and thus, it is difficult to observe the formation process of a downward negative stepped leader (NSL) directly and in detail. This situation has led to some dispute over the actual NSL formation mechanism, and thus has hindered improvements in the lightning shielding analysis model. In this paper, on the basis of controllable long air gap discharge experiments, the formation conditions required for NSLs in negative flashes have been studied. First, a series of simulation experiments on varying scales were designed and carried out. The NSL formation processes were observed, and several ofmore » the characteristic process parameters, including the scale, the propagation velocity, and the dark period, were obtained. By comparing the acquired formation processes and the characteristic parameters with those in natural lightning flashes, the similarity between the NSLs in the simulation experiments and those in natural flashes was proved. Then, based on the local thermodynamic equation and the space charge estimation method, the required NSL formation conditions were deduced, and the space background electric field (E{sub b}) was proposed as the primary parameter for NSL formation. Finally, the critical value of E{sub b} required for the formation of NSLs in natural flashes was determined to be approximately 75 kV/m by extrapolation of the results of the simulation experiments.« less

NSLS-II Preliminary Design Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dierker, S.

2007-11-01

Following the CD0 approval of the National Synchrotron Light Source II (NSLS-II) during August 2005, Brookhaven National Laboratory prepared a conceptual design for a worldclass user facility for scientific research using synchrotron radiation. DOE SC review of the preliminary baseline in December 2006 led to the subsequent CD1 approval (approval of alternative selection and cost range). This report is the documentation of the preliminary design work for the NSLS-II facility. The preliminary design of the Accelerator Systems (Part 1) was developed mostly based of the Conceptual Design Report, except for the Booster design, which was changed from in-storage-ring tunnel configurationmore » to in external- tunnel configuration. The design of beamlines (Part 2) is based on designs developed by engineering firms in accordance with the specification provided by the Project. The conventional facility design (Part 3) is the Title 1 preliminary design by the AE firm that met the NSLS-II requirements. Last and very important, Part 4 documents the ES&H design and considerations related to this preliminary design. The NSLS-II performance goals are motivated by the recognition that major advances in many important technology problems will require scientific breakthroughs in developing new materials with advanced properties. Achieving this will require the development of new tools that will enable the characterization of the atomic and electronic structure, chemical composition, and magnetic properties of materials, at nanoscale resolution. These tools must be nondestructive, to image and characterize buried structures and interfaces, and they must operate in a wide range of temperatures and harsh environments. The NSLS-II facility will provide ultra high brightness and flux and exceptional beam stability. It will also provide advanced insertion devices, optics, detectors, and robotics, and a suite of scientific instruments designed to maximize the scientific output of the facility. Together these will enable the study of material properties and functions with a spatial resolution of {approx}1 nm, an energy resolution of {approx}0.1 meV, and the ultra high sensitivity required to perform spectroscopy on a single atom. In order to meet this need, NSLS-II has been designed to provide world-leading brightness and flux and exceptional beam stability. The brightness is defined as the number of photons emitted per second, per photon energy bandwidth, per solid angle, and per unit source size. Brightness is important because it determines how efficiently an intense flux of photons can be refocused to a small spot size and a small divergence. It scales as the ring current and the number of total periods of the undulator field (both of which contribute linearly to the total flux), as well as eing nversely proportional to the horizontal and vertical emittances (the product of beam size and divergence) of the electron beam. Raising the current in the storage ring to obtain even brighter beams is ultimately limited by beam-driven, collective instabilities in the accelerator. Thus, to maximize the brightness, the horizontal and vertical emittances must be made as small as possible. With the concept of using damping wigglers, low-field bending magnets, and a large number of lattice cells to achieve ultra small emittance, the performance of NSLS-II will be nearly at the ultimate limit of storage ring light sources, set by the intrinsic properties of the synchrotron radiation process. The facility will produce x-rays more than 10,000 times brighter than those produced at NSLS today. The facility, with various insertion devices, including three-pole-wigglers and low-field dipole radiations, has the capability of covering a broad range of radiation spectra, from hard x-ray to far infra-red. The superlative character and combination of capabilities will have broad impact on a wide range of disciplines and scientific initiatives in the coming decades, including new studies of small crystals in structural biology, a wide range of nanometer-resolution probes for nanoscience, coherent imaging of the structure and dynamics of disordered materials, greatly increased applicability of inelastic x-ray scattering, and properties of materials under extreme conditions. Commissioned in 1982, the existing National Synchrotron Light Source (NSLS) provides essential scientific tools for 2,300 scientists per year from more than 400 academic, industrial, and government institutions. Their myriad research programs produce about 800 publications per year, with more than 130 appearing in premier journals. It was designed in the 1970s and is now in its third decade of service. It has been continually upgraded over the years, with the brightness increasing fully five orders of magnitude. However, it has reached the theoretical limits of performance given its small circumference and small periodicity, and only a small number of insertion devices are possible.« less

NSLS-II storage ring insertion device and front-end commissioning and operation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, G., E-mail: gwang@bnl.gov; Shaftan, T.; Amundsen, C.

The National Synchrotron Light Source II (NSLS-II) is a state of the art 3 GeV third generation light source at Brookhaven National Laboratory. During spring/ summer of 2014, the storage ring was commissioned up to 50 mA without insertion devices. In the fall of 2014, we began commissioning of the project beamlines, which included seven insertion devices on six ID ports. Beamlines IXS, HXN, CSX-1, CSX-2, CHX, SRX, and XPD-1 consist of elliptically polarized undulator (EPU), damping wigglers (DW) and in-vacuum undulators (IVU) covering from VUV to hard x-ray range. In this paper, experience with commissioning and operation is discussed.more » We focus on reaching storage ring performance with IDs, including injection, design emittance, compensation of orbit distortions caused by ID residual field, source point stability, beam alignment and tools for control, monitoring and protection of the ring chambers from ID radiation.« less

Nsls-II Boster

NASA Astrophysics Data System (ADS)

Gurov, S. M.; Akimov, A. V.; Akimov, V. E.; Anashin, V. V.; Anchugov, O. V.; Baranov, G. N.; Batrakov, A. M.; Belikov, O. V.; Bekhtenev, E. A.; Blum, E.; Bulatov, A. V.; Burenkov, D. B.; Cheblakov, P. B.; Chernyakin, A. D.; Cheskidov, V. G.; Churkin, I. N.; Davidsavier, M.; Derbenev, A. A.; Erokhin, A. I.; Fliller, R. P.; Fulkerson, M.; Gorchakov, K. M.; Ganetis, G.; Gao, F.; Gurov, D. S.; Hseuh, H.; Hu, Y.; Johanson, M.; Kadyrov, R. A.; Karnaev, S. E.; Karpov, G. V.; Kiselev, V. A.; Kobets, V. V.; Konstantinov, V. M.; Kolmogorov, V. V.; Korepanov, A. A.; Kramer, S.; Krasnov, A. A.; Kremnev, A. A.; Kuper, E. A.; Kuzminykh, V. S.; Levichev, E. B.; Li, Y.; Long, J. De; Makeev, A. V.; Mamkin, V. R.; Medvedko, A. S.; Meshkov, O. I.; Nefedov, N. B.; Neyfeld, V. V.; Okunev, I. N.; Ozaki, S.; Padrazo, D.; Petrov, V. V.; Petrichenkov, M. V.; Philipchenko, A. V.; Polyansky, A. V.; Pureskin, D. N.; Rakhimov, A. R.; Rose, J.; Ruvinskiy, S. I.; Rybitskaya, T. V.; Sazonov, N. V.; Schegolev, L. M.; Semenov, A. M.; Semenov, E. P.; Senkov, D. V.; Serdakov, L. E.; Serednyakov, S. S.; Shaftan, T. V.; Sharma, S.; Shichkov, D. S.; Shiyankov, S. V.; Shvedov, D. A.; Simonov, E. A.; Singh, O.; Sinyatkin, S. V.; Smaluk, V. V.; Sukhanov, A. V.; Tian, Y.; Tsukanova, L. A.; Vakhrushev, R. V.; Vobly, P. D.; Utkin, A. V.; Wang, G.; Wahl, W.; Willeke, F.; Yaminov, K. R.; Yong, H.; Zhuravlev, A.; Zuhoski, P.

The National Synchrotron Light Source II is a third generation light source, which was constructed at Brookhaven National Laboratory. This project includes a highly-optimized 3 GeV electron storage ring, linac preinjector, and full-energy synchrotron injector. Budker Institute of Nuclear Physics built and delivered the booster for NSLS-II. The commissioning of the booster was successfully completed. This paper reviews fulfilled work by participants.

Low-pressure Structural Modification of Aluminum Hydride

DTIC Science & Technology

2011-02-01

Acknowledgments Use of the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory ( BNL ) was supported by the U.S. Department of Energy...National Synchrotron Light Source (NSLS) of Brookhaven National Laboratory ( BNL ). The spectral resolution of ±4 cm–1 was used for all IR measurements...12 List of Symbols, Abbreviations, and Acronyms Al aluminum AlH3 aluminum hydride BNL Brookhaven National Laboratory EOS equation of

Structural and Chemical Properties of the Nitrogen-Rich Energetic Material Triaminoguanidinium 1-methyl-5-nitriminotetrazolate under Pressure

DTIC Science & Technology

2012-08-01

Source (NSLS) of Brookhaven National Laboratory ( BNL ). The syn- chrotron light is extracted from the VUV storage ring in a 40 × 40 mrad solid angle and...Contract No. DE-AC02-06CH11357. Infrared mea- surements were performed at the U2A beamline at the NSLS of BNL (DOE Contract No. DE-AC02-98CH10886). The

Initial performances of first undulator-based hard x-ray beamlines of NSLS-II compared to simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chubar, Oleg, E-mail: chubar@bnl.gov; Chu, Yong S.; Huang, Xiaojing

2016-07-27

Commissioning of the first X-ray beamlines of NSLS-II included detailed measurements of spectral and spatial distributions of the radiation at different locations of the beamlines, from front-ends to sample positions. Comparison of some of these measurement results with high-accuracy calculations of synchrotron (undulator) emission and wavefront propagation through X-ray transport optics, performed using SRW code, is presented.

Optical design and simulation of a new coherence beamline at NSLS-II

NASA Astrophysics Data System (ADS)

Williams, Garth J.; Chubar, Oleg; Berman, Lonny; Chu, Yong S.; Robinson, Ian K.

2017-08-01

We will discuss the optical design for a proposed beamline at NSLS-II, a late-third generation storage ring source, designed to exploit the spatial coherence of the X-rays to extract high-resolution spatial information from ordered and disordered materials through Coherent Diffractive Imaging, executed in the Bragg- and forward-scattering geometries. This technique offers a powerful tool to image sub-10 nm spatial features and, within ordered materials, sub-Angstrom mapping of deformation fields. Driven by the opportunity to apply CDI to a wide range of samples, with sizes ranging from sub-micron to tens-of-microns, two optical designs have been proposed and simulated under a wide variety of optical configurations using the software package Synchrotron Radiation Workshop. The designs, their goals, and the results of the simulation, including NSLS-II ring and undulator source parameters, of the beamline performance as a function of its variable optical components is described.

NATIONAL SYNCHROTRON LIGHT SOURCE ACTIVITY REPORT 1998.

DOE Office of Scientific and Technical Information (OSTI.GOV)

ROTHMAN,E.

1999-05-01

In FY 1998, following the 50th Anniversary Year of Brookhaven National Laboratory, Brookhaven Science Associates became the new Managers of BNL. The new start is an appropriate time to take stock of past achievements and to renew or confirm future goals. During the 1998 NSLS Annual Users Meeting (described in Part 3 of this Activity Report), the DOE Laboratory Operations Board, Chaired by the Under Secretary for Energy, Ernest Moniz met at BNL. By chance all the NSLS Chairmen except Martin Blume (acting NSLS Chair 84-85) were present as recorded in the picture. Under their leadership the NSLS has improvedmore » dramatically: (1) The VUV Ring current has increased from 100 mA in October 1982 to nearly 1 A today. For the following few years 10 Ahrs of current were delivered most weeks - NSLS now exceeds that every day. (2) When the first experiments were performed on the X-ray ring during FY1985 the electron energy was 2 GeV and the current up to 100 mA - the X-Ray Ring now runs routinely at 2.5 GeV and at 2.8 GeV with up to 350 mA of current, with a very much longer beam half-life and improved reliability. (3) Starting in FY 1984 the proposal for the Phase II upgrade, mainly for a building extension and a suite of insertion devices and their associated beamlines, was pursued - the promises were delivered in full so that for some years now the NSLS has been running with two undulators in the VUV Ring and three wigglers and an undulator in the X-Ray Ring. In addition two novel insertion devices have been commissioned in the X13 straight. (4) At the start of FY 1998 the NSLS welcomed its 7000th user - attracted by the opportunity for pursuing research with high quality beams, guaranteed not to be interrupted by 'delivery failures', and welcomed by an efficient and caring user office and first class teams of PRT and NSLS staff. R & D have lead to the possibility of running the X-Ray Ring at the higher energy of 2.8 GeV. Figure 1 shows the first user beam, which was provided thereafter for half of the running time in FY 1998. In combination with the development of narrow gap undulators this mode opens the possibility of new undulators which could produce hard X-rays in the fundamental, perhaps up to 10 keV. On 27 September 1998, a low horizontal emittance lattice became operational at 2.584 GeV. This results in approximately a 50% decrease in the horizontal beam-size on dipole bending magnet beamlines, and somewhat less of a decrease on the insertion device lines. The beam lifetime is not degraded by the low emittance lattice. This represents an important achievement, enhancing for all users the x-ray ring brightness. The reduced horizontal emittance electron beam will produce brighter x-ray beams for all the beamlines, both bending magnets and insertion devices, adding to other recent increases in the X-Ray ring brightness. During FY 1999 users will gain experience of the new running mode and plans are in place to do the same at 2.8GeV during further studies sessions. Independent evidence of the reduced emittance is shown in Figure 2. This is a pinhole camera scan showing the X-ray beam profile, obtained on the diagnostic beamline X28. Finally, work has begun to update and refine the proposal of the Phase III upgrade endorsed by the Birgeneau panel and BESAC last year. With the whole NSLS facility in teenage years and with many demonstrated enhancements available, the time has come to herald in the next stage of life at the Light Source.« less

Weaving the Past into the Present by Digitizing Local History

ERIC Educational Resources Information Center

Schlumpf, Kay; Zschernitz, Rob

2007-01-01

Since its humble beginning, Digital Past, a centralized local history digitization initiative at the North Suburban Library System (NSLS), a multitype consortium in Wheeling, Illinois, has now grown into a large centralized collaboration that consists of 32 libraries and a museum as its primary contributors. With Digital Past, there are various…

Comparison of RF BPM Receivers for NSLS-II Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pinayev,I.; Singh, O.

2009-05-04

The NSLS-II Light Source being built at Brookhaven National Laboratory requires submicron stability of the electron orbit in the storage ring in order to utilize fully very small emittances and electron beam sizes. This sets high stability requirements for beam position monitors and a program has been initiated for the purpose of characterizing RF beam position monitor (BPM) receivers in use at other light sources. Present state-of-the-art performance will be contrasted with more recently available technologies.

Latest experiences and future plans on NSLS-II insertion devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanabe, T.; Hidaka, Y.; Kitegi, C.

National Synchrotron Light Source-II (NSLS-II) is the latest storage ring of 3 GeV energy at the Brookhaven National Laboratory (BNL). The horizontal emittance of the electron beam with the currently installed six damping wigglers is 0.9 nm.rad, which could be further reduced to 0.5 nm.rad with more insertion devices (IDs). With only one RF cavity the beam current is restricted to 200 mA. Five hundred mA operation is envisaged for next year with an addition of the second cavity. Six (plus two branches) beamlines have been commissioned in the initial phase of the project. In July 2015, three NIH fundedmore » beamlines called “Advanced Beamlines for Biological Investigations with X-rays” (ABBIX) will be added for operation. This paper describes the experiences of ID development, installation, and commissioning for the NSLS-II project as well as our future plans to improve the performance of the facility in terms of source development.« less

Macromolecular crystallography beamline X25 at the NSLS

PubMed Central

Héroux, Annie; Allaire, Marc; Buono, Richard; Cowan, Matthew L.; Dvorak, Joseph; Flaks, Leon; LaMarra, Steven; Myers, Stuart F.; Orville, Allen M.; Robinson, Howard H.; Roessler, Christian G.; Schneider, Dieter K.; Shea-McCarthy, Grace; Skinner, John M.; Skinner, Michael; Soares, Alexei S.; Sweet, Robert M.; Berman, Lonny E.

2014-01-01

Beamline X25 at the NSLS is one of the five beamlines dedicated to macromolecular crystallography operated by the Brookhaven National Laboratory Macromolecular Crystallography Research Resource group. This mini-gap insertion-device beamline has seen constant upgrades for the last seven years in order to achieve mini-beam capability down to 20 µm × 20 µm. All major components beginning with the radiation source, and continuing along the beamline and its experimental hutch, have changed to produce a state-of-the-art facility for the scientific community. PMID:24763654

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Jingguang; Frenkel, Anatoly; Rodriguez, Jose

Synchrotron spectroscopies offer unique advantages over conventional techniques, including higher detection sensitivity and molecular specificity, faster detection rate, and more in-depth information regarding the structural, electronic and catalytic properties under in-situ reaction conditions. Despite these advantages, synchrotron techniques are often underutilized or unexplored by the catalysis community due to various perceived and real barriers, which will be addressed in the current proposal. Since its establishment in 2005, the Synchrotron Catalysis Consortium (SCC) has coordinated significant efforts to promote the utilization of cutting-edge catalytic research under in-situ conditions. The purpose of the current renewal proposal is aimed to provide assistance, andmore » to develop new sciences/techniques, for the catalysis community through the following concerted efforts: Coordinating the implementation of a suite of beamlines for catalysis studies at the new NSLS-II synchrotron source; Providing assistance and coordination for catalysis users at an SSRL catalysis beamline during the initial period of NSLS to NSLS II transition; Designing in-situ reactors for a variety of catalytic and electrocatalytic studies; Assisting experimental set-up and data analysis by a dedicated research scientist; Offering training courses and help sessions by the PIs and co-PIs.« less

Emittance and lifetime measurement with damping wigglers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, G. M.; Shaftan, T., E-mail: shaftan@bnl.gov; Cheng, W. X.

National Synchrotron Light Source II (NSLS-II) is a new third-generation storage ring light source at Brookhaven National Laboratory. The storage ring design calls for small horizontal emittance (<1 nm-rad) and diffraction-limited vertical emittance at 12 keV (8 pm-rad). Achieving low value of the beam size will enable novel user experiments with nm-range spatial and meV-energy resolution. The high-brightness NSLS-II lattice has been realized by implementing 30-cell double bend achromatic cells producing the horizontal emittance of 2 nm rad and then halving it further by using several Damping Wigglers (DWs). This paper is focused on characterization of the DW effects inmore » the storage ring performance, namely, on reduction of the beam emittance, and corresponding changes in the energy spread and beam lifetime. The relevant beam parameters have been measured by the X-ray pinhole camera, beam position monitors, beam filling pattern monitor, and current transformers. In this paper, we compare the measured results of the beam performance with analytic estimates for the complement of the 3 DWs installed at the NSLS-II.« less

X-ray optical simulations supporting advanced commissioning of the coherent hard x-ray beamline at NSLS-II

NASA Astrophysics Data System (ADS)

Wiegart, L.; Rakitin, M.; Fluerasu, A.; Chubar, O.

2017-08-01

We present the application of fully- and partially-coherent synchrotron radiation wavefront propagation simulation functions, implemented in the "Synchrotron Radiation Workshop" computer code, to create a `virtual beamline' mimicking the Coherent Hard X-ray scattering beamline at NSLS-II. The beamline simulation includes all optical beamline components, such as the insertion device, mirror with metrology data, slits, double crystal monochromator and refractive focusing elements (compound refractive lenses and kinoform lenses). A feature of this beamline is the exploitation of X-ray beam coherence, boosted by the low-emittance NSLS-II storage-ring, for techniques such as X-ray Photon Correlation Spectroscopy or Coherent Diffraction Imaging. The key performance parameters are the degree of Xray beam coherence and photon flux, and the trade-off between them needs to guide the beamline settings for specific experimental requirements. Simulations of key performance parameters are compared to measurements obtained during beamline commissioning, and include the spectral flux of the undulator source, the degree of transverse coherence as well as focal spot sizes.

Safe operating conditions for NSLS-II Storage Ring Frontends commissioning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seletskiy, S.; Amundsen, C.; Ha, K.

2015-04-02

The NSLS-II Storage Ring Frontends are designed to safely accept the synchrotron radiation fan produced by respective insertion device when the electron beam orbit through the ID is locked inside the predefined Active Interlock Envelope. The Active Interlock is getting enabled at a particular beam current known as AI safe current limit. Below such current the beam orbit can be anywhere within the limits of the SR beam acceptance. During the FE commissioning the beam orbit is getting intentionally disturbed in the particular ID. In this paper we explore safe operating conditions for the Frontends commissioning.

Techniques for transparent lattice measurement and correction

NASA Astrophysics Data System (ADS)

Cheng, Weixing; Li, Yongjun; Ha, Kiman

2017-07-01

A novel method has been successfully demonstrated at NSLS-II to characterize the lattice parameters with gated BPM turn-by-turn (TbT) capability. This method can be used at high current operation. Conventional lattice characterization and tuning are carried out at low current in dedicated machine studies which include beam-based measurement/correction of orbit, tune, dispersion, beta-beat, phase advance, coupling etc. At the NSLS-II storage ring, we observed lattice drifting during beam accumulation in user operation. Coupling and lifetime change while insertion device (ID) gaps are moved. With the new method, dynamical lattice correction is possible to achieve reliable and productive operations. A bunch-by-bunch feedback system excites a small fraction (∼1%) of bunches and gated BPMs are aligned to see those bunch motions. The gated TbT position data are used to characterize the lattice hence correction can be applied. As there are ∼1% of total charges disturbed for a short period of time (several ms), this method is transparent to general user operation. We demonstrated the effectiveness of these tools during high current user operation.

Trace Element Abundance Measurements on Cosmic Dust Particles

NASA Technical Reports Server (NTRS)

Flynn, George

1996-01-01

The X-Ray Microprobe on beamline X-26A at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory was used to determine the abundances of elements from Cr through Sr in individual interplanetary dust particles (IDPs) collected from the Earth's stratosphere and the Scanning Transmission X-ray Microscope (STXM) on beamline X-1A at the NSLS was used to determine the carbon abundances and spatial distributions in IDPs. In addition, modeling was performed in an attempt to associate particular types of IDPs with specific types of parent bodies, and thus to infer the chemistry, mineralogy, and structural properties of those parent bodies.

Single-crystal Raman spectroscopy and X-ray crystallography at beamline X26-C of the NSLS

PubMed Central

Stoner-Ma, Deborah; Skinner, John M.; Schneider, Dieter K.; Cowan, Matt; Sweet, Robert M.; Orville, Allen M.

2011-01-01

Three-dimensional structures derived from X-ray diffraction of protein crystals provide a wealth of information. Features and interactions important for the function of macromolecules can be deduced and catalytic mechanisms postulated. Still, many questions can remain, for example regarding metal oxidation states and the interpretation of ‘mystery density’, i.e. ambiguous or unknown features within the electron density maps, especially at ∼2 Å resolutions typical of most macromolecular structures. Beamline X26-C at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory (BNL), provides researchers with the opportunity to not only determine the atomic structure of their samples but also to explore the electronic and vibrational characteristics of the sample before, during and after X-ray diffraction data collection. When samples are maintained under cryo-conditions, an opportunity to promote and follow photochemical reactions in situ as a function of X-ray exposure is also provided. Plans are in place to further expand the capabilities at beamline X26-C and to develop beamlines at NSLS-II, currently under construction at BNL, which will provide users access to a wide array of complementary spectroscopic methods in addition to high-quality X-ray diffraction data. PMID:21169688

The life science X-ray scattering beamline at NSLS-II

DOE Office of Scientific and Technical Information (OSTI.GOV)

DiFabio, Jonathan; Yang, Lin; Chodankar, Shirish

We report the current development status of the High Brightness X-ray Scattering for Life Sciences (or Life Science X-ray Scattering, LiX) beamline at the NSLS-II facility of Brookhaven National Laboratory. This instrument will operate in the x-ray energy range of 2.1-18 keV, provide variable beam sizes from 1 micron to ~0.5 mm, and support user experiments in three scientific areas: (1) high-throughput solution scattering, in-line size exclusion chromatography and flow mixers-based time-resolved solution scattering of biological macro-molecules, (2) diffraction from single- and multi-layered lipid membranes, and (3) scattering-based scanning probe imaging of biological tissues. In order to satisfy the beammore » stability required for these experiments and to switch rapidly between different types of experiments, we have adopted a secondary source with refractive lenses for secondary focusing, a detector system consisting of three Pilatus detectors, and specialized experimental modules that can be quickly exchanged and each dedicated to a defined set of experiments. The construction of this beamline is on schedule for completion in September 2015. User experiments are expected to start in Spring 2016.« less

The life science X-ray scattering beamline at NSLS-II

DOE PAGES

DiFabio, Jonathan; Yang, Lin; Chodankar, Shirish; ...

2015-09-30

We report the current development status of the High Brightness X-ray Scattering for Life Sciences (or Life Science X-ray Scattering, LiX) beamline at the NSLS-II facility of Brookhaven National Laboratory. This instrument will operate in the x-ray energy range of 2.1-18 keV, provide variable beam sizes from 1 micron to ~0.5 mm, and support user experiments in three scientific areas: (1) high-throughput solution scattering, in-line size exclusion chromatography and flow mixers-based time-resolved solution scattering of biological macro-molecules, (2) diffraction from single- and multi-layered lipid membranes, and (3) scattering-based scanning probe imaging of biological tissues. In order to satisfy the beammore » stability required for these experiments and to switch rapidly between different types of experiments, we have adopted a secondary source with refractive lenses for secondary focusing, a detector system consisting of three Pilatus detectors, and specialized experimental modules that can be quickly exchanged and each dedicated to a defined set of experiments. The construction of this beamline is on schedule for completion in September 2015. User experiments are expected to start in Spring 2016.« less

The life science x-ray scattering beamline at NSLS-II

DOE Office of Scientific and Technical Information (OSTI.GOV)

DiFabio, Jonathan; Chodankar, Shirish; Pjerov, Sal

We report the current development status of the High Brightness X-ray Scattering for Life Sciences (or Life Science X-ray Scattering, LiX) beamline at the NSLS-II facility of Brookhaven National Laboratory. This instrument will operate in the x-ray energy range of 2.1-18 keV, provide variable beam sizes from 1 micron to ∼0.5 mm, and support user experiments in three scientific areas: (1) high-throughput solution scattering, in-line size exclusion chromatography and flow mixers-based time-resolved solution scattering of biological macro-molecules, (2) diffraction from single- and multi-layered lipid membranes, and (3) scattering-based scanning probe imaging of biological tissues. In order to satisfy the beammore » stability required for these experiments and to switch rapidly between different types of experiments, we have adopted a secondary source with refractive lenses for secondary focusing, a detector system consisting of three Pilatus detectors, and specialized experimental modules that can be quickly exchanged and each dedicated to a defined set of experiments. The construction of this beamline is on schedule for completion in September 2015. User experiments are expected to start in Spring 2016.« less

{ital In-situ} x-ray investigation of hydrogen charging in thin film bimetallic electrodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jisrawi, N.M.; Wiesmann, H.; Ruckman, M.W.

Hydrogen uptake and discharge by thin metallic films under potentiostatic control was studied using x-ray diffraction at the National Synchrotron Light Source (NSLS). The formation of metal-hydrogen phases in Pd, Pd-capped Nb and Pd/Nb multilayer electrode structures was deduced from x-ray diffraction data and correlated with the cyclic voltammetry (CV) peaks. The x-ray data was also used to construct a plot of the hydrogen concentration as a function of cell potential for a multilayered thin film. {copyright} {ital 1997 Materials Research Society.}

The New Big Science at the NSLS

NASA Astrophysics Data System (ADS)

Crease, Robert

2016-03-01

The term ``New Big Science'' refers to a phase shift in the kind of large-scale science that was carried out throughout the U.S. National Laboratory system, when large-scale materials science accelerators rather than high-energy physics accelerators became marquee projects at most major basic research laboratories in the post-Cold War era, accompanied by important changes in the character and culture of the research ecosystem at these laboratories. This talk explores some aspects of this phase shift at BNL's National Synchrotron Light Source.

Macromolecular Topography Leaps into the Digital Age

NASA Technical Reports Server (NTRS)

Lovelace, J.; Bellamy, H.; Snell, E. H.; Borgstahl, G.

2003-01-01

A low-cost, real-time digital topography system is under development which will replace x-ray film and nuclear emulsion plates. The imaging system is based on an inexpensive surveillance camera that offers a 1000x1000 array of 8 im square pixels, anti-blooming circuitry, and very quick read out. Currently, the system directly converts x-rays to an image with no phosphor. The system is small and light and can be easily adapted to work with other crystallographic equipment. Preliminary images have been acquired of cubic insulin at the NSLS x26c beam line. NSLS x26c was configured for unfocused monochromatic radiation. Six reflections were collected with stills spaced from 0.002 to 0.001 degrees apart across the entire oscillation range that the reflections were in diffracting condition. All of the reflections were rotated to the vertical to reduce Lorentz and beam related effects. This particular CCD is designed for short exposure applications (much less than 1 sec) and so has a relatively high dark current leading to noisy raw images. The images are processed to remove background and other system noise with a multi-step approach including the use of wavelets, histogram, and mean window filtering. After processing, animations were constructed with the corresponding reflection profile to show the diffraction of the crystal volume vs. the oscillation angle as well as composite images showing the parts of the crystal with the strongest diffraction for each reflection. The final goal is to correlate features seen in reflection profiles captured with fine phi slicing to those seen in the topography images. With this development macromolecular topography finally comes into the digital age.

NSLS II Vacuum System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferreira, M.; Doom, L.; Hseuh, H.

2009-09-13

National Synchrotron Light Source II, being constructed at Brookhaven, is a 3-GeV, 500 mA, 3rd generation synchrotron radiation facility with ultra low emittance electron beams. The storage ring vacuum system has a circumference of 792 m and consists of over 250 vacuum chambers with a simulated average operating pressure of less than 1 x 10{sup -9} mbar. A summary of the update design of the vacuum system including girder supports of the chambers, gauges, vacuum pumps, bellows, beam position monitors and simulation of the average pressure will be shown. A brief description of the techniques and procedures for cleaning andmore » mounting the chambers are given.« less

Multi-element germanium detectors for synchrotron applications

NASA Astrophysics Data System (ADS)

Rumaiz, A. K.; Kuczewski, A. J.; Mead, J.; Vernon, E.; Pinelli, D.; Dooryhee, E.; Ghose, S.; Caswell, T.; Siddons, D. P.; Miceli, A.; Baldwin, J.; Almer, J.; Okasinski, J.; Quaranta, O.; Woods, R.; Krings, T.; Stock, S.

2018-04-01

We have developed a series of monolithic multi-element germanium detectors, based on sensor arrays produced by the Forschungzentrum Julich, and on Application-specific integrated circuits (ASICs) developed at Brookhaven. Devices have been made with element counts ranging from 64 to 384. These detectors are being used at NSLS-II and APS for a range of diffraction experiments, both monochromatic and energy-dispersive. Compact and powerful readout systems have been developed, based on the new generation of FPGA system-on-chip devices, which provide closely coupled multi-core processors embedded in large gate arrays. We will discuss the technical details of the systems, and present some of the results from them.

The NSLS 100 element solid state array detector

PubMed Central

Furenlid, L.R.; Kraner, H.W.; Rogers, L.C.; Cramer, S.P.; Stephani, D.; Beuttenmuller, R.H.; Beren, J.

2015-01-01

X-ray absorption studies of dilute samples require fluorescence detection techniques. Since signal-to-noise ratios are governed by the ratio of fluorescent to scattered photons counted by a detector, solid state detectors which can discriminate between fluorescence and scattered photons have become the instruments of choice for trace element measurements. Commercially available 13 element Ge array detectors permitting total count rates < 500000 counts per second are now in routine use. Since X-ray absorption beamlines at high brightness synchrotron sources can already illuminate most dilute samples with enough flux to saturate the current generation of solid state detectors, the development of next-generation instruments with significantly higher total count rates is essential. We present the design and current status of the 100 element Si array detector being developed in a collaboration between the NSLS and the Instrumentation Division at Brookhaven National Laboratory. The detecting array consists of a 10×10 matrix of 4 mm×4 mm elements laid out on a single piece of ultrahigh purity silicon mounted at the front end of a liquid nitrogen dewar assembly. A matrix of charge sensitive integrating preamplifiers feed signals to an array of shaping amplifiers, single channel analyzers, and scalers. An electronic switch, delay amplifier, linear gate, digital scope, peak sensing A/D converter, and histogramining memory module provide for complete diagnostics and channel calibration. The entire instrument is controlled by a LabView 2 application on a MacII ci; the software also provides full control over beamline hardware and performs the data collection. PMID:26722135

First Structural Steel Erected at NSLS-II

ScienceCinema

None

2017-12-09

Ten steel columns were incorporated into the ever-growing framework for the National Synchrotron Light Source II last week, the first structural steel erected for the future 400,000-square-foot facility.

Background research in support of the new grant proposal: Research consortium for X-ray topography on line X-19 at NSLS

NASA Astrophysics Data System (ADS)

Bilello, J. C.

1983-11-01

The status of the construction and installation of components of the synchrotron topography station is reported as well as progress in the development of hardware for interfacing and software for interactively controlling the 13 motors which automate the facility. Research focuses on the problem of X-ray optics and on techniques for applying topography to materials science. There is colaboration with other researchers in studying the nature of brittle fracture of refractory metals and in interpreting contact in the vicinity of crack tips.

X-Ray Topography of Tetragonal Lysozyme Grown by the Temperature-Controlled Technique

NASA Technical Reports Server (NTRS)

Stojanoff, V.; Siddons, D. P.; Monaco, Lisa A.; Vekilov, Peter; Rosenberger, Franz

1997-01-01

Growth-induced defects in lysozyme crystals were observed by white-beam and monochromatic X-ray topography at the National Synchrotron Light Source (NSLS) at the Brookhaven National Laboratory (BNL). The topographic methods were non-destructive to the extent that traditional diffraction data collection could be performed to high resolution after topography. It was found that changes in growth parameters, defect concentration as detected by X-ray topography, and the diffraction quality obtainable from the crystals were all strongly correlated. In addition, crystals with fewer defects showed lower mosaicity and higher diffraction resolution as expected.

AC orbit bump method of local impedance measurement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smaluk, Victor; Yang, Xi; Blednykh, Alexei

A fast and precise technique of local impedance measurement has been developed and tested at NSLS-II. This technique is based on in-phase sine-wave (AC) excitation of four fast correctors adjacent to the vacuum chamber section, impedance of which is measured. The beam position is measured using synchronous detection. Use of the narrow-band sine-wave signal allows us to improve significantly the accuracy of the orbit bump method. Beam excitation by fast correctors results in elimination of the systematic error caused by hysteresis effect. The systematic error caused by orbit drift is also eliminated because the measured signal is not affected bymore » the orbit motion outside the excitation frequency range. In this article, the measurement technique is described and the result of proof-of-principle experiment carried out at NSLS-II is presented.« less

AC orbit bump method of local impedance measurement

DOE PAGES

Smaluk, Victor; Yang, Xi; Blednykh, Alexei; ...

2017-08-04

A fast and precise technique of local impedance measurement has been developed and tested at NSLS-II. This technique is based on in-phase sine-wave (AC) excitation of four fast correctors adjacent to the vacuum chamber section, impedance of which is measured. The beam position is measured using synchronous detection. Use of the narrow-band sine-wave signal allows us to improve significantly the accuracy of the orbit bump method. Beam excitation by fast correctors results in elimination of the systematic error caused by hysteresis effect. The systematic error caused by orbit drift is also eliminated because the measured signal is not affected bymore » the orbit motion outside the excitation frequency range. In this article, the measurement technique is described and the result of proof-of-principle experiment carried out at NSLS-II is presented.« less

Analysis of coupled-bunch instabilities for the NSLS-II storage ring with a 500MHz 7-cell PETRA-III cavity

DOE PAGES

Bassi, G.; Blednykh, A.; Cheng, W.; ...

2015-12-11

We present the NSLS-II storage ring that is designed to operate with superconducting RF-cavities with the aim to store an average current of 500 mA distributed in 1080 bunches, with a gap in the uniform filling for ion clearing. At the early stage of the commissioning (phase 1), characterized by a bare lattice without damping wigglers and without Landau cavities, a normal conducting 7-cell PETRA-III RF-cavity structure has been installed with the goal to store an average current of 25 mA. In this paper we discuss our analysis of coupled-bunch instabilities driven by the Higher Order Modes (HOMs) of themore » 7-cell PETRA-III RF-cavity. As a cure of the instabilities, we apply a well-known scheme based on a proper detuning of the HOMs frequencies based upon cavity temperature change, and the use of the beneficial effect of the slow head–tail damping at positive chromaticity to increase the transverse coupled-bunch instability thresholds. In addition, we discuss measurements of coupled-bunch instabilities observed during the phase 1 commissioning of the NSLS-II storage ring. In our analysis we rely, in the longitudinal case, on the theory of coupled-bunch instability for uniform fillings, while in the transverse case we complement our studies with numerical simulations with OASIS, a novel parallel particle tracking code for self-consistent simulations of collective effects driven by short and long-range wakefields.« less

Self-Assembly by Instruction: Designing Nanoscale Systems Using DNA-Based Approaches (474th Brookhaven Lecture)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gang, Oleg

2012-01-18

In the field of nanoscience, if you can control how nanoparticles self-assemble in particular structures — joining each other, for example, as molecules can form, atom-by-atom — you can design new materials that have unique properties that industry needs. Nature already uses the DNA genetic code to instruct the building of specific proteins and whole organisms in both plants and people. Taking a cue from nature, scientists at BNL devised a way of using strands of synthetic DNA attached to the surface of nanoparticles to instruct them to self-assemble into specific nanoscale structures, clusters, and three-dimensional organizations. Novel materials designedmore » and fabricated this way promise use in photovoltaics, energy storage, catalysis, cell-targeted systems for more effective medical treatments, and biomolecular sensing for environmental monitoring and medical applications. To find out more about the rapid evolution of this nanoassembly method and its applications, join Physicist Oleg Gang of the Center for Functional Nanomaterials (CFN) as he gives the 474th Brookhaven Lecture, titled “Self-Assembly by Instruction: Designing Nanoscale Systems Using DNA-Based Approaches." Gang, who has led this work at the CFN, will explain the rapid evolution of this nanoassembly method, and discuss its present and future applications in highly specific biosensors, optically active nano-materials, and new ways to fabricate complex architectures in a rational manner via self-assembly. Gang and his colleagues used the CFN and the National Synchrotron Light Source (NSLS) facilities to perform their groundbreaking research. At the CFN, the scientists used electron microscopes and optical methods to visualize the clusters that they fabricated. At the NSLS, they applied x-rays to study a particles-assembly process in solution, DNA’s natural environment. Gang earned a Ph.D. in soft matter physics from Bar-Ilan University in 2000, and he was a Rothschild Fellow at Harvard University from 1999 to 2002. After joining BNL as a Goldhaber Fellow in 2002, he became an assistant scientist at the CFN in 2004. He became the CFN’s leader for Soft and Biological Nanomaterials Theme Group in 2006, and earned the title of scientist in 2009. Gang has received numerous honors and recognitions, including the 2010 Gordon Battelle Prize for Scientific Discovery.« less

Multi-element germanium detectors for synchrotron applications

DOE PAGES

Rumaiz, A. K.; Kuczewski, A. J.; Mead, J.; ...

2018-04-27

In this paper, we have developed a series of monolithic multi-element germanium detectors, based on sensor arrays produced by the Forschungzentrum Julich, and on Application-specific integrated circuits (ASICs) developed at Brookhaven. Devices have been made with element counts ranging from 64 to 384. These detectors are being used at NSLS-II and APS for a range of diffraction experiments, both monochromatic and energy-dispersive. Compact and powerful readout systems have been developed, based on the new generation of FPGA system-on-chip devices, which provide closely coupled multi-core processors embedded in large gate arrays. Finally, we will discuss the technical details of the systems,more » and present some of the results from them.« less

Multi-element germanium detectors for synchrotron applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rumaiz, A. K.; Kuczewski, A. J.; Mead, J.

In this paper, we have developed a series of monolithic multi-element germanium detectors, based on sensor arrays produced by the Forschungzentrum Julich, and on Application-specific integrated circuits (ASICs) developed at Brookhaven. Devices have been made with element counts ranging from 64 to 384. These detectors are being used at NSLS-II and APS for a range of diffraction experiments, both monochromatic and energy-dispersive. Compact and powerful readout systems have been developed, based on the new generation of FPGA system-on-chip devices, which provide closely coupled multi-core processors embedded in large gate arrays. Finally, we will discuss the technical details of the systems,more » and present some of the results from them.« less

National Synchrotron Light Source II

ScienceCinema

Steve Dierker

2017-12-09

The National Synchrotron Light Source II (NSLS-II) at the U.S. Department of Energy's Brookhaven National Laboratory is a proposed new state-of-the-art medium energy storage ring designed to deliver world-leading brightness and flux with top-off operation

An Inside Look: NSLS-II Storage Ring

ScienceCinema

Fries, Gregory

2018-06-12

Look inside the storage ring of the National Synchrotron Light Source II, under construction at Brookhaven Lab. Exactly 843 magnets now encircle the ring. Their job will be to steer, stabilize, and store electrons racing around at near light speed.

Soft x-ray measurements using photoconductive type-IIa and single-crystal chemical vapor deposited diamond detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, A. S.; Bentley, C. D.; Foster, J. M.

2008-10-15

Photoconductive detectors (PCDs) are routinely used alongside vacuum x-ray diodes (XRDs) to provide an alternative x-ray flux measurement at laser facilities such as HELEN at AWE Aldermaston, UK, and Omega at the Laboratory for Laser Energetics. To evaluate diamond PCDs as an alternative to XRD arrays, calibration measurements made at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory are used to accurately calculate the x-ray flux from a laser-heated target. This is compared to a flux measurement using the Dante XRD diagnostic. Estimates indicate that the photoinduced conductivity from measurements made at Omega are too large, and calculationsmore » using the radiometric calibrations made at the NSLS agree with this hypothesis. High-purity, single-crystal, chemical vapor deposited (CVD) diamond samples are compared to natural type-IIa PCDs and show promising high resistivity effects, the corollary of which preliminary results show is a slower response time.« less

Cryogenic Field Measurement of Pr2Fe14B Undulator and Performance Enhancement Options at the NSLS-II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanabe, T.; Chubar, O.; Harder, David A.

2009-09-27

Short period (14.5mm) hybrid undulator arrays composed of Praseodymium Iron Boron (Pr{sub 2}Fe{sub 14}B) magnets (CR53, NEOMAX, Inc.) and vanadium permendur poles have been fabricated at Brookhaven National Laboratory. Unlike Neodymium Iron Boron (Nd{sub 2}Fe{sub 14}B) magnets which exhibit spin reorientation at temperatures below 150K, PrFeB arrays monotonically increase performance with lower operating temperature. It opens up the posibility for use in operating a cryo-permanent magnet undulator (CPMU) in the range of 40K to 60K where very efficient cryocoolers are available. Magnetic flux density profiles were measured at various temperature ranges from room temperature down to liquid helium (LHe) usingmore » the Vertical Testing Facility (VTF) at the National Snchrotron Light Source-II (NSLS-II). Temperature variations of phase error have been characterized. In addition, we examined the use of textured Dysprosium (Dy) poles to replace permendur poles to obtain further improvement in performance.« less

Extraction of saponifiable lipids from wet microalgal biomass for biodiesel production.

PubMed

Jiménez Callejón, María J; Robles Medina, Alfonso; Macías Sánchez, María D; Hita Peña, Estrella; Esteban Cerdán, Luis; González Moreno, Pedro A; Molina Grima, Emilio

2014-10-01

Saponifiable lipids (SLs) were extracted with hexane from wet biomass (86 wt% water) of the microalga Nannochloropsis gaditana in order to transform them into fatty acid methyl esters (FAMEs, biodiesel). The influence of homogenization pressure on SL extraction yield at low temperature (20-22 °C) was studied. Homogenization at 1700 bar tripled the SL extraction yield. Two biomass batches with similar total lipid content but different lipidic compositions were used. Batch 1 contained fewer SLs (12.0 wt%) and neutral saponifiable lipids (NSLs, 7.9 wt%) than batch 2 (21.6 and 17.2 wt%, respectively). For this reason, and due to the selectivity of hexane toward NSLs, high SL yield (69.1 wt%) and purity (71.0 wt%) were obtained from batch 2. Moreover, this extract contains a small percentage of polyunsaturated fatty acids (16.9 wt%), thereby improving the biodiesel quality. Finally, up to 97.0% of extracted SLs were transformed to FAMEs by acid catalyzed transesterification. Copyright © 2014 Elsevier Ltd. All rights reserved.

Elemental Composition of Mars Return Samples Using X-Ray Fluorescence Imaging at the National Synchrotron Light Source II

NASA Astrophysics Data System (ADS)

Thieme, J.; Hurowitz, J. A.; Schoonen, M. A.; Fogelqvist, E.; Gregerson, J.; Farley, K. A.; Sherman, S.; Hill, J.

2018-04-01

NSLS-II at BNL provides a unique and critical capability to perform assessments of the elemental composition and the chemical state of Mars returned samples using synchrotron radiation X-ray fluorescence imaging and X-ray absorption spectroscopy.

CONCEPTUAL DESIGN REPORT

DOE Office of Scientific and Technical Information (OSTI.GOV)

ROBINSON,K.

2006-12-31

Brookhaven National Laboratory has prepared a conceptual design for a world class user facility for scientific research using synchrotron radiation. This facility, called the ''National Synchrotron Light Source II'' (NSLS-II), will provide ultra high brightness and flux and exceptional beam stability. It will also provide advanced insertion devices, optics, detectors, and robotics, and a suite of scientific instruments designed to maximize the scientific output of the facility. Together these will enable the study of material properties and functions with a spatial resolution of {approx}1 nm, an energy resolution of {approx}0.1 meV, and the ultra high sensitivity required to perform spectroscopymore » on a single atom. The overall objective of the NSLS-II project is to deliver a research facility to advance fundamental science and have the capability to characterize and understand physical properties at the nanoscale, the processes by which nanomaterials can be manipulated and assembled into more complex hierarchical structures, and the new phenomena resulting from such assemblages. It will also be a user facility made available to researchers engaged in a broad spectrum of disciplines from universities, industries, and other laboratories.« less

Cryogenic Field Measurement of Pr{sub 2}Fe{sub 14}B Undulator and Performance Enhancement Options at the NSLS-II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanabe, Toshiya; Chubar, Oleg; Harder, David A.

2010-06-23

Short period (14.5mm) hybrid undulator arrays composed of Praseodymium Iron Boron (Pr{sub 2}Fe{sub 14}B) magnets (CR53, NEOMAX, Inc.) and vanadium permendur poles have been fabricated at Brookhaven National Laboratory. Unlike Neodymium Iron Boron (Nd{sub 2}Fe{sub 14}B) magnets which exhibit spin reorientation at a temperatures below 150 K, PrFeB arrays monotonically increase performance with lower operating temperature. It opens up the possibility for use in operating a cryo-permanent magnet undulator (CPMU) in the range of 40 K to 60 K where very efficient cryocoolers are available. Magnetic flux density profiles were measured at various temperature ranges from room temperature down tomore » liquid helium (LHe) using the Vertical Testing Facility (VTF) at the National Synchrotron Light Source-II (NSLS-II). Temperature variations of phase error have been characterized. In addition, we examined the use of textured Dysprosium (Dy) poles to replace permendur poles to obtain further improvement in performance.« less

Heating-freezing effects on the orientation of kaolin clay particles

DOE PAGES

Jaradat, Karam A.; Darbari, Zubin; Elbakhshwan, Mohamed; ...

2017-09-29

The effects of temperature changes on the particle orientation of a consolidated kaolin are studied using XRD experiments. Here, two sets of equipment were utilized in this study: a benchtop equipment, and a synchrotron beamline at the National Synchrotron Light Source II (NSLS-II) at Brookhaven National Laboratory. The kaolin specimens tested in the benchtop XRD were subjected to elevated and freezing temperatures ex-situ, while those used for the NSLS-II experiment were exposed to the temperature changes in-situ. The temperatures considered in this study range from freezing (-10 °C) to elevated temperature below boiling (90 °C). The thermally-induced reorientation of claymore » mineral particles is highly dependent on the relative orientation of the clay mineral particles with respect to the applied thermal gradient. For example, kaolin samples with kaolinite particles oriented perpendicular to the thermal gradient, and to the expected thermally-induced pore water flow, experience much higher particles reorientations compared to samples with particles initially oriented parallel to the thermal gradient. Lastly, freezing kaolin preserved its microstructure as ice crystals form.« less

Heating-freezing effects on the orientation of kaolin clay particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaradat, Karam A.; Darbari, Zubin; Elbakhshwan, Mohamed

The effects of temperature changes on the particle orientation of a consolidated kaolin are studied using XRD experiments. Here, two sets of equipment were utilized in this study: a benchtop equipment, and a synchrotron beamline at the National Synchrotron Light Source II (NSLS-II) at Brookhaven National Laboratory. The kaolin specimens tested in the benchtop XRD were subjected to elevated and freezing temperatures ex-situ, while those used for the NSLS-II experiment were exposed to the temperature changes in-situ. The temperatures considered in this study range from freezing (-10 °C) to elevated temperature below boiling (90 °C). The thermally-induced reorientation of claymore » mineral particles is highly dependent on the relative orientation of the clay mineral particles with respect to the applied thermal gradient. For example, kaolin samples with kaolinite particles oriented perpendicular to the thermal gradient, and to the expected thermally-induced pore water flow, experience much higher particles reorientations compared to samples with particles initially oriented parallel to the thermal gradient. Lastly, freezing kaolin preserved its microstructure as ice crystals form.« less

Wavefront propagation simulations for a UV/soft x-ray beamline: Electron Spectro-Microscopy beamline at NSLS-II

NASA Astrophysics Data System (ADS)

Canestrari, N.; Bisogni, V.; Walter, A.; Zhu, Y.; Dvorak, J.; Vescovo, E.; Chubar, O.

2014-09-01

A "source-to-sample" wavefront propagation analysis of the Electron Spectro-Microscopy (ESM) UV / soft X-ray beamline, which is under construction at the National Synchrotron Light Source II (NSLS-II) in the Brookhaven National Laboratory, has been conducted. All elements of the beamline - insertion device, mirrors, variable-line-spacing gratings and slits - are included in the simulations. Radiation intensity distributions at the sample position are displayed for representative photon energies in the UV range (20 - 100 eV) where diffraction effects are strong. The finite acceptance of the refocusing mirrors is the dominating factor limiting the spatial resolution at the sample (by ~3 μm at 20 eV). Absolute estimates of the radiation flux and energy resolution at the sample are also obtained from the electromagnetic calculations. The analysis of the propagated UV range undulator radiation at different deflection parameter values demonstrates that within the beamline angular acceptance a slightly "red-shifted" radiation provides higher flux at the sample and better energy resolution compared to the on-axis resonant radiation of the fundamental harmonic.

Shielding NSLS-II light source: Importance of geometry for calculating radiation levels from beam losses

NASA Astrophysics Data System (ADS)

Kramer, S. L.; Ghosh, V. J.; Breitfeller, M.; Wahl, W.

2016-11-01

Third generation high brightness light sources are designed to have low emittance and high current beams, which contribute to higher beam loss rates that will be compensated by Top-Off injection. Shielding for these higher loss rates will be critical to protect the projected higher occupancy factors for the users. Top-Off injection requires a full energy injector, which will demand greater consideration of the potential abnormal beam miss-steering and localized losses that could occur. The high energy electron injection beam produces significantly higher neutron component dose to the experimental floor than a lower energy beam injection and ramped operations. Minimizing this dose will require adequate knowledge of where the miss-steered beam can occur and sufficient EM shielding close to the loss point, in order to attenuate the energy of the particles in the EM shower below the neutron production threshold (<10 MeV), which will spread the incident energy on the bulk shield walls and thereby the dose penetrating the shield walls. Designing supplemental shielding near the loss point using the analytic shielding model is shown to be inadequate because of its lack of geometry specification for the EM shower process. To predict the dose rates outside the tunnel requires detailed description of the geometry and materials that the beam losses will encounter inside the tunnel. Modern radiation shielding Monte-Carlo codes, like FLUKA, can handle this geometric description of the radiation transport process in sufficient detail, allowing accurate predictions of the dose rates expected and the ability to show weaknesses in the design before a high radiation incident occurs. The effort required to adequately define the accelerator geometry for these codes has been greatly reduced with the implementation of the graphical interface of FLAIR to FLUKA. This made the effective shielding process for NSLS-II quite accurate and reliable. The principles used to provide supplemental shielding to the NSLS-II accelerators and the lessons learned from this process are presented.

X-ray Photon Correlation Spectroscopy: A New Probe of Short Wavelength Dynamics

NASA Astrophysics Data System (ADS)

Dierker, S. B.

1996-03-01

The new field of x-ray photon correlation spectroscopy (XPCS) offers an unprecedented opportunity to extend the range of length scales over which a material's low frequency dynamics can be studied down to interatomic spacings. The critical development which has now made XPCS a feasible technique is the high brightness of insertion devices at second and third generation synchrotron sources. In this talk, I will describe the principles of the XPCS technique and how it is practiced, as well as its potential use for a variety of important problems in the low frequency dynamics of condensed matter systems, such as complex fluids, glasses, surfaces, and metallic alloys. Illustrations will be drawn from our(Research done in collaboration with R. Pindak, R. M. Fleming, I. K. Robinson, L. Berman, G. Grubel, and D. L. Abernathy. S.B.D. supported by NSF DMR92-17956. I.K.R. supported by NSF MDR 93-15691. The NSLS is supported by DOE DE-AC02-76CH00016.) results(S. B. Dierker, R. Pindak, R. M. Fleming, I. K. Robinson, L. Berman, Phys. Rev. Lett. 75), 449 (1995). on using XPCS to study the Brownian motion of a gold colloid. We made small angle x-ray scattering measurements of the static structure factor of an optically opaque gold colloid dispersed in the viscous liquid glycerol. We discovered a novel effect due to photoemission induced charging of the gold colloid which could be suppressed by the addition of salt. We determined the dynamic correlation functions for the Brownian motion of the colloid particles at wavevectors between 10-3 <= q <= 10-2 Åwhich extends well beyond the range of visible light scattering. The resulting diffusion coefficient is very q dependent, scaling approximately as D(q) = D_o/S(q). The results of recent progress in using the Prototype Small Gap Undulator (PSGU) at beam line X13 at the NSLS will also be described. We(Research done in collaboration with L. Berman, Z. Yin, and E. Dufresne.) have achieved a coherent flux of > 10^10 photons/second in a `pink' beam at 3 keV by using a mirror to filter out the harmonics. This should be an excellent source for small angle XPCS measurements. The results of initial experiments conducted with the PSGU will be presented. The experiments were conducted at the wiggler beam line X25 and the PSGU beamline X13 at the NSLS and at the undulator beamline 9/ID10 (Troika) at the ESRF.

High resolution microtomography for density and spatial infomation about wood structures

Treesearch

Barbara Illman; Betsy Dowd

1999-01-01

Microtomography has successfully been used to characterize loss of structural integrity of wood. Tomographic images were generated with the newly developed third generation x-ray computed microtomography (XCMT) instrument at the X27A beamline at the national Synchrotron Light source (NSLS). The beamline is equipped with high-flux x-ray monochromator based on multilayer...

National Synchrotron Light Source II

ScienceCinema

Hill, John; Dooryhee, Eric; Wilkins, Stuart; Miller, Lisa; Chu, Yong

2018-01-16

NSLS-II is a synchrotron light source helping researchers explore solutions to the grand energy challenges faced by the nation, and open up new regimes of scientific discovery that will pave the way to discoveries in physics, chemistry, and biology — advances that will ultimately enhance national security and help drive the development of abundant, safe, and clean energy technologies.

Genetic algorithm enhanced by machine learning in dynamic aperture optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yongjun; Cheng, Weixing; Yu, Li Hua

With the aid of machine learning techniques, the genetic algorithm has been enhanced and applied to the multi-objective optimization problem presented by the dynamic aperture of the National Synchrotron Light Source II (NSLS-II) Storage Ring. During the evolution processes employed by the genetic algorithm, the population is classified into different clusters in the search space. The clusters with top average fitness are given “elite” status. Intervention on the population is implemented by repopulating some potentially competitive candidates based on the experience learned from the accumulated data. These candidates replace randomly selected candidates among the original data pool. The average fitnessmore » of the population is therefore improved while diversity is not lost. Maintaining diversity ensures that the optimization is global rather than local. The quality of the population increases and produces more competitive descendants accelerating the evolution process significantly. When identifying the distribution of optimal candidates, they appear to be located in isolated islands within the search space. Some of these optimal candidates have been experimentally confirmed at the NSLS-II storage ring. Furthermore, the machine learning techniques that exploit the genetic algorithm can also be used in other population-based optimization problems such as particle swarm algorithm.« less

Shielding calculations for the National Synchrotron Light Source-II experimental beamlines

NASA Astrophysics Data System (ADS)

Job, Panakkal K.; Casey, William R.

2013-01-01

Brookhaven National Laboratory is in the process of building a new Electron storage ring for scientific research using synchrotron radiation. This facility, called the "National Synchrotron Light Source II" (NSLS-II), will provide x-ray radiation of ultra-high brightness and exceptional spatial and energy resolution. It will also provide advanced insertion devices, optics, detectors, and robotics, designed to maximize the scientific output of the facility. The project scope includes the design of an electron storage ring and the experimental beamlines, which stores a maximum of 500 mA electron beam current at an energy of 3.0 GeV. When fully built there will be at least 58 beamlines using synchrotron radiation for experimental programs. It is planned to operate the facility primarily in a top-off mode, thereby maintaining the maximum variation in the synchrotron radiation flux to <1%. Because of the very demanding requirements for synchrotron radiation brilliance for the experiments, each of the 58 beamlines will be unique in terms of the source properties and experimental configuration. This makes the shielding configuration of each of the beamlines unique. The shielding calculation methodology and the results for five representative beamlines of NSLS-II, have been presented in this paper.

Genetic algorithm enhanced by machine learning in dynamic aperture optimization

NASA Astrophysics Data System (ADS)

Li, Yongjun; Cheng, Weixing; Yu, Li Hua; Rainer, Robert

2018-05-01

With the aid of machine learning techniques, the genetic algorithm has been enhanced and applied to the multi-objective optimization problem presented by the dynamic aperture of the National Synchrotron Light Source II (NSLS-II) Storage Ring. During the evolution processes employed by the genetic algorithm, the population is classified into different clusters in the search space. The clusters with top average fitness are given "elite" status. Intervention on the population is implemented by repopulating some potentially competitive candidates based on the experience learned from the accumulated data. These candidates replace randomly selected candidates among the original data pool. The average fitness of the population is therefore improved while diversity is not lost. Maintaining diversity ensures that the optimization is global rather than local. The quality of the population increases and produces more competitive descendants accelerating the evolution process significantly. When identifying the distribution of optimal candidates, they appear to be located in isolated islands within the search space. Some of these optimal candidates have been experimentally confirmed at the NSLS-II storage ring. The machine learning techniques that exploit the genetic algorithm can also be used in other population-based optimization problems such as particle swarm algorithm.

Genetic algorithm enhanced by machine learning in dynamic aperture optimization

DOE PAGES

Li, Yongjun; Cheng, Weixing; Yu, Li Hua; ...

2018-05-29

With the aid of machine learning techniques, the genetic algorithm has been enhanced and applied to the multi-objective optimization problem presented by the dynamic aperture of the National Synchrotron Light Source II (NSLS-II) Storage Ring. During the evolution processes employed by the genetic algorithm, the population is classified into different clusters in the search space. The clusters with top average fitness are given “elite” status. Intervention on the population is implemented by repopulating some potentially competitive candidates based on the experience learned from the accumulated data. These candidates replace randomly selected candidates among the original data pool. The average fitnessmore » of the population is therefore improved while diversity is not lost. Maintaining diversity ensures that the optimization is global rather than local. The quality of the population increases and produces more competitive descendants accelerating the evolution process significantly. When identifying the distribution of optimal candidates, they appear to be located in isolated islands within the search space. Some of these optimal candidates have been experimentally confirmed at the NSLS-II storage ring. Furthermore, the machine learning techniques that exploit the genetic algorithm can also be used in other population-based optimization problems such as particle swarm algorithm.« less

Modeling the interaction of a heavily beam loaded SRF cavity with its low-level RF feedback loops

NASA Astrophysics Data System (ADS)

Liu, Zong-Kai; Wang, Chaoen; Chang, Lung-Hai; Yeh, Meng-Shu; Chang, Fu-Yu; Chang, Mei-Hsia; Chang, Shian-Wen; Chen, Ling-Jhen; Chung, Fu-Tsai; Lin, Ming-Chyuan; Lo, Chih-Hung; Yu, Tsung-Chi

2018-06-01

A superconducting radio frequency (SRF) cavity provides superior stability to power high intensity light sources and can suppress coupled-bunch instabilities due to its smaller impedance for higher order modes. Because of these features, SRF cavities are commonly used for modern light sources, such as the TLS, CLS, DLS, SSRF, PLS-II, TPS, and NSLS-II, with an aggressive approach to operate the light sources at high beam currents. However, operating a SRF cavity at high beam currents may result with unacceptable stability problems of the low level RF (LLRF) system, due to drifts of the cavity resonant frequency caused by unexpected perturbations from the environment. As the feedback loop gets out of control, the cavity voltage may start to oscillate with a current-dependent characteristic frequency. Such situations can cause beam abort due to the activation of the interlock protection system, i.e. false alarm of quench detection. This malfunction of the light source reduces the reliability of SRF operation. Understanding this unstable mechanism to prevent its appearance becomes a primary task in the pursuit of highly reliable SRF operation. In this paper, a Pedersen model, including the response of the LLRF system, was used to simulate the beam-cavity interaction of a SRF cavity under heavy beam loading. Causes for the onset of instability at high beam current will be discussed as well as remedies to assure the design of a stable LLRF system.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yongjun; Yang, Lingyun

We report an efficient dynamic aperture (DA) optimization approach using multiobjective genetic algorithm (MOGA), which is driven by nonlinear driving terms computation. It was found that having small low order driving terms is a necessary but insufficient condition of having a decent DA. Then direct DA tracking simulation is implemented among the last generation candidates to select the best solutions. The approach was demonstrated successfully in optimizing NSLS-II storage ring DA.

Shielding NSLS-II light source: Importance of geometry for calculating radiation levels from beam losses

DOE PAGES

Kramer, S. L.; Ghosh, V. J.; Breitfeller, M.; ...

2016-08-10

We present that third generation high brightness light sources are designed to have low emittance and high current beams, which contribute to higher beam loss rates that will be compensated by Top-Off injection. Shielding for these higher loss rates will be critical to protect the projected higher occupancy factors for the users. Top-Off injection requires a full energy injector, which will demand greater consideration of the potential abnormal beam miss-steering and localized losses that could occur. The high energy electron injection beam produces significantly higher neutron component dose to the experimental floor than a lower energy beam injection and rampedmore » operations. Minimizing this dose will require adequate knowledge of where the miss-steered beam can occur and sufficient EM shielding close to the loss point, in order to attenuate the energy of the particles in the EM shower below the neutron production threshold (<10 MeV), which will spread the incident energy on the bulk shield walls and thereby the dose penetrating the shield walls. Designing supplemental shielding near the loss point using the analytic shielding model is shown to be inadequate because of its lack of geometry specification for the EM shower process. To predict the dose rates outside the tunnel requires detailed description of the geometry and materials that the beam losses will encounter inside the tunnel. Modern radiation shielding Monte-Carlo codes, like FLUKA, can handle this geometric description of the radiation transport process in sufficient detail, allowing accurate predictions of the dose rates expected and the ability to show weaknesses in the design before a high radiation incident occurs. The effort required to adequately define the accelerator geometry for these codes has been greatly reduced with the implementation of the graphical interface of FLAIR to FLUKA. In conclusion, this made the effective shielding process for NSLS-II quite accurate and reliable. The principles used to provide supplemental shielding to the NSLS-II accelerators and the lessons learned from this process are presented.« less

Elemental X-ray Imaging Using the Maia Detector Array: The Benefits and Challenges of Large Solid-Angle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryan, C.G.; De Geronimo, G.; Kirkham, R.

2009-11-13

The fundamental parameter method for quantitative SXRF and PIXE analysis and imaging using the dynamic analysis method is extended to model the changing X-ray yields and detector sensitivity with angle across large detector arrays. The method is implemented in the GeoPIXE software and applied to cope with the large solid-angle of the new Maia 384 detector array and its 96 detector prototype developed by CSIRO and BNL for SXRF imaging applications at the Australian and NSLS synchrotrons. Peak-to-background is controlled by mitigating charge-sharing between detectors through careful optimization of a patterned molybdenum absorber mask. A geological application demonstrates the capabilitymore » of the method to produce high definition elemental images up to {approx}100 M pixels in size.« less

Brookhaven National Laboratory technology transfer report, fiscal year 1987

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1987-01-01

The Brookhaven Office of Research and Technology Applications (ORTA) inaugurated two major initiatives. The effort by our ORTA in collaboration with the National Synchrotron Light Source (NSLS) has succeeded in alerting American industry to the potential of using a synchrotron x-ray source for high resolution lithography. We are undertaking a preconstruction study for the construction of a prototype commercial synchrotron and development of an advanced commercial cryogenic synchrotron (XLS). ORTA sponsored a technology transfer workshop where industry expressed its views on how to transfer accelerator technology during the construction of the prototype commercial machine. The Northeast Regional utility Initiative broughtmore » 14 utilities to a workshop at the Laboratory in November. One recommendation of this workshop was to create a Center at the Laboratory for research support on issues of interest to utilities in the region where BNL has unique capability. The ORTA has initiated discussions with the New York State Science and Technology Commission, Cornell University's world renowned Nannofabrication Center and the computer aided design capabilities at SUNY at Stony Brook to create, centered around the NSLS and the XLS, the leading edge semiconductor process technology development center when the XLS becomes operational in two and a half years. 1 fig.« less

When Protein Crystallography Won't Show You the Membranes (446th Brookhaven Lecture)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Lin

High fever, stomach ache, coughing, sneezing, and fatigue -- these are all painful signs that you may have caught the flu virus. But how does your body actually 'catch' a virus? Somewhere along the way, the virus infected your body by penetrating the membranes, or surfaces, of some of your body's cells. And then it spreads. Cell membranes are permeable surfaces made of proteins and lipids that allow vital materials to enter and exit cells. Many proteins and cell structures are studied at Brookhaven's National Synchrotron Light Source (NSLS) using a procedure called protein crystallography. But they sometimes have uniquemore » characteristics that do not allow them to be easily studied using this widely adopted method. These characteristics make it difficult to understand the cell membrane structure and its ability to both welcome and refuse certain materials and viruses, such as the flu, on behalf of the cell's internal components. Yang will explain the protein crystallography procedure, the simple structure of the cell membrane, and the unusual characteristics of its proteins and lipids. He will also discuss a new, unique method being developed at the NSLS to study proteins and lipids within their native environment as they form the essential permeable surface of a cell membrane.« less

Multi-objective dynamic aperture optimization for storage rings

DOE PAGES

Li, Yongjun; Yang, Lingyun

2016-11-30

We report an efficient dynamic aperture (DA) optimization approach using multiobjective genetic algorithm (MOGA), which is driven by nonlinear driving terms computation. It was found that having small low order driving terms is a necessary but insufficient condition of having a decent DA. Then direct DA tracking simulation is implemented among the last generation candidates to select the best solutions. The approach was demonstrated successfully in optimizing NSLS-II storage ring DA.

THE FIRST LASING OF 193 NM SASE, 4TH HARMONIC HGHG AND ESASE AT THE NSLS SDL.

DOE Office of Scientific and Technical Information (OSTI.GOV)

WANG, X.J.; SHEN Y.; WATANABE, T.

2006-08-28

The first lasing of three types of single-pass high-gain FELs, SASE at 193 nm, 4th harmonic HGHG at 199 nm and ESASE at the Source Development Lab (SDL) of Brookhaven National Laboratory (BNL) is reported. The saturation of 4th harmonic HGHG and ESASE FELs was observed. We also observed the spectral broadening and instability of the 4th harmonic HGHG.

Defining the safe current limit for opening ID photon shutter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seletskiy, S.

The NSLS-II storage ring is protected from possible damage from insertion devices (IDs) synchrotron radiation by a dedicated active interlock system (AIS). It monitors electron beam position and angle and triggers beam drop if beam orbit exceeds the boundaries of pre-calculated active interlock envelope (AIE). The beamlines (BL) and beamline frontends (FE) are designed under assumption that the electron beam is interlocked within the AIE. For historic reasons the AIS engages the ID active interlock (AI-ID) at any non-zero beam current whenever the ID photon shutter (IDPS) is getting opened. Such arrangement creates major inconveniences for BLs commissioning. Apparently theremore » is some IDPS safe current limit (SCL) under which the IDPS can be opened without interlocking the e-beam. The goal of this paper is to find such limit.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gofron, K. J., E-mail: kgofron@bnl.gov; Cai, Y. Q.; Coburn, D. S.

A novel on-axis X-ray microscope with 3 µm resolution, 3x magnification, and a working distance of 600 mm for in-situ sample alignment and X-ray beam visualization for the Inelastic X-ray Scattering (IXS) beamline at NSLS-II is presented. The microscope uses reflective optics, which minimizes dispersion, and allows imaging from Ultraviolet (UV) to Infrared (IR) with specifically chosen objective components (coatings, etc.). Additionally, a portable high resolution X-ray microscope for KB mirror alignment and X-ray beam characterization was developed.

Fluorescence tomography using synchrotron radiation at the NSLS

NASA Astrophysics Data System (ADS)

Boisseau, P.; Grodzins, L.

1987-03-01

Fluorescence tomography utilizing focussed, tunable, monoenergetic X-rays from synchrotron light sources hold the promise of a non-invasive analytic tool for studying trace elements in specimens, particularly biological, at spatial resolutions of the order of micrometers. This note reports an early test at the National Synchrotron Light Source at Brookhaven National Laboratories in which fluorescence tomographic scans were successfully made of trace elements of iron and titanium in NBS standard glass and in a bee.

REQUIREMENTS AND GUIDELINES FOR NSLS EXPERIMENTAL BEAM LINE VACUUM SYSTEMS-REVISION B.

DOE Office of Scientific and Technical Information (OSTI.GOV)

FOERSTER,C.

Typical beam lines are comprised of an assembly of vacuum valves and shutters referred to as a ''front end'', optical elements to monochromatize, focus and split the photon beam, and an experimental area where a target sample is placed into the photon beam and data from the interaction is detected and recorded. Windows are used to separate sections of beam lines that are not compatible with storage ring ultra high vacuum. Some experimental beam lines share a common vacuum with storage rings. Sections of beam lines are only allowed to vent up to atmospheric pressure using pure nitrogen gas aftermore » a vacuum barrier is established to protect ring vacuum. The front end may only be bled up when there is no current in the machine. This is especially true on the VUV storage ring where for most experiments, windows are not used. For the shorter wavelength, more energetic photons of the x-ray ring, beryllium windows are used at various beam line locations so that the monochromator, mirror box or sample chamber may be used in a helium atmosphere or rough vacuum. The window separates ring vacuum from the environment of the downstream beam line components. The stored beam lifetime in the storage rings and the maintenance of desirable reflection properties of optical surfaces depend upon hydrocarbon-free, ultra-high vacuum systems. Storage ring vacuum systems will operate at pressures of {approximately} 1 x 10{sup {minus}10} Torr without beam and {approximately} 1 x 10{sup {minus}9} Torr with beam. Systems are free of hydrocarbons in the sense that no pumps, valves, etc. containing organics are used. Components are all-metal, chemically cleaned and bakeable. To the extent that beam lines share a common vacuum with the storage ring, the same criteria will hold for beam line components. The design philosophy for NSLS beam lines is to use all-metal, hydrocarbon-free front end components and recommend that experimenters use this approach for common vacuum hardware downstream of front ends. O-ring-sealed valves, if used, are not permitted upstream of the monochromator exit aperture. It will be the responsibility of users to demonstrate that their experiment will not degrade the pressure or quality of the storage ring vacuum. As a matter of operating policy, all beam lines will be monitored for prescribed pressure and the contribution of high mass gases to this pressure each time a beam line has been opened to ring vacuum.« less

Evaluation of Heat Dissipation in the BPM Buttons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pinayev,I.; Blednyhk, A.

2009-05-04

Growth of circulating current in the storage rings drastically increases heating of the beam position monitor (BPM) buttons due to the induced trapped modes is drastically increasing. Excessive heating can lead to the errors in the measuring of beam position or even catastrophic failures of the pick-up assembly. In this paper we present calculations of heat generated in the button for different geometries and materials. The obtained results are used for the optimization of the NSLS-II BPM buttons design.

X-Ray Crystallographic Studies on Acetylcholinesterase and on Its Interaction with Anticholinesterase Agents.

DTIC Science & Technology

1994-11-24

complexes with reversible ligands, including edrophonium, d-tubocurarine and huperzine A , diffracting to similar resolution. The X26c Laue beam line...The EMBL-DESY synchrotron facility at Hamburg was employed to collect a complete 2.3 A data set for a crystal of native Torpedo AChE, as well as for...at the NSLS synchrotron facility at Brookhaven National Laboratory (BNL) was used to obtain a Laue diffraction pattern for a crystal of native Torpedo

BEAM DYNAMICS SIMULATIONS FOR A DC GUN BASED INJECTOR FOR PERL.

DOE Office of Scientific and Technical Information (OSTI.GOV)

ZHOU,F.; BEN-ZVI,I.; WANG,X.J.

2001-06-18

The National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) is considering an upgrade based on the Photoinjected Energy Recovering Linac (PERL). The various injector schemes for this machine are being extensively investigated at BNL. One of the possible options is photocathode DC gun. The schematic layout of a PERL DC gun based injector and its preliminary beam dynamics are presented in this paper. The transverse and longitudinal emittance of photo-electron beam were optimized for a DC field 500 kV.

Silicon Photodiode Soft X-Ray Detectors for Pulsed Power Experiments

DTIC Science & Technology

1997-06-01

AXUV -100 silicon photodiode were performed at the National Institute of Standards and Technology (NIST), our Bechtel Nevada laboratories, and the...NSLS at Brookhaven National Laboratory. The AXUV -100 diode is covered with a 60 angstrom Si02 window over its entire surface. The higher response lobes...in the visible and at higher x-ray energies seen by the HS-1 are absent in the AXUV -100 calibrations. The two model calculations assume 2.73 x 105 A

Design and performance of an X-ray scanning microscope at the Hard X-ray Nanoprobe beamline of NSLS-II

DOE PAGES

Nazaretski, E.; Yan, H.; Lauer, K.; ...

2017-10-05

A hard X-ray scanning microscope installed at the Hard X-ray Nanoprobe beamline of the National Synchrotron Light Source II has been designed, constructed and commissioned. The microscope relies on a compact, high stiffness, low heat dissipation approach and utilizes two types of nanofocusing optics. It is capable of imaging with ~15 nm × 15 nm spatial resolution using multilayer Laue lenses and 25 nm × 26 nm resolution using zone plates. Fluorescence, diffraction, absorption, differential phase contrast, ptychography and tomography are available as experimental techniques. The microscope is also equipped with a temperature regulation system which allows the temperature ofmore » a sample to be varied in the range between 90 K and 1000 K. The constructed instrument is open for general users and offers its capabilities to the material science, battery research and bioscience communities.« less

Design and performance of an X-ray scanning microscope at the Hard X-ray Nanoprobe beamline of NSLS-II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nazaretski, E.; Yan, H.; Lauer, K.

A hard X-ray scanning microscope installed at the Hard X-ray Nanoprobe beamline of the National Synchrotron Light Source II has been designed, constructed and commissioned. The microscope relies on a compact, high stiffness, low heat dissipation approach and utilizes two types of nanofocusing optics. It is capable of imaging with ~15 nm × 15 nm spatial resolution using multilayer Laue lenses and 25 nm × 26 nm resolution using zone plates. Fluorescence, diffraction, absorption, differential phase contrast, ptychography and tomography are available as experimental techniques. The microscope is also equipped with a temperature regulation system which allows the temperature ofmore » a sample to be varied in the range between 90 K and 1000 K. The constructed instrument is open for general users and offers its capabilities to the material science, battery research and bioscience communities.« less

From the meso to the nanoscopic scale through synchrotron imaging approaches: advances and near future at the NSLS-II SRX beamline

NASA Astrophysics Data System (ADS)

De Andrade, V.; Thieme, J.; Ganne, J.; Beck, P.; Fayard, B.; Salomé, M.

2012-12-01

Earth and planetary samples are commonly complex polycrystalline systems with various scale-level chemical and structural heterogeneities. They can present various crystallinity states, fine mechanical mixings of phases within a micrometer cube, micro-domains differentially affected by diverse geodynamic events. During the last decade, many questions in Earth Sciences were addressed with synchrotron techniques. Indeed, these big instruments now worldwide spreads are well equipped for unraveling the wealth of information stored in geomaterials. A large spectrum of cutting edge techniques (enabling phase identification, 3D chemical imaging, elemental speciation determination…) is available with mm to ~10 nm large X-ray beams, with sensitivity in some cases below the ppm. In this presentation, we will first underscore the predominant contribution of a newly developed synchrotron imaging technique[1] to metamorphic rocks studies. The technique allows to perform hard X-rays full-field imaging spectroscopy with high spectral and spatial resolution (<1 μm). It is currently the unique method for providing mega-pixel redox maps with a large field of view (≈1 mm2), while conserving a sub-micrometer resolution. This approach is also revealed to be a powerful tool for local identification of phases in finely divided materials like clays. The potential of these high resolution XANES images is demonstrated through two studies concerning the aqueous alteration of CI and CM meteorites[2], and a Palaeoproterozoic greenstone belt from the West Africa Craton[3]. Here, the conjoint use of redox and EPMA X-ray fluorescence maps led to the first discovery of high pressure low temperature (blueschist) metamorphic conditions preserved within greenstone belts. These results suggest the existence of modern destructive plate boundaries at 2.15 Ga. At last, we will give an overview of the Submicron Resolution X-ray spectroscopy beamline[4] (SRX) that will be doubtless a very powerful instrument for Earth Sciences. SRX is one of the first 6 project beamlines of the new National Synchrotron Light Source II (NSLS-II). Operating from 4.65 to 28 keV, SRX will comprise a high flux station and a nanoprobe (switchable within a couple of minutes), both operating with a world leading flux. SRX will start early science experiments in spring 2014. References [1] De Andrade, V., Susini, et al., "Submicrometer Hyperspectral X-ray Imaging of Heterogeneous Rocks and Geomaterials: Applications at the Fe K-Edge," Analytical Chemistry, 83(11), 4220-4227 (2011). [2] Beck P., De Andrade V., et al., "The redox state of iron in the matrix of CI, CM and metamorphosed CM chondrites by XANES spectroscopy". In press GCA. [3] Ganne J., De Andrade, et al., "Modern-style plate subduction and HP-LT rocks preserved in the Palaeoproterozoic West African Craton," Nature Geosciences, 5, 60-65, (2012). [4] De Andrade V., Thieme, J, et al., "The sub-micron resolution X-ray spectroscopy beamline at NSLS-II", Nuclear Instruments and Methods in Physics Research Section A, 649(1), 46-48 (2011).

Density Measurement of Liquid FeS Under High Pressure and High Temperature

NASA Astrophysics Data System (ADS)

Yu, T.; Young, C.; Chen, J.; Baldwin, K.

2005-05-01

Sulfur is considered one of the possible light elements in the core which might be responsible for the density deficit. We studied the liquid state of sulfur in iron due to sulfur¡¦s lack of amount in the mantle; easiness to alloy with iron; and the predicted 5% ~ 10% amount of this light element in the core (Ahrens, 1979; Sherman, 1997). Restricted by the modern development of the multianvil high pressure experimental equipments, the experiments are limited at a lower pressure range (<30GPa) comparing with the outer core pressure condition. Therefore, extrapolation of data derived at low pressure range to the condition of the outer core (130-330GPa) has to be applied and may produce results which are way far from the true numbers. However, at the point while the techniques are limited, studying the physical properties of the molten FeS at relatively low pressure still provides us a better picture of the physical behaviors of the liquid outer core comparing with data derived from solid state FeS experiments. The lack of melt density data at low pressure provides another motivation for us to study the physical properties of melt. The radiography (shadowgraphy) system on Beam Line X17B2, NSLS at the Brookhaven National Laboratory is an add-on system attached to the in situ x-ray beam line setup. It includes a YAG fluorescent screen, an optical mirror, focusing-magnification lenses, and a CCD camera and/or a video camera. Before the melting temperature, the radiograph system yields a maximum 1% difference in density comparing with the data collected by the traditional x-ray diffraction method. We have successfully examined liquid FeS samples by applying this technique at the NSLS. With a sapphire (Al2O3) sphere surrounded by FeS powder. The image of the sphere was clearly shown due to the absorption coefficient difference between these two materials. The density fitting method developed by our group has produced convincing data. The preliminary results of the density measurements of molten FeS show that the derived liquid density variation for the same sample remains under 1%. This study has collected in situ high pressure and high temperature x-ray diffraction data of the FeS sample up to 4GPa and 1400°C. Combined with the derived density data, the equation of state of the liquid FeS can be constructed.

Protein Crystal Movements and Fluid Flows During Microgravity Growth

NASA Technical Reports Server (NTRS)

Boggon, Titus J.; Chayen, Naomi E.; Snell, Edward H.; Dong, Jun; Lautenschlager, Peter; Potthast, Lothar; Siddons, D. Peter; Stojanoff, Vivian; Gordon, Elspeth; Thompson, Andrew W.;

One-dimensional ion-beam figuring for grazing-incidence reflective optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Lin; Idir, Mourad; Bouet, Nathalie

2016-01-01

One-dimensional ion-beam figuring (1D-IBF) can improve grazing-incidence reflective optics, such as Kirkpatrick–Baez mirrors. 1D-IBF requires only one motion degree of freedom, which reduces equipment complexity, resulting in compact and low-cost IBF instrumentation. Furthermore, 1D-IBF is easy to integrate into a single vacuum system with other fabrication processes, such as a thin-film deposition. The NSLS-II Optical Metrology and Fabrication Group has recently integrated the 1D-IBF function into an existing thin-film deposition system by adding an RF ion source to the system. Using a rectangular grid, a 1D removal function needed to perform 1D-IBF has been produced. In this paper, demonstration experimentsmore » of the 1D-IBF process are presented on one spherical and two plane samples. The final residual errors on both plane samples are less than 1 nm r.m.s. In conclusion, the surface error on the spherical sample has been successfully reduced by a factor of 12. The results show that the 1D-IBF method is an effective method to process high-precision 1D synchrotron optics.« less

Spherical grating monochromator with interferometer control and in-vacuum reference

NASA Astrophysics Data System (ADS)

Holly, D. J.; Mason, W. P.; Sailor, T.; Smith, R. E.; Wahl, D.

2002-03-01

Physical Science Laboratory's new generation of spherical grating monochromators incorporates a laser interferometer to control scan angle and an in-vacuum absolute angle reference, as well as other improvements. The design accommodates up to six gratings which can be moved axially (under motor control, with encoder position readback) at any scan angle. The gratings are cooled by means of spring-loaded clamps which conduct heat to a water-cooled plate. The instruments feature hollow roller bearings on the scan axis to minimize bearing runout, and a pseudosine-bar drive for precise control of grating angle. The interferometer angle-measuring optics are mounted inside the vacuum chamber and measure the angle between the grating scan axis and the instrument's granite base. The laser interferometer measures the grating angle with a resolution of approximately 0.02 arcsec over the entire scan range of 40°. To provide a reference for the interferometer angle measurement, we have built an in-vacuum optical reference which uses custom chrome-on-glass reticles mounted inside the vacuum chamber. Collimated light from a source outside the vacuum passes through the reticles to yield quadrature signals which precisely define an absolute reference angle for the interferometer. Repeatability of the grating angle is within a range of ±0.05 arcsec. Two of these instruments are in operation at SRRC (Taiwan) and a third instrument has been delivered to NSLS (Brookhaven).

Non-destructive trace element microanalysis of as-received cometary nucleus samples using synchrotron x ray fluorescence

NASA Technical Reports Server (NTRS)

Sutton, S. R.

1989-01-01

The Synchrotron X ray Fluorescence (SXRF) microprobe at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory, will be an excellent instrument for non-destructive trace element analyses of cometary nucleus samples. Trace element analyses of as-received cometary nucleus material will also be possible with this technique. Bulk analysis of relatively volatile elements will be important in establishing comet formation conditions. However, as demonstrated for meteorites, microanalyses of individual phases in their petrographic context are crucial in defining the histories of particular components in unequilibrated specimens. Perhaps most informative in comparing cometary material with meteorites will be the halogens and trace metals. In-situ, high spatial resolution microanalyses will be essential in establishing host phases for these elements and identifying terrestrial (collection/processing) overprints. The present SXRF microprobe is a simple, yet powerful, instrument in which specimens are excited with filtered, continuum synchrotron radiation from a bending magnet on a 2.5 GeV electron storage ring. A refrigerated cell will be constructed to permit analyses at low temperatures. The cell will consist essentially of an air tight housing with a cold stage. Kapton windows will be used to allow the incident synchrotron beam to enter the cell and fluorescent x rays to exit it. The cell will be either under vacuum or continuous purge by ultrapure helium during analyses. Several other improvements of the NSLS microprobe will be made prior to the cometary nucleus sample return mission that will greatly enhance the sensitivity of the technique.

Infrastructure development for radioactive materials at the NSLS-II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sprouster, D. J.; Weidner, R.; Ghose, S. K.

2018-02-01

The X-ray Powder Diffraction (XPD) Beamline at the National Synchrotron Light Source-II is a multipurpose instrument designed for high-resolution, high-energy X-ray scattering techniques. In this article, the capabilities, opportunities and recent developments in the characterization of radioactive materials at XPD are described. The overarching goal of this work is to provide researchers access to advanced synchrotron techniques suited to the structural characterization of materials for advanced nuclear energy systems. XPD is a new beamline providing high photon flux for X-ray Diffraction, Pair Distribution Function analysis and Small Angle X-ray Scattering. The infrastructure and software described here extend the existing capabilitiesmore » at XPD to accommodate radioactive materials. Such techniques will contribute crucial information to the characterization and quantification of advanced materials for nuclear energy applications. We describe the automated radioactive sample collection capabilities and recent X-ray Diffraction and Small Angle X-ray Scattering results from neutron irradiated reactor pressure vessel steels and oxide dispersion strengthened steels.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bassi, Gabriele; Blednykh, Alexei; Smalyuk, Victor

A novel algorithm for self-consistent simulations of long-range wakefield effects has been developed and applied to the study of both longitudinal and transverse coupled-bunch instabilities at NSLS-II. The algorithm is implemented in the new parallel tracking code space (self-consistent parallel algorithm for collective effects) discussed in the paper. The code is applicable for accurate beam dynamics simulations in cases where both bunch-to-bunch and intrabunch motions need to be taken into account, such as chromatic head-tail effects on the coupled-bunch instability of a beam with a nonuniform filling pattern, or multibunch and single-bunch effects of a passive higher-harmonic cavity. The numericalmore » simulations have been compared with analytical studies. For a beam with an arbitrary filling pattern, intensity-dependent complex frequency shifts have been derived starting from a system of coupled Vlasov equations. The analytical formulas and numerical simulations confirm that the analysis is reduced to the formulation of an eigenvalue problem based on the known formulas of the complex frequency shifts for the uniform filling pattern case.« less

Infrastructure development for radioactive materials at the NSLS-II

DOE PAGES

Sprouster, David J.; Weidner, R.; Ghose, S. K.; ...

2017-11-04

The X-ray Powder Diffraction (XPD) Beamline at the National Synchrotron Light Source-II is a multipurpose instrument designed for high-resolution, high-energy X-ray scattering techniques. In this paper, the capabilities, opportunities and recent developments in the characterization of radioactive materials at XPD are described. The overarching goal of this work is to provide researchers access to advanced synchrotron techniques suited to the structural characterization of materials for advanced nuclear energy systems. XPD is a new beamline providing high photon flux for X-ray Diffraction, Pair Distribution Function analysis and Small Angle X-ray Scattering. The infrastructure and software described here extend the existing capabilitiesmore » at XPD to accommodate radioactive materials. Such techniques will contribute crucial information to the characterization and quantification of advanced materials for nuclear energy applications. Finally, we describe the automated radioactive sample collection capabilities and recent X-ray Diffraction and Small Angle X-ray Scattering results from neutron irradiated reactor pressure vessel steels and oxide dispersion strengthened steels.« less

Tests of monolithic active pixel sensors at national synchrotron light source

NASA Astrophysics Data System (ADS)

Deptuch, G.; Besson, A.; Carini, G. A.; Siddons, D. P.; Szelezniak, M.; Winter, M.

2007-01-01

The paper discusses basic characterization of Monolithic Active Pixel Sensors (MAPS) carried out at the X12A beam-line at National Synchrotron Light Source (NSLS), Upton, NY, USA. The tested device was a MIMOSA V (MV) chip, back-thinned down to the epitaxial layer. This 1M pixels device features a pixel size of 17×17 μm2 and was designed in a 0.6 μm CMOS process. The X-ray beam energies used range from 5 to 12 keV. Examples of direct X-ray imaging capabilities are presented.

Remote Access to the PXRR Macromolecular Crystallography Facilities at the NSLS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soares, A.S.; Schneider, D. K.; Skinner, J. M.

2008-09-01

The most recent surge of innovations that have simplified and streamlined the process of determining macromolecular structures by crystallography owes much to the efforts of the structural genomics community. However, this was only the last step in a long evolution that saw the metamorphosis of crystallography from an heroic effort that involved years of dedication and skill into a straightforward measurement that is occasionally almost trivial. Many of the steps in this remarkable odyssey involved reducing the physical labor that is demanded of experimenters in the field. Other steps reduced the technical expertise required for conducting those experiments.

Remote Access to the PXRR Macromolecular Crystallography Facilities at the NSLS

DOE Office of Scientific and Technical Information (OSTI.GOV)

A Soares; D Schneider; J Skinner

2011-12-31

The most recent surge of innovations that have simplified and streamlined the process of determining macromolecular structures by crystallography owes much to the efforts of the structural genomics community. However, this was only the last step in a long evolution that saw the metamorphosis of crystallography from an heroic effort that involved years of dedication and skill into a straightforward measurement that is occasionally almost trivial. Many of the steps in this remarkable odyssey involved reducing the physical labor that is demanded of experimenters in the field. Other steps reduced the technical expertise required for conducting those experiments.

Nm-scale spatial resolution x-ray imaging with MLL nanofocusing optics: instrumentational requirements and challenges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nazaretski, E.; Yan, H.; Lauer, K.

2016-08-30

The Hard X-ray Nanoprobe (HXN) beamline at NSLS-II has been designed and constructed to enable imaging experiments with unprecedented spatial resolution and detection sensitivity. The HXN X-ray Microscope is a key instrument for the beamline, providing a suite of experimental capabilities which includes scanning fluorescence, diffraction, differential phase contrast and ptychography utilizing Multilayer Laue Lenses (MLL) and zoneplate (ZP) as nanofocusing optics. In this paper, we present technical requirements for the MLL-based scanning microscope, outline the development concept and present first ~15 x 15 nm 2 spatial resolution x-ray fluorescence images.

Pushing x-ray photon correlation spectroscopy beyond the continuous frame rate limit

DOE PAGES

Dufresne, Eric M.; Narayanan, Suresh; Sandy, Alec R.; ...

2016-01-06

We demonstrate delayed-frame X-ray Photon Correlation Spectroscopy with 120 microsecond time resolution, limited only by sample scattering rates, with a prototype Pixel-array detector capable of taking two image frames separated by 153 ns or less. Although the overall frame rate is currently limited to about 4 frame pairs per second, we easily measured millisecond correlation functions. In conclusion, this technology, coupled to the use of brighter synchrotrons such as Petra III or the NSLS-II should enable X-ray Photon Correlation Spectroscopy on microsecond time scales on a wider variety of materials.

Shear induced structures in crystallizing cocoa butter

NASA Astrophysics Data System (ADS)

Mazzanti, Gianfranco; Guthrie, Sarah E.; Sirota, Eric B.; Marangoni, Alejandro G.; Idziak, Stefan H. J.

2004-03-01

Cocoa butter is the main structural component of chocolate and many cosmetics. It crystallizes in several polymorphs, called phases I to VI. We used Synchrotron X-ray diffraction to study the effect of shear on its crystallization. A previously unreported phase (phase X) was found and a crystallization path through phase IV under shear was observed. Samples were crystallized under shear from the melt in temperature controlled Couette cells, at final crystallization temperatures of 17.5^oC, 20^oC and 22.5^oC in Beamline X10A of NSLS. The formation of phase X was observed at low shear rates (90 s-1) and low crystallization temperature (17.5^oC), but was absent at high shear (720 s-1) and high temperature (20^oC). The d-spacing and melting point suggest that this new phase is a mixture rich on two of the three major components of cocoa butter. We also found that, contrary to previous reports, the transition from phase II to phase V can happen through the intermediate phase IV, at high shear rates and temperature.

Multi-MW accelerator target material properties under proton irradiation at Brookhaven National Laboratory linear isotope producer

DOE PAGES

Simos, N.; Ludewig, H.; Kirk, H.; ...

2018-05-29

The effects of proton beams irradiating materials considered for targets in high-power accelerator experiments have been studied using the Brookhaven National Laboratory’s (BNL) 200 MeV proton linac. A wide array of materials and alloys covering a wide range of the atomic number (Z) are being scoped by the high-power accelerator community prompting the BNL studies to focus on materials representing each distinct range, i.e. low-Z, mid-Z and high-Z. The low range includes materials such as beryllium and graphite, the midrange alloys such as Ti-6Al-4V, gum metal and super-Invar and finally the high-Z range pure tungsten and tantalum. Of interest inmore » assessing proton irradiation effects are (a) changes in physiomechanical properties which are important in maintaining high-power target functionality, (b) identification of possible limits of proton flux or fluence above which certain materials cease to maintain integrity, (c) the role of material operating temperature in inducing or maintaining radiation damage reversal, and (d) phase stability and microstructural changes. The paper presents excerpt results deduced from macroscopic and microscopic post-irradiation evaluation (PIE) following several irradiation campaigns conducted at the BNL 200 MeV linac and specifically at the isotope producer beam-line/target station. The microscopic PIE relied on high energy x-ray diffraction at the BNL NSLS X17B1 and NSLS II XPD beam lines. The studies reveal the dramatic effects of irradiation on phase stability in several of the materials, changes in physical properties and ductility loss as well as thermally induced radiation damage reversal in graphite and alloys such as super-Invar.« less

Multi-MW accelerator target material properties under proton irradiation at Brookhaven National Laboratory linear isotope producer

NASA Astrophysics Data System (ADS)

Simos, N.; Ludewig, H.; Kirk, H.; Dooryhee, E.; Ghose, S.; Zhong, Z.; Zhong, H.; Makimura, S.; Yoshimura, K.; Bennett, J. R. J.; Kotsinas, G.; Kotsina, Z.; McDonald, K. T.

2018-05-01

The effects of proton beams irradiating materials considered for targets in high-power accelerator experiments have been studied using the Brookhaven National Laboratory's (BNL) 200 MeV proton linac. A wide array of materials and alloys covering a wide range of the atomic number (Z) are being scoped by the high-power accelerator community prompting the BNL studies to focus on materials representing each distinct range, i.e. low-Z, mid-Z and high-Z. The low range includes materials such as beryllium and graphite, the midrange alloys such as Ti-6Al-4V, gum metal and super-Invar and finally the high-Z range pure tungsten and tantalum. Of interest in assessing proton irradiation effects are (a) changes in physiomechanical properties which are important in maintaining high-power target functionality, (b) identification of possible limits of proton flux or fluence above which certain materials cease to maintain integrity, (c) the role of material operating temperature in inducing or maintaining radiation damage reversal, and (d) phase stability and microstructural changes. The paper presents excerpt results deduced from macroscopic and microscopic post-irradiation evaluation (PIE) following several irradiation campaigns conducted at the BNL 200 MeV linac and specifically at the isotope producer beam-line/target station. The microscopic PIE relied on high energy x-ray diffraction at the BNL NSLS X17B1 and NSLS II XPD beam lines. The studies reveal the dramatic effects of irradiation on phase stability in several of the materials, changes in physical properties and ductility loss as well as thermally induced radiation damage reversal in graphite and alloys such as super-Invar.

Speciation and Elemental Mapping of Metal Containing Aerosols

NASA Astrophysics Data System (ADS)

Fraund, M. W.; Moffet, R.; Harder, T.; Williams, G.; Chen-Wiegart, Y. C. K.; Laskin, A.; Gilles, M. K.; Schoonen, M. A.; Thieme, J.

2017-12-01

Transition metals play a key roles in biogeochemical processes and health effects of aerosols. The Submicron Resolution X-ray (SRX) beamline at the second National Synchrotron Light Source (NSLS-II) can be used to obtain spatially resolved elemental composition using X-ray fluorescence (XRF) as well as element specific molecular information through X-ray absorption near edge structure (XANES) spectroscopy. Here, XANES spectroscopy was used to identify the oxidation state of iron-rich particles collected from the Cape Hedo Observatory on the island of Okinawa, Japan which is subject to aerosols from both biogenic (Gobi desert) and anthropogenic sources (e.g. Beijing and Shanghai). This data was compared with standards to help classify the minerology and source of these aerosol particles with regards to their potential solubility and bioavailability. In another application of the XRF/XANES measurements from NSLS-II, Pb rich particles from Mexico City were probed for distribution and speciation of Pb. Prior study has indicated that elevated concentrations of Pb occur in an industrialized section of northern Mexico City. It has been established that Pb and Zn are internally mixed in atmospheric aerosol and that Zn primarily exists as ZnCl2 and Zn(NO3)2. Based on these observations, it is hypothesized that Pb also exists as PbCl2 and Pb(NO3)­2. In this study it is shown that X-ray absorption near edge structure (XANES) spectroscopy at the Pb L-edge supports Pb being present as PbCl2 and Pb(NO3)2. Submicron resolution X-ray fluorescence mapping is also used to provide complimentary information on the collocation of other high-Z elements.

Multi-MW accelerator target material properties under proton irradiation at Brookhaven National Laboratory linear isotope producer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simos, N.; Ludewig, H.; Kirk, H.

The effects of proton beams irradiating materials considered for targets in high-power accelerator experiments have been studied using the Brookhaven National Laboratory’s (BNL) 200 MeV proton linac. A wide array of materials and alloys covering a wide range of the atomic number (Z) are being scoped by the high-power accelerator community prompting the BNL studies to focus on materials representing each distinct range, i.e. low-Z, mid-Z and high-Z. The low range includes materials such as beryllium and graphite, the midrange alloys such as Ti-6Al-4V, gum metal and super-Invar and finally the high-Z range pure tungsten and tantalum. Of interest inmore » assessing proton irradiation effects are (a) changes in physiomechanical properties which are important in maintaining high-power target functionality, (b) identification of possible limits of proton flux or fluence above which certain materials cease to maintain integrity, (c) the role of material operating temperature in inducing or maintaining radiation damage reversal, and (d) phase stability and microstructural changes. The paper presents excerpt results deduced from macroscopic and microscopic post-irradiation evaluation (PIE) following several irradiation campaigns conducted at the BNL 200 MeV linac and specifically at the isotope producer beam-line/target station. The microscopic PIE relied on high energy x-ray diffraction at the BNL NSLS X17B1 and NSLS II XPD beam lines. The studies reveal the dramatic effects of irradiation on phase stability in several of the materials, changes in physical properties and ductility loss as well as thermally induced radiation damage reversal in graphite and alloys such as super-Invar.« less

Omega Dante Soft X-Ray Power Diagnostic Component Calibration at the National Synchrotron Light Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campbell, K; Weber, F; Dewald, E

2004-04-15

The Dante soft x-ray spectrometer installed on the Omega laser facility at the Laboratory for Laser Energetics, University of Rochester is a twelve-channel filter-edge defined x-ray power diagnostic. It is used to measure the absolute flux from direct drive, indirect drive (hohlraums) and other plasma sources. Calibration efforts using two beam lines, U3C (50eV-1keV) and X8A (1keV-6keV) at the National Synchrotron Light Source (NSLS) have been implemented to insure the accuracy of these measurements. We have calibrated vacuum x-ray diodes, mirrors and filters.

Zone plate lenses for X-ray microscopy

NASA Astrophysics Data System (ADS)

Vladimirsky, Y.; Kern, D. P.; Chang, T. H. P.; Attwood, D. T.; Iskander, N.; Rothman, S.; McQuaide, K.; Kirz, J.; Ade, H.; McNulty, I.; Rarback, H.; Shu, D.

1988-04-01

Fresnel zone plate lenses with feature sizes as small as 50 nm have been constructed and used in the Stony Brook/NSLS scanning X-ray microscope with 3.1 nm radiation from Brookhaven's X-17 mini-undulator. The zone plates were fabricated at IBM using electron beam writing techniques, moiré pattern techniques to monitor ellipticity, and a double development/double plating technique to provide additional thickness in the central region. A spatial resolution down to 75 nm was measured in the microscope. Using these zone plates, biological images were obtained of unaltered subcellular components. The images highlight protein concentration in unsectioned, unfixed, and unstained enzymatic granules in an aqueous environment.

Self-consistent Simulations and Analysis of the Coupled-Bunch Instability for Arbitrary Multi-Bunch Configurations

DOE PAGES

Bassi, Gabriele; Blednykh, Alexei; Smalyuk, Victor

2016-02-24

A novel algorithm for self-consistent simulations of long-range wakefield effects has been developed and applied to the study of both longitudinal and transverse coupled-bunch instabilities at NSLS-II. The algorithm is implemented in the new parallel tracking code space (self-consistent parallel algorithm for collective effects) discussed in the paper. The code is applicable for accurate beam dynamics simulations in cases where both bunch-to-bunch and intrabunch motions need to be taken into account, such as chromatic head-tail effects on the coupled-bunch instability of a beam with a nonuniform filling pattern, or multibunch and single-bunch effects of a passive higher-harmonic cavity. The numericalmore » simulations have been compared with analytical studies. For a beam with an arbitrary filling pattern, intensity-dependent complex frequency shifts have been derived starting from a system of coupled Vlasov equations. The analytical formulas and numerical simulations confirm that the analysis is reduced to the formulation of an eigenvalue problem based on the known formulas of the complex frequency shifts for the uniform filling pattern case.« less

Synchrotron topography project. Progress report, January 20, 1982-October 20, 1982

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bilello, J.C.; Chen, H.; Hmelo, A.B.

1982-01-01

The collaborators have participated in the Synchrotron Topography Project (STP) which has designed and developed instrumentation for an x-ray topography station at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL). The two principle instruments constructed consist of a White Beam Camera (WBC) and a Multiple Crystal Camera (MCC) with high planar collimation and wide area image coverage. It is possible to perform in-situ studies in a versatile environmental chamber equipped with a miniature mechanical testing stage for both the WBC and MCC systems. Real-time video imaging plus a rapid feed cassette holder for high resolution photographic platesmore » are available for recording topographs. Provisions are made for other types of photon detection as well as spectroscopy. The facilities for the entire station have been designed for remote operation using a LSI-11/23 plus suitable interfacing. These instruments will be described briefly and the current status of the program will be reviewed. The Appendix of this report presents titles, authors and abstracts of other technical work associated with this project during the current period.« less

Sirepo for Synchrotron Radiation Workshop

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagler, Robert; Moeller, Paul; Rakitin, Maksim

Sirepo is an open source framework for cloud computing. The graphical user interface (GUI) for Sirepo, also known as the client, executes in any HTML5 compliant web browser on any computing platform, including tablets. The client is built in JavaScript, making use of the following open source libraries: Bootstrap, which is fundamental for cross-platform web applications; AngularJS, which provides a model–view–controller (MVC) architecture and GUI components; and D3.js, which provides interactive plots and data-driven transformations. The Sirepo server is built on the following Python technologies: Flask, which is a lightweight framework for web development; Jinja, which is a secure andmore » widely used templating language; and Werkzeug, a utility library that is compliant with the WSGI standard. We use Nginx as the HTTP server and proxy, which provides a scalable event-driven architecture. The physics codes supported by Sirepo execute inside a Docker container. One of the codes supported by Sirepo is the Synchrotron Radiation Workshop (SRW). SRW computes synchrotron radiation from relativistic electrons in arbitrary magnetic fields and propagates the radiation wavefronts through optical beamlines. SRW is open source and is primarily supported by Dr. Oleg Chubar of NSLS-II at Brookhaven National Laboratory.« less

Low-frequency quadrupole impedance of undulators and wigglers

DOE PAGES

Blednykh, A.; Bassi, G.; Hidaka, Y.; ...

2016-10-25

An analytical expression of the low-frequency quadrupole impedance for undulators and wigglers is derived and benchmarked against beam-based impedance measurements done at the 3 GeV NSLS-II storage ring. The adopted theoretical model, valid for an arbitrary number of electromagnetic layers with parallel geometry, allows to calculate the quadrupole impedance for arbitrary values of the magnetic permeability μ r. Here, in the comparison of the analytical results with the measurements for variable magnet gaps, two limit cases of the permeability have been studied: the case of perfect magnets (μ r → ∞), and the case in which the magnets are fullymore » saturated (μ r = 1).« less

A method for simultaneous linear optics and coupling correction for storage rings with turn-by-turn beam position monitor data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Xi; Huang, Xiaobiao

2016-05-13

Here, we propose a method to simultaneously correct linear optics errors and linear coupling for storage rings using turn-by-turn (TbT) beam position monitor (BPM) data. The independent component analysis (ICA) method is used to isolate the betatron normal modes from the measured TbT BPM data. The betatron amplitudes and phase advances of the projections of the normal modes on the horizontal and vertical planes are then extracted, which, combined with dispersion measurement, are used to fit the lattice model. The fitting results are used for lattice correction. Finally, the method has been successfully demonstrated on the NSLS-II storage ring.

A method for simultaneous linear optics and coupling correction for storage rings with turn-by-turn beam position monitor data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Xi; Huang, Xiaobiao

2016-08-01

We propose a method to simultaneously correct linear optics errors and linear coupling for storage rings using turn-by-turn (TbT) beam position monitor (BPM) data. The independent component analysis (ICA) method is used to isolate the betatron normal modes from the measured TbT BPM data. The betatron amplitudes and phase advances of the projections of the normal modes on the horizontal and vertical planes are then extracted, which, combined with dispersion measurement, are used to fit the lattice model. Furthermore, the fitting results are used for lattice correction. Our method has been successfully demonstrated on the NSLS-II storage ring.

A method for simultaneous linear optics and coupling correction for storage rings with turn-by-turn beam position monitor data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Xi; Huang, Xiaobiao

2016-08-01

We propose a method to simultaneously correct linear optics errors and linear coupling for storage rings using turn-by-turn (TbT) beam position monitor (BPM) data. The independent component analysis (ICA) method is used to isolate the betatron normal modes from the measured TbT BPM data. The betatron amplitudes and phase advances of the projections of the normal modes on the horizontal and vertical planes are then extracted, which, combined with dispersion measurement, are used to fit the lattice model. The fitting results are used for lattice correction. The method has been successfully demonstrated on the NSLS-II storage ring.

Functionalizing Designer DNA Crystals

NASA Astrophysics Data System (ADS)

Chandrasekaran, Arun Richard

Three-dimensional crystals have been self-assembled from a DNA tensegrity triangle via sticky end interaction. The tensegrity triangle is a rigid DNA motif containing three double helical edges connected pair-wise by three four-arm junctions. The symmetric triangle contains 3 unique strands combined in a 3:3:1 ratio: 3 crossover, 3 helical and 1 central. The length of the sticky end reported previously was two nucleotides (nt) (GA:TC) and the motif with 2-helical turns of DNA per edge diffracted to 4.9 A at beam line NSLS-X25 and to 4 A at beam line ID19 at APS. The purpose of these self-assembled DNA crystals is that they can be used as a framework for hosting external guests for use in crystallographic structure solving or the periodic positioning of molecules for nanoelectronics. This thesis describes strategies to improve the resolution and to incorporate guests into the 3D lattice. The first chapter describes the effect of varying sticky end lengths and the influence of 5'-phosphate addition on crystal formation and resolution. X-ray diffraction data from beam line NSLS-X25 revealed that the crystal resolution for 1-nt (G:C) sticky end was 3.4 A. Motifs with every possible combination of 1-nt and 2-nt sticky-ended phosphorylated strands were crystallized and X-ray data were collected. The position of the 5'-phosphate on either the crossover (strand 1), helical (strand 2), or central strand (3) had an impact on the resolution of the self-assembled crystals with the 1-nt 1P-2-3 system diffracting to 2.62 A at APS and 3.1 A at NSLS-X25. The second chapter describes the sequence-specific recognition of DNA motifs with triplex-forming oligonucleotides (TFOs). This study examined the feasibility of using TFOs to bind to specific locations within a 3-turn DNA tensegrity triangle motif. The TFO 5'-TTCTTTCTTCTCT was used to target the tensegrity motif containing an appropriately embedded oligopurine.oligopyrimidine binding site. As triplex formation involving cytidine nucleotides is usually pH dependent (pH < 6) four different TFOs were examined: TFO-1 was unmodified while TFOs 2-4 contained additional stabilizing analogues capable of extending triplex formation to pH 7. In addition, each of the TFOs contained a Cy5 dye at the 5'-end of the oligonucleotide to aid in characterization of TFO binding - crystals were obtained with all four variations of TFOs. Formation of DNA triplex in the motif was characterized by an electrophoretic mobility shift assay (EMSA), UV melting studies and FRET. Crystals containing TFO-1 (unmodified) and TFO-2 (with 2'-amino ethoxy modification) were isolated and flash-frozen in liquid nitrogen for X-ray data collection at beam line NSLS-X25. X-ray data was also collected for crystals of the 3-turn triangle without any TFO bound to it. Difference maps were done between the crystals with TFO against the one without to identify any additional electron density corresponding to the third strand in the triplex binding region. The data from the crystal containing TFO-2 was used to further analyze if the additional density can match the expected position of the TFO on the triangle motif. Since the additional density did not correspond to the entire binding region, 2Fo-Fc, 3Fo-2Fc and 4Fo-3Fc maps were done to check for missing pieces of the electron density. From the resulting 2Fo-Fc map, the asymmetric unit from the 3-turn triangle (31-bp duplex model based on previous structure 3UBI) was inserted into the density as a reference. However, the electron density corresponding to the TFO was still not continuous throughout the 13-nt triplex binding region and allowed only a partial fit of the TFO. The third nucleotide in positions 1, 3, 4, 6, 7 were fit into the density in the major groove of the underlying duplex with proper triplex configuration. The third chapter describes the triplex approach to position a functional group (the UV cross-linking agent psoralen) within a pre-formed DNA motif. Triplex formation and psoralen cross-linking of the motif were analyzed by native and denaturing gel electrophoresis respectively. Motifs containing the Psoralen-TFO were also successfully crystallized and the crosslinking shown by analyzing the denatured crystals on a gel. The end goal would be to form a crosslinked designed DNA crystal that can diffract to a higher resolution. The fourth chapter describes the use of serial femtosecond crystallography for structure determination of designed DNA lattices. X-ray diffraction data from self-assembled 3D DNA microcrystals were collected from a stream of crystals in solution. Serial femtosecond crystallography eliminates the need for large crystals and the need for freezing, thus overcoming any associated crystal defects and radiation damage. Self-assembled nano/microcrystals were successfully made and were diffracted at room temperature. The best diffraction was from the 1-nt SE motif to an extent of 3.5 A in resolution.

Sample environment for in situ synchrotron XRD measurements for CO2 interaction with subsurface materials

NASA Astrophysics Data System (ADS)

Elbakhshwan, M.; Gill, S.; Weidner, R.; Ecker, L.

2017-12-01

Sequestration of CO2 in geological formations requires a deep understanding of its interaction with the cement-casing components in the depleted oil and gas wells. Portland cement is used to seal the wellbores; however it tends to interact with the CO2. Therefore it is critical to investigate the wellbore integrity over long term exposure to CO2. Studies showed that, CO2 leakage is due to the flow through the casing-cement microannulus, cement-cement fractures, or the cement-caprock interface. The objective of this work is to gain a better understanding of the dissolution process of the cement-casing in the CO2 flow channels alongside with the carbonation reactions at the interfaces using XRF, XANES and X-ray tomography techniques. In this study, a synthetic wellbore system, consisting of cement with an embedded rectangular length of steel casing that had grooves to accommodate fluid flow, was used to investigate the casing-cement microannulus through core-flood experiments. The objective of this work is to gain a better understanding of the dissolution process of the cement-casing in the CO2 flow channels alongside with the carbonation reactions at the interfaces using a sample environment designed and built for in situ X-ray diffraction in the National Synchrotron Light Source II (NSLS II). The formation of carbonate phases at cement -fluid and cement-steel/fluid interfaces will be monitored in real time. Samples may be exposed to super critical CO2 at pressures above 1100 psi and temperatures around 50°C. The reaction cell is built from hastealloy to provide corrosion resistance, while the experimental temperature and pressure are controlled with thermocouples and pressure vessel.

Nuclear Bragg scattering studies in [sup 57]Fe with synchrotron radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haustein, P.E.

1993-01-01

Studies of nuclear Bragg x-ray scattering of synchrotron radiation, using crystals of [alpha]-[sup 57]Fe[sub 2]O[sub 3], have been carried out at the NSLS at Brookhaven National Laboratory and at the Cornell University CHESS facility. These studies have demonstrated that nuclear resonance states can be used to produce filtered x-ray beams which have extremely narrow bandwidth, small angular divergence and unique polarization and temporal properties. this combination of characteristics, unobtainable with radioactive sources, makes synchrotron-based Moessbauer spectroscopy feasible and is an important complement to existing methods. A review of the experimental methodology is presented. As well as come suggestions for fullermore » exploitation of this new technique.« less

Nuclear Bragg scattering studies in {sup 57}Fe with synchrotron radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haustein, P.E.

1993-03-01

Studies of nuclear Bragg x-ray scattering of synchrotron radiation, using crystals of {alpha}-{sup 57}Fe{sub 2}O{sub 3}, have been carried out at the NSLS at Brookhaven National Laboratory and at the Cornell University CHESS facility. These studies have demonstrated that nuclear resonance states can be used to produce filtered x-ray beams which have extremely narrow bandwidth, small angular divergence and unique polarization and temporal properties. this combination of characteristics, unobtainable with radioactive sources, makes synchrotron-based Moessbauer spectroscopy feasible and is an important complement to existing methods. A review of the experimental methodology is presented. As well as come suggestions for fullermore » exploitation of this new technique.« less

Comparing olivine single crystal and polycrystal rheology: evidence for supplementary accommodation mechanisms at grain boundaries

NASA Astrophysics Data System (ADS)

Bollinger, C.; Merkel, S.; Raterron, P.; Castelnau, O.; Detrez, F.

2013-12-01

Rheology in the Earth's upper-mantle is mostly constrained by the plastic properties of olivine. Over recent years, several groups have been carrying out deformation experiments on single crystals and polycrystals of olivine at upper mantle pressure (P) and temperature (T). Yet, the rheology of olivine at mantle conditions is still not well constrained. We carried out deformation experiments on San Carlos olivine polycrystals, at P and T ranging from 3 to 8 GPa and 1373 to 1673 K, respectively, and at strain rates ranging from 10-6 to 10-4 s-1, using the D-DIA apparatus installed at the NSLS X17B2 beamline (NY, USA). The deformation rates of the polycrystals are compared to those of single crystals oriented along the soft orientations [110]c, [011]c, [101]c which activate the easiest slip systems (Raterron et al., 2012). This comparison suggests that, in olivine polycrystals deforming in the dislocation creep regime, other relaxation mechanisms need to be considered to account for the observed polycrystal strain rates. This highlights the importance of supplementary mechanisms, such as those occurring at grain boundaries, to properly model olivine aggregates plasticity.

Fast and precise technique for magnet lattice correction via sine-wave excitation of fast correctors

DOE PAGES

Yang, X.; Smaluk, V.; Yu, L. H.; ...

2017-05-02

A novel technique has been developed to improve the precision and shorten the measurement time of the LOCO (linear optics from closed orbits) method. This technique, named AC LOCO, is based on sine-wave (ac) beam excitation via fast correctors. Such fast correctors are typically installed at synchrotron light sources for the fast orbit feedback. The beam oscillations are measured by beam position monitors. The narrow band used for the beam excitation and measurement not only allows us to suppress effectively the beam position noise but also opens the opportunity for simultaneously exciting multiple correctors at different frequencies (multifrequency mode). Wemore » demonstrated at NSLS-II that AC LOCO provides better lattice corrections and works much faster than the traditional LOCO method.« less

High Temperature Mechanical Properties, Fractography and Synchrotron Studies of ATF clad materials from the UCSB-NSUF Irradiations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saleh, Tarik A.; Maloy, Stuart Andrew; Romero, Tobias J.

2015-02-23

A variety of tensile samples of Ferritic and Oxide Dispersion Strengthened (ODS or nanostructured ferritic) steels were placed the ATR reactor over 2 years achieving doses of roughly 4-6 dpa at temperatures of roughly 290°C. Samples were shipped to Wing 9 in the CMR facility at Los Alamos National Laboratory and imaged then tested in tension. This report summarizes the room temperature tensile tests, the elevated temperature tensile tests (300°C) and fractography and reduction of area calculations on those samples. Additionally small samples were cut from the undeformed grip section of these tensile samples and sent to the NSLS synchrotronmore » for high energy X-ray analysis, initial results will be described here.« less

Following the movement of Cu ions in a SSZ-13 zeolite during dehydration, reduction and adsorption: a combined in situ TP-XRD, XANES/DRIFTS study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kwak, Ja Hun; Varga, Tamas; Peden, Charles HF

2014-05-05

Cu-SSZ-13 has been shown to possess high activity and superior N2 formation selectivity in the selective catalytic reduction of NOx under oxygen rich conditions. Here, a combination of synchrotron-based (XRD and XANES) and vibrational (DRIFTS) spectroscopy tools have been used to follow the changes in the location and coordination environment of copper ions in a Cu-SSZ-13 zeolite during calcinations, reduction with CO, and adsorption of CO and H2O. XANES spectra collected during these procedures provides critical information not only on the variation in the oxidation state of the copper species in the zeolite structure, but also on the changes inmore » the coordination environment around these ions as they interact with the framework, and with different adsorbates (H2O and CO). Time-resolved XRD data indicate the movement of copper ions and the consequent variation of the unit cell parameters during dehydration. DRIFT spectra provide information about the adsorbed species present in the zeolite, as well as the oxidation states of and coordination environment around the copper ions. A careful analysis of the asymmetric T-O-T vibrations of the CHA framework perturbed by copper ions in different coordination environments proved to be especially informative. The results of this study will aid the identification of the location, coordination and oxidation states of copper ions obtained during in operando catalytic studies. Financial support was provided by the US Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Program. Part of this work (sample preparation) was performed in the Environmental Molecular Sciences Laboratory (EMSL) at Pacific Northwest National Laboratory (PNNL). The EMSL is a national scientific user facility supported by the US DOE, Office of Biological and Environmental Research. PNNL is a multi-program national laboratory operated for the US DOE by Battelle. All of the spectroscopy work reported here was carried out at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL). NSLS is a national scientific user facility supported by the US DOE.« less

Photocathodes for High Repetition Rate Light Sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ben-Zvi, Ilan

2014-04-20

This proposal brought together teams at Brookhaven National Laboratory (BNL), Lawrence Berkeley National Laboratory (LBNL) and Stony Brook University (SBU) to study photocathodes for high repetition rate light sources such as Free Electron Lasers (FEL) and Energy Recovery Linacs (ERL). Below details the Principal Investigators and contact information. Each PI submits separately for a budget through his corresponding institute. The work done under this grant comprises a comprehensive program on critical aspects of the production of the electron beams needed for future user facilities. Our program pioneered in situ and in operando diagnostics for alkali antimonide growth. The focus ismore » on development of photocathodes for high repetition rate Free Electron Lasers (FELs) and Energy Recovery Linacs (ERLs), including testing SRF photoguns, both normal-­conducting and superconducting. Teams from BNL, LBNL and Stony Brook University (SBU) led this research, and coordinated their work over a range of topics. The work leveraged a robust infrastructure of existing facilities and the support was used for carrying out the research at these facilities. The program concentrated in three areas: a) Physics and chemistry of alkali-­antimonide cathodes (BNL – LBNL) b) Development and testing of a diamond amplifier for photocathodes (SBU -­ BNL) c) Tests of both cathodes in superconducting RF photoguns (SBU) and copper RF photoguns (LBNL) Our work made extensive use of synchrotron radiation materials science techniques, such as powder-­ and single-­crystal diffraction, x-­ray fluorescence, EXAFS and variable energy XPS. BNL and LBNL have many complementary facilities at the two light sources associated with these laboratories (NSLS and ALS, respectively); use of these will be a major thrust of our program and bring our understanding of these complex materials to a new level. In addition, CHESS at Cornell will be used to continue seamlessly throughout the NSLS dark period and new diffraction facilities at ALS will be utilized. We also will continue to make use of the excellent analytical facilities at the CNF (BNL) and the Molecular Foundry (LBNL), where we have access to state of the art UHV XPS, SPM, SEM and scanning Auger microscopy.« less

X-ray induced damage observations in ZERODUR mirrors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takacs, P.Z.; Furenlid, K.; Furenlid, L.

1997-07-01

Catastrophic damage has been observed in some ZERODUR mirrors used as first mirrors in two beam lines at the National Synchrotron Light Source (NSLS). Despite the high reflectivity of the coatings used on these mirrors, a significant flux of high energy photons penetrates below the coating and is absorbed in the substrate. Although model calculations indicate that the local temperature does not increase significantly, the authors suspect that over long time periods the absorbed flux produces structural changes in the material, leading to a build-up of surface stress, gross figure changes, and growth of fractures. These changes are probably relatedmore » to the nature of the two-phase glass-ceramic composition of the ZERODUR material. Metal mirrors and single-phase materials do not exhibit such catastrophic damage under similar exposure conditions.« less

NSLS-II: Nonlinear Model Calibration for Synchrotrons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bengtsson, J.

This tech note is essentially a summary of a lecture we delivered to the Acc. Phys. Journal Club Apr, 2010. However, since the estimated accuracy of these methods has been naive and misleading in the field of particle accelerators, i.e., ignores the impact of noise, we will elaborate on this in some detail. A prerequisite for a calibration of the nonlinear Hamiltonian is that the quadratic part has been understood, i.e., that the linear optics for the real accelerator has been calibrated. For synchrotron light source operations, this problem has been solved by the interactive LOCO technique/tool (Linear Optics frommore » Closed Orbits). Before that, in the context of hadron accelerators, it has been done by signal processing of turn-by-turn BPM data. We have outlined how to make a basic calibration of the nonlinear model for synchrotrons. In particular, we have shown how this was done for LEAR, CERN (antiprotons) in the mid-80s. Specifically, our accuracy for frequency estimation was {approx} 1 x 10{sup -5} for 1024 turns (to calibrate the linear optics) and {approx} 1 x 10{sup -4} for 256 turns for tune footprint and betatron spectrum. For a comparison, the estimated tune footprint for stable beam for NSLS-II is {approx}0.1. Since the transverse damping time is {approx}20 msec, i.e., {approx}4,000 turns. There is no fundamental difference for: antiprotons, protons, and electrons in this case. Because the estimated accuracy for these methods in the field of particle accelerators has been naive, i.e., ignoring the impact of noise, we have also derived explicit formula, from first principles, for a quantitative statement. For e.g. N = 256 and 5% noise we obtain {delta}{nu} {approx} 1 x 10{sup -5}. A comparison with the state-of-the-arts in e.g. telecomm and electrical engineering since the 60s is quite revealing. For example, Kalman filter (1960), crucial for the: Ranger, Mariner, and Apollo (including the Lunar Module) missions during the 60s. Or Claude Shannon et al since the 40s for that matter. Conclusion: what's elementary in the latter is considered 'advanced', if at all, in the former. It is little surprise then that published measurements typically contains neither error bars (for the random errors) nor estimates for the systematic in the former discipline. We have also showed how to estimate the state space by turn-by-turn data from two adjacent BPMs. And how to improve the resolution of the nonlinear resonance spectrum by Fourier analyzing the linear action variables instead of the betatron motion. In fact, the state estimator could be further improved by adding a Kalman filter. For transparency, we have also summarized on how these techniques provide a framework- and method for a TQM (Total Quality Management) approach for the main ring. Of course, to make the ($2.5M) turn-by-turn data acquisition system that is being implemented (for all the BPMs) useful, a means ({approx}10% contingency for the BPM system) to drive the beam is obviously required.« less

Experimental Deformation of Enstatite Single Crystals at Mantle Pressure and Temperature

NASA Astrophysics Data System (ADS)

Raterron, P. C.; Holyoke, C. W.; Girard, J.

2012-12-01

Orthopyroxenes (OPx) is the second most abundant constituent of the upper mantle, thus may significantly influence mantle plasticity. However, little is known on OPx rheology at high pressure; this is because apparatuses allowing controlled deformation experiments at asthenospheric pressures (P > 3 GPa) are available since only a decade (see Raterron and Merkel, 2009, J. Synch. Rad., 16, 748-756). Mackwell (1991, GRL, 18, 2027-2030) reports a preliminary study of the high-temperature rheology of enstatite single crystals, but these experiments were carried out at room pressure, i.e. in the protoenstatite stability field, and the results cannot directly apply to mantle phases. In order to quantify the effect of pressure on OPx rheology, deformation experiments were carried out in compression on natural enstatite (En90) single crystals in the Deformation-DIA apparatus (D-DIA), at P > 5 GPa and high temperature (T > 1200°C) within the orthoenstatite stability field. The applied stress and specimen strain rates were measured in situ using X-ray diffraction and imaging techniques at the X17B2 beamline of the National Synchrotron Light Source (NSLS, NY, USA). The cylindrical specimens were oriented with their axis - the compression direction - along [101]c crystallographic direction which forms a 45° angle with both [100] and [001] directions. This geometry imposes during compression a maximum shear stress in (001) plane along [001] direction, which results in the activation of [001](001) dislocation slip system known as the weakest slip in OPx. Specimens were deformed together with other crystals or aggregates - two by two, one atop the other in the compression column - in order to compare [101]c crystal plasticity with that of either [011]c enstatite crystals - within which [001](010) slip system is activated - or enstatite aggregates, or again orientated San Carlos olivine crystals of known rheology. Run products microstructures were investigated by electron microscopy. We will present these results which bring new light on the activity of orthoenstatite dislocation slips at mantle P and T conditions.

Experimental Investigation of Superradiance in a Tapered Free-Electron Laser Amplifier

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hidaka, Y.; She, Y.; Murphy, J.B.

2011-03-28

We report experimental studies of the effect of undulator tapering on superradiance in a single-pass high-gain free-electron laser (FEL) amplifier. The experiments were performed at the Source Development Laboratory (SDL) of National Synchrotron Light Source (NSLS). Efficiency was nearly tripled with tapering. Both the temporal and spectral properties of the superradiant FEL along the uniform and tapered undulator were experimentally characterized using frequency-resolved optical gating (FROG) images. Numerical studies predicted pulse broadening and spectral cleaning by undulator tapering Pulse broadening was experimentally verified. However, spectral cleanliness degraded with tapering. We have performed first experiments with a tapered undulator and amore » short seed laser pulse. Pulse broadening with tapering expected from simulations was experimentally confirmed. However, the experimentally obtained spectra degraded with tapering, whereas the simulations predicted improvement. A further numerical study is under way to resolve this issue.« less

Storage Rings for Science with: Electron-Positron Collisions, Hadron Collisions and Synchrotron Light

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ozaki,S.

2009-05-04

The author is honored to receive the 2009 Robert Wilson Prize and the recognition that comes with it. The citation for the prize reads, 'For his outstanding contribution to the design and construction of accelerators that has led to the realization of major machines for fundamental science on two continents and his promotion of international collaboration.' In this article, he will discuss the two construction projects, which he led, one (TRISTAN e{sup +}e{sup -} Collider at KEK) in Japan and the other (RHIC at BNL) in the USA, covering project issues and lessons learned from these projects. Although both ofmore » them were built on separate continents, it is interesting to note that they are both built on long off-shore islands. He will also add comments on his recent engagement in the development of the Conceptual Design for the National Synchrotron Light Source II (NSLS-II).« less

Comparison of Finite Element Modeling and Experimental Pressure Distribution in a Diamond Anvil Cell

NASA Astrophysics Data System (ADS)

Kondrat'yev, Andreiy I.; Murphy, Michael J.; Weir, Samuel T.; Vohra, Yogesh K.

2002-10-01

Ultra high pressures can be obtained in a Diamond Anvil Cell (DAC) device by optimizing the geometrical shape of diamond anvil and by use of high strength gasket materials. Radial pressure distribution in a diamond-coated rhenium gasket was measured by the micro-collimated X-ray diffraction techniques at NSLS, Brookhaven National Laboratory up to peak pressure of 220 GPa. The process of DAC compression was described by finite element analysis using NIKE-2D software. The mechanical properties of the diamond-coated gasket material were modeled and radial pressure distribution obtained was in good agreement with the experimental data. The calculated shear stress in diamond in the axial direction was shown to depend strongly on the yield strength of the gasket material and may limit the ultimate pressure that can be obtained with the use of high strength gasket materials. Supported by the National Science Foundation (NSF) Grant No. DMR-0203779.

Potential High Resolution Dosimeters For MRT

NASA Astrophysics Data System (ADS)

Bräuer-Krisch, E.; Rosenfeld, A.; Lerch, M.; Petasecca, M.; Akselrod, M.; Sykora, J.; Bartz, J.; Ptaszkiewicz, M.; Olko, P.; Berg, A.; Wieland, M.; Doran, S.; Brochard, T.; Kamlowski, A.; Cellere, G.; Paccagnella, A.; Siegbahn, E. A.; Prezado, Y.; Martinez-Rovira, I.; Bravin, A.; Dusseau, L.; Berkvens, P.

2010-07-01

Microbeam Radiation Therapy (MRT) uses highly collimated, quasi-parallel arrays of X-ray microbeams of 50-600 keV, produced by 2nd and 3rd generation synchrotron sources, such as the National Synchrotron Light Source (NSLS) in the U.S., and the European Synchrotron Radiation Facility (ESRF) in France, respectively. High dose rates are necessary to deliver therapeutic doses in microscopic volumes, to avoid spreading of the microbeams by cardiosynchronous movement of the tissues. A small beam divergence and a filtered white beam spectrum in the energy range between 30 and 250 keV results in the advantage of steep dose gradients with a sharper penumbra than that produced in conventional radiotherapy. MRT research over the past 20 years has allowed a vast number of results from preclinical trials on different animal models, including mice, rats, piglets and rabbits. Microbeams in the range between 10 and 100 micron width show an unprecedented sparing of normal radiosensitive tissues as well as preferential damage to malignant tumor tissues. Typically, MRT uses arrays of narrow (˜25-100 micron-wide) microplanar beams separated by wider (100-400 microns centre-to-centre, c-t-c) microplanar spaces. We note that thicker microbeams of 0.1-0.68 mm used by investigators at the NSLS are still called microbeams, although some invesigators in the community prefer to call them minibeams. This report, however, limits it discussion to 25-100 μm microbeams. Peak entrance doses of several hundreds of Gy are surprisingly well tolerated by normal tissues. High resolution dosimetry has been developed over the last two decades, but typical dose ranges are adapted to dose delivery in conventional Radiation Therapy (RT). Spatial resolution in the sub-millimetric range has been achieved, which is currently required for quality assurance measurements in Gamma-knife RT. Most typical commercially available detectors are not suitable for MRT applications at a dose rate of 16000 Gy/s, micron resolution and a dose range over several orders of magnitude. This paper will give an overview of all dosimeters tested in the past at the ESRF with their advantages and drawbacks. These detectors comprise: Ionization chambers, Alanine Dosimeters, MOSFET detectors, Gafchromic® films, Radiochromic polymers, TLDs, Polymer gels, Fluorescent Nuclear Track Detectors (Al2O3:C, Mg single crystal detectors), OSL detectors and Floating Gate-based dosimetry system. The aim of such a comparison shall help with a decision on which of these approaches is most suitable for high resolution dose measurements in MRT. The principle of these detectors will be presented including a comparison for some dosimeters exposed with the same irradiation geometry, namely a 1×1 cm5 field size with microbeam exposures at the surface, 0.1 cm and 1 cm in depth of a PMMA phantom. For these test exposures, the most relevant irradiation parameters for future clinical trials have been chosen: 50 micron FWHM and 400 micron c-t-c distance. The experimental data are compared with Monte Carlo calculations.

Analysis of blind identification methods for estimation of kinetic parameters in dynamic medical imaging

NASA Astrophysics Data System (ADS)

Riabkov, Dmitri

Compartment modeling of dynamic medical image data implies that the concentration of the tracer over time in a particular region of the organ of interest is well-modeled as a convolution of the tissue response with the tracer concentration in the blood stream. The tissue response is different for different tissues while the blood input is assumed to be the same for different tissues. The kinetic parameters characterizing the tissue responses can be estimated by blind identification methods. These algorithms use the simultaneous measurements of concentration in separate regions of the organ; if the regions have different responses, the measurement of the blood input function may not be required. In this work it is shown that the blind identification problem has a unique solution for two-compartment model tissue response. For two-compartment model tissue responses in dynamic cardiac MRI imaging conditions with gadolinium-DTPA contrast agent, three blind identification algorithms are analyzed here to assess their utility: Eigenvector-based Algorithm for Multichannel Blind Deconvolution (EVAM), Cross Relations (CR), and Iterative Quadratic Maximum Likelihood (IQML). Comparisons of accuracy with conventional (not blind) identification techniques where the blood input is known are made as well. The statistical accuracies of estimation for the three methods are evaluated and compared for multiple parameter sets. The results show that the IQML method gives more accurate estimates than the other two blind identification methods. A proof is presented here that three-compartment model blind identification is not unique in the case of only two regions. It is shown that it is likely unique for the case of more than two regions, but this has not been proved analytically. For the three-compartment model the tissue responses in dynamic FDG PET imaging conditions are analyzed with the blind identification algorithms EVAM and Separable variables Least Squares (SLS). A method of identification that assumes that FDG blood input in the brain can be modeled as a function of time and several parameters (IFM) is analyzed also. Nonuniform sampling SLS (NSLS) is developed due to the rapid change of the FDG concentration in the blood during the early postinjection stage. Comparisons of accuracy of EVAM, SLS, NSLS and IFM identification techniques are made.

Olivine Instability: An Experimental View of Mechanism of Deep Earthquakes

NASA Astrophysics Data System (ADS)

Long, H.; Weidner, D.; Li, L.; Chen, J.; Wang, L.

2007-12-01

Olivine (¦Á-(Mg,Fe)2SiO4) is the major constituent of the upper mantle and the ocean lithosphere. In subduction zone, where the earthquakes happen, the rheology of slab is mainly controlled by that of olivine. Several different mechanisms for deep focus earthquakes have been suggested, which include olivine instability (Bridgman, 1936; Orowan, 1960; Post, 1977; Ogawa, 1987; Hobbs and Ord, 1988; Kao and Chen, 1995), shear-induced melting (Griggs, 1954, 1972; Griggs and Handin, 1960; Griggs and Baker, 1969), phase transformation (Bridgman, 1945; Benioff, 1963; Meade and Jeanloz, 1989), dehydration of hydrous specimens (Meade and Jeanloz, 1991), and olivine metastability-induced anticrack (Green and Houston, 1995). Since the low temperature of the ¡°cold¡± slab, which can be as low as 600¡ãC in transition zone, olivine may still exist there and thus its shear instability may still be the possible mechanism for the deep-focus earthquakes. In our experimental study on deformation of San Carlos olivine at subduction zone conditions carried out on a D-DIA apparatus, Sam85 at X17B2, NSLS, we observed that the transitional temperature between regimes of insensitive to temperature and sensitive to temperature can be as high as 900¡ãC or even higher for the annealed polycrystal olivine sample, while that for unannealed sample can be as low as 450¡ãC. Our results for the unannealed sample are consistent to the result of Raterron et al (2004), which is concluded from the relaxation experiments. The annealed and unannealed olivine can be present the natural olivine in non-fault systems and that in pre-existing fault systems in subduction zone, respectively. We therefore propose a new olivine instability model with a ¡°sandwich¡± formation for the deep focus earthquakes: In this model the pre-existing fault system is surrounded by the no-fault systems. When the slab dives down, the olivine in both systems undergoes a stress- build-up process and can hold very high stress in both cases. However, as it keeps diving to the transition zone, the slab is heated and its temperature arrives at the boundary temperature from the insensitive temperature regime to the sensitive to temperature regime for the olivine in pre-existing fault system. As a result, while the olivine in non-fault system is still in regime of insensitive to temperature and can still hold the built high stress, the olivine in pre-existing fault system can not hold the built stress any more and gives a stress release. The pre- existing fault is re-active and heat from the re-active fault accelerates the ongoing process. Earthquake happens.

Another Nobel Prize linked to synchrotron radiation work

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hasnain, S.

The 2008 Nobel Prize in Chemistry went to Osamu Shimomura, Martin Chalfie and Roger Tsien 'for the discovery and development of the green fluorescent protein, GFP'. This year's Nobel Prize in Chemistry rewards the initial discovery of GFP and a series of important developments which have led to its use as a tagging tool in bioscience. By using DNA technology, researchers can now connect GFP to other interesting, but otherwise invisible, proteins. This glowing marker allows the movements, positions and interactions of the tagged proteins to be monitored. Osamu Shimomura was the first to isolate GFP from the jellyfish Aequoreamore » victoria, found off the west coast of North America, and discovered the protein's green glow [Shimomura et al. (1962). J. Cell. Comp. Physiol. 59, 223-240]. Martin Chalfie demonstrated the value of GFP as a luminous genetic tag. In one of his first experiments he coloured six individual cells in the transparent roundworm Caenorhabditis elegans with the aid of GFP. He had obtained the GFP gene (gfp) clone from Prasher [Prasher et al. (1992). Gene, 111, 229-233] and expressed it in E. coli. The GFP protein displayed a bright green fluorescence in this heterologous organism, suggesting that it could indeed serve as a versatile genetic marker in virtually all organisms. Chalfie transformed C. elegans with gfp under the control of a promoter regulating the expression of {beta}-tubulin, abundant in six touch receptor neurons in C. elegans. The organism subsequently expressed GFP from distinct positions in its body and at distinct times in its development [Chalfie et al. (1994). Science, 263, 802-805]. Roger Tsien contributed to the general understanding of how GFP glows by determining the formation of the GFP chromophore, a chemical group that absorbs and emits light. Tsien is best known for extending the colour palette of GFP beyond green, allowing researchers to follow several different biological processes at the same time. According to background on the Nobel Prize website, 'An important step forward, allowing for rational design of mutants, was the solution of the crystal structure of GFP.' Tsien collaborated with Jim Remington and his team who solved the structure of GFP at 1.9 {angstrom} using data in part collected at NSLS beamline X4A. Tsien and Remington were able to use the structural information and design specific mutants (Thr203, to Tyr or His) which resulted in significantly red-shifted excitation and emission maxima and thus converting GFP into YFP (yellow fluorescence protein) [Ormo et al. (1996). Science, 273, 1392-1395]. Acknowledging the contribution of NSLS Brookhaven, University of Oregon scientist Remington said 'The data collected at beamline X4A were essential to solve the structure of GFP. We were unable to solve the structure using native and heavy-atom-derivative data sets collected at home'. Remington added 'In those days the technology to flash freeze crystals had not been fully worked out and so diffraction data had to be collected at temperatures above freezing. Crystal lifetime was very short. At X4A, a crystal cooling system enabled data collection at close to zero degrees Celsius, extending the crystal lifetime, while the intense beam permitted data to be collected at significantly higher resolution. In addition, the tunable nature of the source allowed us to collect data at the selenomethionine absorption edge, which dramatically improved the signal for phasing purposes. The improved phasing, combined with higher resolution data, resulted in an interpretable electron density map. The first look at the GFP chromophore in that electron density map was one of the most exciting moments of my entire career.'« less

Synchrotron-induced X-ray fluorescence from rat bone and lumber vertebra of different age groups

NASA Astrophysics Data System (ADS)

Rao, Donepudi V.; Swapna, Medasani; Cesareo, Roberto; Brunetti, Antonio; Akatsuka, Tako; Yuasa, Tetsuya; Takeda, Tohoru; Tromba, Giuliana; Gigante, Giovanni E.

2009-02-01

The fluorescence spectra from rat bones of different age groups (8, 56 and 78 weeks) and lumber vertebra were measured with 8, 10 and 12 keV synchrotron X-rays. We have utilized the new hard X-ray micro-spectroscopy beamline facility, X27A, available at NSLS with a primary beam spot size of the order of ˜10 μm. With this spatial resolution and high flux throughput, X-ray fluorescent intensities for Ca and other trace elements were measured using a liquid-nitrogen-cooled 13-element energy-dispersive high-purity germanium detector. Regarding the lumber vertebra, we acquired the fluorescence spectra from the left, right and middle portions and calcium accumulation was evaluated and compared with the other samples. We have identified the major trace elements of Ca, Ni, Fe and Zn and minor trace elements of Ti, Cr and Mn in the sample. The percentage of scattered radiation and trace element contributions from these samples were highlighted at different energies.

Performance of the PRAXyS X-Ray Polarimeter

NASA Technical Reports Server (NTRS)

Iwakiri, W. B.; Black, J. K.; Cole, R.; Enoto, T.; Hayato, A.; Hill, J. E.; Jahoda, Keith M.; Kaaret, P.; Kitaguchi, T.; Kubota, M.

2016-01-01

The performance of the Time Projection Chamber (TPC) polarimeter for the Polarimeter for Relativistic Astrophysical X-ray Sources (PRAXyS) Small Explorer was evaluated using polarized and unpolarized X-ray sources. The PRAXyS mission will enable exploration of the universe through X-ray polarimetry in the 2-10 keV energy band. We carried out performance tests of the polarimeter at the Brookhaven National Laboratory, National Synchrotron Light Source (BNL-NSLS) and at NASA's Goddard Space Flight Center. The polarimeter was tested with linearly polarized, monochromatic X-rays at 11 different energies between 2.5 and 8.0 keV. At maximum sensitivity, the measured modulation factors at 2.7, 4.5 and 8.0 keV are 27%, 43% and 59%, respectively and the measured angle of polarization is consistent with the expected value at all energies. Measurements with a broadband, unpolarized X-ray source placed a limit of less than 1% on false polarization in the PRAXyS polarimeter.

Performance of the PRAXyS X-ray polarimeter

NASA Astrophysics Data System (ADS)

Iwakiri, W. B.; Black, J. K.; Cole, R.; Enoto, T.; Hayato, A.; Hill, J. E.; Jahoda, K.; Kaaret, P.; Kitaguchi, T.; Kubota, M.; Marlowe, H.; McCurdy, R.; Takeuchi, Y.; Tamagawa, T.

2016-12-01

The performance of the Time Projection Chamber (TPC) polarimeter for the Polarimeter for Relativistic Astrophysical X-ray Sources (PRAXyS) Small Explorer was evaluated using polarized and unpolarized X-ray sources. The PRAXyS mission will enable exploration of the universe through X-ray polarimetry in the 2-10 keV energy band. We carried out performance tests of the polarimeter at the Brookhaven National Laboratory, National Synchrotron Light Source (BNL-NSLS) and at NASA's Goddard Space Flight Center. The polarimeter was tested with linearly polarized, monochromatic X-rays at 11 different energies between 2.5 and 8.0 keV. At maximum sensitivity, the measured modulation factors at 2.7, 4.5 and 8.0 keV are 27%, 43% and 59%, respectively and the measured angle of polarization is consistent with the expected value at all energies. Measurements with a broadband, unpolarized X-ray source placed a limit of less than 1% on false polarization in the PRAXyS polarimeter.

Report on in-situ studies of flash sintering of uranium dioxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raftery, Alicia Marie

Flash sintering is a novel type of field assisted sintering that uses an electric field and current to provide densification of materials on very short time scales. The potential for field assisted sintering techniques to be used in producing nuclear fuel is gaining recognition due to the potential economic benefits and improvements in material properties. The flash sintering behavior has so far been linked to applied and material parameters, but the underlying mechanisms active during flash sintering have yet to be identified. This report summarizes the efforts to investigate flash sintering of uranium dioxide using dilatometer studies at Los Alamosmore » National Laboratory and two separate sets of in-situ studies at Brookhaven National Laboratory’s NSLS-II XPD-1 beamline. The purpose of the dilatometer studies was to understand individual parameter (applied and material) effects on the flash behavior and the purpose of the in-situ studies was to better understand the mechanisms active during flash sintering. As far as applied parameters, it was found that stoichiometry, or oxygen-to-metal ratio, has a significant effect on the flash behavior (time to flash and speed of flash). Composite systems were found to have degraded sintering behavior relative to pure UO 2. The critical field studies are complete for UO 2.00 and will be analyzed against an existing model for comparison. The in-situ studies showed that the strength of the field and current are directly related to the sample temperature, with temperature-driven phase changes occurring at high values. The existence of an ‘incubation time’ has been questioned, due to a continuous change in lattice parameter values from the moment that the field is applied. Some results from the in-situ experiments, which should provide evidence regarding ion migration, are still being analyzed. Some preliminary conclusions can be made from these results with regard to using field assisted sintering to fabricate nuclear fuel. First, the pure UO 2-based system shows promising behavior with flash sintering, but composite systems are likely to show better sintering behavior with spark plasma sintering. Efforts to develop these methods should therefore be tailored towards the likelihood of success. Additionally, modeling is a rapidly developing aspect of current flash sintering research and should be used in parallel with experiments. Ultimately, ongoing flash sintering studies on various materials, like those summarized in this report, are rapidly contributing to the feasibility of controlling this method for use in the future.« less

Deformation of Olivine at Subduction Zone Conditions Determined from In situ Measurements with Synchrotron Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

H Long; D Weidner; L Li

2011-12-31

We report measurements of the deformation stress for San Carlos olivine at pressures of 3-5 GPa, temperatures of 25-1150 C, and strain rates of 10{sup -7}-10{sup -5} s{sup -1}. We determine a deformation stress of approximately 2.5 GPa that is relatively temperature and strain rate independent in the temperature range of 400-900 C. The deformation experiments have been carried out on a deformation DIA (D-DIA) apparatus, Sam85, at X17B2, NSLS. Powder samples are used in these experiments. Enstatite (MgSiO{sub 3}) (3-5% total quality of sample) is used as the buffer to control the activity of silica. Ni foil is usedmore » in some experiments to buffer the oxygen fugacity. Water content is confirmed by IR spectra of the recovered samples. Samples are compressed at room temperature and are then annealed at 1200 C for at least 2 h before deformation. The total (plastic and elastic) strains (macroscopic) are derived from the direct measurements of the images taken by X-ray radiograph technique. The differential stresses are derived from the diffraction determined elastic strains. In the regime of 25-400 C, there is a small decrease of stress at steady state as temperature increases; in the regime of 400 C to the 'transition temperature', the differential stress at steady state ({approx}2.5 GPa) is relatively insensitive to the changes of temperature and strain rate; however, it drastically decreases to about 1 GPa and becomes temperature-dependent above the transition temperature and thereafter. The transition temperature is near 900 C. Above the transition temperature, the flow agrees with power law creep measurements of previous investigations. The anisotropy of differential stress in individual planes indicates that the deformation of olivine at low temperature is dominated by [0 0 1](1 0 0). Accounting to a slower strain rate in the natural system, the transition temperature for the olivine in the slab is most likely in the range of 570-660 C.« less

Fine tune of elasticity and plasticity of olivine by water: a key to reconcile discrepancy between mineral physics and seismology models

NASA Astrophysics Data System (ADS)

Chen, J.; Girard, J.

2012-12-01

Study of mechanical properties of mantle minerals has unveiled many mysteries of Earth's interior alluded through seismic events. However, some details of seismic models remain unexplained. For instance, magnitude of seismic discontinuity at 410 km depth in seismic models is significantly larger than that derived from elastic properties of dominant minerals at such depth. For another example, although the attenuation of seismic anisotropy in the upper mantle at about 200-220 km depth can be attributed to switchover of active dislocation slip system in the dominant mineral, olivine, the depth and its variation are discrepant from that derived from the pressure at which such switchover is observed in the deformation experiment of mineral plasticity study. We have investigated influence of water on elastic and plastic behaviors of olivine through equation of state and rheological creep experiments using synchrotron x-rays at the X17C and X17B2 beamlines of the NSLS. Results indicate water significantly weakens the mineral. Elastically, 0.4 wt% H2O in olivine results in a 5% reduction in bulk modulus (i.e. from 130 GPa for anhydrous sample to 123 GPa for hydrous sample). Plastically, structural H2O in olivine influences different dislocation slip system very differently, and therefore alters the pressure of active slip system switchover with respect to "dry" sample. Even 30 ppm H2O in weight may lower down the pressure for transition from [100](010) slip to [001](010) slip by 2 GPa (i.e. from 8 GPa in dry condition to 6 GPa in wet condition). Implications of these results will be discussed in this presentation. Together with previously reported results on elastic and plastic properties of mantle dominant minerals, we are able to reconcile the discrepancies between mineral physics and seismology models for the magnitude of 410 km discontinuity and for the attenuation of seismic anisotropy at about 200-220 km respectively.

Experimental Investigation of Orthoenstatite Single Crystal Rheology

NASA Astrophysics Data System (ADS)

fraysse, G.; Girard, J.; Holyoke, C. W.; Raterron, P.

2013-12-01

The plasticity of enstatite, upper mantle second most abundant mineral, is still poorly constrained, mostly because of its high-temperature (T) transformation into proto- and clino-enstatite at low pressure (P). Mackwell (1991, GRL, 18, 2027) reports a pioneer study of protoenstatite (Pbcn) single-crystal rheology, but the results do not directly apply to the orthorhombic (Pbca) mantle phase. Ohuchi et al. (2011, Contri. Mineral. Petrol , 161, 961) carried out deformation experiments at P=1.3 GPa on oriented orthoenstatite crystals, investigating the activity of [001](100) and [001](010) dislocation slip systems; they report the first rheological laws for orthoenstatite crystals. However, strain and stress were indirectly constrained in their experiments, which questioned whether steady state conditions of deformation were achieved. Also, data reported for [001](100) slip system were obtained after specimens had transformed by twinning into clinoenstatite. We report here new data from deformation experiments carried out at high T and P ranging from 3.5 to 6.2 GPa on natural Fe-bearing enstatite single crystals, using the Deformation-DIA apparatus (D-DIA) that equipped the X17B2 beamline of the NSLS (NY, USA). The applied stress and specimen strain rates were measured in situ by X-ray diffraction and imaging techniques (e.g., Raterron & Merkel, 2009, J. Sync. Rad., 16, 748; Raterron et al., 2013, Rev. Sci. Instr., 84, 043906). Three specimen orientations were tested: i) with the compression direction along [101]c crystallographic direction, which forms a 45° angle with both [100] and [001] axes, to investigate [001](100) slip-system activity; ii) along [011]c direction to investigate [001](010) system activity; iii) and along enstatite [125] axis, to activate both slip systems together. Crystals were deformed two by two, to compare slip system activities, or against enstatite aggregates or orientated olivine crystals of known rheology for comparison. Run products microstructures were investigated by transmission electron microscopy. Despite a significant hardening with P, enstatite [001](100) slip system is found to be the easiest system at mantle P and T. Furthermore, orthoenstatite crystals exhibit a higher sensitivity to stress than olivine crystals, i.e. a higher n exponent in classical power laws. At the low stress level prevailing in the Earth mantle, enstatite crystals are thus harder than olivine crystals.

Reviewed approach to defining the Active Interlock Envelope for Front End ray tracing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seletskiy, S.; Shaftan, T.

To protect the NSLS-II Storage Ring (SR) components from damage from synchrotron radiation produced by insertion devices (IDs) the Active Interlock (AI) keeps electron beam within some safe envelope (a.k.a Active Interlock Envelope or AIE) in the transverse phase space. The beamline Front Ends (FEs) are designed under assumption that above certain beam current (typically 2 mA) the ID synchrotron radiation (IDSR) fan is produced by the interlocked e-beam. These assumptions also define how the ray tracing for FE is done. To simplify the FE ray tracing for typical uncanted ID it was decided to provide the Mechanical Engineering groupmore » with a single set of numbers (x,x’,y,y’) for the AIE at the center of the long (or short) ID straight section. Such unified approach to the design of the beamline Front Ends will accelerate the design process and save valuable human resources. In this paper we describe our new approach to defining the AI envelope and provide the resulting numbers required for design of the typical Front End.« less

Teaming with Brookhaven National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, G.

BNL has started growing CdZnTeSe crystals for room-temperature radiation detector applications. The addition of Se to CdTe reduces the concentration of secondary phases and sub-grain boundary networks. The addition of Zn increases the energy band gap. Material characterization to understand the limiting factors of radiation detection material and to improve the properties continues to be a core element of an extensive R&D program at the LBNL’s ALS and BNL’s NSLS-II synchrotron facilities. ALS’s Beamline 3.3.2 is available for 60% of its beamtime and allows us to perform both White Beam X-ray Diffraction Topography and Micron Scale X-ray Detector Mapping. Themore » latter technique is extremely useful when measuring scintillators because it allows us to subtract contributions from the variability in the counting statistics, and also the fluctuations due to delta electrons, and non-proportionality. BNL has recently developed a new type of thermal neutron detector using pad technology in combination with 3He gas operated in ionization mode. The new detector is used for coded aperture thermal neutron imaging.« less

Towards 10 meV resolution: The design of an ultrahigh resolution soft X-ray RIXS spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dvorak, Joseph; Jarrige, Ignace; Bisogni, Valentina

Here we present the optical design of the Centurion soft X-ray resonant inelastic X-ray scattering (RIXS) spectrometer to be located on the SIX beamline at NSLS-II. The spectrometer is designed to reach a resolving power of 100 000 at 1000 eV at its best resolution. It is also designed to have continuously variable 2θ motion over a range of 112° using a custom triple rotating flange. We have analyzed several possible spectrometer designs capable of reaching the target resolution. After careful analysis, we have adopted a Hettrick-Underwood spectrometer design, with an additional plane mirror to maintain a fixed direction formore » the outgoing beam. The spectrometer can cancel defocus and coma aberrations at all energies, has an erect focal plane, and minimizes mechanical motions of the detector. When the beamline resolution is accounted for, the net spectral resolution will be 14 meV at 1000 eV. Lastly, this will open up many low energy excitations to study and will expand greatly the power of soft X-ray RIXS.« less

Towards 10 meV resolution: The design of an ultrahigh resolution soft X-ray RIXS spectrometer

DOE PAGES

Dvorak, Joseph; Jarrige, Ignace; Bisogni, Valentina; ...

2016-11-10

Here we present the optical design of the Centurion soft X-ray resonant inelastic X-ray scattering (RIXS) spectrometer to be located on the SIX beamline at NSLS-II. The spectrometer is designed to reach a resolving power of 100 000 at 1000 eV at its best resolution. It is also designed to have continuously variable 2θ motion over a range of 112° using a custom triple rotating flange. We have analyzed several possible spectrometer designs capable of reaching the target resolution. After careful analysis, we have adopted a Hettrick-Underwood spectrometer design, with an additional plane mirror to maintain a fixed direction formore » the outgoing beam. The spectrometer can cancel defocus and coma aberrations at all energies, has an erect focal plane, and minimizes mechanical motions of the detector. When the beamline resolution is accounted for, the net spectral resolution will be 14 meV at 1000 eV. Lastly, this will open up many low energy excitations to study and will expand greatly the power of soft X-ray RIXS.« less

EUV multilayer coatings for the Atmospheric Imaging Assembly instrument aboard the Solar Dynamics Observatory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soufli, R; Windt, D L; Robinson, J C

2006-02-09

Multilayer coatings for the 7 EUV channels of the AIA have been developed and completed successfully on all AIA flight mirrors. Mo/Si coatings (131, 171, 193.5, 211 {angstrom}) were deposited at Lawrence Livermore National Laboratory (LLNL). Mg/SiC (304, 335 {angstrom}) and Mo/Y (94 {angstrom}) coatings were deposited at Columbia University. EUV reflectance of the 131/335 {angstrom}, 171 {angstrom}, 193.5/211 {angstrom} primary and secondary flight mirrors and the 94/304 {angstrom} secondary flight mirror was measured at beamline 6.3.2. of the Advanced Light Source (ALS) at LBNL. EUV reflectance of the 94/304 {angstrom} primary and secondary flight mirrors was measured at beamlinemore » X24C of the National Synchrotron Light Source (NSLS) at Brookhaven National Lab. Preliminary EUV reflectance measurements of the 94, 304 and 335 {angstrom} coatings were performed with a laser plasma source reflectometer located at Columbia University. Prior to multilayer coating, Atomic Force Microscopy (AFM) characterization and cleaning of all flight substrates was performed at LLNL.« less

Surface Structure as a Foundation of Nanotechnology

NASA Astrophysics Data System (ADS)

Robinson, Ian

2007-03-01

The three generations of synchrotron sources achieved to date, parasitic, dedicated and undulator-based, have each time revolutionized the field of X-ray diffraction. Surface structure determination, demonstrated (but very difficult) already with Coolidge tube sources, benefited from the enormous flux gain in the first generation, such as SSRL. Dedicated 2nd-generation sources, such as NSLS, allowed in-situ surface preparation and reliable steady beams to be available when a surface was ready to measure. Third generation sources, such as APS, enormously improved the brightness, hence coherence, and thus allowed access to the surfaces of nanoparticles. This talk will illustrate how these technological advances led to two significant scientific breakthroughs. The concept of crystal truncation rods (CTR) led to new views of how the surface is a modification of, but still an extension of the bulk crystal structure. The development of lensless coherent x-ray diffraction (CXD) imaging has allowed access to the structure of nanocrystalline materials by three-dimensional phase mapping of the particle interiors. The structural principles of these new nano materials are being investigated at present using these new methods.

Enhancement of the Microscopy Facilities at the NSLS X1A Beamline

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacobson, Chris

1999-08-31

As originally proposed, the authors constructed a new Scanning Transmission X-ray Microscope, STXM IV. The design and construction was led by Chris Jacobsen, and involved graduate students Michael Feser, Mary Carlucci-Dayton and Tobias Beetz. This microscope has the following new features: It has a new and improved high resolution scanning stage that should make it possible to perform higher resolution imaging without distortions. Preliminary results indicate that the stage performs as designed. It has an enclosure that can be evacuated and backfilled with helium. This makes it possible to perform imaging in the neighborhood of the nitrogen and oxygen edgesmore » without interference from residual air. It has a motorized detector stage for easy interchange of detectors and alignment microscope. We expect to use this to align the new segmented detector which makes it possible to perform brightfield and dark field microscopy simultaneously, and to record images in differential phase contrast as well. The microscope is located upstream of cryoSTXM, the instrument we use to examine specimens in a frozen hydrated state. The design of STXM IV is such that it makes it quick and easy to switch between STXM IV and cryo-STXM operations and vice versa. IEEE488 based control electronics provides multiple channels of data collection. The microscope is run from a LINUX PC with all new software, developed in-house. The stages for the zone plate and the order sorting aperture (OSA) have kinematic mounts. This way different sets of zone plates (optimized for different wavelengths and working distances) can be exchanged without the need for complete realignment of the instrument. The enclosure can be used as a glove-box, making it possible to examine specimens which require anaerobic handling.« less

Final Technical Report - Nuclear Studies with Intermediate Energy Probes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norum, Blaine

During the almost 20 year period of this grant research was carried out on atomic nuclei and their constituents using both photons and electrons. Research was carried out at the electron accelerator facility of the Netherlands Institute for Nuclear and High Energy Physics (NIKHEFK, Amsterdam) until the electron accelerator facility was closed in 1998. Subsequently, research was carried out at the Laser-Electron Gamma Source (LEGS) of the National Synchrotron Light Source (NSLS) located at the Brookhaven National Laboratory (BNL) until the LEGS was closed at the end of 2006. During the next several years research was carried out at bothmore » the Thomas Jefferson National Accelerator Facility (JLAB) and the High Intensity Gamma Source (HIGS) of the Tri-Universities Nuclear Laboratory (TUNL) located on the campus of Duke University. Since approximately 2010 the principal focus was on research at TUNL, although analysis of data from previous research at other facilities continued. The principal early focus of the research was on the role of pions in nuclei. This was studied by studying the production of pions using both photons (at LEGS) and electrons (at NIKHEF-K and JLAB). Measurements of charged pion photoproduction from deuterium at LEGS resulted in the most interesting result of these two decades of work. By measuring the production of a charged pion (p + ) in coincidence with an emitted photon we observed structures in the residual two-nucleon system. These indicated the existence of long-lived states not explicable by standard nuclear theory; they suggest a set of configurations not explicable in terms of a nucleon-nucleon pair. The existence of such “exotic” structures has formed the foundation for most of the work that has ensued.« less

BEAM DIAGNOSTICS USING BPM SIGNALS FROM INJECTED AND STORED BEAMS IN A STORAGE RING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, G.M.; Shaftan; T.

2011-03-28

Many modern light sources are operating in top-off injection mode or are being upgraded to top-off injection mode. The storage ring always has the stored beam and injected beam for top-off injection mode. So the BPM data is the mixture of both beam positions and the injected beam position cannot be measured directly. We propose to use dedicated wide band BPM electronics in the NSLS II storage ring to retrieve the injected beam trajectory with the singular value decomposition (SVD) method. The beam position monitor (BPM) has the capability to measure bunch-by-bunch beam position. Similar electronics can be used tomore » measure the bunch-by-bunch beam current which is necessary to get the injection beam position. The measurement precision of current needs to be evaluated since button BPM sum signal has position dependence. The injected beam trajectory can be measured and monitored all the time without dumping the stored beam. We can adjust and optimize the injected beam trajectory to maximize the injection efficiency. We can also measure the storage ring acceptance by mapping the injected beam trajectory.« less

SPE-LEEM Studies on the Surface and Electronic Structure of 2-D Transition Metal Dichalcogenides (Part II)

NASA Astrophysics Data System (ADS)

Jin, Wencan; Yeh, Po-Chun; Zaki, Nader; Zhang, Datong; Sadowski, Jerzy; Al-Mahboob, Abdullah; van de Zande, Arend; Chenet, Daniel; Dadap, Jerry; Herman, Irving; Sutter, Peter; Hone, James; Osgood, Richard

2014-03-01

In this work, we studied the surface and electronic structure of monolayer and few-layer exfoliated MoS2 and WSe2, as well as chemical-vapor-deposition (CVD) grown MoS2, using Spectroscopic Photoemission and Low Energy Electron Microscope (SPE-LEEM). LEEM measurements reveal that, unlike exfoliated MoS2, CVD-grown MoS2 exhibits grain-boundary alterations due to surface strain. However, LEEM and micro-probe low energy electron diffraction show that the quality of CVD-grown MoS2 is comparable to that of exfoliated MoS2. Micrometer-scale angle-resolved photoemission spectroscopy (ARPES) measurement on exfoliated MoS2 and WSe2 single-crystals provides direct evidence for the shifting of the valence band maximum from Γ to K, when the layer number is thinned down to one, as predicted by density functional theory. Our measurements of the k-space resolved electronic structure allow for further comparison with other theoretical predictions and with transport measurements. This work is supported by DOE grant DE-FG 02-04-ER-46157, research carried out in part at the CFN and NSLS, Brookhaven National Laboratory.

Main functions, recent updates, and applications of Synchrotron Radiation Workshop code

NASA Astrophysics Data System (ADS)

Chubar, Oleg; Rakitin, Maksim; Chen-Wiegart, Yu-Chen Karen; Chu, Yong S.; Fluerasu, Andrei; Hidas, Dean; Wiegart, Lutz

2017-08-01

The paper presents an overview of the main functions and new application examples of the "Synchrotron Radiation Workshop" (SRW) code. SRW supports high-accuracy calculations of different types of synchrotron radiation, and simulations of propagation of fully-coherent radiation wavefronts, partially-coherent radiation from a finite-emittance electron beam of a storage ring source, and time-/frequency-dependent radiation pulses of a free-electron laser, through X-ray optical elements of a beamline. An extended library of physical-optics "propagators" for different types of reflective, refractive and diffractive X-ray optics with its typical imperfections, implemented in SRW, enable simulation of practically any X-ray beamline in a modern light source facility. The high accuracy of calculation methods used in SRW allows for multiple applications of this code, not only in the area of development of instruments and beamlines for new light source facilities, but also in areas such as electron beam diagnostics, commissioning and performance benchmarking of insertion devices and individual X-ray optical elements of beamlines. Applications of SRW in these areas, facilitating development and advanced commissioning of beamlines at the National Synchrotron Light Source II (NSLS-II), are described.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, Vinita J.; Schaefer, Charles; Kahnhauser, Henry

The National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory was shut down in September 2014. Lead bricks used as radiological shadow shielding within the accelerator were exposed to stray radiation fields during normal operations. The FLUKA code, a fully integrated Monte Carlo simulation package for the interaction and transport of particles and nuclei in matter, was used to estimate induced radioactivity in this shielding and stainless steel beam pipe from known beam losses. The FLUKA output was processed using MICROSHIELD® to estimate on-contact exposure rates with individually exposed bricks to help design and optimize the radiological survey process. Thismore » entire process can be modeled using FLUKA, but use of MICROSHIELD® as a secondary method was chosen because of the project’s resource constraints. Due to the compressed schedule and lack of shielding configuration data, simple FLUKA models were developed in this paper. FLUKA activity estimates for stainless steel were compared with sampling data to validate results, which show that simple FLUKA models and irradiation geometries can be used to predict radioactivity inventories accurately in exposed materials. During decommissioning 0.1% of the lead bricks were found to have measurable levels of induced radioactivity. Finally, post-processing with MICROSHIELD® provides an acceptable secondary method of estimating residual exposure rates.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

WATANABE, T.; LIU, D.; MURPHY, J.B.

The strong focusing VISA undulator is presented in this report. The proposed FEL will operate at the 1 {micro}m water window. Extensive simulations were performed to optimize an FEL amplifier based on the two-meter long VISA undulator which has a period of 1.8 cm and an undulator parameter K = 1.26. The betatron function inside the VISA undulator is about 30 cm. For an electron beam with a peak current {approx}1 kA and a normalized emittance of 5 mm-mrad, the FEL peak power can exceed 1 GW within the 2 m VISA undulator using a 5 kW peak power seedmore » laser. Such a device can produce a megawatt of average power for a 700 MHz rep rate. The transverse distribution of the FEL radiation along the undulator, as well as after the undulator, is explored by numerical simulation. The FEL power density at 5 m downstream from the undulator is less than 100 kW/cm{sup 2} for this MW-class FEL. We will also discuss the feasibility of an experimental demonstration of the laser seeded FEL amplifier based on the 2-m VISA undulator at the NSLS Source Development Lab (SDL).« less

Radiological implications of top-off operation at national synchrotron light source-II

NASA Astrophysics Data System (ADS)

Job, P. K.; Casey, W. R.

2011-08-01

High current and low emittance have been specified to achieve ultra high brightness in the third generation medium energy Synchrotron Radiation Sources. This leads to the electron beam lifetime limited by Touschek scattering, and after commissioning may settle in at as low as ∼3 h. It may well be less in the early days of operation. At the same time, the intensity stability specified by the user community for the synchrotron beam is 1% or better. Given the anticipated lifetime of the beam, incremental filling called top-off injection at intervals on the order of ∼1 min will be required to maintain this beam stability. It is judged to be impractical to make these incremental fills by closing the beam shutters at each injection. In addition, closing the front end beam shutters during each injection will adversely affect the stability of beamline optics due to thermal cycling. Hence the radiological consequences of injection with front end beam shutters open must be evaluated. This paper summarizes results of radiological analysis carried out for the proposed top-off injection at National Synchrotron Light Source-II (NSLS-II) with beam shutters open.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baig, M.; Brown, A.; Eswaramoorthy, S.

Klebsiella pneumoniae, a gram-negative enteric bacterium, is found in nosocomial infections which are acquired during hospital stays for about 10% of hospital patients in the United States. The crystal structure of a putative oxidoreductase from K. pneumoniae has been determined. The structural information of this K. pneumoniae protein was used to understand its function. Crystals of the putative oxidoreductase enzyme were obtained by the sitting drop vapor diffusion method using Polyethylene glycol (PEG) 3350, Bis-Tris buffer, pH 5.5 as precipitant. These crystals were used to collect X-ray data at beam line X12C of the National Synchrotron Light Source (NSLS) atmore » Brookhaven National Laboratory (BNL). The crystal structure was determined using the SHELX program and refi ned with CNS 1.1. This protein, which is involved in the catalysis of an oxidation-reduction (redox) reaction, has an alpha/beta structure. It utilizes nicotinamide adenine dinucleotide phosphate (NADP) or nicotine adenine dinucleotide (NAD) to perform its function. This structure could be used to determine the active and co-factor binding sites of the protein, information that could help pharmaceutical companies in drug design and in determining the protein’s relationship to disease treatment such as that for pneumonia and other related pathologies.« less

Development of beamline U3A for AXAF synchrotron reflectivity calibrations

NASA Astrophysics Data System (ADS)

Burek, Anthony J.; Cobuzzi, J. C.; Fitch, Jonathan J.; Graessle, Dale E.; Ingram, R. H.; Sweeney, J. B.; Blake, Richard L.; Francoeur, R.; Sullivan, E. S.

1998-11-01

We discuss the development of beamline U3A at NSLS for AXAF telescope witness mirror reflectivity calibrations in the 1- 2 keV energy range. The beamline was originally constructed as a white light beamline and has been upgraded with the addition of a monochromator to meet the needs of the AXAF calibration program. The beamline consists of an upstream horizontally focussing gold coated elliptical mirror, a differential pumping section, a sample/filter chamber, a monochromator and a downstream filter set. The mirror is set at a 2 degree incident angle for a nominal high energy cutoff at 2 keV. The monochromator is a separated element, scanning, double crystal/multilayer design having low to moderate energy resolution. A fixed exit beam is maintained through the 7-70 degree Bragg angle range by longitudinal translation of the second scanning crystal. Tracking is achieved by computer control of the scan motors with lookup table positioning of the crystal rotary tables. All motors are in vacuum and there are no motional feedthroughs. Several different multilayer or crystal pairs are co-mounted on the monochromator crystal holders and can be exchanged in situ. Currently installed are a W/Si multilayer pair, beryl, and Na-(beta) alumina allowing energy coverage from 180 eV to 2000 eV. Measurements with Na-(beta) alumina and beryl show that beam impurity less than 0.1 percent can be achieved in the 1-2 keV energy range. Measured resolving powers are E/(Delta) E equals 60 for W/Si, 500-800 for (beta) alumina and 1500 to 3000 for beryl. Initial results suggest that signal to noise and beam purity are adequate in the 1-2 keV region to achieve the 1 percent calibration accuracy required by AXAF. This allows overlap of Ir MV edge data taken on x-ray beamline X8A and with low energy data taken on ALS beamline 6.3.2.

Development and In Situ Characterization of New Electrolyte and Electrode materials for Rechargeable Lithium Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, X -Q; Xing, X K; Daroux, M

The object of this project is to develop new electrolyte and cathode materials for rechargeable lithium batteries, especially for lithium ion and lithium polymer batteries. Enhancing performance, reducing cost, and replacing toxic materials by environmentally benign materials, are strategic goals of DOE in lithium battery research. This proposed project will address these goals on two important material studies, namely the new electrolytes and new cathode materials. For the new electrolyte materials, aza based anion receptors as additives, organic lithium salts and plasticizers which have been developed by BNL team under Energy Research programs of DOE, will be evaluated by Gouldmore » for potential use in commercial battery cells. All of these three types of compounds are aimed to enhance the conductivity and lithium transference number of lithium battery electrolytes and reduce the use of toxic salts in these electrolytes. BNL group will be working closely with Gould to further develop these compounds for commercialization. For the cathode material studies, BNL efforts wi U be focused on developing new superior characterization methclds, especially in situ techniques utilize the unique user facility of DOE at BNL, namely the National Synchrotrons Light Source (NSLS). In situ x-ray absorption and x-ray diftlaction spectroscopy will be used to study the relationship between performance and the electronic and structural characteristics of intercalation compounds such as LiNi0 2, LiCo0 2, and LiMn 20 4 spinel. The study will be focused on LiMn 20 4 spinel materials. Gould team will contribute their expertise in choosing the most promising compounds, providing overall performance requirements, and will use the results of this study to guide their procedure for quality control. The knowledge gained through this project will not only benefit Gould and BNL, but will be very valuable to the scientific community in battery research.« less

APS 6BM-B Large Volume High Pressure Beamline: A Workhorse for Rock and Mineral Physics

NASA Astrophysics Data System (ADS)

Chen, H.; Whitaker, M. L.; Baldwin, K. J.; Huebsch, W. R.; Vaughan, M. T.; Weidner, D. J.

2017-12-01

With the inheritance of decades of technical innovations at the NSLS X17B2 Beamline, APS 6BM-B Beamline was established in 2015 and is a dedicated beamline for synchrotron-based large volume high pressure research in earth sciences, especially rock and mineral physics. Currently a 250-ton hydraulic press equipped with a D-DIA module is installed and a Rotational Drickamer Apparatus from Yale University is hosted every cycle, covering a pressure range from crust to lower mantle. 6BM-B operates in white beam mode with an effective energy range of 20-100 keV. Energy dispersive X-ray diffraction data is collected using a 10-element solid state Ge array detector arranged in a circular geometry to allow for the real time assessment of stress. Direct radiographic imaging using Prosillica CCD camera and scintillating YAG crystals yields sample strain and strain rate. In addition to applications in phase transitions, equation of states measurements, sound velocity measurements, this setup is ideal for studies of steady state and dynamic deformation process. In this presentation, technical features and strengths of 6BM-B will be discussed. Most recent progress and science highlights of our user community will be showcased.

Induced Radioactivity in Lead Shielding at the National Synchrotron Light Source

DOE PAGES

Ghosh, Vinita J.; Schaefer, Charles; Kahnhauser, Henry

2017-06-30

The National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory was shut down in September 2014. Lead bricks used as radiological shadow shielding within the accelerator were exposed to stray radiation fields during normal operations. The FLUKA code, a fully integrated Monte Carlo simulation package for the interaction and transport of particles and nuclei in matter, was used to estimate induced radioactivity in this shielding and stainless steel beam pipe from known beam losses. The FLUKA output was processed using MICROSHIELD® to estimate on-contact exposure rates with individually exposed bricks to help design and optimize the radiological survey process. Thismore » entire process can be modeled using FLUKA, but use of MICROSHIELD® as a secondary method was chosen because of the project’s resource constraints. Due to the compressed schedule and lack of shielding configuration data, simple FLUKA models were developed in this paper. FLUKA activity estimates for stainless steel were compared with sampling data to validate results, which show that simple FLUKA models and irradiation geometries can be used to predict radioactivity inventories accurately in exposed materials. During decommissioning 0.1% of the lead bricks were found to have measurable levels of induced radioactivity. Finally, post-processing with MICROSHIELD® provides an acceptable secondary method of estimating residual exposure rates.« less

Overview of Lattice Design and Evaluation for the APS Upgrade

DOE PAGES

Borland, M.; Emery, L.; Lindberg, R.; ...

2017-08-01

The Advanced Photon Source (APS) is a 7-GeV synchrotron light source that has been in operation since 1996. Since that time, the effective emittance has been decreased from 8 nm to 3.1 nm, which is very competitive for a 3rd-generation light source. However, newer facilities such as PETRA-III, NSLS-II, and MAX-IV are pushing the emittance to significantly smaller values. MAX-IV in particular has set the current benchmark with an emittance of about 300 pm at 3 GeV. This was accomplished by use of a multi-bend achromat lattice, which takes advantage of the 1/M3 scaling of the emittance with respect tomore » the number of dipoles M. In order to ensure that our facility remains competitive, APS is pursuing a major upgrade, which involves replacement of the existing double-bend lattice with a seven-bend achromat lattice, promising a 40-fold reduction in emittance. This paper describes the process of developing and evaluating candidate lattice designs. Two candidate 6-GeV lattices are described: one providing a natural emittance of 67 pm and the other providing 41 pm. Our analysis includes single-particle dynamics as well as single- and multi-bunch collective effects.« less

Laser Shock Compression Studies of Phase Changes in Ce3 Al Metallic Glass

NASA Astrophysics Data System (ADS)

Bryant, Alex; Wehrenberg, Christopher; Alamgir, Faisal; Remington, Bruce; Thadhani, Naresh

2017-06-01

Laser shock-compression of Ce3 Al metallic glass (MG) was performed to probe pressure-induced phase transitions. Ce3 Al MG has been previously shown to crystallize into a single crystal FCC phase during static compression at 25 GPa. In the present work, experiments were performed using the 3J Nd:YAG pulse laser at Georgia Tech and the high energy laser at the OMEGA facility. Characterization of shock compressed samples recovered from the OMEGA laser experiments were performed using XRD and PDF measurements at the NSLS-2 synchrotron at Brookhaven National Lab. The results showed evidence of a permanent polyamorphous phase change at pressures > 10 GPa and crystallization at pressures > 75 GPa. Particle velocities were measured using VISAR in experiments performed at Georgia Tech and simulated using Hyades and Abaqus to create an empirical equation of state and correlate with results obtained from XRD and PDF characterization. The results attained to-date in terms of the evolution of the high pressure amorphous and crystalline phases and their correlations with the shock conditions will be presented. This work is supported in part by ARO Grant No. W9HNF-09-1-0403 and the National Science Foundation Graduate Research Fellowship Program awarded to Alex Bryant under Grant No. 0946809.

Induced Radioactivity in Lead Shielding at the National Synchrotron Light Source.

PubMed

Ghosh, Vinita J; Schaefer, Charles; Kahnhauser, Henry

2017-06-01

The National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory was shut down in September 2014. Lead bricks used as radiological shadow shielding within the accelerator were exposed to stray radiation fields during normal operations. The FLUKA code, a fully integrated Monte Carlo simulation package for the interaction and transport of particles and nuclei in matter, was used to estimate induced radioactivity in this shielding and stainless steel beam pipe from known beam losses. The FLUKA output was processed using MICROSHIELD® to estimate on-contact exposure rates with individually exposed bricks to help design and optimize the radiological survey process. This entire process can be modeled using FLUKA, but use of MICROSHIELD® as a secondary method was chosen because of the project's resource constraints. Due to the compressed schedule and lack of shielding configuration data, simple FLUKA models were developed. FLUKA activity estimates for stainless steel were compared with sampling data to validate results, which show that simple FLUKA models and irradiation geometries can be used to predict radioactivity inventories accurately in exposed materials. During decommissioning 0.1% of the lead bricks were found to have measurable levels of induced radioactivity. Post-processing with MICROSHIELD® provides an acceptable secondary method of estimating residual exposure rates.

Advanced Test Reactor National Scientific User Facility (ATR NSUF) Monthly ReportJanuary 2015

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soelberg, Renae

2015-01-01

Highlights; Mike Worley and Shane Johnson visited INL Jan. 22 for an NSUF strategy discussion; Rory Kennedy attended a NSLS-2 Beamline Advisory Team meeting at Brookhaven; Provided a final cost estimate to the NSUF Program Office in support of the NEET/NSUF proposal, “Metal-ceramic and metal-metal composites for extreme radiation and temperature environment: An in situ interface stability and mechanical behavior study by high energy x-ray diffraction with a synchrotron probe.”; Assisted in the development of conceptual designs and performed a preliminary thermal hydraulic analysis for two NEET/NSUF proposals. The challenge for both experiments is to provide high (>1000 C andmore » up to 1600 C)) specimen temperatures in a small space (0.5" diameter ATR Outboard A-position) without overheating the coolant. Several designs were analyzed and found to be feasible, although detailed design and analysis will be required after the projects are awarded; and A single USU TEM specimen is packaged and awaiting shipment from MFC to CAES. Once at CAES, SEM, TEM and LEAP analysis will be performed. Professor Ban has requested additional sub-samples to be made to take back to his laboratory at USU for thermal diffusivity studies.« less

Estimating nitrogen oxides emissions at city scale in China with a nightlight remote sensing model.

PubMed

Jiang, Jianhui; Zhang, Jianying; Zhang, Yangwei; Zhang, Chunlong; Tian, Guangming

2016-02-15

Increasing nitrogen oxides (NOx) emissions over the fast developing regions have been of great concern due to their critical associations with the aggravated haze and climate change. However, little geographically specific data exists for estimating spatio-temporal trends of NOx emissions. In order to quantify the spatial and temporal variations of NOx emissions, a spatially explicit approach based on the continuous satellite observations of artificial nighttime stable lights (NSLs) from the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) was developed to estimate NOx emissions from the largest emission source of fossil fuel combustion. The NSL based model was established with three types of data including satellite data of nighttime stable lights, geographical data of administrative boundaries, and provincial energy consumptions in China, where a significant growth of NOx emission has experienced during three policy stages corresponding to the 9th-11th)Five-Year Plan (FYP, 1995-2010). The estimated national NOx emissions increased by 8.2% per year during the study period, and the total annual NOx emissions in China estimated by the NSL-based model were approximately 4.1%-13.8% higher than the previous estimates. The spatio-temporal variations of NOx emissions at city scale were then evaluated by the Moran's I indices. The global Moran's I indices for measuring spatial agglomerations of China's NOx emission increased by 50.7% during 1995-2010. Although the inland cities have shown larger contribution to the emission growth than the more developed coastal cities since 2005, the High-High clusters of NOx emission located in Beijing-Tianjin-Hebei regions, the Yangtze River Delta, and the Pearl River Delta should still be the major focus of NOx mitigation. Our results indicate that the readily available DMSP/OLS nighttime stable lights based model could be an easily accessible and effective tool for achieving strategic decision making toward NOx reduction. Copyright © 2015 Elsevier B.V. All rights reserved.

High Pressure-Temperature Phase Diagram of 1,1-diamino-2,2-dinitroethylene

NASA Astrophysics Data System (ADS)

Bishop, Matthew; Chellappa, Raja; Liu, Zhenxian; Preston, Daniel; Sandstrom, Mary; Dattelbaum, Dana; Vohra, Yogesh; Velisavljevic, Nenad

2013-06-01

1,1-diamino-2,2-dinitroethelyne (FOX-7) is a less sensitive energetic material with performance comparable to commonly used secondary explosives such as RDX and HMX. At ambient pressure, FOX-7 exhibits complex polymorphism with at least three structurally distinct phases (α, β, and γ) . In this study, we have investigated the high P-T stability of FOX-7 polymorphs using synchrotron mid-infrared (MIR) spectroscopy. At ambient pressure, our MIR spectra confirmed the known α --> β (110 °C) and β --> γ (160 °C) phase transitions; as well as, indicated an additional phase transition, γ --> δ (210°C), with the δ phase being stable up to 250 °C prior to melt/decomposition. In situ MIR spectra obtained during isobaric heating at 0.9 GPa revealed that the α --> β transition occurs at 180 °C, while β --> β + δ phase transition shifted to 300 °C with suppression of γ phase. Decomposition was observed above 325 °C. Based on multiple high P-T measurements, we have established the first high P-T phase diagram of FOX-7. This work was, in part, supported by the US DOE under contract No. DE-AC52-06NA25396 and Science Campaign 2 Program. MB acknowledges additional support from the NSF BD program. Use of NSLS (DE-AC02-98CH10886) beamline U2A (COMPRES, No.EAR01-35554, CDAC).

Radiological considerations for bulk shielding calculations of national synchrotron light source-II

NASA Astrophysics Data System (ADS)

Job, Panakkal K.; Casey, William R.

2011-12-01

Brookhaven National Laboratory is designing a new electron synchrotron for scientific research using synchrotron radiation. This facility, called the “National Synchrotron Light Source II” (NSLS-II), will provide x-ray radiation of ultra-high brightness and exceptional spatial and energy resolution. It will also provide advanced insertion devices, optics, detectors and robotics, and a suite of scientific instruments designed to maximize the scientific output of the facility. The project scope includes the design, construction, installation, and commissioning of the following accelerators: a 200 MeV linac, a booster synchrotron operating from 200 MeV to 3.0 GeV, and the storage ring which stores a maximum of 500 mA current of electrons at an energy of 3.0 GeV. It is planned to operate the facility primarily in a top-off mode, thereby maintaining the maximum variation in stored beam current to <1%. Because of the very demanding requirements for beam emittance and synchrotron radiation brilliance, the beam life-time is expected to be quite low, on the order of 2 h. Analysis of the bulk shielding for operating this facility and the input parameters used for this analysis have been discussed in this paper. The characteristics of each of the accelerators and their operating modes have been summarized with the input assumptions for the bulk shielding analysis.

Trace element distribution in the rat cerebellum

NASA Astrophysics Data System (ADS)

Kwiatek, W. M.; Long, G. J.; Pounds, J. G.; Reuhl, K. R.; Hanson, A. L.; Jones, K. W.

1990-04-01

Spatial distributions and concentrations of trace elements (TE) in the brain are important because TE perform catalytic and structural functions in enzymes which regulate brain function and development. We have investigated the distributions of TE in rat cerebellum. Structures were sectioned and analyzed by the Synchrotron Radiation Induced X-ray Emission (SRIXE) method using the NSLS X-26 white-light microprobe facility. Advantages important for TE analysis of biological specimens with X-ray microscopy include short time of measurement, high brightness and flux, good spatial resolution, multielemental detection, good sensitivity, and nondestructive irradiation. Trace elements were measured in thin rat brain sections of 20 μm thickness. The analyses were performed on sample volumes as small as 0.2 nl with Minimum Detectable Limits (MDL) of 50 ppb wet weight for Fe, 100 ppb wet weight for Cu, and Zn, and 1 ppm wet weight for Pb. The distribution of TE in the molecular cell layer, granule cell layer and fiber tract of rat cerebella was investigated. Both point analyses and two-dimensional semiquantitative mapping of the TE distribution in a section were used. All analyzed elements were observed in each structure of the cerebellum except mercury which was not observed in granule cell layer or fiber tract. This approach permits an exacting correlation of the TE distribution in complex structure with the diet, toxic elements, and functional status of the animal.

Performance verification of the Gravity and Extreme Magnetism Small explorer (GEMS) x-ray polarimeter

NASA Astrophysics Data System (ADS)

Enoto, Teruaki; Black, J. Kevin; Kitaguchi, Takao; Hayato, Asami; Hill, Joanne E.; Jahoda, Keith; Tamagawa, Toru; Kaneko, Kenta; Takeuchi, Yoko; Yoshikawa, Akifumi; Marlowe, Hannah; Griffiths, Scott; Kaaret, Philip E.; Kenward, David; Khalid, Syed

2014-07-01

Polarimetry is a powerful tool for astrophysical observations that has yet to be exploited in the X-ray band. For satellite-borne and sounding rocket experiments, we have developed a photoelectric gas polarimeter to measure X-ray polarization in the 2-10 keV range utilizing a time projection chamber (TPC) and advanced micro-pattern gas electron multiplier (GEM) techniques. We carried out performance verification of a flight equivalent unit (1/4 model) which was planned to be launched on the NASA Gravity and Extreme Magnetism Small Explorer (GEMS) satellite. The test was performed at Brookhaven National Laboratory, National Synchrotron Light Source (NSLS) facility in April 2013. The polarimeter was irradiated with linearly-polarized monochromatic X-rays between 2.3 and 10.0 keV and scanned with a collimated beam at 5 different detector positions. After a systematic investigation of the detector response, a modulation factor >=35% above 4 keV was obtained with the expected polarization angle. At energies below 4 keV where the photoelectron track becomes short, diffusion in the region between the GEM and readout strips leaves an asymmetric photoelectron image. A correction method retrieves an expected modulation angle, and the expected modulation factor, ~20% at 2.7 keV. Folding the measured values of modulation through an instrument model gives sensitivity, parameterized by minimum detectable polarization (MDP), nearly identical to that assumed at the preliminary design review (PDR).

Development of Partially-Coherent Wavefront Propagation Simulation Methods for 3rd and 4th Generation Synchrotron Radiation Sources.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chubar O.; Berman, L; Chu, Y.S.

2012-04-04

Partially-coherent wavefront propagation calculations have proven to be feasible and very beneficial in the design of beamlines for 3rd and 4th generation Synchrotron Radiation (SR) sources. These types of calculations use the framework of classical electrodynamics for the description, on the same accuracy level, of the emission by relativistic electrons moving in magnetic fields of accelerators, and the propagation of the emitted radiation wavefronts through beamline optical elements. This enables accurate prediction of performance characteristics for beamlines exploiting high SR brightness and/or high spectral flux. Detailed analysis of radiation degree of coherence, offered by the partially-coherent wavefront propagation method, ismore » of paramount importance for modern storage-ring based SR sources, which, thanks to extremely small sub-nanometer-level electron beam emittances, produce substantial portions of coherent flux in X-ray spectral range. We describe the general approach to partially-coherent SR wavefront propagation simulations and present examples of such simulations performed using 'Synchrotron Radiation Workshop' (SRW) code for the parameters of hard X-ray undulator based beamlines at the National Synchrotron Light Source II (NSLS-II), Brookhaven National Laboratory. These examples illustrate general characteristics of partially-coherent undulator radiation beams in low-emittance SR sources, and demonstrate advantages of applying high-accuracy physical-optics simulations to the optimization and performance prediction of X-ray optical beamlines in these new sources.« less

Putting tools in the toolbox: Development of a free, open-source toolbox for quantitative image analysis of porous media.

NASA Astrophysics Data System (ADS)

Iltis, G.; Caswell, T. A.; Dill, E.; Wilkins, S.; Lee, W. K.

2014-12-01

X-ray tomographic imaging of porous media has proven to be a valuable tool for investigating and characterizing the physical structure and state of both natural and synthetic porous materials, including glass bead packs, ceramics, soil and rock. Given that most synchrotron facilities have user programs which grant academic researchers access to facilities and x-ray imaging equipment free of charge, a key limitation or hindrance for small research groups interested in conducting x-ray imaging experiments is the financial cost associated with post-experiment data analysis. While the cost of high performance computing hardware continues to decrease, expenses associated with licensing commercial software packages for quantitative image analysis continue to increase, with current prices being as high as $24,000 USD, for a single user license. As construction of the Nation's newest synchrotron accelerator nears completion, a significant effort is being made here at the National Synchrotron Light Source II (NSLS-II), Brookhaven National Laboratory (BNL), to provide an open-source, experiment-to-publication toolbox that reduces the financial and technical 'activation energy' required for performing sophisticated quantitative analysis of multidimensional porous media data sets, collected using cutting-edge x-ray imaging techniques. Implementation focuses on leveraging existing open-source projects and developing additional tools for quantitative analysis. We will present an overview of the software suite that is in development here at BNL including major design decisions, a demonstration of several test cases illustrating currently available quantitative tools for analysis and characterization of multidimensional porous media image data sets and plans for their future development.

Sirepo: a web-based interface for physical optics simulations - its deployment and use at NSLS-II

NASA Astrophysics Data System (ADS)

Rakitin, Maksim S.; Chubar, Oleg; Moeller, Paul; Nagler, Robert; Bruhwiler, David L.

2017-08-01

"Sirepo" is an open source cloud-based software framework which provides a convenient and user-friendly web-interface for scientific codes such as Synchrotron Radiation Workshop (SRW) running on a local machine or a remote server side. SRW is a physical optics code allowing to simulate the synchrotron radiation from various insertion devices (undulators and wigglers) and bending magnets. Another feature of SRW is a support of high-accuracy simulation of fully- and partially-coherent radiation propagation through X-ray optical beamlines, facilitated by so-called "Virtual Beamline" module. In the present work, we will discuss the most important features of Sirepo/SRW interface with emphasis on their use for commissioning of beamlines and simulation of experiments at National Synchrotron Light Source II. In particular, "Flux through Finite Aperture" and "Intensity" reports, visualizing results of the corresponding SRW calculations, are being routinely used for commissioning of undulators and X-ray optical elements. Material properties of crystals, compound refractive lenses, and some other optical elements can be dynamically obtained for the desired photon energy from the databases publicly available at Argonne National Lab and at Lawrence Berkeley Lab. In collaboration with the Center for Functional Nanomaterials (CFN) of BNL, a library of samples for coherent scattering experiments has been implemented in SRW and the corresponding Sample optical element was added to Sirepo. Electron microscope images of artificially created nanoscale samples can be uploaded to Sirepo to simulate scattering patterns created by synchrotron radiation in different experimental schemes that can be realized at beamlines.

NSLS-II biomedical beamlines for micro-crystallography, FMX, and for highly automated crystallography, AMX: New opportunities for advanced data collection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fuchs, Martin R., E-mail: mfuchs@bnl.gov; Bhogadi, Dileep K.; Jakoncic, Jean

We present the final design of the x-ray optics and experimental stations of two macromolecular crystallography (MX) beamlines at the National Synchrotron Light Source-II. The microfocusing FMX beamline will deliver a flux of ∼5×10{sup 12} ph/s at 1 Å into a 1 – 20 µm spot, its flux density surpassing current MX beamlines by up to two orders of magnitude. It covers an energy range from 5 – 30 keV. The highly automated AMX beamline is optimized for high throughput, with beam sizes from 4 – 100 µm, an energy range of 5 – 18 keV and a flux atmore » 1 Å of ∼10{sup 13} ph/s. A focus in designing the beamlines lay on achieving high beam stability, for example by implementing a horizontal bounce double crystal monochromator at FMX. A combination of compound refractive lenses and bimorph mirror optics at FMX supports rapid beam size changes. Central components of the in-house developed experimental stations are horizontal axis goniometers with a target sphere of confusion of 100 nm, piezo-slits for dynamic beam size changes during diffraction experiments, dedicated secondary goniometers for data collection from specimen in crystallization plates, and next generation pixel array detectors. FMX and AMX will support a broad range of biomedical structure determination methods from serial crystallography on micron-sized crystals, to structure determination of complexes in large unit cells, to rapid sample screening and room temperature data collection of crystals in trays.« less

Chemical speciation of polyurethane polymers by soft-x-ray spectromicroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rightor, E.G.; Hitchcock, A.P.; Urquhart, S.G.

1997-04-01

Polyurethane polymers are a versatile class of materials which have numerous applications in modern life, from automotive body panels, to insulation, to household furnishings. Phase segregation helps to determine the physical properties of several types of polyurethanes. Polymer scientists believe that understanding the connections between formulation chemistry, the chemical nature of the segregated phases, and the physical properties of the resulting polymer, would greatly advance development of improved polyurethane materials. However, the sub-micron size of segregated features precludes their chemical analysis by existing methods, leaving only indirect means of characterizing these features. For the past several years the authors havemore » been developing near edge X-ray absorption spectromicroscopy to study the chemical nature of individual segregated phases. Part of this work has involved studies of molecular analogues and model polymers, in conjunction with quantum calculations, in order to identify the characteristic near edge spectral transitions of important chemical groups. This spectroscopic base is allowing the authors to study phase segregation in polyurethanes by taking advantage of several unique capabilities of scanning transmission x-ray microscopy (STXM) - high spatial resolution ({approximately} 0.1 {mu}m), high spectral resolution ({approximately}0.1 eV at the C 1s edge), and the ability to record images and spectra with relatively low radiation damage. The beamline 7.0 STXM at ALS is being used to study microtomed sections or cast films of polyurethanes. Based on the pioneering work of Ade, Kirz and collaborators at the NSLS X-1A STXM, it is clear that scanning X-ray transmission microscopy using soft X-rays can provide information about the chemical origin of phase segregation in radiation-sensitive materials on a sub-micron scale. This information is difficult or impossible to obtain by other means.« less

PROCEEDING OF THE SEEDED X-RAY FREE ELECTRON LASER WORKSHOP.

DOE Office of Scientific and Technical Information (OSTI.GOV)

WANG,X.J.; MURPHY,J.B.; YU,L.H.

2002-12-13

The underlying theory of a high gain free electron laser (FEL) has existed for two decades [1-2], but it is only in the last few years that these novel radiation sources have been realized experimentally. Several high gain FELs have successfully reached saturation in the infrared, visible and the VUV portion of the spectrum: the High Gain Harmonic Generation (HGHG) free electron lasers [3] at BNL and the Self Amplified Spontaneous Emission (SASE) FELs at LEUTL, VISA and TTF [4-6]. The outstanding challenges for future FELs are to extend high gain FELs to the X-ray regime, improve the longitudinal coherencemore » of the radiation using seeded FEL schemes and generate ultrashort pulses (<100 fs). The National Synchrotron Light Source (NSLS) of the Brookhaven National Laboratory (BNL) sponsored a Seeded X-ray Free Electron Laser Workshop on December 13-14, 2002 to explore these challenging issues. Representatives from BNL, DESY, LBNL, SLAC and UCLA made presentations on the novel schemes under consideration at their laboratories. Workshop participants had a lively discussion on the feasibility, performance and R&D issues associated with the seeded XFEL schemes. An improvement of the electron beam quality will certainly be necessary to drive the XFEL. Self-seeding SASE, cascaded HGHG, and SASE pulse compression FELs show the most promise for producing short pulse X-rays. Of these, only the self-seeded and HGHG schemes generate longitudinally coherent radiation. While the pulse length in the self-seeded scheme is determined by the electron bunch length ({approx}100 fs), the pulse length in the HGHG scheme is determined by the short pulse seed laser, and so can be much shorter ({approx} 20 fs).« less

Building a Unified Computational Model for the Resonant X-Ray Scattering of Strongly Correlated Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansil, Arun

2016-12-01

Basic-Energy Sciences of the Department of Energy (BES/DOE) has made large investments in x-ray sources in the U.S. (NSLS-II, LCLS, NGLS, ALS, APS) as powerful enabling tools for opening up unprecedented new opportunities for exploring properties of matter at various length and time scales. The coming online of the pulsed photon source literally allows us to see and follow the dynamics of processes in materials at their natural timescales. There is an urgent need therefore to develop theoretical methodologies and computational models for understanding how x-rays interact with matter and the related spectroscopies of materials. The present project addressed aspectsmore » of this grand challenge of X-ray science. In particular, our Collaborative Research Team (CRT) focused on understanding and modeling of elastic and inelastic resonant X-ray scattering processes. We worked to unify the three different computational approaches currently used for modeling X-ray scattering—density functional theory, dynamical mean-field theory, and small-cluster exact diagonalization—to achieve a more realistic material-specific picture of the interaction between X-rays and complex matter. To achieve a convergence in the interpretation and to maximize complementary aspects of different theoretical methods, we concentrated on the cuprates, where most experiments have been performed. Our team included both US and international researchers, and it fostered new collaborations between researchers currently working with different approaches. In addition, we developed close relationships with experimental groups working in the area at various synchrotron facilities in the US. Our CRT thus helped toward enabling the US to assume a leadership role in the theoretical development of the field, and to create a global network and community of scholars dedicated to X-ray scattering research.« less

In-situ Diffraction Study of Magnetite at Simultaneous High Pressure and High Temperature Using Synchrotron Radiation

NASA Astrophysics Data System (ADS)

Wang, L.; Zhang, J.; Wang, S.; Chen, H.; Zhao, Y.

2014-12-01

Magnetite intertwined with the evolution of human civilizations, and remains so today. It is technologically and scientifically important by virtue of its unique magnetic and electrical properties. Magnetite is a common mineral found in a variety of geologic environments, and plays an important role in deciphering the oxygen evolution in the Earth's atmosphere and its deep interiors. The latter application asks for the knowledge of the thermal and elastic properties of magnetite at high pressures and temperatures, which is currently not available in literature. We have carried out a few in-situ diffraction experiments on magnetite using white synchrotron radiation at beamline X17B2 of National Synchrotron Light Source (NSLS). A DIA module in an 1100-ton press and WC anvils were employed for compression, and diffraction spectra were collected at simultaneous high pressures (P) and temperatures (T) (up to 9 GPa and 900 oC). Mixture of amorphous boron and epoxy resin was used as pressure medium, and NaCl as pressure marker. Temperature was recorded by W-Re thermocouples. Commercially purchased magnetite powder and a mixture of the said powder and NaCl (1:1) were used as starting material in separate experiments. Preliminary data analyses have yielded following observations: (1) Charge disordering seen at ambient pressure remains active in current experiments, especially at lower pressures (< 6 GPa); (2) Though at each condition potentially complicated by charge disordering process, isothermal compression curves remains simple and reproducible; (3) During cooling, the reversibility and degree of cation disordering depend on the starting material and/or experimental P-T path; and (4) cation disordering notably reduces the apparent bulk moduli of magnetite.

Density and Viscosity Measurement of Liquid FeS at High Pressure and High Temperature Using Synchrotron X-ray

NASA Astrophysics Data System (ADS)

Yu, T.; Long, H.; Young, C.; Wang, L.; Chen, J.

2005-12-01

From previous experimental and theoretical studies, sulfur has been considered one of the possible light elements in the core that might be responsible for the large density deficit when compared with the theoretical pure Fe core (Ganapathy and Anders, 1974; Ahrens and Jeanloz, 1987). Therefore, understanding the physical properties of liquid FeS will help us reveal the details of the Earth?|s core. This study focused on the liquid state of sulfur in iron due to sulfur?|s lack of amount in the mantle; easiness to alloy with iron; and the predicted 5 wt% ~10 wt% amount of this light element in the core (Ahrens, 1979; Sherman, 1997). Modern development of the multi-anvil high pressure apparatus limits the pressure range of the experiments (<30 GPa). It is somewhat low if comparing with the outer core pressure condition. Therefore, extrapolation of data derived at low pressure range to the condition of the outer core (>130 GPa) has to be applied, and may produce results that are far from the true numbers. However, at the point while the techniques are limited, studying the physical properties of the liquid-phase FeS at relatively low pressures still provides us a better picture of the physical behavior of the outer core comparing with data derived from solid state FeS experiments. Pervious studies on the viscosity of the Fe-FeS system (LeBlanc and Secco, 1996; Dobson et al., 2000; Urakawa et al., 2001; Secco et al., 2002) have presented different values of viscosity numbers with a maximum difference of two orders of magnitude. We have conducted the density measurements of liquid FeS (~36 wt% of S) up to 5.6 GPa in pressure and 1673K in temperature using the in-situ synchrotron-source x-ray absorption setup at Beamline X17B2, NSLS. The viscosity measurements were conducted by the x-ray radiograph technique combined with the falling sphere method. The falling sphere method applied at the experiment is suitable for liquids with viscosities between 10-3 Pa-s and 105 Pa-s (LeBlanc et al., 1999). We used tungsten spheres in our viscosity measurement experiments. We analyzed the sphere falling motion in the sample chamber at high pressure and high temperature. And by applying our density compression curve of liquid FeS to the Stokes?| viscometry method, we were able to derive the viscosity of liquid FeS.

The x ray reflectivity of the AXAF VETA-I optics

NASA Technical Reports Server (NTRS)

Kellogg, Edwin M.; Chartas, G.; Graessle, D.; Hughes, John P.; Vanspeybroeck, Leon; Zhao, Ping; Weisskopf, M. C.; Elsner, R. F.; Odell, S. L.

1992-01-01

The x-ray reflectivity of the VETA-I optic, the outermost shell of the AXAF x-ray telescope, with a bare Zerodur surface, is measured and compared with theoretical predictions. Measurements made at energies of 0.28, 0.9, 1.5, 2.1, and 2.3 keV are compared with predictions based on ray trace calculations. The data were obtained at the x-ray calibrations facility at Marshall Space Flight Center with an electron impact x-ray source located 528 m from the grazing incidence mirror. The source used photoelectric absorption filters to eliminate bremsstrahlung continuum. The mirror has a diameter of 1.2 m and a focal length of 10 m. The incident and reflected x-ray flux are detected using two proportional counters, one located in the incident beam of x-rays at the entrance aperture of the VETA-I, and the other in the focal plane behind an aperture of variable size. Results on the variation of the reflectivity with energy as well as the absolute value of the reflectivity are presented. We also present a synchrotron reflectivity measurement with high energy resolution over the range 0.26 to 1.8 keV on a flat Zerodur sample, done at NSLS. We present evidence for contamination of the flat by a thin layer of carbon on the surface, and the possibility of alteration of the surface composition of the VETA-I mirror perhaps by the polishing technique. The overall agreement between the measured and calculated effective area of VETA-I is between 2.6 percent and 10 percent, depending on which model for the surface composition is adopted. Measurements at individual energies deviate from the best-fitting calculation to 0.3 to 0.8 percent, averaging 0.6 percent at energies below the high energy cutoff of the mirror reflectivity, and are as high as 20.7 percent at the cutoff. We also discuss the approach to the final preflight calibration of the full AXAF flight mirror.

Systems and Methods for Derivative-Free Adaptive Control

NASA Technical Reports Server (NTRS)

Calise, Anthony J. (Inventor); Yucelen, Tansel (Inventor); Kim, Kilsoo (Inventor)

2015-01-01

An adaptive control system is disclosed. The control system can control uncertain dynamic systems. The control system can employ one or more derivative-free adaptive control architectures. The control system can further employ one or more derivative-free weight update laws. The derivative-free weight update laws can comprise a time-varying estimate of an ideal vector of weights. The control system of the present invention can therefore quickly stabilize systems that undergo sudden changes in dynamics, caused by, for example, sudden changes in weight. Embodiments of the present invention can also provide a less complex control system than existing adaptive control systems. The control system can control aircraft and other dynamic systems, such as, for example, those with non-minimum phase dynamics.

Systems and Methods for Parameter Dependent Riccati Equation Approaches to Adaptive Control

NASA Technical Reports Server (NTRS)

Kim, Kilsoo (Inventor); Yucelen, Tansel (Inventor); Calise, Anthony J. (Inventor)

2015-01-01

Systems and methods for adaptive control are disclosed. The systems and methods can control uncertain dynamic systems. The control system can comprise a controller that employs a parameter dependent Riccati equation. The controller can produce a response that causes the state of the system to remain bounded. The control system can control both minimum phase and non-minimum phase systems. The control system can augment an existing, non-adaptive control design without modifying the gains employed in that design. The control system can also avoid the use of high gains in both the observer design and the adaptive control law.

Description of the SSF PMAD DC testbed control system data acquisition function

NASA Technical Reports Server (NTRS)

Baez, Anastacio N.; Mackin, Michael; Wright, Theodore

1992-01-01

The NASA LeRC in Cleveland, Ohio has completed the development and integration of a Power Management and Distribution (PMAD) DC Testbed. This testbed is a reduced scale representation of the end to end, sources to loads, Space Station Freedom Electrical Power System (SSF EPS). This unique facility is being used to demonstrate DC power generation and distribution, power management and control, and system operation techniques considered to be prime candidates for the Space Station Freedom. A key capability of the testbed is its ability to be configured to address system level issues in support of critical SSF program design milestones. Electrical power system control and operation issues like source control, source regulation, system fault protection, end-to-end system stability, health monitoring, resource allocation, and resource management are being evaluated in the testbed. The SSF EPS control functional allocation between on-board computers and ground based systems is evolving. Initially, ground based systems will perform the bulk of power system control and operation. The EPS control system is required to continuously monitor and determine the current state of the power system. The DC Testbed Control System consists of standard controllers arranged in a hierarchical and distributed architecture. These controllers provide all the monitoring and control functions for the DC Testbed Electrical Power System. Higher level controllers include the Power Management Controller, Load Management Controller, Operator Interface System, and a network of computer systems that perform some of the SSF Ground based Control Center Operation. The lower level controllers include Main Bus Switch Controllers and Photovoltaic Controllers. Power system status information is periodically provided to the higher level controllers to perform system control and operation. The data acquisition function of the control system is distributed among the various levels of the hierarchy. Data requirements are dictated by the control system algorithms being implemented at each level. A functional description of the various levels of the testbed control system architecture, the data acquisition function, and the status of its implementationis presented.

Component Control System for a Vehicle

NASA Technical Reports Server (NTRS)

Lee, Chunhao J. (Inventor); Fraser-Chanpong, Nathan (Inventor); Vitale, Robert L. (Inventor); Akinyode, Akinjide Akinniyi (Inventor); Dawson, Andrew D. (Inventor); Guo, Raymond (Inventor); Waligora, Thomas M. (Inventor); Spain, Ivan (Inventor); Bluethmann, William J. (Inventor); Reed, Ryan M. (Inventor)

2016-01-01

A vehicle includes a chassis, a modular component, and a central operating system. The modular component is supported by the chassis. The central operating system includes a component control system, a primary master controller, and a secondary master controller. The component control system is configured for controlling the modular component. The primary and secondary master controllers are in operative communication with the component control system. The primary and secondary master controllers are configured to simultaneously transmit commands to the component control system. The component control system is configured to accept commands from the secondary master controller only when a fault occurs in the primary master controller.

Supervisory Control and Data Acquisition System | Energy Systems

Science.gov Websites

Integration Facility | NREL Supervisory Control and Data Acquisition System Supervisory Control supervisory control and data acquisition (SCADA) system monitors and controls safety systems and gathers real Energy Systems Integration Facility control room. The Energy Systems Integration Facility's SCADA system

Development of similarity theory for control systems

NASA Astrophysics Data System (ADS)

Myshlyaev, L. P.; Evtushenko, V. F.; Ivushkin, K. A.; Makarov, G. V.

2018-05-01

The area of effective application of the traditional similarity theory and the need necessity of its development for systems are discussed. The main statements underlying the similarity theory of control systems are given. The conditions for the similarity of control systems and the need for similarity control control are formulated. Methods and algorithms for estimating and similarity control of control systems and the results of research of control systems based on their similarity are presented. The similarity control of systems includes the current evaluation of the degree of similarity of control systems and the development of actions controlling similarity, and the corresponding targeted change in the state of any element of control systems.

Temperature Control. Honeywell Planning Guide.

ERIC Educational Resources Information Center

Honeywell, Inc., Minneapolis, Minn.

Presents planning considerations in selecting proper temperature control systems. Various aspects are discussed including--(1) adequate environmental control, (2) adequate control area, (3) control system design, (4) operators rate their systems, (5) type of control components, (6) basic control system, (7) automatic control systems, and (8)…

Performance of Control System Using Microcontroller for Sea Water Circulation

NASA Astrophysics Data System (ADS)

Indriani, A.; Witanto, Y.; Pratama, A. S.; Supriyadi; Hendra; Tanjung, A.

2018-02-01

Now a day control system is very important rule for any process. Control system have been used in the automatic system. Automatic system can be seen in the industrial filed, mechanical field, electrical field and etc. In industrial and mechanical field, control system are used for control of motion component such as motor, conveyor, machine, control of process made of product, control of system and soon. In electrical field, control system can met for control of electrical system as equipment or part electrical like fan, rice cooker, refrigerator, air conditioner and etc. Control system are used for control of temperature and circulation gas, air and water. Control system of temperature and circulation of water also can be used for fisher community. Control system can be create by using microcontroller, PLC and other automatic program [1][2]. In this paper we will focus on the close loop system by using microcontroller Arduino Mega to control of temperature and circulation of sea water for fisher community. Performance control system is influenced by control equipment, sensor sensitivity, test condition, environment and others. The temperature sensor is measured using the DS18S20 and the sea water clarity sensor for circulation indicator with turbidity sensor. From the test results indicated that this control system can circulate sea water and maintain the temperature and clarity of seawater in a short time.

An adaptive control system for a shell-and-tube heat exchanger

NASA Astrophysics Data System (ADS)

Skorospeshkin, M. V.; Sukhodoev, M. S.; Skorospeshkin, V. N.; Rymashevskiy, P. O.

2017-01-01

This article suggests an adaptive control system for a hydrocarbon perspiration temperature control. This control system consists of a PI-controller and a pseudolinear compensating device that modifies control system dynamic properties. As a result, the behaviour research of the developed temperature control system has been undertaken. This article shows high effectiveness of the represented adaptive control system during changing control object parameters.

Mechanization of and experience with a triplex fly-by-wire backup control system

NASA Technical Reports Server (NTRS)

Lock, W. P.; Petersen, W. R.; Whitman, G. B.

1976-01-01

A redundant three axis analog control system was designed and developed to back up a digital fly by wire control system for an F-8C airplane. The mechanization and operational experience with the backup control system, the problems involved in synchronizing it with the primary system, and the reliability of the system are discussed. The backup control system was dissimilar to the primary system, and it provided satisfactory handling through the flight envelope evaluated. Limited flight tests of a variety of control tasks showed that control was also satisfactory when the backup control system was controlled by a minimum displacement (force) side stick. The operational reliability of the F-8 digital fly by wire control system was satisfactory, with no unintentional downmodes to the backup control system in flight. The ground and flight reliability of the system's components is discussed.

Precision digital control systems

NASA Astrophysics Data System (ADS)

Vyskub, V. G.; Rozov, B. S.; Savelev, V. I.

This book is concerned with the characteristics of digital control systems of great accuracy. A classification of such systems is considered along with aspects of stabilization, programmable control applications, digital tracking systems and servomechanisms, and precision systems for the control of a scanning laser beam. Other topics explored are related to systems of proportional control, linear devices and methods for increasing precision, approaches for further decreasing the response time in the case of high-speed operation, possibilities for the implementation of a logical control law, and methods for the study of precision digital control systems. A description is presented of precision automatic control systems which make use of electronic computers, taking into account the existing possibilities for an employment of computers in automatic control systems, approaches and studies required for including a computer in such control systems, and an analysis of the structure of automatic control systems with computers. Attention is also given to functional blocks in the considered systems.

Completion of the LANSCE Proton Storage Ring Control System Upgrade -- A Successful Integration of EPICS Into a Running Control System

NASA Astrophysics Data System (ADS)

Schaller, S. C.; Bjorklund, E. A.; Carr, G. P.; Faucett, J. A.; Oothoudt, M. A.

1997-05-01

The Los Alamos Neutron Scattering Center (LANSCE) Proton Storage Ring (PSR) control system upgrade was completed in 1996. In previous work, much of a PDP-11-based control system was replaced with Experimental Physics and Industrial Control System (EPICS) controls. Several parts of the old control system which used a VAX for operator displays and direct access to a CAMAC serial highway still remained. The old system was preserved as a "fallback" if the new EPICS-based system had problems. The control system upgrade completion included conversion of several application programs to EPICS-based operator interfaces, moving some data acquisition hardware to EPICS Input-Output Controllers (IOCs), and the implementation of new gateway software to complete the overall control system interoperability. Many operator interface (OPI) screens, written by LANSCE operators, have been incorporated in the new system. The old PSR control system hardware was removed. The robustness and reliability of the new controls obviated the need for a fallback capability.

Control system design method

DOEpatents

Wilson, David G [Tijeras, NM; Robinett, III, Rush D.

2012-02-21

A control system design method and concomitant control system comprising representing a physical apparatus to be controlled as a Hamiltonian system, determining elements of the Hamiltonian system representation which are power generators, power dissipators, and power storage devices, analyzing stability and performance of the Hamiltonian system based on the results of the determining step and determining necessary and sufficient conditions for stability of the Hamiltonian system, creating a stable control system based on the results of the analyzing step, and employing the resulting control system to control the physical apparatus.

Attitude control study for a large flexible spacecraft using a Solar Electric Propulsion System (SEPS)

NASA Technical Reports Server (NTRS)

Tolivar, A. F.; Key, R. W.

1980-01-01

The attitude control performance of the solar electric propulsion system (SEPS) was evaluated. A thrust vector control system for powered flight control was examined along with a gas jet reaction control system, and a reaction wheel system, both of which have been proposed for nonpowered flight control. Comprehensive computer simulations of each control system were made and evaluated using a 30 mode spacecraft model. Results obtained indicate that thrust vector control and reaction wheel systems offer acceptable smooth proportional control. The gas jet control system is shown to be risky for a flexible structure such as SEPS, and is therefore, not recommended as a primary control method.

46 CFR 63.20-1 - Specific control system requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Specific control system requirements. 63.20-1 Section 63... AUXILIARY BOILERS Additional Control System Requirements § 63.20-1 Specific control system requirements. In... following requirements apply for specific control systems: (a) Primary safety control system. Following...

46 CFR 63.20-1 - Specific control system requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Specific control system requirements. 63.20-1 Section 63... AUXILIARY BOILERS Additional Control System Requirements § 63.20-1 Specific control system requirements. In... following requirements apply for specific control systems: (a) Primary safety control system. Following...

Optimal preview control for a linear continuous-time stochastic control system in finite-time horizon

NASA Astrophysics Data System (ADS)

Wu, Jiang; Liao, Fucheng; Tomizuka, Masayoshi

2017-01-01

This paper discusses the design of the optimal preview controller for a linear continuous-time stochastic control system in finite-time horizon, using the method of augmented error system. First, an assistant system is introduced for state shifting. Then, in order to overcome the difficulty of the state equation of the stochastic control system being unable to be differentiated because of Brownian motion, the integrator is introduced. Thus, the augmented error system which contains the integrator vector, control input, reference signal, error vector and state of the system is reconstructed. This leads to the tracking problem of the optimal preview control of the linear stochastic control system being transformed into the optimal output tracking problem of the augmented error system. With the method of dynamic programming in the theory of stochastic control, the optimal controller with previewable signals of the augmented error system being equal to the controller of the original system is obtained. Finally, numerical simulations show the effectiveness of the controller.

14 CFR 27.395 - Control system.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Control system. 27.395 Section 27.395... STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Control Surface and System Loads § 27.395 Control system. (a) The part of each control system from the pilot's controls to the control stops must be...

Mechanization of and experience with a triplex fly-by-wire backup control system

NASA Technical Reports Server (NTRS)

Lock, W. P.; Petersen, W. R.; Whitman, G. B.

1975-01-01

A redundant three-axis analog control system was designed and developed to back up a digital fly-by-wire control system for an F-8C airplane. Forty-two flights, involving 58 hours of flight time, were flown by six pilots. The mechanization and operational experience with the backup control system, the problems involved in synchronizing it with the primary system, and the reliability of the system are discussed. The backup control system was dissimilar to the primary system, and it provided satisfactory handling through the flight envelope evaluated. Limited flight tests of a variety of control tasks showed that control was also satisfactory when the backup control system was controlled by a minimum-displacement (force) side stick. The operational reliability of the F-8 digital fly-by-wire control system was satisfactory, with no unintentional downmodes to the backup control system in flight. The ground and flight reliability of the system's components is discussed.

14 CFR 23.685 - Control system details.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Control Systems § 23.685 Control system details. (a) Each detail of each control system must be designed... cables or tubes against other parts. (d) Each element of the flight control system must have design... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Control system details. 23.685 Section 23...

14 CFR 23.685 - Control system details.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Control Systems § 23.685 Control system details. (a) Each detail of each control system must be designed... cables or tubes against other parts. (d) Each element of the flight control system must have design... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Control system details. 23.685 Section 23...

14 CFR 23.685 - Control system details.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Control Systems § 23.685 Control system details. (a) Each detail of each control system must be designed... cables or tubes against other parts. (d) Each element of the flight control system must have design... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Control system details. 23.685 Section 23...

14 CFR 23.685 - Control system details.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Control Systems § 23.685 Control system details. (a) Each detail of each control system must be designed... cables or tubes against other parts. (d) Each element of the flight control system must have design... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Control system details. 23.685 Section 23...

14 CFR 23.685 - Control system details.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Control Systems § 23.685 Control system details. (a) Each detail of each control system must be designed... cables or tubes against other parts. (d) Each element of the flight control system must have design... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Control system details. 23.685 Section 23...

Summary of compliant and multi-arm control at NASA. Langley Research Center

NASA Technical Reports Server (NTRS)

Harrison, Fenton W.

1992-01-01

The topics are presented in viewgraph form and include the: single arm system, single arm axis system, single arm control systems, single arm hand controller axis system, single arm position axis system, single arm vision axis system, single arm force axis system, multi-arm system, multi-arm axis system, and the dual arm hand control axis system with control signals.

Underwater hydraulic shock shovel control system

NASA Astrophysics Data System (ADS)

Liu, He-Ping; Luo, A.-Ni; Xiao, Hai-Yan

2008-06-01

The control system determines the effectiveness of an underwater hydraulic shock shovel. This paper begins by analyzing the working principles of these shovels and explains the importance of their control systems. A new type of control system’s mathematical model was built and analyzed according to those principles. Since the initial control system’s response time could not fulfill the design requirements, a PID controller was added to the control system. System response time was still slower than required, so a neural network was added to nonlinearly regulate the proportional element, integral element and derivative element coefficients of the PID controller. After these improvements to the control system, system parameters fulfilled the design requirements. The working performance of electrically-controlled parts such as the rapidly moving high speed switch valve is largely determined by the control system. Normal control methods generally can’t satisfy a shovel’s requirements, so advanced and normal control methods were combined to improve the control system, bringing good results.

Energy Systems Integration Facility Control Room | Energy Systems

Science.gov Websites

Integration Facility | NREL Energy Systems Integration Facility Control Room Energy Systems Integration Facility Control Room The Energy Systems Integration Facility control room allows system engineers as the monitoring point for the facility's integrated safety and control systems. Photo of employees

Research on Integrated Control of Microgrid Operation Mode

NASA Astrophysics Data System (ADS)

Cheng, ZhiPing; Gao, JinFeng; Li, HangYu

2018-03-01

The mode switching control of microgrid is the focus of its system control. According to the characteristics of different control, an integrated control system is put forward according to the detecting voltage and frequency deviation after switching of microgrid operating mode. This control system employs master-slave and peer-to-peer control. Wind turbine and photovoltaic(PV) adopt P/Q control, so the maximum power output can be achieved. The energy storage will work under the droop control if the system is grid-connected. When the system is off-grid, whether to employ droop control or P/f control is determined by system status. The simulation has been done and the system performance can meet the requirement.

Structural makeup, biopolymer conformation, and biodegradation characteristics of a newly developed super genotype of oats (CDC SO-I versus conventional varieties): a novel approach.

PubMed

Damiran, Daalkhaijav; Yu, Peiqiang

2010-02-24

Recently, a new "super" genotype of oats (CDC SO-I or SO-I) has been developed. The objectives of this study were to determine structural makeup (features) of oat grain in endosperm and pericarp regions and to reveal and identify differences in protein amide I and II and carbohydrate structural makeup (conformation) between SO-I and two conventional oats (CDC Dancer and Derby) grown in western Canada in 2006, using advanced synchrotron radiation based Fourier transform infrared microspectroscopy (SRFTIRM). The SRFTIRM experiments were conducted at National Synchrotron Light Sources, Brookhaven National Laboratory (NSLS, BNL, U.S. Department of Energy). From the results, it was observed that comparison between the new genotype oats and conventional oats showed (1) differences in basic chemical and protein subfraction profiles and energy values with the new SO-I oats containing lower lignin (21 g/kg of DM) and higher soluble crude protein (530 g/kg CP), crude fat (59 g/kg of DM), and energy values (TDN, 820 g/kg of DM; NE(L3x), 7.8 MJ/kg of DM); (2) significant differences in rumen biodegradation kinetics of dry matter, starch, and protein with the new SO-I oats containing lower EDDM (638 g/kg of DM) and higher EDCP (103 g/kg of DM); (3) significant differences in nutrient supply with highest truly absorbed rumen undegraded protein (ARUP, 23 g/kg of DM) and total metabolizable protein supply (MP, 81 g/kg of DM) from the new SO-I oats; and (4) significant differences in structural makeup in terms of protein amide I in the endosperm region (with amide I peak height from 0.13 to 0.22 IR absorbance unit) and cellulosic compounds to carbohydrate ratio in the pericarp region (ratio from 0.02 to 0.06). The results suggest that with the SRFTIRM technique, the structural makeup differences between the new genotype oats (SO-I) and two conventional oats (Dancer and Derby) could be revealed.

Structural Make-up, Biopolymer Conformation, and Biodegradation Characteristics of Newly Developed Super Genotype of Oats (CDC SO-I vs. Conventional Varieties): Novel Approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Damiran, D.; Yu, P

Recently, a new 'super' genotype of oats (CDC SO-I or SO-I) has been developed. The objectives of this study were to determine structural makeup (features) of oat grain in endosperm and pericarp regions and to reveal and identify differences in protein amide I and II and carbohydrate structural makeup (conformation) between SO-I and two conventional oats (CDC Dancer and Derby) grown in western Canada in 2006, using advanced synchrotron radiation based Fourier transform infrared microspectroscopy (SRFTIRM). The SRFTIRM experiments were conducted at National Synchrotron Light Sources, Brookhaven National Laboratory (NSLS, BNL, U.S. Department of Energy). From the results, it wasmore » observed that comparison between the new genotype oats and conventional oats showed (1) differences in basic chemical and protein subfraction profiles and energy values with the new SO-I oats containing lower lignin (21 g/kg of DM) and higher soluble crude protein (530 g/kg CP), crude fat (59 g/kg of DM), and energy values (TDN, 820 g/kg of DM; NE{sub L3x}, 7.8 MJ/kg of DM); (2) significant differences in rumen biodegradation kinetics of dry matter, starch, and protein with the new SO-I oats containing lower EDDM (638 g/kg of DM) and higher EDCP (103 g/kg of DM); (3) significant differences in nutrient supply with highest truly absorbed rumen undegraded protein (ARUP, 23 g/kg of DM) and total metabolizable protein supply (MP, 81 g/kg of DM) from the new SO-I oats; and (4) significant differences in structural makeup in terms of protein amide I in the endosperm region (with amide I peak height from 0.13 to 0.22 IR absorbance unit) and cellulosic compounds to carbohydrate ratio in the pericarp region (ratio from 0.02 to 0.06). The results suggest that with the SRFTIRM technique, the structural makeup differences between the new genotype oats (SO-I) and two conventional oats (Dancer and Derby) could be revealed.« less

Robust Extraction and Multi-Technique Analysis of Micrometeoroids Captured in Low Earth Orbit

NASA Technical Reports Server (NTRS)

Westphal, A. J.; Graham, G. A.; Bench, G.; Brennan, S.; Luening, K.; Pianetta, P.; Keller, L. P.; Flynn, G. J.; Snead, C.; Dominquez, G.

2003-01-01

The use of low-density silica aerogel as the primary capture cell technology for the NASA Discovery mission Stardust to Comet Wild-2 [1] is a strong motivation for researchers within the Meteoritics community to develop techniques to handle this material. The unique properties of silica aerogel allow dust particles to be captured at hypervelocity speeds and to remain partially intact. The same unique properties present difficulties in the preparation of particles for analysis. Using tools borrowed from microbiologists, we have developed techniques for robustly extracting captured hypervelocity dust particles and their residues from aerogel collectors[2-3]. It is important not only to refine these extraction techniques but also to develop protocols for analyzing the captured particles. Since Stardust does not return material to Earth until 2006, researchers must either analyze particles that are impacted in the laboratory using light-gasgun facilities [e.g. 41 or examine aerogel collectors that have been exposed in low-Earth orbit (LEO) [5]. While there are certainly benefits in laboratory shots, i.e. accelerating known compositions of projectiles into aerogel, the LEO capture particles offer the opportunity to investigate real particles captured under real conditions. The aerogel collectors used in this research are part of the NASA Orbital Debris Collection Experiment that was exposed on the MIR Space Station for 18 months [5]. We have developed the capability at the UCB Space Sciences Laboratory to extract tiny volumes of aerogel that completely contain each impact event, and to mount them on micromachined fixtures so that they can be analyzed with no interfering support (Fig.1). These aerogel keystones simultaneously bring the terminal particle and the particle track to within 10 m (15 g cm- ) of the nearest aerogel surface. The extracted aerogel wedges containing both the impact tracks and the captured particles have been characterized using the synchrotron total external reflection X-ray fluorescence (TXRF) microprobe at SSRL, the Nuclear Microprobe at LLNL, synchrotron infrared microscopy at the ALS facility at LBL and the NSLS at BNL, and the Total Reflection X-ray Fluorescence (TXRF) facility at SLAC.

Model and Study on Cascade Control System Based on IGBT Chopping Control

NASA Astrophysics Data System (ADS)

Niu, Yuxin; Chen, Liangqiao; Wang, Shuwen

2018-01-01

Thyristor cascade control system has a wide range of applications in the industrial field, but the traditional cascade control system has some shortcomings, such as a low power factor, serious harmonic pollution. In this paper, not only analyzing its system structure and working principle, but also discussing the two main factors affecting the power factor. Chopping-control cascade control system, adopted a new power switching device IGBT, which could overcome traditional cascade control system’s two main drawbacks efficiently. The basic principle of this cascade control system is discussed in this paper and the model of speed control system is built by using MATLAB/Simulink software. Finally, the simulation results of the system shows that the system works efficiently. This system is worthy to be spread widely in engineering application.

Adaptive control system having hedge unit and related apparatus and methods

NASA Technical Reports Server (NTRS)

Johnson, Eric Norman (Inventor); Calise, Anthony J. (Inventor)

2003-01-01

The invention includes an adaptive control system used to control a plant. The adaptive control system includes a hedge unit that receives at least one control signal and a plant state signal. The hedge unit generates a hedge signal based on the control signal, the plant state signal, and a hedge model including a first model having one or more characteristics to which the adaptive control system is not to adapt, and a second model not having the characteristic(s) to which the adaptive control system is not to adapt. The hedge signal is used in the adaptive control system to remove the effect of the characteristic from a signal supplied to an adaptation law unit of the adaptive control system so that the adaptive control system does not adapt to the characteristic in controlling the plant.

Active optical control system design of the SONG-China Telescope

NASA Astrophysics Data System (ADS)

Ye, Yu; Kou, Songfeng; Niu, Dongsheng; Li, Cheng; Wang, Guomin

2012-09-01

The standard SONG node structure of control system is presented. The active optical control system of the project is a distributed system, and a host computer and a slave intelligent controller are included. The host control computer collects the information from wave front sensor and sends commands to the slave computer to realize a closed loop model. For intelligent controller, a programmable logic controller (PLC) system is used. This system combines with industrial personal computer (IPC) and PLC to make up a control system with powerful and reliable.

78 FR 24368 - Airworthiness Directives; Bell Helicopter Textron, Inc. (Bell) Model Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-25

... chain and cable control system with a push-pull control system. Since we issued that AD, we have... requires replacing the existing chain and cable control system with a push-pull control system. Both... Model 205A-1 to replace the tail rotor chain and cable control system with a push-pull control system...

Automotive Stirling engine system component review

NASA Technical Reports Server (NTRS)

Hindes, Chip; Stotts, Robert

1987-01-01

The design and testing of the power and combustion control system for the basic Stirling engine, Mod II, are examined. The power control system is concerned with transparent operation, and the Mod II uses engine working gas pressure variation to control the power output of the engine. The main components of the power control system, the power control valve, the pump-down system, and the hydrogen stable system, are described. The combustion control system consists of a combustion air supply system and an air/fuel ratio control system, and the system is to maintain constant heater head temperature, and to maximize combustion efficiency and to minimize exhaust emissions.

Networked event-triggered control: an introduction and research trends

NASA Astrophysics Data System (ADS)

Mahmoud, Magdi S.; Sabih, Muhammad

2014-11-01

A physical system can be studied as either continuous time or discrete-time system depending upon the control objectives. Discrete-time control systems can be further classified into two categories based on the sampling: (1) time-triggered control systems and (2) event-triggered control systems. Time-triggered systems sample states and calculate controls at every sampling instant in a periodic fashion, even in cases when states and calculated control do not change much. This indicates unnecessary and useless data transmission and computation efforts of a time-triggered system, thus inefficiency. For networked systems, the transmission of measurement and control signals, thus, cause unnecessary network traffic. Event-triggered systems, on the other hand, have potential to reduce the communication burden in addition to reducing the computation of control signals. This paper provides an up-to-date survey on the event-triggered methods for control systems and highlights the potential research directions.

Analysis of the use of industrial control systems in simulators: state of the art and basic guidelines.

PubMed

Carrasco, Juan A; Dormido, Sebastián

2006-04-01

The use of industrial control systems in simulators facilitates the execution of engineering activities related with the installation and the optimization of the control systems in real plants. "Industrial control system" intends to be a valid term that would represent all the control systems which can be installed in an industrial plant, ranging from complex distributed control systems and SCADA packages to small single control devices. This paper summarizes the current alternatives for the development of simulators of industrial plants and presents an analysis of the process of integrating an industrial control system into a simulator, with the aim of helping in the installation of real control systems in simulators.

Weld Nugget Temperature Control in Thermal Stir Welding

NASA Technical Reports Server (NTRS)

Ding, R. Jeffrey (Inventor)

2014-01-01

A control system for a thermal stir welding system is provided. The control system includes a sensor and a controller. The sensor is coupled to the welding system's containment plate assembly and generates signals indicative of temperature of a region adjacent and parallel to the welding system's stir rod. The controller is coupled to the sensor and generates at least one control signal using the sensor signals indicative of temperature. The controller is also coupled to the welding system such that at least one of rotational speed of the stir rod, heat supplied by the welding system's induction heater, and feed speed of the welding system's weld material feeder are controlled based on the control signal(s).

Adaptive variable structure hierarchical fuzzy control for a class of high-order nonlinear dynamic systems.

PubMed

Mansouri, Mohammad; Teshnehlab, Mohammad; Aliyari Shoorehdeli, Mahdi

2015-05-01

In this paper, a novel adaptive hierarchical fuzzy control system based on the variable structure control is developed for a class of SISO canonical nonlinear systems in the presence of bounded disturbances. It is assumed that nonlinear functions of the systems be completely unknown. Switching surfaces are incorporated into the hierarchical fuzzy control scheme to ensure the system stability. A fuzzy soft switching system decides the operation area of the hierarchical fuzzy control and variable structure control systems. All the nonlinearly appeared parameters of conclusion parts of fuzzy blocks located in different layers of the hierarchical fuzzy control system are adjusted through adaptation laws deduced from the defined Lyapunov function. The proposed hierarchical fuzzy control system reduces the number of rules and consequently the number of tunable parameters with respect to the ordinary fuzzy control system. Global boundedness of the overall adaptive system and the desired precision are achieved using the proposed adaptive control system. In this study, an adaptive hierarchical fuzzy system is used for two objectives; it can be as a function approximator or a control system based on an intelligent-classic approach. Three theorems are proven to investigate the stability of the nonlinear dynamic systems. The important point about the proposed theorems is that they can be applied not only to hierarchical fuzzy controllers with different structures of hierarchical fuzzy controller, but also to ordinary fuzzy controllers. Therefore, the proposed algorithm is more general. To show the effectiveness of the proposed method four systems (two mechanical, one mathematical and one chaotic) are considered in simulations. Simulation results demonstrate the validity, efficiency and feasibility of the proposed approach to control of nonlinear dynamic systems. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Hybrid supervisory control using recurrent fuzzy neural network for tracking periodic inputs.

PubMed

Lin, F J; Wai, R J; Hong, C M

2001-01-01

A hybrid supervisory control system using a recurrent fuzzy neural network (RFNN) is proposed to control the mover of a permanent magnet linear synchronous motor (PMLSM) servo drive for the tracking of periodic reference inputs. First, the field-oriented mechanism is applied to formulate the dynamic equation of the PMLSM. Then, a hybrid supervisory control system, which combines a supervisory control system and an intelligent control system, is proposed to control the mover of the PMLSM for periodic motion. The supervisory control law is designed based on the uncertainty bounds of the controlled system to stabilize the system states around a predefined bound region. Since the supervisory control law will induce excessive and chattering control effort, the intelligent control system is introduced to smooth and reduce the control effort when the system states are inside the predefined bound region. In the intelligent control system, the RFNN control is the main tracking controller which is used to mimic a idea control law and a compensated control is proposed to compensate the difference between the idea control law and the RFNN control. The RFNN has the merits of fuzzy inference, dynamic mapping and fast convergence speed, In addition, an online parameter training methodology, which is derived using the Lyapunov stability theorem and the gradient descent method, is proposed to increase the learning capability of the RFNN. The proposed hybrid supervisory control system using RFNN can track various periodic reference inputs effectively with robust control performance.

CONTROL ROOM WITH SPRINKLER SYSTEM CONTROLS, INCLUDING MANUAL CONTROL BOXES ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CONTROL ROOM WITH SPRINKLER SYSTEM CONTROLS, INCLUDING MANUAL CONTROL BOXES FOR THE VENTILATION SYSTEM AND A PLC SWITCH FOR AUTOMATIC CO (CARBON MONOXIDE) SYSTEM. THE AIR TESTING SYSTEM IS FREE STANDING AND THE FANS ARE COMPUTER-OPERATED. - Alaskan Way Viaduct and Battery Street Tunnel, Seattle, King County, WA

A New Design Method of Automotive Electronic Real-time Control System

NASA Astrophysics Data System (ADS)

Zuo, Wenying; Li, Yinguo; Wang, Fengjuan; Hou, Xiaobo

Structure and functionality of automotive electronic control system is becoming more and more complex. The traditional manual programming development mode to realize automotive electronic control system can't satisfy development needs. So, in order to meet diversity and speedability of development of real-time control system, combining model-based design approach and auto code generation technology, this paper proposed a new design method of automotive electronic control system based on Simulink/RTW. Fristly, design algorithms and build a control system model in Matlab/Simulink. Then generate embedded code automatically by RTW and achieve automotive real-time control system development in OSEK/VDX operating system environment. The new development mode can significantly shorten the development cycle of automotive electronic control system, improve program's portability, reusability and scalability and had certain practical value for the development of real-time control system.

40 CFR 63.746 - Standards: Depainting operations.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., or paragraph (c) where organic HAP are controlled using a control system. This section does not apply... filter system, three-stage filter system, or other control system equivalent to the three-stage filter... operation shall be reduced by the use of a control system. Each control system that was installed before the...

40 CFR 63.746 - Standards: Depainting operations.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., or paragraph (c) where organic HAP are controlled using a control system. This section does not apply... filter system, three-stage filter system, or other control system equivalent to the three-stage filter... operation shall be reduced by the use of a control system. Each control system that was installed before the...

40 CFR 63.746 - Standards: Depainting operations.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., or paragraph (c) where organic HAP are controlled using a control system. This section does not apply... filter system, three-stage filter system, or other control system equivalent to the three-stage filter... operation shall be reduced by the use of a control system. Each control system that was installed before the...

40 CFR 63.746 - Standards: Depainting operations.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., or paragraph (c) where organic HAP are controlled using a control system. This section does not apply... filter system, three-stage filter system, or other control system equivalent to the three-stage filter... operation shall be reduced by the use of a control system. Each control system that was installed before the...

Research on the man in the loop control system of the robot arm based on gesture control

NASA Astrophysics Data System (ADS)

Xiao, Lifeng; Peng, Jinbao

2017-03-01

The Man in the loop control system of the robot arm based on gesture control research complex real-world environment, which requires the operator to continuously control and adjust the remote manipulator, as the background, completes the specific mission human in the loop entire system as the research object. This paper puts forward a kind of robot arm control system of Man in the loop based on gesture control, by robot arm control system based on gesture control and Virtual reality scene feedback to enhance immersion and integration of operator, to make operator really become a part of the whole control loop. This paper expounds how to construct a man in the loop control system of the robot arm based on gesture control. The system is a complex system of human computer cooperative control, but also people in the loop control problem areas. The new system solves the problems that the traditional method has no immersion feeling and the operation lever is unnatural, the adjustment time is long, and the data glove mode wears uncomfortable and the price is expensive.

Experience with synchronous and asynchronous digital control systems

NASA Technical Reports Server (NTRS)

Regenie, V. A.; Chacon, C. V.; Lock, W. P.

1986-01-01

Flight control systems have undergone a revolution since the days of simple mechanical linkages; presently the most advanced systems are full-authority, full-time digital systems controlling unstable aircraft. With the use of advanced control systems, the aerodynamic design can incorporate features that allow greater performance and fuel savings, as can be seen on the new Airbus design and advanced tactical fighter concepts. These advanced aircraft will be and are relying on the flight control system to provide the stability and handling qualities required for safe flight and to allow the pilot to control the aircraft. Various design philosophies have been proposed and followed to investigate system architectures for these advanced flight control systems. One major area of discussion is whether a multichannel digital control system should be synchronous or asynchronous. This paper addressed the flight experience at the Dryden Flight Research Facility of NASA's Ames Research Center with both synchronous and asynchronous digital flight control systems. Four different flight control systems are evaluated against criteria such as software reliability, cost increases, and schedule delays.

Evolving Systems and Adaptive Key Component Control

NASA Technical Reports Server (NTRS)

Frost, Susan A.; Balas, Mark J.

2009-01-01

We propose a new framework called Evolving Systems to describe the self-assembly, or autonomous assembly, of actively controlled dynamical subsystems into an Evolved System with a higher purpose. An introduction to Evolving Systems and exploration of the essential topics of the control and stability properties of Evolving Systems is provided. This chapter defines a framework for Evolving Systems, develops theory and control solutions for fundamental characteristics of Evolving Systems, and provides illustrative examples of Evolving Systems and their control with adaptive key component controllers.

The Galileo scan platform pointing control system - A modern control theoretic viewpoint

NASA Technical Reports Server (NTRS)

Sevaston, G. E.; Macala, G. A.; Man, G. K.

1985-01-01

The current Galileo scan platform pointing control system (SPPCS) is described, and ways in which modern control concepts could serve to enhance it are considered. Of particular interest are: the multi-variable design model and overall control system architecture, command input filtering, feedback compensator and command input design, stability robustness constraint for both continuous time control systems and for sampled data control systems, and digital implementation of the control system. The proposed approach leads to the design of a system that is similar to current Galileo SPPCS configuration, but promises to be more systematic.

Reliable actuators for twin rotor MIMO system

NASA Astrophysics Data System (ADS)

Rao, Vidya S.; V. I, George; Kamath, Surekha; Shreesha, C.

2017-11-01

Twin Rotor MIMO System (TRMS) is a bench mark system to test flight control algorithms. One of the perturbations on TRMS which is likely to affect the control system is actuator failure. Therefore, there is a need for a reliable control system, which includes H infinity controller along with redundant actuators. Reliable control refers to the design of a control system to tolerate failures of a certain set of actuators or sensors while retaining desired control system properties. Output of reliable controller has to be transferred to the redundant actuator effectively to make the TRMS reliable even under actual actuator failure.

Wireless sensing and vibration control with increased redundancy and robustness design.

PubMed

Li, Peng; Li, Luyu; Song, Gangbing; Yu, Yan

2014-11-01

Control systems with long distance sensor and actuator wiring have the problem of high system cost and increased sensor noise. Wireless sensor network (WSN)-based control systems are an alternative solution involving lower setup and maintenance costs and reduced sensor noise. However, WSN-based control systems also encounter problems such as possible data loss, irregular sampling periods (due to the uncertainty of the wireless channel), and the possibility of sensor breakdown (due to the increased complexity of the overall control system). In this paper, a wireless microcontroller-based control system is designed and implemented to wirelessly perform vibration control. The wireless microcontroller-based system is quite different from regular control systems due to its limited speed and computational power. Hardware, software, and control algorithm design are described in detail to demonstrate this prototype. Model and system state compensation is used in the wireless control system to solve the problems of data loss and sensor breakdown. A positive position feedback controller is used as the control law for the task of active vibration suppression. Both wired and wireless controllers are implemented. The results show that the WSN-based control system can be successfully used to suppress the vibration and produces resilient results in the presence of sensor failure.

Solar Dynamic Power System Stability Analysis and Control

NASA Technical Reports Server (NTRS)

Momoh, James A.; Wang, Yanchun

1996-01-01

The objective of this research is to conduct dynamic analysis, control design, and control performance test of solar power system. Solar power system consists of generation system and distribution network system. A bench mark system is used in this research, which includes a generator with excitation system and governor, an ac/dc converter, six DDCU's and forty-eight loads. A detailed model is used for modeling generator. Excitation system is represented by a third order model. DDCU is represented by a seventh order system. The load is modeled by the combination of constant power and constant impedance. Eigen-analysis and eigen-sensitivity analysis are used for system dynamic analysis. The effects of excitation system, governor, ac/dc converter control, and the type of load on system stability are discussed. In order to improve system transient stability, nonlinear ac/dc converter control is introduced. The direct linearization method is used for control design. The dynamic analysis results show that these controls affect system stability in different ways. The parameter coordination of controllers are recommended based on the dynamic analysis. It is concluded from the present studies that system stability is improved by the coordination of control parameters and the nonlinear ac/dc converter control stabilize system oscillation caused by the load change and system fault efficiently.

Design and Analysis of Morpheus Lander Flight Control System

NASA Technical Reports Server (NTRS)

Jang, Jiann-Woei; Yang, Lee; Fritz, Mathew; Nguyen, Louis H.; Johnson, Wyatt R.; Hart, Jeremy J.

2014-01-01

The Morpheus Lander is a vertical takeoff and landing test bed vehicle developed to demonstrate the system performance of the Guidance, Navigation and Control (GN&C) system capability for the integrated autonomous landing and hazard avoidance system hardware and software. The Morpheus flight control system design must be robust to various mission profiles. This paper presents a design methodology for employing numerical optimization to develop the Morpheus flight control system. The design objectives include attitude tracking accuracy and robust stability with respect to rigid body dynamics and propellant slosh. Under the assumption that the Morpheus time-varying dynamics and control system can be frozen over a short period of time, the flight controllers are designed to stabilize all selected frozen-time control systems in the presence of parametric uncertainty. Both control gains in the inner attitude control loop and guidance gains in the outer position control loop are designed to maximize the vehicle performance while ensuring robustness. The flight control system designs provided herein have been demonstrated to provide stable control systems in both Draper Ares Stability Analysis Tool (ASAT) and the NASA/JSC Trick-based Morpheus time domain simulation.

Experimental Deformation of Olivine Crystals at Mantle P and T: Evidences for a Pressure-Induced Slip Transition and Implications for Upper-Mantle Seismic Anisotropy and Low Viscosity Zone

NASA Astrophysics Data System (ADS)

Raterron, P.; Chen, J.; Geenen, T.; Girard, J.

2009-04-01

Recent developments in high-pressure deformation devices coupled with synchrotron radiation allow investigating the rheology of mantle minerals and aggregates at the extreme pressure (P) and temperature (T) of their natural occurrence in the Earth. This is particularly true in the case of olivine, which rheology has been recently investigated in the Deformation-DIA apparatus (D-DIA, see Wang et al., 2003, Rev. Scientific Instr., 74, 3002) at upper-mantle P and T conditions. Olivine deforms by dislocation creep in the shallow upper-mantle, as revealed by the seismic velocity anisotropy observed in this region. The attenuation of seismic anisotropy at depth greater than 200 km is interpreted as a pressure-induced change in olivine main deformation mechanism. It was first attributed to a transition from dislocation creep to diffusion creep (Karato and Wu, 1993, Science, 260, 771). This interpretation has been challenged by deformation data obtained at high pressure (P > 3 GPa) in the dislocation creep regime (Couvy et al., 2004, EJM, 16, 877; Raterron et al., 2007, Am. Miner., 92, 1436; Raterron et al., 2009, PEPI, 72, 74), which support a second interpretation: a transition in olivine dominant dislocation slip, from [100] slip at low P to [001] slip at high P (e.g., Mainprice et al., 2005, Nature, 433, 731). Such a P -induced [100]/[001] slip transition is also supported by recent theoretical studies based on first-principle calculations of olivine dislocation slips (Durinck et al., 2005, PCM, 32, 646; Durinck et al., 2007, Eur. J. Mineral., 19, 631). In order to further constrain the effect of pressure on olivine slip system activities, deformation experiments were carried out in poor water condition at P > 5 GPa and T =1400˚ C, on pure forsterite (Fo100) and San Carlos olivine crystals, using the D-DIA at the X17B2 beamline of the NSLS (Upton, NY, USA). Crystals were oriented in order to active either [100] slip alone or [001] slip alone in (010) plane, or both [100](001) and [001](100) systems together. Constant applied stress < 300 MPa and specimen strain rates were monitored in situ using time-resolved X-ray diffraction and radiography, respectively. Run products were investigated by transmission electron microscopy (TEM) in order to verify the actual activation of the tested dislocation slip systems. The obtained data were compared with rheological data previously obtained at comparable T and conditions, but at room P (Darot and Gueguen, 1981, JGR, 86, 6219; Bai et al., 1991, JGR, 96, 2441), resulting in creep power laws which quantify the effect of P on olivine rheology. The new data confirm the occurrence of a P -induced [100]/[001] slip transition, and suggest that [001](010) system dominates olivine deformation in the deep upper mantle. Extrapolation of the obtained rheological laws to natural condition along upper-mantle geotherms, shows that the [100] / [001] slip transition should occur in the Earth at ~ 200 km depth, thus can explain the attenuation of seismic anisotropy in the deep upper mantle. The obtained rheological laws were also integrated into a straightforward olivine aggregate model, then extrapolated to mantle condition using a 2-D geodynamic modeling application (Van den Berg et al., 1993, Geophys. J. International, 115, 62), which is the simplest approach to investigate upper-mantle steady-state deformation. In the application, the velocity of the lower boundary (the transition-zone boundary at 410-km depth) was set to 0, while that at the Earth's surface was set to 2 cm/year. Results from this modeling suggest that the combine activity of [100] and [001] slips in olivine aggregates may significantly decrease mantle viscosity below the oceanic lithosphere, thus, may contribute to the low viscosity zone (LVZ) required in plate tectonics to decouple rigid plates from the more ductile asthenophere underneath.

Robust Operation of Tendon-Driven Robot Fingers Using Force and Position-Based Control Laws

NASA Technical Reports Server (NTRS)

Hargrave, Brian (Inventor); Abdallah, Muhammad E (Inventor); Reiland, Matthew J (Inventor); Diftler, Myron A (Inventor); Strawser, Philip A (Inventor); Platt, Jr., Robert J. (Inventor); Ihrke, Chris A. (Inventor)

2013-01-01

A robotic system includes a tendon-driven finger and a control system. The system controls the finger via a force-based control law when a tension sensor is available, and via a position-based control law when a sensor is not available. Multiple tendons may each have a corresponding sensor. The system selectively injects a compliance value into the position-based control law when only some sensors are available. A control system includes a host machine and a non-transitory computer-readable medium having a control process, which is executed by the host machine to control the finger via the force- or position-based control law. A method for controlling the finger includes determining the availability of a tension sensor(s), and selectively controlling the finger, using the control system, via the force or position-based control law. The position control law allows the control system to resist disturbances while nominally maintaining the initial state of internal tendon tensions.

Minimum Control Requirements for Advanced Life Support Systems

NASA Technical Reports Server (NTRS)

Boulange, Richard; Jones, Harry; Jones, Harry

2002-01-01

Advanced control technologies are not necessary for the safe, reliable and continuous operation of Advanced Life Support (ALS) systems. ALS systems can and are adequately controlled by simple, reliable, low-level methodologies and algorithms. The automation provided by advanced control technologies is claimed to decrease system mass and necessary crew time by reducing buffer size and minimizing crew involvement. In truth, these approaches increase control system complexity without clearly demonstrating an increase in reliability across the ALS system. Unless these systems are as reliable as the hardware they control, there is no savings to be had. A baseline ALS system is presented with the minimal control system required for its continuous safe reliable operation. This baseline control system uses simple algorithms and scheduling methodologies and relies on human intervention only in the event of failure of the redundant backup equipment. This ALS system architecture is designed for reliable operation, with minimal components and minimal control system complexity. The fundamental design precept followed is "If it isn't there, it can't fail".

Computer optimization techniques for NASA Langley's CSI evolutionary model's real-time control system

NASA Technical Reports Server (NTRS)

Elliott, Kenny B.; Ugoletti, Roberto; Sulla, Jeff

1992-01-01

The evolution and optimization of a real-time digital control system is presented. The control system is part of a testbed used to perform focused technology research on the interactions of spacecraft platform and instrument controllers with the flexible-body dynamics of the platform and platform appendages. The control system consists of Computer Automated Measurement and Control (CAMAC) standard data acquisition equipment interfaced to a workstation computer. The goal of this work is to optimize the control system's performance to support controls research using controllers with up to 50 states and frame rates above 200 Hz. The original system could support a 16-state controller operating at a rate of 150 Hz. By using simple yet effective software improvements, Input/Output (I/O) latencies and contention problems are reduced or eliminated in the control system. The final configuration can support a 16-state controller operating at 475 Hz. Effectively the control system's performance was increased by a factor of 3.

Interaction of feel system and flight control system dynamics on lateral flying qualities

NASA Technical Reports Server (NTRS)

Bailey, Randall E.; Powers, Bruce G.; Shafer, Mary F.

1988-01-01

An investigation of feel system and flight control system dynamics on lateral flying qualities was conducted using the variable stability USAF NT-33 aircraft. Experimental variations in feel system natural frequency, force-deflection gradient, control system command architecture type, flight control system filter frequency, and control system delay were made. The experiment data include pilot ratings using the Cooper-Harper (1969) rating scale, pilot comments, and tracking performance statistic. Three test pilots served as evaluators. The data indicate that as the feel system natural frequency is reduced lateral flying qualities degrade. At the slowest feel system frequency, the closed-loop response becomes nonlinear with a 'bobweight' effect apparent in the feel system. Feel system influences were essentially independent of the control system architecture. The flying qualities influence due to the feel system was different than when the identical dynamic systenm was used as a flight control system element.

Verification and Validation Challenges for Adaptive Flight Control of Complex Autonomous Systems

NASA Technical Reports Server (NTRS)

Nguyen, Nhan T.

2018-01-01

Autonomy of aerospace systems requires the ability for flight control systems to be able to adapt to complex uncertain dynamic environment. In spite of the five decades of research in adaptive control, the fact still remains that currently no adaptive control system has ever been deployed on any safety-critical or human-rated production systems such as passenger transport aircraft. The problem lies in the difficulty with the certification of adaptive control systems since existing certification methods cannot readily be used for nonlinear adaptive control systems. Research to address the notion of metrics for adaptive control began to appear in the recent years. These metrics, if accepted, could pave a path towards certification that would potentially lead to the adoption of adaptive control as a future control technology for safety-critical and human-rated production systems. Development of certifiable adaptive control systems represents a major challenge to overcome. Adaptive control systems with learning algorithms will never become part of the future unless it can be proven that they are highly safe and reliable. Rigorous methods for adaptive control software verification and validation must therefore be developed to ensure that adaptive control system software failures will not occur, to verify that the adaptive control system functions as required, to eliminate unintended functionality, and to demonstrate that certification requirements imposed by regulatory bodies such as the Federal Aviation Administration (FAA) can be satisfied. This presentation will discuss some of the technical issues with adaptive flight control and related V&V challenges.

Dilution cycle control for an absorption refrigeration system

DOEpatents

Reimann, Robert C.

1984-01-01

A dilution cycle control system for an absorption refrigeration system is disclosed. The control system includes a time delay relay for sensing shutdown of the absorption refrigeration system and for generating a control signal only after expiration of a preselected time period measured from the sensed shutdown of the absorption refrigeration system, during which the absorption refrigeration system is not restarted. A dilution cycle for the absorption refrigeration system is initiated in response to generation of a control signal by the time delay relay. This control system is particularly suitable for use with an absorption refrigeration system which is frequently cycled on and off since the time delay provided by the control system prevents needless dilution of the absorption refrigeration system when the system is turned off for only a short period of time and then is turned back on.

14 CFR 25.395 - Control system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Control system. 25.395 Section 25.395... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.395 Control system. (a) Longitudinal, lateral, directional, and drag control system and their supporting structures must...

14 CFR 25.395 - Control system.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Control system. 25.395 Section 25.395... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.395 Control system. (a) Longitudinal, lateral, directional, and drag control system and their supporting structures must...

Control of solar energy systems

NASA Astrophysics Data System (ADS)

Sizov, Iu. M.; Zakhidov, R. A.; Baranov, V. G.

Two approaches to the control of large solar energy systems, i.e., programmed control and control systems relying on the use of orientation transducers and feedback, are briefly reviewed, with particular attention given to problems associated with these control systems. A new control system for large solar power plants is then proposed which is based on a combination of these approaches. The general design of the control system is shown and its principle of operation described. The efficiency and cost effectiveness of the approach proposed here are demonstrated.

Gas turbine engine control system

NASA Technical Reports Server (NTRS)

Idelchik, Michael S. (Inventor)

1991-01-01

A control system and method of controlling a gas turbine engine. The control system receives an error signal and processes the error signal to form a primary fuel control signal. The control system also receives at least one anticipatory demand signal and processes the signal to form an anticipatory fuel control signal. The control system adjusts the value of the anticipatory fuel control signal based on the value of the error signal to form an adjusted anticipatory signal and then the adjusted anticipatory fuel control signal and the primary fuel control signal are combined to form a fuel command signal.

Software control and system configuration management: A systems-wide approach

NASA Technical Reports Server (NTRS)

Petersen, K. L.; Flores, C., Jr.

1984-01-01

A comprehensive software control and system configuration management process for flight-crucial digital control systems of advanced aircraft has been developed and refined to insure efficient flight system development and safe flight operations. Because of the highly complex interactions among the hardware, software, and system elements of state-of-the-art digital flight control system designs, a systems-wide approach to configuration control and management has been used. Specific procedures are implemented to govern discrepancy reporting and reconciliation, software and hardware change control, systems verification and validation testing, and formal documentation requirements. An active and knowledgeable configuration control board reviews and approves all flight system configuration modifications and revalidation tests. This flexible process has proved effective during the development and flight testing of several research aircraft and remotely piloted research vehicles with digital flight control systems that ranged from relatively simple to highly complex, integrated mechanizations.

Implementation method of multi-terminal DC control system

NASA Astrophysics Data System (ADS)

Yi, Liu; Hao-Ran, Huang; Jun-Wen, Zhou; Hong-Guang, Guo; Yu-Yong, Zhou

2018-04-01

Currently the multi-terminal DC system (MTDC) has more stations. Each station needs operators to monitor and control the device. It needs much more operation and maintenance, low efficiency and small reliability; for the most important reason, multi-terminal DC system has complex control mode. If one of the stations has some problem, the control of the whole system should have problems. According to research of the characteristics of multi-terminal DC (VSC-MTDC) systems, this paper presents a strong implementation of the multi-terminal DC Supervisory Control and Data Acquisition (SCADA) system. This system is intelligent, can be networking, integration and intelligent. A master control system is added in each station to communication with the other stations to send current and DC voltage value to pole control system for each station. Based on the practical application and information feedback in the China South Power Grid research center VSC-MTDC project, this system is higher efficiency and save the cost on the maintenance of convertor station to improve the intelligent level and comprehensive effect. And because of the master control system, a multi-terminal system hierarchy coordination control strategy is formed, this make the control and protection system more efficiency and reliability.

Embedded Control System for Smart Walking Assistance Device.

PubMed

Bosnak, Matevz; Skrjanc, Igor

2017-03-01

This paper presents the design and implementation of a unique control system for a smart hoist, a therapeutic device that is used in rehabilitation of walking. The control system features a unique human-machine interface that allows the human to intuitively control the system just by moving or rotating its body. The paper contains an overview of the complete system, including the design and implementation of custom sensors, dc servo motor controllers, communication interfaces and embedded-system based central control system. The prototype of the complete system was tested by conducting a 6-runs experiment on 11 subjects and results are showing that the proposed control system interface is indeed intuitive and simple to adopt by the user.

Implementation of EPICS based vacuum control system for variable energy cyclotron centre, Kolkata

NASA Astrophysics Data System (ADS)

Roy, Anindya; Bhole, R. B.; Nandy, Partha P.; Yadav, R. C.; Pal, Sarbajit; Roy, Amitava

2015-03-01

The vacuum system of the Room Temperature (K = 130) Cyclotron of Variable Energy Cyclotron Centre is comprised of vacuum systems of main machine and Beam Transport System. The vacuum control system is upgraded to a PLC based Automated system from the initial relay based Manual system. The supervisory control of the vacuum system is implemented in Experimental Physics and Industrial Control System (EPICS). An EPICS embedded ARM based vacuum gauge controller is developed to mitigate the requirement of vendor specific gauge controller for gauges and also for seamless integration of the gauge controllers with the control system. A set of MS-Windows ActiveX components with embedded EPICS Channel Access interface are developed to build operator interfaces with less complex programming and to incorporate typical Windows feature, e.g., user authentication, file handling, better fonts, colors, mouse actions etc. into the operator interfaces. The control parameters, monitoring parameters, and system interlocks of the system are archived in MySQL based EPICS MySQL Archiver developed indigenously. In this paper, we describe the architecture, the implementation details, and the performance of the system.

Implementation of EPICS based vacuum control system for variable energy cyclotron centre, Kolkata.

PubMed

Roy, Anindya; Bhole, R B; Nandy, Partha P; Yadav, R C; Pal, Sarbajit; Roy, Amitava

2015-03-01

The vacuum system of the Room Temperature (K = 130) Cyclotron of Variable Energy Cyclotron Centre is comprised of vacuum systems of main machine and Beam Transport System. The vacuum control system is upgraded to a PLC based Automated system from the initial relay based Manual system. The supervisory control of the vacuum system is implemented in Experimental Physics and Industrial Control System (EPICS). An EPICS embedded ARM based vacuum gauge controller is developed to mitigate the requirement of vendor specific gauge controller for gauges and also for seamless integration of the gauge controllers with the control system. A set of MS-Windows ActiveX components with embedded EPICS Channel Access interface are developed to build operator interfaces with less complex programming and to incorporate typical Windows feature, e.g., user authentication, file handling, better fonts, colors, mouse actions etc. into the operator interfaces. The control parameters, monitoring parameters, and system interlocks of the system are archived in MySQL based EPICS MySQL Archiver developed indigenously. In this paper, we describe the architecture, the implementation details, and the performance of the system.

Comparison of conventional rule based flow control with control processes based on fuzzy logic in a combined sewer system.

PubMed

Klepiszewski, K; Schmitt, T G

2002-01-01

While conventional rule based, real time flow control of sewer systems is in common use, control systems based on fuzzy logic have been used only rarely, but successfully. The intention of this study is to compare a conventional rule based control of a combined sewer system with a fuzzy logic control by using hydrodynamic simulation. The objective of both control strategies is to reduce the combined sewer overflow volume by an optimization of the utilized storage capacities of four combined sewer overflow tanks. The control systems affect the outflow of four combined sewer overflow tanks depending on the water levels inside the structures. Both systems use an identical rule base. The developed control systems are tested and optimized for a single storm event which affects heterogeneously hydraulic load conditions and local discharge. Finally the efficiencies of the two different control systems are compared for two more storm events. The results indicate that the conventional rule based control and the fuzzy control similarly reach the objective of the control strategy. In spite of the higher expense to design the fuzzy control system its use provides no advantages in this case.

Application of control theory to dynamic systems simulation

NASA Technical Reports Server (NTRS)

Auslander, D. M.; Spear, R. C.; Young, G. E.

1982-01-01

The application of control theory is applied to dynamic systems simulation. Theory and methodology applicable to controlled ecological life support systems are considered. Spatial effects on system stability, design of control systems with uncertain parameters, and an interactive computing language (PARASOL-II) designed for dynamic system simulation, report quality graphics, data acquisition, and simple real time control are discussed.

14 CFR 29.395 - Control system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Control system. (a) The reaction to the loads prescribed in § 29.397 must be provided by— (1) The control... its limit of motion); (4) The attachment of the control system to the rotor blade pitch control horn... of its motion); and (5) The attachment of the control system to the control surface horn (with the...

14 CFR 29.395 - Control system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Control system. (a) The reaction to the loads prescribed in § 29.397 must be provided by— (1) The control... its limit of motion); (4) The attachment of the control system to the rotor blade pitch control horn... of its motion); and (5) The attachment of the control system to the control surface horn (with the...

Research flight-control system development for the F-18 high alpha research vehicle

NASA Technical Reports Server (NTRS)

Pahle, Joseph W.; Powers, Bruce; Regenie, Victoria; Chacon, Vince; Degroote, Steve; Murnyak, Steven

1991-01-01

The F-18 high alpha research vehicle was recently modified by adding a thrust vectoring control system. A key element in the modification was the development of a research flight control system integrated with the basic F-18 flight control system. Discussed here are design requirements, system development, and research utility of the resulting configuration as an embedded system for flight research in the high angle of attack regime. Particular emphasis is given to control system modifications and control law features required for high angle of attack flight. Simulation results are used to illustrate some of the thrust vectoring control system capabilities and predicted maneuvering improvements.

Experience with synchronous and asynchronous digital control systems. [for flight

NASA Technical Reports Server (NTRS)

Regenie, Victoria A.; Chacon, Claude V.; Lock, Wilton P.

1986-01-01

Flight control systems have undergone a revolution since the days of simple mechanical linkages; presently the most advanced systems are full-authority, full-time digital systems controlling unstable aircraft. With the use of advanced control systems, the aerodynamic design can incorporate features that allow greater performance and fuel savings, as can be seen on the new Airbus design and advanced tactical fighter concepts. These advanced aircraft will be and are relying on the flight control system to provide the stability and handling qualities required for safe flight and to allow the pilot to control the aircraft. Various design philosophies have been proposed and followed to investigate system architectures for these advanced flight control systems. One major area of discussion is whether a multichannel digital control system should be synchronous or asynchronous. This paper addressed the flight experience at the Dryden Flight Research Facility of NASA's Ames Research Center with both synchronous and asynchronous digital flight control systems. Four different flight control systems are evaluated against criteria such as software reliability, cost increases, and schedule delays.

The trend of digital control system design for nuclear power plants in Korea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, S. H.; Jung, H. Y.; Yang, C. Y.

2006-07-01

Currently there are 20 nuclear power plants (NPPs) in operation, and 6 more units are under construction in Korea. The control systems of those NPPs have also been developed together with the technology advancement. Control systems started with On-Off control using the relay logic, had been evolved into Solid-State logic using TTL ICs, and applied with the micro-processors since the Yonggwang NPP Units 3 and 4 which started its construction in 1989. Multiplexers are also installed at the local plant areas to collect field input and to send output signals while communicating with the controllers located in the system cabinetsmore » near the main control room in order to reduce the field wiring cables. The design of the digital control system technology for the NPPs in Korea has been optimized to maximize the operability as well as the safety through the design, construction, start-up and operation experiences. Both Shin-Kori Units 1 and 2 and Shin-Wolsong Units 1 and 2 NPP projects under construction are being progressed at the same time. Digital Plant Control Systems of these projects have adopted multi-loop controllers, redundant loop configuration, and soft control system for the radwaste system. Programmable Logic Controller (PLC) and Distributed Control System (DCS) are applied with soft control system in Shin-Kori Units 3 and 4. This paper describes the evolvement of control system at the NPPs in Korea and the experience and design improvement through the observation of the latest failure of the digital control system. In addition, design concept and its trend of the digital control system being applied to the NPP in Korea are introduced. (authors)« less

Development of adaptive control applied to chaotic systems

NASA Astrophysics Data System (ADS)

Rhode, Martin Andreas

1997-12-01

Continuous-time derivative control and adaptive map-based recursive feedback control techniques are used to control chaos in a variety of systems and in situations that are of practical interest. The theoretical part of the research includes the review of fundamental concept of control theory in the context of its applications to deterministic chaotic systems, the development of a new adaptive algorithm to identify the linear system properties necessary for control, and the extension of the recursive proportional feedback control technique, RPF, to high dimensional systems. Chaos control was applied to models of a thermal pulsed combustor, electro-chemical dissolution and the hyperchaotic Rossler system. Important implications for combustion engineering were suggested by successful control of the model of the thermal pulsed combustor. The system was automatically tracked while maintaining control into regions of parameter and state space where no stable attractors exist. In a simulation of the electrochemical dissolution system, application of derivative control to stabilize a steady state, and adaptive RPF to stabilize a period one orbit, was demonstrated. The high dimensional adaptive control algorithm was applied in a simulation using the Rossler hyperchaotic system, where a period-two orbit with two unstable directions was stabilized and tracked over a wide range of a system parameter. In the experimental part, the electrochemical system was studied in parameter space, by scanning the applied potential and the frequency of the rotating copper disk. The automated control algorithm is demonstrated to be effective when applied to stabilize a period-one orbit in the experiment. We show the necessity of small random perturbations applied to the system in order to both learn the dynamics and control the system at the same time. The simultaneous learning and control capability is shown to be an important part of the active feedback control.

14 CFR 25.685 - Control system details.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Control system details. 25.685 Section 25... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Control Systems § 25.685 Control system details. (a) Each detail of each control system must be designed and installed to prevent jamming...

14 CFR 25.685 - Control system details.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Control Systems § 25.685 Control system details. (a) Each detail of each control system must be designed and installed to prevent jamming... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Control system details. 25.685 Section 25...

14 CFR 25.685 - Control system details.

Code of Federal Regulations, 2011 CFR

2011-01-01

... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Control Systems § 25.685 Control system details. (a) Each detail of each control system must be designed and installed to prevent jamming... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Control system details. 25.685 Section 25...

14 CFR 25.685 - Control system details.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Control Systems § 25.685 Control system details. (a) Each detail of each control system must be designed and installed to prevent jamming... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Control system details. 25.685 Section 25...

14 CFR 25.685 - Control system details.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Control Systems § 25.685 Control system details. (a) Each detail of each control system must be designed and installed to prevent jamming... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Control system details. 25.685 Section 25...

14 CFR 27.685 - Control system details.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Control Systems § 27.685 Control system details. (a) Each detail of each control system must be designed to prevent jamming, chafing, and... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Control system details. 27.685 Section 27...

14 CFR 29.685 - Control system details.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Control Systems § 29.685 Control system details. (a) Each detail of each control system must be designed to prevent jamming, chafing, and... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Control system details. 29.685 Section 29...

The study on servo-control system in the large aperture telescope

NASA Astrophysics Data System (ADS)

Hu, Wei; Zhenchao, Zhang; Daxing, Wang

2008-08-01

Large astronomical telescope or extremely enormous astronomical telescope servo tracking technique will be one of crucial technology that must be solved in researching and manufacturing. To control technique feature of large astronomical telescope or extremely enormous astronomical telescope, this paper design a sort of large astronomical telescope servo tracking control system. This system composes a principal and subordinate distributed control system, host computer sends steering instruction and receive slave computer functional mode, slave computer accomplish control algorithm and execute real-time control. Large astronomical telescope servo control use direct drive machine, and adopt DSP technology to complete direct torque control algorithm, Such design can not only increase control system performance, but also greatly reduced volume and costs of control system, which has a significant occurrence. The system design scheme can be proved reasonably by calculating and simulating. This system can be applied to large astronomical telescope.

Naval Open Architecture Machinery Control Systems for Next Generation Integrated Power Systems

DTIC Science & Technology

2012-05-01

PORTABLE) OS / RTOS ADAPTATION MIDDLEWARE (FOR OS PORTABILITY) MACHINERY CONTROLLER FRAMEWORK MACHINERY CONTROL SYSTEM SERVICES POWER CONTROL SYSTEM...SERVICES SHIP SYSTEM SERVICES TTY 0 TTY N … OPERATING SYSTEM ( OS / RTOS ) COMPUTER HARDWARE UDP IP TCP RAW DEV 0 DEV N … POWER MANAGEMENT CONTROLLER...operating systems (DOS, Windows, Linux, OS /2, QNX, SCO Unix ...) COMPUTERS: ISA compatible motherboards, workstations and portables (Compaq, Dell

Biologically inspired rate control of chaos.

PubMed

Olde Scheper, Tjeerd V

2017-10-01

The overall intention of chaotic control is to eliminate chaos and to force the system to become stable in the classical sense. In this paper, I demonstrate a more subtle method that does not eliminate all traces of chaotic behaviour; yet it consistently, and reliably, can provide control as intended. The Rate Control of Chaos (RCC) method is derived from metabolic control processes and has several remarkable properties. RCC can control complex systems continuously, and unsupervised, it can also maintain control across bifurcations, and in the presence of significant systemic noise. Specifically, I show that RCC can control a typical set of chaotic models, including the 3 and 4 dimensional chaotic Lorenz systems, in all modes. Furthermore, it is capable of controlling spatiotemporal chaos without supervision and maintains control of the system across bifurcations. This property of RCC allows a dynamic system to operate in parameter spaces that are difficult to control otherwise. This may be particularly interesting for the control of forced systems or dynamic systems that are chaotically perturbed. These control properties of RCC are applicable to a range of dynamic systems, thereby appearing to have far-reaching effects beyond just controlling chaos. RCC may also point to the existence of a biochemical control function of an enzyme, to stabilise the dynamics of the reaction cascade.

About development of automation control systems

NASA Astrophysics Data System (ADS)

Myshlyaev, L. P.; Wenger, K. G.; Ivushkin, K. A.; Makarov, V. N.

2018-05-01

The shortcomings of approaches to the development of modern control automation systems and ways of their improvement are given: the correct formation of objects for study and optimization; a joint synthesis of control objects and control systems, an increase in the structural diversity of the elements of control systems. Diagrams of control systems with purposefully variable structure of their elements are presented. Structures of control algorithms for an object with a purposefully variable structure are given.

Control and modeling of a CELSS (Controlled Ecological Life Support System)

NASA Technical Reports Server (NTRS)

Auslander, D. M.; Spear, R. C.; Babcock, P. S.; Nadel, M.

1983-01-01

Research topics that arise from the conceptualization of control for closed life support systems which are life support systems in which all or most of the mass is recycled are discussed. Modeling and control of uncertain and poorly defined systems, resource allocation in closed life support systems, and control structures or systems with delay and closure are emphasized.

Substantiation of the Necessity for Design of Geohod Control System

NASA Astrophysics Data System (ADS)

Aksenov, Vladimir; Chicherin, Ivan; Kostinez, Irina; Kazantsev, Anton; Efremenkov, Andrey

2017-11-01

The article proves the necessity of creatinga control system for the geohod. The scope of application of the geohod is described. The general scheme of the geohod with the main structural elements - cutter drum, head and tail sections, external mover - is described. Enlarged tasks that need to be addressed when creating a control system for the geohod are identified. The tasks of motion control of the geohod in the geomedium, improving the efficiency of the geohod, positioning the geohod in space, control of the support systems, diagnostics of the condition of the geohod, interaction of the control system with the operator are described. The directions of further Zresearch are identified: to formulate the requirements for the geohod control system; to analyze tasks solved by the geohod control system; develop the structure, mathematical models and algorithms for the operation of subsystems of the geohod control system; to develop software to simulate the interaction of subsystems of the geohod control system with each other, with the geomedium and the operator.

Energy Systems Integration News | Energy Systems Integration Facility |

Science.gov Websites

hierarchical control architecture that enables a hybrid control approach, where centralized control systems will be complemented by distributed control algorithms for solar inverters and autonomous control of ), involves developing a novel control scheme that provides system-wide monitoring and control using a small

Indirect learning control for nonlinear dynamical systems

NASA Technical Reports Server (NTRS)

Ryu, Yeong Soon; Longman, Richard W.

1993-01-01

In a previous paper, learning control algorithms were developed based on adaptive control ideas for linear time variant systems. The learning control methods were shown to have certain advantages over their adaptive control counterparts, such as the ability to produce zero tracking error in time varying systems, and the ability to eliminate repetitive disturbances. In recent years, certain adaptive control algorithms have been developed for multi-body dynamic systems such as robots, with global guaranteed convergence to zero tracking error for the nonlinear system euations. In this paper we study the relationship between such adaptive control methods designed for this specific class of nonlinear systems, and the learning control problem for such systems, seeking to converge to zero tracking error in following a specific command repeatedly, starting from the same initial conditions each time. The extension of these methods from the adaptive control problem to the learning control problem is seen to be trivial. The advantages and disadvantages of using learning control based on such adaptive control concepts for nonlinear systems, and the use of other currently available learning control algorithms are discussed.

Communication Needs Assessment for Distributed Turbine Engine Control

NASA Technical Reports Server (NTRS)

Culley, Dennis E.; Behbahani, Alireza R.

2008-01-01

Control system architecture is a major contributor to future propulsion engine performance enhancement and life cycle cost reduction. The control system architecture can be a means to effect net weight reduction in future engine systems, provide a streamlined approach to system design and implementation, and enable new opportunities for performance optimization and increased awareness about system health. The transition from a centralized, point-to-point analog control topology to a modular, networked, distributed system is paramount to extracting these system improvements. However, distributed engine control systems are only possible through the successful design and implementation of a suitable communication system. In a networked system, understanding the data flow between control elements is a fundamental requirement for specifying the communication architecture which, itself, is dependent on the functional capability of electronics in the engine environment. This paper presents an assessment of the communication needs for distributed control using strawman designs and relates how system design decisions relate to overall goals as we progress from the baseline centralized architecture, through partially distributed and fully distributed control systems.

Verification of operation of the actuator control system using the integration the B&R Automation Studio software with a virtual model of the actuator system

NASA Astrophysics Data System (ADS)

Herbuś, K.; Ociepka, P.

2017-08-01

In the work is analysed a sequential control system of a machine for separating and grouping work pieces for processing. Whereas, the area of the considered problem is related with verification of operation of an actuator system of an electro-pneumatic control system equipped with a PLC controller. Wherein to verification is subjected the way of operation of actuators in view of logic relationships assumed in the control system. The actuators of the considered control system were three drives of linear motion (pneumatic cylinders). And the logical structure of the system of operation of the control system is based on the signals flow graph. The tested logical structure of operation of the electro-pneumatic control system was implemented in the Automation Studio software of B&R company. This software is used to create programs for the PLC controllers. Next, in the FluidSIM software was created the model of the actuator system of the control system of a machine. To verify the created program for the PLC controller, simulating the operation of the created model, it was utilized the approach of integration these two programs using the tool for data exchange in the form of the OPC server.

Software control and system configuration management - A process that works

NASA Technical Reports Server (NTRS)

Petersen, K. L.; Flores, C., Jr.

1983-01-01

A comprehensive software control and system configuration management process for flight-crucial digital control systems of advanced aircraft has been developed and refined to insure efficient flight system development and safe flight operations. Because of the highly complex interactions among the hardware, software, and system elements of state-of-the-art digital flight control system designs, a systems-wide approach to configuration control and management has been used. Specific procedures are implemented to govern discrepancy reporting and reconciliation, software and hardware change control, systems verification and validation testing, and formal documentation requirements. An active and knowledgeable configuration control board reviews and approves all flight system configuration modifications and revalidation tests. This flexible process has proved effective during the development and flight testing of several research aircraft and remotely piloted research vehicles with digital flight control systems that ranged from relatively simple to highly complex, integrated mechanizations.

Framework and Method for Controlling a Robotic System Using a Distributed Computer Network

NASA Technical Reports Server (NTRS)

Sanders, Adam M. (Inventor); Strawser, Philip A. (Inventor); Barajas, Leandro G. (Inventor); Permenter, Frank Noble (Inventor)

2015-01-01

A robotic system for performing an autonomous task includes a humanoid robot having a plurality of compliant robotic joints, actuators, and other integrated system devices that are controllable in response to control data from various control points, and having sensors for measuring feedback data at the control points. The system includes a multi-level distributed control framework (DCF) for controlling the integrated system components over multiple high-speed communication networks. The DCF has a plurality of first controllers each embedded in a respective one of the integrated system components, e.g., the robotic joints, a second controller coordinating the components via the first controllers, and a third controller for transmitting a signal commanding performance of the autonomous task to the second controller. The DCF virtually centralizes all of the control data and the feedback data in a single location to facilitate control of the robot across the multiple communication networks.

Microgrid Controls | Grid Modernization | NREL

Science.gov Websites

Systems Integration Facility. Microgrid Controller Interaction with Distribution Management Systems This project investigates the interaction of distribution management systems with local controllers, including microgrid controllers. The project is developing integrated control and management systems for distribution

76 FR 9265 - Special Conditions: Gulfstream Model GVI Airplane; Electronic Flight Control System: Control...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-17

... for transport category airplanes. These design features include an electronic flight control system... Design Features The GVI has an electronic flight control system and no direct coupling from the cockpit...: Gulfstream Model GVI Airplane; Electronic Flight Control System: Control Surface Position Awareness AGENCY...

Simulation comparison of a decoupled longitudinal control system and a velocity vector control wheel steering system during landings in wind shear

NASA Technical Reports Server (NTRS)

Kimball, G., Jr.

1980-01-01

A simulator comparison of the velocity vector control wheel steering (VCWS) system and a decoupled longitudinal control system is presented. The piloting task was to use the electronic attitude direction indicator (EADI) to capture and maintain a 3 degree glide slope in the presence of wind shear and to complete the landing using the perspective runway included on the EADI. The decoupled control system used constant prefilter and feedback gains to provide steady state decoupling of flight path angle, pitch angle, and forward velocity. The decoupled control system improved the pilots' ability to control airspeed and flight path angle during the final stages of an approach made in severe wind shear. The system also improved their ability to complete safe landings. The pilots preferred the decoupled control system in severe winds and, on a pilot rating scale, rated the approach and landing task with the decoupled control system as much as 3 to 4 increments better than use of the VCWS system.

User's instructions for the Grodins' respiratory control model using the UNIVAC 1110 remote batch and demand processing

NASA Technical Reports Server (NTRS)

1974-01-01

The transient and steady state response of the respiratory control system for variations in volumetric fractions of inspired gases and special system parameters are modeled. The program contains the capability to change workload. The program is based on Grodins' respiratory control model and can be envisioned as a feedback control system comprised of a plant (the controlled system) and the regulating component (controlling system). The controlled system is partitioned into 3 compartments corresponding to lungs, brain, and tissue with a fluid interconnecting patch representing the blood.

Passivity-Based Control for Two-Wheeled Robot Stabilization

NASA Astrophysics Data System (ADS)

Uddin, Nur; Aryo Nugroho, Teguh; Agung Pramudito, Wahyu

2018-04-01

A passivity-based control system design for two-wheeled robot (TWR) stabilization is presented. A TWR is a statically-unstable non-linear system. A control system is applied to actively stabilize the TWR. Passivity-based control method is applied to design the control system. The design results in a state feedback control law that makes the TWR closed loop system globally asymptotically stable (GAS). The GAS is proven mathematically. The TWR stabilization is demonstrated through computer simulation. The simulation results show that the designed control system is able to stabilize the TWR.

A robust and stable PLC based control system for 40kJ/25kV EMM system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Vijay; Saroj, P.C.; Kulkarni, M.R.

2014-07-01

This paper describes the PLC based control system developed for a 40kJ/25kV Electro-magnetic machining (EMM) system. In EMM system large capacitor banks is charged with high voltage to store large energy and the banks is made to discharge into a coil within few milli-seconds using a triggered spark gaps. During discharge of the capacitor large surges and transients are generated in the system. The control system monitors/controls and interlocks all the units of the system for proper operation. The control system is the only subsystem which is electrically connected to all the low and high voltage subsystems. Care should bemore » taken at the signal interfacing with the control system to protect the control system. (author)« less

Application of Calspan pitch rate control system to the Space Shuttle for approach and landing

NASA Technical Reports Server (NTRS)

Weingarten, N. C.; Chalk, C. R.

1983-01-01

A pitch rate control system designed for use in the shuttle during approach and landing was analyzed and compared with a revised control system developed by NASA and the existing OFT control system. The design concept control system uses filtered pitch rate feedback with proportional plus integral paths in the forward loop. Control system parameters were designed as a function of flight configuration. Analysis included time and frequency domain techniques. Results indicate that both the Calspan and NASA systems significantly improve the flying qualities of the shuttle over the OFT. Better attitude and flight path control and less time delay are the primary reasons. The Calspan system is preferred because of reduced time delay and simpler mechanization. Further testing of the improved flight control systems in an in-flight simulator is recommended.

Prototype space station automation system delivered and demonstrated at NASA

NASA Technical Reports Server (NTRS)

Block, Roger F.

1987-01-01

The Automated Subsystem Control for Life Support System (ASCLSS) program has successfully developed and demonstrated a generic approach to the automation and control of Space Station subsystems. The hierarchical and distributed real time controls system places the required controls authority at every level of the automation system architecture. As a demonstration of the automation technique, the ASCLSS system automated the Air Revitalization Group (ARG) of the Space Station regenerative Environmental Control and Life Support System (ECLSS) using real-time, high fidelity simulators of the ARG processess. This automation system represents an early flight prototype and an important test bed for evaluating Space Station controls technology including future application of ADA software in real-time control and the development and demonstration of embedded artificial intelligence and expert systems (AI/ES) in distributed automation and controls systems.

Quantitative safety assessment of air traffic control systems through system control capacity

NASA Astrophysics Data System (ADS)

Guo, Jingjing

Quantitative Safety Assessments (QSA) are essential to safety benefit verification and regulations of developmental changes in safety critical systems like the Air Traffic Control (ATC) systems. Effectiveness of the assessments is particularly desirable today in the safe implementations of revolutionary ATC overhauls like NextGen and SESAR. QSA of ATC systems are however challenged by system complexity and lack of accident data. Extending from the idea "safety is a control problem" in the literature, this research proposes to assess system safety from the control perspective, through quantifying a system's "control capacity". A system's safety performance correlates to this "control capacity" in the control of "safety critical processes". To examine this idea in QSA of the ATC systems, a Control-capacity Based Safety Assessment Framework (CBSAF) is developed which includes two control capacity metrics and a procedural method. The two metrics are Probabilistic System Control-capacity (PSC) and Temporal System Control-capacity (TSC); each addresses an aspect of a system's control capacity. And the procedural method consists three general stages: I) identification of safety critical processes, II) development of system control models and III) evaluation of system control capacity. The CBSAF was tested in two case studies. The first one assesses an en-route collision avoidance scenario and compares three hypothetical configurations. The CBSAF was able to capture the uncoordinated behavior between two means of control, as was observed in a historic midair collision accident. The second case study compares CBSAF with an existing risk based QSA method in assessing the safety benefits of introducing a runway incursion alert system. Similar conclusions are reached between the two methods, while the CBSAF has the advantage of simplicity and provides a new control-based perspective and interpretation to the assessments. The case studies are intended to investigate the potential and demonstrate the utilities of CBSAF and are not intended for thorough studies of collision avoidance and runway incursions safety, which are extremely challenging problems. Further development and thorough validations are required to allow CBSAF to reach implementation phases, e.g. addressing the issues of limited scalability and subjectivity.

Electronic firing systems and methods for firing a device

DOEpatents

Frickey, Steven J [Boise, ID; Svoboda, John M [Idaho Falls, ID

2012-04-24

An electronic firing system comprising a control system, a charging system, an electrical energy storage device, a shock tube firing circuit, a shock tube connector, a blasting cap firing circuit, and a blasting cap connector. The control system controls the charging system, which charges the electrical energy storage device. The control system also controls the shock tube firing circuit and the blasting cap firing circuit. When desired, the control system signals the shock tube firing circuit or blasting cap firing circuit to electrically connect the electrical energy storage device to the shock tube connector or the blasting cap connector respectively.

Control and protection system for paralleled modular static inverter-converter systems

NASA Technical Reports Server (NTRS)

Birchenough, A. G.; Gourash, F.

1973-01-01

A control and protection system was developed for use with a paralleled 2.5-kWe-per-module static inverter-converter system. The control and protection system senses internal and external fault parameters such as voltage, frequency, current, and paralleling current unbalance. A logic system controls contactors to isolate defective power conditioners or loads. The system sequences contactor operation to automatically control parallel operation, startup, and fault isolation. Transient overload protection and fault checking sequences are included. The operation and performance of a control and protection system, with detailed circuit descriptions, are presented.

46 CFR 62.25-10 - Manual alternate control systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... automatic primary control system failure; (2) Be suitable for manual control for prolonged periods; (3) Be... 46 Shipping 2 2011-10-01 2011-10-01 false Manual alternate control systems. 62.25-10 Section 62.25... AUTOMATION General Requirements for All Automated Vital Systems § 62.25-10 Manual alternate control systems...

14 CFR 29.679 - Control system locks.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Control system locks. 29.679 Section 29.679... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Control Systems § 29.679 Control system locks. If there is a device to lock the control system with the rotorcraft on the ground or water, there...

14 CFR 27.679 - Control system locks.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Control system locks. 27.679 Section 27.679... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Control Systems § 27.679 Control system locks. If there is a device to lock the control system with the rotorcraft on the ground or water, there...

49 CFR 193.2619 - Control systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false Control systems. 193.2619 Section 193.2619...: FEDERAL SAFETY STANDARDS Maintenance § 193.2619 Control systems. (a) Each control system must be properly adjusted to operate within design limits. (b) If a control system is out of service for 30 days or more, it...

49 CFR 193.2619 - Control systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Control systems. 193.2619 Section 193.2619...: FEDERAL SAFETY STANDARDS Maintenance § 193.2619 Control systems. (a) Each control system must be properly adjusted to operate within design limits. (b) If a control system is out of service for 30 days or more, it...

49 CFR 193.2619 - Control systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Control systems. 193.2619 Section 193.2619...: FEDERAL SAFETY STANDARDS Maintenance § 193.2619 Control systems. (a) Each control system must be properly adjusted to operate within design limits. (b) If a control system is out of service for 30 days or more, it...

49 CFR 193.2619 - Control systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false Control systems. 193.2619 Section 193.2619...: FEDERAL SAFETY STANDARDS Maintenance § 193.2619 Control systems. (a) Each control system must be properly adjusted to operate within design limits. (b) If a control system is out of service for 30 days or more, it...

49 CFR 193.2619 - Control systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false Control systems. 193.2619 Section 193.2619...: FEDERAL SAFETY STANDARDS Maintenance § 193.2619 Control systems. (a) Each control system must be properly adjusted to operate within design limits. (b) If a control system is out of service for 30 days or more, it...

14 CFR 27.679 - Control system locks.

Code of Federal Regulations, 2013 CFR

2013-01-01

... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Control Systems § 27.679 Control system locks. If there is a device to lock the control system with the rotorcraft on the ground or water, there... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Control system locks. 27.679 Section 27.679...

14 CFR 23.679 - Control system locks.

Code of Federal Regulations, 2012 CFR

2012-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.679 Control system locks. If there is a device to lock the control system on the ground or... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Control system locks. 23.679 Section 23.679...

14 CFR 23.679 - Control system locks.

Code of Federal Regulations, 2011 CFR

2011-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.679 Control system locks. If there is a device to lock the control system on the ground or... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Control system locks. 23.679 Section 23.679...

14 CFR 23.679 - Control system locks.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.679 Control system locks. If there is a device to lock the control system on the ground or... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Control system locks. 23.679 Section 23.679...

14 CFR 23.679 - Control system locks.

Code of Federal Regulations, 2013 CFR

2013-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.679 Control system locks. If there is a device to lock the control system on the ground or... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Control system locks. 23.679 Section 23.679...

14 CFR 23.679 - Control system locks.

Code of Federal Regulations, 2014 CFR

2014-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.679 Control system locks. If there is a device to lock the control system on the ground or... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Control system locks. 23.679 Section 23.679...

14 CFR 29.679 - Control system locks.

Code of Federal Regulations, 2013 CFR

2013-01-01

... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Control Systems § 29.679 Control system locks. If there is a device to lock the control system with the rotorcraft on the ground or water, there... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Control system locks. 29.679 Section 29.679...

Evaluating Multi-Input/Multi-Output Digital Control Systems

NASA Technical Reports Server (NTRS)

Pototzky, Anthony S.; Wieseman, Carol D.; Hoadley, Sherwood T.; Mukhopadhyay, Vivek

1994-01-01

Controller-performance-evaluation (CPE) methodology for multi-input/multi-output (MIMO) digital control systems developed. Procedures identify potentially destabilizing controllers and confirm satisfactory performance of stabilizing ones. Methodology generic and used in many types of multi-loop digital-controller applications, including digital flight-control systems, digitally controlled spacecraft structures, and actively controlled wind-tunnel models. Also applicable to other complex, highly dynamic digital controllers, such as those in high-performance robot systems.

An Improved Method to Control the Critical Parameters of a Multivariable Control System

NASA Astrophysics Data System (ADS)

Subha Hency Jims, P.; Dharmalingam, S.; Wessley, G. Jims John

2017-10-01

The role of control systems is to cope with the process deficiencies and the undesirable effect of the external disturbances. Most of the multivariable processes are highly iterative and complex in nature. Aircraft systems, Modern Power Plants, Refineries, Robotic systems are few such complex systems that involve numerous critical parameters that need to be monitored and controlled. Control of these important parameters is not only tedious and cumbersome but also is crucial from environmental, safety and quality perspective. In this paper, one such multivariable system, namely, a utility boiler has been considered. A modern power plant is a complex arrangement of pipework and machineries with numerous interacting control loops and support systems. In this paper, the calculation of controller parameters based on classical tuning concepts has been presented. The controller parameters thus obtained and employed has controlled the critical parameters of a boiler during fuel switching disturbances. The proposed method can be applied to control the critical parameters like elevator, aileron, rudder, elevator trim rudder and aileron trim, flap control systems of aircraft systems.

Control system for 5 MW neutral beam ion source for SST1

NASA Astrophysics Data System (ADS)

Patel, G. B.; Onali, Raja; Sharma, Vivek; Suresh, S.; Tripathi, V.; Bandyopadhyay, M.; Singh, N. P.; Thakkar, Dipal; Gupta, L. N.; Singh, M. J.; Patel, P. J.; Chakraborty, A. K.; Baruah, U. K.; Mattoo, S. K.

2006-01-01

This article describes the control system for a 5MW ion source of the NBI (neutral beam injector) for steady-state superconducting tokamak-1 (SST-1). The system uses both hardware and software solutions. It comprises a DAS (data acquisition system) and a control system. The DAS is used to read the voltage and current signals from eight filament heater power supplies and 24 discharge power supplies. The control system is used to adjust the filament heater current in order to achieve an effective control on the discharge current in the plasma box. The system consists of a VME (Verse Module Eurocard) system and C application program running on a VxWorks™ real-time operating system. A PID (proportional, integral, and differential) algorithm is used to control the filament heater current. Experiments using this system have shown that the discharge current can be controlled within 1% accuracy for a PID loop time of 20ms. Response of the control system to the pressure variation of the gas in the chamber has also been studied and compared with the results obtained from those of an uncontrolled system. The present approach increases the flexibility of the control system. It not only eases the control of the plasma but also allows an easy changeover to various operation scenarios.

SPring-8 beamline control system.

PubMed

Ohata, T; Konishi, H; Kimura, H; Furukawa, Y; Tamasaku, K; Nakatani, T; Tanabe, T; Matsumoto, N; Ishii, M; Ishikawa, T

1998-05-01

The SPring-8 beamline control system is now taking part in the control of the insertion device (ID), front end, beam transportation channel and all interlock systems of the beamline: it will supply a highly standardized environment of apparatus control for collaborative researchers. In particular, ID operation is very important in a third-generation synchrotron light source facility. It is also very important to consider the security system because the ID is part of the storage ring and is therefore governed by the synchrotron ring control system. The progress of computer networking systems and the technology of security control require the development of a highly flexible control system. An interlock system that is independent of the control system has increased the reliability. For the beamline control system the so-called standard model concept has been adopted. VME-bus (VME) is used as the front-end control system and a UNIX workstation as the operator console. CPU boards of the VME-bus are RISC processor-based board computers operated by a LynxOS-based HP-RT real-time operating system. The workstation and the VME are linked to each other by a network, and form the distributed system. The HP 9000/700 series with HP-UX and the HP 9000/743rt series with HP-RT are used. All the controllable apparatus may be operated from any workstation.

Management and control of self-replicating systems: A systems model

NASA Technical Reports Server (NTRS)

Vontiesenhausen, G.

1982-01-01

In 1980, a conceptual engineering approach to self-replicating systems was achieved. The design was based on von Newmann's kinematic version of self-replicating automata. The systems management and control and the organization of the control elements are reported. After developing the functional requirements of such a system, a hierarchy of three management and control levels is described. These are an autonomous, an external, and an intelligent management and control system. Systems recycling, systems specialization, and information replication are discussed.

Data-Driven Based Asynchronous Motor Control for Printing Servo Systems

NASA Astrophysics Data System (ADS)

Bian, Min; Guo, Qingyun

Modern digital printing equipment aims to the environmental-friendly industry with high dynamic performances and control precision and low vibration and abrasion. High performance motion control system of printing servo systems was required. Control system of asynchronous motor based on data acquisition was proposed. Iterative learning control (ILC) algorithm was studied. PID control was widely used in the motion control. However, it was sensitive to the disturbances and model parameters variation. The ILC applied the history error data and present control signals to approximate the control signal directly in order to fully track the expect trajectory without the system models and structures. The motor control algorithm based on the ILC and PID was constructed and simulation results were given. The results show that data-driven control method is effective dealing with bounded disturbances for the motion control of printing servo systems.

ISHN Ion Source Control System. First Steps Toward an EPICS Based ESS-Bilbao Accelerator Control System

NASA Astrophysics Data System (ADS)

Eguiraun, M.; Jugo, J.; Arredondo, I.; del Campo, M.; Feuchtwanger, J.; Etxebarria, V.; Bermejo, F. J.

2013-04-01

ISHN (Ion Source Hydrogen Negative) consists of a Penning type ion source in operation at ESS-Bilbao facilities. From the control point of view, this source is representative of the first steps and decisions taken towards the general control architecture of the whole accelerator to be built. The ISHN main control system is based on a PXI architecture, under a real-time controller which is programmed using LabVIEW. This system, with additional elements, is connected to the general control system. The whole system is based on EPICS for the control network, and the modularization of the communication layers of the accelerator plays an important role in the proposed control architecture.

Implementation of EPICS based vacuum control system for variable energy cyclotron centre, Kolkata

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy, Anindya, E-mail: r-ani@vecc.gov.in; Bhole, R. B.; Nandy, Partha P.

2015-03-15

The vacuum system of the Room Temperature (K = 130) Cyclotron of Variable Energy Cyclotron Centre is comprised of vacuum systems of main machine and Beam Transport System. The vacuum control system is upgraded to a PLC based Automated system from the initial relay based Manual system. The supervisory control of the vacuum system is implemented in Experimental Physics and Industrial Control System (EPICS). An EPICS embedded ARM based vacuum gauge controller is developed to mitigate the requirement of vendor specific gauge controller for gauges and also for seamless integration of the gauge controllers with the control system. A setmore » of MS-Windows ActiveX components with embedded EPICS Channel Access interface are developed to build operator interfaces with less complex programming and to incorporate typical Windows feature, e.g., user authentication, file handling, better fonts, colors, mouse actions etc. into the operator interfaces. The control parameters, monitoring parameters, and system interlocks of the system are archived in MySQL based EPICS MySQL Archiver developed indigenously. In this paper, we describe the architecture, the implementation details, and the performance of the system.« less

Requirements for implementing real-time control functional modules on a hierarchical parallel pipelined system

NASA Technical Reports Server (NTRS)

Wheatley, Thomas E.; Michaloski, John L.; Lumia, Ronald

1989-01-01

Analysis of a robot control system leads to a broad range of processing requirements. One fundamental requirement of a robot control system is the necessity of a microcomputer system in order to provide sufficient processing capability.The use of multiple processors in a parallel architecture is beneficial for a number of reasons, including better cost performance, modular growth, increased reliability through replication, and flexibility for testing alternate control strategies via different partitioning. A survey of the progression from low level control synchronizing primitives to higher level communication tools is presented. The system communication and control mechanisms of existing robot control systems are compared to the hierarchical control model. The impact of this design methodology on the current robot control systems is explored.

Behaviour of a series of reservoirs separated by drowned gates

NASA Astrophysics Data System (ADS)

Kolechkina, Alla; van Nooijen, Ronald

2017-04-01

Modern control systems tend to be based on computers and therefore to operate by sending commands to structures at given intervals (discrete time control system). Moreover, for almost all water management control systems there are practical lower limits on the time interval between structure adjustments and even between measurements. The water resource systems that are being controlled are physical systems whose state changes continuously. If we combine a continuously changing system and a discrete time controller we get a hybrid system. We use material from recent control theory literature to examine the behaviour of a series of reservoirs separated by drowned gates where the gates are under computer control.

Intrusion Detection in Control Systems using Sequence Characteristics

NASA Astrophysics Data System (ADS)

Kiuchi, Mai; Onoda, Takashi

Intrusion detection is considered effective in control systems. Sequences of the control application behavior observed in the communication, such as the order of the control device to be controlled, are important in control systems. However, most intrusion detection systems do not effectively reflect sequences in the application layer into the detection rules. In our previous work, we considered utilizing sequences for intrusion detection in control systems, and demonstrated the usefulness of sequences for intrusion detection. However, manually writing the detection rules for a large system can be difficult, so using machine learning methods becomes feasible. Also, in the case of control systems, there have been very few observed cyber attacks, so we have very little knowledge of the attack data that should be used to train the intrusion detection system. In this paper, we use an approach that combines CRF (Conditional Random Field) considering the sequence of the system, thus able to reflect the characteristics of control system sequences into the intrusion detection system, and also does not need the knowledge of attack data to construct the detection rules.

49 CFR 235.5 - Changes requiring filing of application.

Code of Federal Regulations, 2010 CFR

2010-10-01

... system, automatic train stop, train control, or cab signal system or other similar appliance or device..., automatic train stop, train control, or cab signal system; or (3) The modification of a block signal system, interlocking, traffic control system, automatic train stop, train control, or cab signal system. (b) [Reserved...

49 CFR 235.5 - Changes requiring filing of application.

Code of Federal Regulations, 2011 CFR

2011-10-01

... system, automatic train stop, train control, or cab signal system or other similar appliance or device..., automatic train stop, train control, or cab signal system; or (3) The modification of a block signal system, interlocking, traffic control system, automatic train stop, train control, or cab signal system. (b) [Reserved...

Real-time closed-loop simulation and upset evaluation of control systems in harsh electromagnetic environments

NASA Technical Reports Server (NTRS)

Belcastro, Celeste M.

1989-01-01

Digital control systems for applications such as aircraft avionics and multibody systems must maintain adequate control integrity in adverse as well as nominal operating conditions. For example, control systems for advanced aircraft, and especially those with relaxed static stability, will be critical to flight and will, therefore, have very high reliability specifications which must be met regardless of operating conditions. In addition, multibody systems such as robotic manipulators performing critical functions must have control systems capable of robust performance in any operating environment in order to complete the assigned task reliably. Severe operating conditions for electronic control systems can result from electromagnetic disturbances caused by lightning, high energy radio frequency (HERF) transmitters, and nuclear electromagnetic pulses (NEMP). For this reason, techniques must be developed to evaluate the integrity of the control system in adverse operating environments. The most difficult and illusive perturbations to computer-based control systems that can be caused by an electromagnetic environment (EME) are functional error modes that involve no component damage. These error modes are collectively known as upset, can occur simultaneously in all of the channels of a redundant control system, and are software dependent. Upset studies performed to date have not addressed the assessment of fault tolerant systems and do not involve the evaluation of a control system operating in a closed-loop with the plant. A methodology for performing a real-time simulation of the closed-loop dynamics of a fault tolerant control system with a simulated plant operating in an electromagnetically harsh environment is presented. In particular, considerations for performing upset tests on the controller are discussed. Some of these considerations are the generation and coupling of analog signals representative of electromagnetic disturbances to a control system under test, analog data acquisition, and digital data acquisition from fault tolerant systems. In addition, a case study of an upset test methodology for a fault tolerant electromagnetic aircraft engine control system is presented.

Dynamic Programming Method for Impulsive Control Problems

ERIC Educational Resources Information Center

Balkew, Teshome Mogessie

2015-01-01

In many control systems changes in the dynamics occur unexpectedly or are applied by a controller as needed. The time at which a controller implements changes is not necessarily known a priori. For example, many manufacturing systems and flight operations have complicated control systems, and changes in the control systems may be automatically…

Interactive Implementation of the Optimal Systems Control Design Program (OPTSYSX) on the IBM 3033.

DTIC Science & Technology

1984-03-01

DAS A44 159 INTERACTIVE IMPLEMENTATION OF THE OPTIMAL SYSTEMS I CONTROL DESIGN PROGRAM (OPTSYSX) ON THE 1DM 3033(U NAVAL POSTGRADUATE SCHOOL MONTEREY...noesear end idswtif’r b block number) Optimal Systems Control Systems Control Control Systems 10.; ABSTRACT (Continu an reveree side ff Roe684v ad Id yI...34 by block number) .- This thesis discusses the modification of an existing Optimal Systems Control FORTRAN program (OPTSYS) originally obtained from

Propulsion system/flight control integration for supersonic aircraft

NASA Technical Reports Server (NTRS)

Reukauf, P. J.; Burcham, F. W., Jr.

1976-01-01

Digital integrated control systems are studied. Such systems allow minimization of undesirable interactions while maximizing performance at all flight conditions. One such program is the YF-12 cooperative control program. The existing analog air data computer, autothrottle, autopilot, and inlet control systems are converted to digital systems by using a general purpose airborne computer and interface unit. Existing control laws are programed and tested in flight. Integrated control laws, derived using accurate mathematical models of the airplane and propulsion system in conjunction with modern control techniques, are tested in flight. Analysis indicates that an integrated autothrottle autopilot gives good flight path control and that observers are used to replace failed sensors.

Towards A Taxonomy Of Attacks Against Energy Control Systems

NASA Astrophysics Data System (ADS)

Fleury, Terry; Khurana, Himanshu; Welch, Von

Control systems in the energy sector (e.g., supervisory control and data acquisition (SCADA) systems) involve a hierarchy of sensing, monitoring and control devices connected to centralized control stations or centers. The incorporation of commercial off-the-shelf technologies in energy control systems makes them vulnerable to cyber attacks. A taxonomy of cyber attacks against control systems can assist the energy sector in managing the cyber threat. This paper takes the first step towards a taxonomy by presenting a comprehensive model of attacks, vulnerabilities and damage related to control systems. The model is populated based on a survey of the technical literature from industry, academia and national laboratories.

Development and Operation of an Automatic Rotor Trim Control System for the UH-60 Individual Blade Control Wind Tunnel Test

NASA Technical Reports Server (NTRS)

Theodore, Colin R.; Tischler, Mark B.

2010-01-01

An automatic rotor trim control system was developed and successfully used during a wind tunnel test of a full-scale UH-60 rotor system with Individual Blade Control (IBC) actuators. The trim control system allowed rotor trim to be set more quickly, precisely and repeatably than in previous wind tunnel tests. This control system also allowed the rotor trim state to be maintained during transients and drift in wind tunnel flow, and through changes in IBC actuation. The ability to maintain a consistent rotor trim state was key to quickly and accurately evaluating the effect of IBC on rotor performance, vibration, noise and loads. This paper presents details of the design and implementation of the trim control system including the rotor system hardware, trim control requirements, and trim control hardware and software implementation. Results are presented showing the effect of IBC on rotor trim and dynamic response, a validation of the rotor dynamic simulation used to calculate the initial control gains and tuning of the control system, and the overall performance of the trim control system during the wind tunnel test.

Switching Systems: Controllability and Control Design

DTIC Science & Technology

2009-04-25

controllable linear time invariant (LTI) systems ẋ = Ax+Bu are stabilizable and the stabilization can be always done by a...to control the system is bounded. As an application controllability conditions for a class of bimodal linear time invariant (LTI) systems are also...There exist a universal ( finite ) switching sequence σ such that the time varying system ẋ = A(σ)x+ B(σ)u is globally controllable . Proof: The

Design and development progress of a LLRF control system for a 500 MHz superconducting cavity

NASA Astrophysics Data System (ADS)

Lee, Y. S.; Kim, H. W.; Song, H. S.; Lee, J. H.; Park, K. H.; Yu, I. H.; Chai, J. S.

2012-07-01

The LLRF (low-level radio-frequency) control system which regulates the amplitude and the phase of the accelerating voltage inside a RF cavity is essential to ensure the stable operation of charged particle accelerators. Recent advances in digital signal processors and data acquisition systems have allowed the LLRF control system to be implemented in digitally and have made it possible to meet the higher demands associated with the performance of LLRF control systems, such as stability, accuracy, etc. For this reason, many accelerator laboratories have completed or are completing the developments of digital LLRF control systems. The digital LLRF control system has advantages related with flexibility and fast reconfiguration. This paper describes the design of the FPGA (field programmable gate array) based LLRF control system and the status of development for this system. The proposed LLRF control system includes an analog front-end, a digital board (ADC (analog to digital converter), DAC (digital to analog converter), FPGA, etc.) and a RF & clock generation system. The control algorithms will be implemented by using the VHDL (VHSIC (very high speed integrated circuits) hardware description language), and the EPICS (experiment physics and industrial control system) will be ported to the host computer for the communication. In addition, the purpose of this system is to control a 500 MHz RF cavity, so the system will be applied to the superconducting cavity to be installed in the PLS storage ring, and its performance will be tested.

An intelligent position-specific training system for mission operations

NASA Technical Reports Server (NTRS)

Schneider, M. P.

1992-01-01

Marshall Space Flight Center's (MSFC's) payload ground controller training program provides very good generic training; however, ground controller position-specific training can be improved by including position-specific training systems in the training program. This report explains why MSFC needs to improve payload ground controller position-specific training. The report describes a generic syllabus for position-specific training systems, a range of system designs for position-specific training systems, and a generic development process for developing position-specific training systems. The report also describes a position-specific training system prototype that was developed for the crew interface coordinator payload operations control center ground controller position. The report concludes that MSFC can improve the payload ground controller training program by incorporating position-specific training systems for each ground controller position; however, MSFC should not develop position-specific training systems unless payload ground controller position experts will be available to participate in the development process.

Development of monitoring and control system for a mine main fan based on frequency converter

NASA Astrophysics Data System (ADS)

Zhang, Y. C.; Zhang, R. W.; Kong, X. Z.; Y Gong, J.; Chen, Q. G.

2013-12-01

In the process of mine exploitation, the requirement of air flow rate often changes. The procedure of traditional control mode of the fan is complex and it is hard to meet the worksite requirement for air. This system is based on Principal Computer (PC) monitoring system and high performance PLC control system. In this system, the frequency converter is adapted to adjust the fan speed and the air of worksite can be regulated steplessly. The function of the monitoring and control system contains on-line monitoring and centralized control. The system can monitor the parameters of fan in real-time, control the operation of frequency converter, as well as, control the fan and its accessory equipments. At the same time, the automation level of the system is highly, the field equipments can be monitored and controlled automatically. So, the system is an important safeguard for mine production.

Nuclear electric propulsion reactor control systems status

NASA Technical Reports Server (NTRS)

Ferg, D. A.

1973-01-01

The thermionic reactor control system design studies conducted over the past several years for a nuclear electric propulsion system are described and summarized. The relevant reactor control system studies are discussed in qualitative terms, pointing out the significant advantages and disadvantages including the impact that the various control systems would have on the nuclear electric propulsion system design. A recommendation for the reference control system is made, and a program for future work leading to an engineering model is described.

Modeling and Simulation of Control Actuation System with Fuzzy-PID Logic Controlled Brushless Motor Drives for Missiles Glider Applications

PubMed Central

Muniraj, Murali; Arulmozhiyal, Ramaswamy

2015-01-01

A control actuation system has been used extensively in automotive, aerospace, and defense applications. The major challenges in modeling control actuation system are rise time, maximum peak to peak overshoot, and response to nonlinear system with percentage error. This paper addresses the challenges in modeling and real time implementation of control actuation system for missiles glider applications. As an alternative fuzzy-PID controller is proposed in BLDC motor drive followed by linkage mechanism to actuate fins in missiles and gliders. The proposed system will realize better rise time and less overshoot while operating in extreme nonlinear dynamic system conditions. A mathematical model of BLDC motor is derived in state space form. The complete control actuation system is modeled in MATLAB/Simulink environment and verified by performing simulation studies. A real time prototype of the control actuation is developed with dSPACE-1104 hardware controller and a detailed analysis is carried out to confirm the viability of the proposed system. PMID:26613102

Modeling and Simulation of Control Actuation System with Fuzzy-PID Logic Controlled Brushless Motor Drives for Missiles Glider Applications.

PubMed

Muniraj, Murali; Arulmozhiyal, Ramaswamy

2015-01-01

A control actuation system has been used extensively in automotive, aerospace, and defense applications. The major challenges in modeling control actuation system are rise time, maximum peak to peak overshoot, and response to nonlinear system with percentage error. This paper addresses the challenges in modeling and real time implementation of control actuation system for missiles glider applications. As an alternative fuzzy-PID controller is proposed in BLDC motor drive followed by linkage mechanism to actuate fins in missiles and gliders. The proposed system will realize better rise time and less overshoot while operating in extreme nonlinear dynamic system conditions. A mathematical model of BLDC motor is derived in state space form. The complete control actuation system is modeled in MATLAB/Simulink environment and verified by performing simulation studies. A real time prototype of the control actuation is developed with dSPACE-1104 hardware controller and a detailed analysis is carried out to confirm the viability of the proposed system.

Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project. ACT/Control/Guidance System study, volume 1

NASA Technical Reports Server (NTRS)

1982-01-01

The active control technology (ACT) control/guidance system task of the integrated application of active controls (IAAC) technology project within the NASA energy efficient transport program was documented. The air traffic environment of navigation and air traffic control systems and procedures were extrapolated. An approach to listing flight functions which will be performed by systems and crew of an ACT configured airplane of the 1990s, and a determination of function criticalities to safety of flight, are the basis of candidate integrated ACT/Control/Guidance System architecture. The system mechanizes five active control functions: pitch augmented stability, angle of attack limiting, lateral/directional augmented stability, gust load alleviation, and maneuver load control. The scope and requirements of a program for simulating the integrated ACT avionics and flight deck system, with pilot in the loop, are defined, system and crew interface elements are simulated, and mechanization is recommended. Relationships between system design and crew roles and procedures are evaluated.

Automated Subsystem Control for Life Support System (ASCLSS)

NASA Technical Reports Server (NTRS)

Block, Roger F.

1987-01-01

The Automated Subsystem Control for Life Support Systems (ASCLSS) program has successfully developed and demonstrated a generic approach to the automation and control of space station subsystems. The automation system features a hierarchical and distributed real-time control architecture which places maximum controls authority at the lowest or process control level which enhances system autonomy. The ASCLSS demonstration system pioneered many automation and control concepts currently being considered in the space station data management system (DMS). Heavy emphasis is placed on controls hardware and software commonality implemented in accepted standards. The approach demonstrates successfully the application of real-time process and accountability with the subsystem or process developer. The ASCLSS system completely automates a space station subsystem (air revitalization group of the ASCLSS) which moves the crew/operator into a role of supervisory control authority. The ASCLSS program developed over 50 lessons learned which will aide future space station developers in the area of automation and controls..

DEVS representation of dynamical systems - Event-based intelligent control. [Discrete Event System Specification

NASA Technical Reports Server (NTRS)

Zeigler, Bernard P.

1989-01-01

It is shown how systems can be advantageously represented as discrete-event models by using DEVS (discrete-event system specification), a set-theoretic formalism. Such DEVS models provide a basis for the design of event-based logic control. In this control paradigm, the controller expects to receive confirming sensor responses to its control commands within definite time windows determined by its DEVS model of the system under control. The event-based contral paradigm is applied in advanced robotic and intelligent automation, showing how classical process control can be readily interfaced with rule-based symbolic reasoning systems.

Control of a solar-energy-supplied electrical-power system without intermediate circuitry

NASA Astrophysics Data System (ADS)

Leistner, K.

A computer control system is developed for electric-power systems comprising solar cells and small numbers of users with individual centrally controlled converters (and storage facilities when needed). Typical system structures are reviewed; the advantages of systems without an intermediate network are outlined; the demands on a control system in such a network (optimizing generator working point and power distribution) are defined; and a flexible modular prototype system is described in detail. A charging station for lead batteries used in electric automobiles is analyzed as an example. The power requirements of the control system (30 W for generator control and 50 W for communications and distribution control) are found to limit its use to larger networks.

14 CFR 25.1161 - Fuel jettisoning system controls.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel jettisoning system controls. 25.1161... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 25.1161 Fuel jettisoning system controls. Each fuel jettisoning system control must have guards...

14 CFR 25.1161 - Fuel jettisoning system controls.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel jettisoning system controls. 25.1161... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 25.1161 Fuel jettisoning system controls. Each fuel jettisoning system control must have guards...

14 CFR 25.1161 - Fuel jettisoning system controls.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel jettisoning system controls. 25.1161... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 25.1161 Fuel jettisoning system controls. Each fuel jettisoning system control must have guards...

14 CFR 25.1161 - Fuel jettisoning system controls.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel jettisoning system controls. 25.1161... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 25.1161 Fuel jettisoning system controls. Each fuel jettisoning system control must have guards...

14 CFR 25.1161 - Fuel jettisoning system controls.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel jettisoning system controls. 25.1161... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 25.1161 Fuel jettisoning system controls. Each fuel jettisoning system control must have guards...

Controllability of discrete bilinear systems with bounded control.

NASA Technical Reports Server (NTRS)

Tarn, T. J.; Elliott, D. L.; Goka, T.

1973-01-01

The subject of this paper is the controllability of time-invariant discrete-time bilinear systems. Bilinear systems are classified into two categories; homogeneous and inhomogeneous. Sufficient conditions which ensure the global controllability of discrete-time bilinear systems are obtained by localized analysis in control variables.

Hybrid feedforward and feedback controller design for nuclear steam generators over wide range operation using genetic algorithm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Y.; Edwards, R.M.; Lee, K.Y.

1997-03-01

In this paper, a simplified model with a lower order is first developed for a nuclear steam generator system and verified against some realistic environments. Based on this simplified model, a hybrid multi-input and multi-out (MIMO) control system, consisting of feedforward control (FFC) and feedback control (FBC), is designed for wide range conditions by using the genetic algorithm (GA) technique. The FFC control, obtained by the GA optimization method, injects an a priori command input into the system to achieve an optimal performance for the designed system, while the GA-based FBC control provides the necessary compensation for any disturbances ormore » uncertainties in a real steam generator. The FBC control is an optimal design of a PI-based control system which would be more acceptable for industrial practices and power plant control system upgrades. The designed hybrid MIMO FFC/FBC control system is first applied to the simplified model and then to a more complicated model with a higher order which is used as a substitute of the real system to test the efficacy of the designed control system. Results from computer simulations show that the designed GA-based hybrid MIMO FFC/FBC control can achieve good responses and robust performances. Hence, it can be considered as a viable alternative to the current control system upgrade.« less

Evaluation of power control concepts using the PMAD systems test bed. [Power Management and Distribution

NASA Technical Reports Server (NTRS)

Beach, R. F.; Kimnach, G. L.; Jett, T. A.; Trash, L. M.

1989-01-01

The Lewis Research Center's Power Management and Distribution (PMAD) System testbed and its use in the evaluation of control concepts applicable to the NASA Space Station Freedom electric power system (EPS) are described. The facility was constructed to allow testing of control hardware and software in an environment functionally similar to the space station electric power system. Control hardware and software have been developed to allow operation of the testbed power system in a manner similar to a supervisory control and data acquisition (SCADA) system employed by utility power systems for control. The system hardware and software are described.

Mechanical Backup For Fly-By-Wire Control System

NASA Technical Reports Server (NTRS)

Stewart, Eric C.

1992-01-01

Mechanical device eliminates need for redundant fly-by-wire subsystems. Main components are two linkages. One connected to control column in conventional, reversible control system. Other slides inside first linkage and connected to pilot's control wheel. In addition to aircraft applications, design used in control systems in which computer control desirable but safety backup systems required; for example, in boat rudders, engine controls in boats and automobiles, and controls in construction equipment.

An Evaluation of Automatic Control System Concepts for General Aviation Airplanes

NASA Technical Reports Server (NTRS)

Stewart, E. C.

1990-01-01

A piloted simulation study of automatic longitudinal control systems for general aviation airplanes has been conducted. These automatic control systems were designed to make the simulated airplane easy to fly for a beginning or infrequent pilot. Different control systems are presented and their characteristics are documented. In a conventional airplane control system each cockpit controller commands combinations of both the airspeed and the vertical speed. The best system in the present study decoupled the airspeed and vertical speed responses to cockpit controller inputs. An important feature of the automatic system was that neither changing flap position nor maneuvering in steeply banked turns affected either the airspeed or the vertical speed. All the pilots who flew the control system simulation were favorably impressed with the very low workload and the excellent handling qualities of the simulated airplane.

Method study on fuzzy-PID adaptive control of electric-hydraulic hitch system

NASA Astrophysics Data System (ADS)

Li, Mingsheng; Wang, Liubu; Liu, Jian; Ye, Jin

2017-03-01

In this paper, fuzzy-PID adaptive control method is applied to the control of tractor electric-hydraulic hitch system. According to the characteristics of the system, a fuzzy-PID adaptive controller is designed and the electric-hydraulic hitch system model is established. Traction control and position control performance simulation are carried out with the common PID control method. A field test rig was set up to test the electric-hydraulic hitch system. The test results showed that, after the fuzzy-PID adaptive control is adopted, when the tillage depth steps from 0.1m to 0.3m, the system transition process time is 4s, without overshoot, and when the tractive force steps from 3000N to 7000N, the system transition process time is 5s, the system overshoot is 25%.

Control algorithms and applications of the wavefront sensorless adaptive optics

NASA Astrophysics Data System (ADS)

Ma, Liang; Wang, Bin; Zhou, Yuanshen; Yang, Huizhen

2017-10-01

Compared with the conventional adaptive optics (AO) system, the wavefront sensorless (WFSless) AO system need not to measure the wavefront and reconstruct it. It is simpler than the conventional AO in system architecture and can be applied to the complex conditions. Based on the analysis of principle and system model of the WFSless AO system, wavefront correction methods of the WFSless AO system were divided into two categories: model-free-based and model-based control algorithms. The WFSless AO system based on model-free-based control algorithms commonly considers the performance metric as a function of the control parameters and then uses certain control algorithm to improve the performance metric. The model-based control algorithms include modal control algorithms, nonlinear control algorithms and control algorithms based on geometrical optics. Based on the brief description of above typical control algorithms, hybrid methods combining the model-free-based control algorithm with the model-based control algorithm were generalized. Additionally, characteristics of various control algorithms were compared and analyzed. We also discussed the extensive applications of WFSless AO system in free space optical communication (FSO), retinal imaging in the human eye, confocal microscope, coherent beam combination (CBC) techniques and extended objects.

Autonomous Operations System: Development and Application

NASA Technical Reports Server (NTRS)

Toro Medina, Jaime A.; Wilkins, Kim N.; Walker, Mark; Stahl, Gerald M.

2016-01-01

Autonomous control systems provides the ability of self-governance beyond the conventional control system. As the complexity of mechanical and electrical systems increases, there develops a natural drive for developing robust control systems to manage complicated operations. By closing the bridge between conventional automated systems to knowledge based self-awareness systems, nominal control of operations can evolve into relying on safe critical mitigation processes to support any off-nominal behavior. Current research and development efforts lead by the Autonomous Propellant Loading (APL) group at NASA Kennedy Space Center aims to improve cryogenic propellant transfer operations by developing an automated control and health monitoring system. As an integrated systems, the center aims to produce an Autonomous Operations System (AOS) capable of integrating health management operations with automated control to produce a fully autonomous system.

49 CFR 236.401 - Automatic block signal system and interlocking standards applicable to traffic control systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.401 Automatic... 49 Transportation 4 2011-10-01 2011-10-01 false Automatic block signal system and interlocking standards applicable to traffic control systems. 236.401 Section 236.401 Transportation Other Regulations...

Digital control analysis and design of a field-sensed magnetic suspension system.

PubMed

Li, Jen-Hsing; Chiou, Juing-Shian

2015-03-13

Magnetic suspension systems are mechatronic systems and crucial in several engineering applications, such as the levitation of high-speed trains, frictionless bearings, and wind tunnels. Magnetic suspension systems are nonlinear and unstable systems; therefore, they are suitable educational benchmarks for testing various modeling and control methods. This paper presents the digital modeling and control of magnetic suspension systems. First, the magnetic suspension system is stabilized using a digital proportional-derivative controller. Subsequently, the digital model is identified using recursive algorithms. Finally, a digital mixed linear quadratic regulator (LQR)/H∞ control is adopted to stabilize the magnetic suspension system robustly. Simulation examples and a real-world example are provided to demonstrate the practicality of the study results. In this study, a digital magnetic suspension system model was developed and reviewed. In addition, equivalent state and output feedback controls for magnetic suspension systems were developed. Using this method, the controller design for magnetic suspension systems was simplified, which is the novel contribution of this study. In addition, this paper proposes a complete digital controller design procedure for magnetic suspension systems.

Robust high-performance control for robotic manipulators

NASA Technical Reports Server (NTRS)

Seraji, Homayoun (Inventor)

1991-01-01

Model-based and performance-based control techniques are combined for an electrical robotic control system. Thus, two distinct and separate design philosophies have been merged into a single control system having a control law formulation including two distinct and separate components, each of which yields a respective signal component that is combined into a total command signal for the system. Those two separate system components include a feedforward controller and a feedback controller. The feedforward controller is model-based and contains any known part of the manipulator dynamics that can be used for on-line control to produce a nominal feedforward component of the system's control signal. The feedback controller is performance-based and consists of a simple adaptive PID controller which generates an adaptive control signal to complement the nominal feedforward signal.

Robust high-performance control for robotic manipulators

NASA Technical Reports Server (NTRS)

Seraji, Homayoun (Inventor)

1989-01-01

Model-based and performance-based control techniques are combined for an electrical robotic control system. Thus, two distinct and separate design philosophies were merged into a single control system having a control law formulation including two distinct and separate components, each of which yields a respective signal componet that is combined into a total command signal for the system. Those two separate system components include a feedforward controller and feedback controller. The feedforward controller is model-based and contains any known part of the manipulator dynamics that can be used for on-line control to produce a nominal feedforward component of the system's control signal. The feedback controller is performance-based and consists of a simple adaptive PID controller which generates an adaptive control signal to complement the nomical feedforward signal.

Robust approximation-free prescribed performance control for nonlinear systems and its application

NASA Astrophysics Data System (ADS)

Sun, Ruisheng; Na, Jing; Zhu, Bin

2018-02-01

This paper presents a robust prescribed performance control approach and its application to nonlinear tail-controlled missile systems with unknown dynamics and uncertainties. The idea of prescribed performance function (PPF) is incorporated into the control design, such that both the steady-state and transient control performance can be strictly guaranteed. Unlike conventional PPF-based control methods, we further tailor a recently proposed systematic control design procedure (i.e. approximation-free control) using the transformed tracking error dynamics, which provides a proportional-like control action. Hence, the function approximators (e.g. neural networks, fuzzy systems) that are widely used to address the unknown nonlinearities in the nonlinear control designs are not needed. The proposed control design leads to a robust yet simplified function approximation-free control for nonlinear systems. The closed-loop system stability and the control error convergence are all rigorously proved. Finally, comparative simulations are conducted based on nonlinear missile systems to validate the improved response and the robustness of the proposed control method.

Real-Time Adaptive Control of a Magnetic Levitation System with a Large Range of Load Disturbance.

PubMed

Zhang, Zhizhou; Li, Xiaolong

2018-05-11

In an idle light-load or a full-load condition, the change of the load mass of a suspension system is very significant. If the control parameters of conventional control methods remain unchanged, the suspension performance of the control system deteriorates rapidly or even loses stability when the load mass changes in a large range. In this paper, a real-time adaptive control method for a magnetic levitation system with large range of mass changes is proposed. First, the suspension control system model of the maglev train is built up, and the stability of the closed-loop system is analyzed. Then, a fast inner current-loop is used to simplify the design of the suspension control system, and an adaptive control method is put forward to ensure that the system is still in a stable state when the load mass varies in a wide range. Simulations and experiments show that when the load mass of the maglev system varies greatly, the adaptive control method is effective to suspend the system stably with a given displacement.

Real-Time Adaptive Control of a Magnetic Levitation System with a Large Range of Load Disturbance

PubMed Central

Zhang, Zhizhou; Li, Xiaolong

2018-01-01

In an idle light-load or a full-load condition, the change of the load mass of a suspension system is very significant. If the control parameters of conventional control methods remain unchanged, the suspension performance of the control system deteriorates rapidly or even loses stability when the load mass changes in a large range. In this paper, a real-time adaptive control method for a magnetic levitation system with large range of mass changes is proposed. First, the suspension control system model of the maglev train is built up, and the stability of the closed-loop system is analyzed. Then, a fast inner current-loop is used to simplify the design of the suspension control system, and an adaptive control method is put forward to ensure that the system is still in a stable state when the load mass varies in a wide range. Simulations and experiments show that when the load mass of the maglev system varies greatly, the adaptive control method is effective to suspend the system stably with a given displacement. PMID:29751610

Pegasus power system facility upgrades

NASA Astrophysics Data System (ADS)

Lewicki, B. T.; Kujak-Ford, B. A.; Winz, G. R.

2008-11-01

Two key Pegasus systems have been recently upgraded: the Ohmic-transformer IGCT bridge control system, and the plasma-gun injector power system. The Ohmic control system contains two new microprocessor controlled components to provide an interface between the PWM controller and the IGCT bridges. An interface board conditions the command signals from the PWM controller. A splitter/combiner board routes the conditioned PWM commands to an array of IGCT bridges and interprets IGCT bridge status. This system allows for any PWM controller to safely control IGCT bridges. Future developments will include a transition to a polyphasic bridge control. This will allow for 3 to 4 times the present pulse length and provide a much higher switching frequency. The plasma gun injector system now includes active current feedback control on gun bias current via PWM buck type power supplies. Near term goals include a doubling or tripling of the applied bias voltage. Future arc bias system power supplies may include a simpler boost type system which will allow access to even higher voltages using existing low voltage energy storage systems.

Cyber Security Assessment Report: Adventium Labs

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2007-12-31

Major control system components often have life spans of 15-20 years. Many systems in our Nation's critical infrastructure were installed before the Internet became a reality and security was a concern. Consequently, control systems are generally insecure. Security is now being included in the development of new control system devices; however, legacy control systems remain vulnerable. Most efforts to secure control systems are aimed at protecting network borers, but if an intruder gets inside the network these systems are vulnerable to a cyber attack.

Integrated propulsion/energy transfer control systems for lift-fan V/STOL aircraft. [reduction of total propulsion system and control system installation requirements

NASA Technical Reports Server (NTRS)

Deckert, W. H.; Rolls, L. S.

1974-01-01

An integrated propulsion/control system for lift-fan transport aircraft is described. System behavior from full-scale experimental and piloted simulator investigations are reported. The lift-fan transport is a promising concept for short-to-medium haul civil transportation and for other missions. The lift-fan transport concept features high cruise airspeed, favorable ride qualities, small perceived noise footprints, high utilization, transportation system flexibility, and adaptability to VTOL, V/STOL, or STOL configurations. The lift-fan transport has high direct operating costs in comparison to conventional aircraft, primarily because of propulsion system and aircraft low-speed control system installation requirements. An integrated lift-fan propulsion system/aircraft low-speed control system that reduces total propulsion system and control system installation requirements is discussed.

Digital redesign of the control system for the Robotics Research Corporation model K-1607 robot

NASA Technical Reports Server (NTRS)

Carroll, Robert L.

1989-01-01

The analog control system for positioning each link of the Robotics Research Corporation Model K-1607 robot manipulator was redesigned for computer control. In order to accomplish the redesign, a linearized model of the dynamic behavior of the robot was developed. The parameters of the model were determined by examination of the input-output data collected in closed-loop operation of the analog control system. The robot manipulator possesses seven degrees of freedom in its motion. The analog control system installed by the manufacturer of the robot attempts to control the positioning of each link without feedback from other links. Constraints on the design of a digital control system include: the robot cannot be disassembled for measurement of parameters; the digital control system must not include filtering operations if possible, because of lack of computer capability; and criteria of goodness of control system performing is lacking. The resulting design employs sampled-data position and velocity feedback. The criteria of the design permits the control system gain margin and phase margin, measured at the same frequencies, to be the same as that provided by the analog control system.

Multicriteria Gain Tuning for Rotorcraft Flight Controls (also entitled The Development of the Conduit Advanced Control System Design and Evaluation Interface with a Case Study Application Fly by Wire Helicopter Design)

NASA Technical Reports Server (NTRS)

Biezad, Daniel

1997-01-01

Handling qualities analysis and control law design would seem to be naturally complimenting components of aircraft flight control system design, however these two closely coupled disciplines are often not well integrated in practice. Handling qualities engineers and control system engineers may work in separate groups within an aircraft company. Flight control system engineers and handling quality specialists may come from different backgrounds and schooling and are often not aware of the other group's research. Thus while the handling qualities specifications represent desired aircraft response characteristics, these are rarely incorporated directly in the control system design process. Instead modem control system design techniques are based on servo-loop robustness specifications, and simple representations of the desired control response. Comprehensive handling qualities analysis is often left until the end of the design cycle and performed as a check of the completed design for satisfactory performance. This can lead to costly redesign or less than satisfactory aircraft handling qualities when the flight testing phase is reached. The desire to integrate the fields of handling qualities and flight,control systems led to the development of the CONDUIT system. This tool facilitates control system designs that achieve desired handling quality requirements and servo-loop specifications in a single design process. With CONDUIT, the control system engineer is now able to directly design and control systems to meet the complete handling specifications. CONDUIT allows the designer to retain a preferred control law structure, but then tunes the system parameters to meet the handling quality requirements.

Design of an all-attitude flight control system to execute commanded bank angles and angles of attack

NASA Technical Reports Server (NTRS)

Burgin, G. H.; Eggleston, D. M.

1976-01-01

A flight control system for use in air-to-air combat simulation was designed. The input to the flight control system are commanded bank angle and angle of attack, the output are commands to the control surface actuators such that the commanded values will be achieved in near minimum time and sideslip is controlled to remain small. For the longitudinal direction, a conventional linear control system with gains scheduled as a function of dynamic pressure is employed. For the lateral direction, a novel control system, consisting of a linear portion for small bank angle errors and a bang-bang control system for large errors and error rates is employed.

Flight-determined benefits of integrated flight-propulsion control systems

NASA Technical Reports Server (NTRS)

Stewart, James F.; Burcham, Frank W., Jr.; Gatlin, Donald H.

1992-01-01

Over the last two decades, NASA has conducted several experiments in integrated flight-propulsion control. Benefits have included improved maneuverability; increased thrust, range, and survivability; reduced fuel consumption; and reduced maintenance. This paper presents the basic concepts for control integration, examples of implementation, and benefits. The F-111E experiment integrated the engine and inlet control systems. The YF-12C incorporated an integral control system involving the inlet, autopilot, autothrottle, airdata, navigation, and stability augmentation systems. The F-15 research involved integration of the engine, flight, and inlet control systems. Further extension of the integration included real-time, onboard optimization of engine, inlet, and flight control variables; a self-repairing flight control system; and an engines-only control concept for emergency control. The F-18A aircraft incorporated thrust vectoring integrated with the flight control system to provide enhanced maneuvering at high angles of attack. The flight research programs and the resulting benefits of each program are described.

Robust Fixed-Structure Controller Synthesis

NASA Technical Reports Server (NTRS)

Corrado, Joseph R.; Haddad, Wassim M.; Gupta, Kajal (Technical Monitor)

2000-01-01

The ability to develop an integrated control system design methodology for robust high performance controllers satisfying multiple design criteria and real world hardware constraints constitutes a challenging task. The increasingly stringent performance specifications required for controlling such systems necessitates a trade-off between controller complexity and robustness. The principle challenge of the minimal complexity robust control design is to arrive at a tractable control design formulation in spite of the extreme complexity of such systems. Hence, design of minimal complexitY robust controllers for systems in the face of modeling errors has been a major preoccupation of system and control theorists and practitioners for the past several decades.

Control technology for future aircraft propulsion systems

NASA Technical Reports Server (NTRS)

Zeller, J. R.; Szuch, J. R.; Merrill, W. C.; Lehtinen, B.; Soeder, J. F.

1984-01-01

The need for a more sophisticated engine control system is discussed. The improvements in better thrust-to-weight ratios demand the manipulation of more control inputs. New technological solutions to the engine control problem are practiced. The digital electronic engine control (DEEC) system is a step in the evolution to digital electronic engine control. Technology issues are addressed to ensure a growth in confidence in sophisticated electronic controls for aircraft turbine engines. The need of a control system architecture which permits propulsion controls to be functionally integrated with other aircraft systems is established. Areas of technology studied include: (1) control design methodology; (2) improved modeling and simulation methods; and (3) implementation technologies. Objectives, results and future thrusts are summarized.

Digital flight control actuation system study

NASA Technical Reports Server (NTRS)

Rossing, R.; Hupp, R.

1974-01-01

Flight control actuators and feedback sensors suitable for use in a redundant digital flight control system were examined. The most appropriate design approach for an advanced digital flight control actuation system for development and use in a fly-by-wire system was selected. The concept which was selected consisted of a PM torque motor direct drive. The selected system is compatible with concurrent and independent development efforts on the computer system and the control law mechanizations.

Design and Stability of an On-Orbit Attitude Control System Using Reaction Control Thrusters

NASA Technical Reports Server (NTRS)

Hall, Robert A.; Hough, Steven; Orphee, Carolina; Clements, Keith

2015-01-01

Principles for the design and stability of a spacecraft on-orbit attitude control system employing on-off Reaction Control System (RCS) thrusters is presented. Both the vehicle dynamics and the control system actuators are inherently nonlinear, hence traditional linear control system design approaches are not directly applicable. This paper has three main aspects: It summarizes key RCS control System design principles from the Space Shuttle and Space Station programs, it demonstrates a new approach to develop a linear model of a phase plane control system using describing functions, and applies each of these to the initial development of the NASA's next generation of upper stage vehicles. Topics addressed include thruster hardware specifications, phase plane design and stability, jet selection approaches, filter design metrics, and automaneuver logic.

Development of technology for creating intelligent control systems for power plants and propulsion systems for marine robotic systems

NASA Astrophysics Data System (ADS)

Iakovleva, E. V.; Momot, B. A.

2017-10-01

The object of this study is to develop a power plant and an electric propulsion control system for autonomous remotely controlled vessels. The tasks of the study are as follows: to assess remotely controlled vessels usage reasonability, to define the requirements for this type of vessel navigation. In addition, the paper presents the analysis of technical diagnostics systems. The developed electric propulsion control systems for vessels should provide improved reliability and efficiency of the propulsion complex to ensure the profitability of remotely controlled vessels.

Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project: Current and advanced act control system definition study. Volume 2: Appendices

NASA Technical Reports Server (NTRS)

Hanks, G. W.; Shomber, H. A.; Dethman, H. A.; Gratzer, L. B.; Maeshiro, A.; Gangsaas, D.; Blight, J. D.; Buchan, S. M.; Crumb, C. B.; Dorwart, R. J.

1981-01-01

The current status of the Active Controls Technology (ACT) for the advanced subsonic transport project is investigated through analysis of the systems technical data. Control systems technologies under examination include computerized reliability analysis, pitch axis fly by wire actuator, flaperon actuation system design trade study, control law synthesis and analysis, flutter mode control and gust load alleviation analysis, and implementation of alternative ACT systems. Extensive analysis of the computer techniques involved in each system is included.

Control aspects of the Schuchuli Village stand-alone photovoltaic power system

NASA Astrophysics Data System (ADS)

Groumpos, P. P.; Culler, J. E.; Delombard, R.

1984-11-01

A photovoltaic power system in an Arizona Indian village was installed. The control subsystem of this photovoltaic power system was analyzed. The four major functions of the control subsystem are: (1) voltage regulation; (2) load management; (3) water pump control; and (4) system protection. The control subsystem functions flowcharts for the control subsystem operation, and a computer program that models the control subsystem are presented.

Control aspects of the Schuchuli Village stand-alone photovoltaic power system

NASA Technical Reports Server (NTRS)

Groumpos, P. P.; Culler, J. E.; Delombard, R.

1984-01-01

A photovoltaic power system in an Arizona Indian village was installed. The control subsystem of this photovoltaic power system was analyzed. The four major functions of the control subsystem are: (1) voltage regulation; (2) load management; (3) water pump control; and (4) system protection. The control subsystem functions flowcharts for the control subsystem operation, and a computer program that models the control subsystem are presented.

Wisdom Appliance Control System

NASA Astrophysics Data System (ADS)

Hendrick; Jheng, Jyun-Teng; Tsai, Chen-Chai; Liou, Jia-Wei; Wang, Zhi-Hao; Jong, Gwo-Jia

2017-07-01

Intelligent appliances wisdom involves security, home care, convenient and energy saving, but the home automation system is still one of the core unit, and also using micro-processing electronics technology to centralized and control the home electrical products and systems, such as: lighting, television, fan, air conditioning, stereo, it composed of front-controller systems and back-controller panels, user using front-controller to control command, and then through the back-controller to powered the device.

40 CFR 63.749 - Compliance dates and determinations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... control system efficiency, Ek, as determined using the procedures specified in § 63.750(g) for control systems containing carbon adsorbers and in § 63.750(h) for control systems with other control devices, is... device is used, (A) The overall control system efficiency, Ek, as determined using the procedures...

40 CFR 63.749 - Compliance dates and determinations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... control system efficiency, Ek, as determined using the procedures specified in § 63.750(g) for control systems containing carbon adsorbers and in § 63.750(h) for control systems with other control devices, is... device is used, (A) The overall control system efficiency, Ek, as determined using the procedures...

40 CFR 63.749 - Compliance dates and determinations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... control system efficiency, Ek, as determined using the procedures specified in § 63.750(g) for control systems containing carbon adsorbers and in § 63.750(h) for control systems with other control devices, is... device is used, (A) The overall control system efficiency, Ek, as determined using the procedures...

40 CFR 63.749 - Compliance dates and determinations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... control system efficiency, Ek, as determined using the procedures specified in § 63.750(g) for control systems containing carbon adsorbers and in § 63.750(h) for control systems with other control devices, is... device is used, (A) The overall control system efficiency, Ek, as determined using the procedures...

46 CFR 184.620 - Propulsion engine control systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Propulsion engine control systems. 184.620 Section 184... Communications Systems § 184.620 Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of...

46 CFR 184.620 - Propulsion engine control systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Propulsion engine control systems. 184.620 Section 184... Communications Systems § 184.620 Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of...

46 CFR 62.35-5 - Remote propulsion-control systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Remote propulsion-control systems. 62.35-5 Section 62.35... AUTOMATION Requirements for Specific Types of Automated Vital Systems § 62.35-5 Remote propulsion-control systems. (a) Manual propulsion control. All vessels having remote propulsion control from the navigating...

46 CFR 62.35-5 - Remote propulsion-control systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Remote propulsion-control systems. 62.35-5 Section 62.35... AUTOMATION Requirements for Specific Types of Automated Vital Systems § 62.35-5 Remote propulsion-control systems. (a) Manual propulsion control. All vessels having remote propulsion control from the navigating...

46 CFR 184.620 - Propulsion engine control systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Propulsion engine control systems. 184.620 Section 184... Communications Systems § 184.620 Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of...

46 CFR 62.35-5 - Remote propulsion-control systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Remote propulsion-control systems. 62.35-5 Section 62.35... AUTOMATION Requirements for Specific Types of Automated Vital Systems § 62.35-5 Remote propulsion-control systems. (a) Manual propulsion control. All vessels having remote propulsion control from the navigating...

46 CFR 62.35-5 - Remote propulsion-control systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Remote propulsion-control systems. 62.35-5 Section 62.35... AUTOMATION Requirements for Specific Types of Automated Vital Systems § 62.35-5 Remote propulsion-control systems. (a) Manual propulsion control. All vessels having remote propulsion control from the navigating...

46 CFR 184.620 - Propulsion engine control systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Propulsion engine control systems. 184.620 Section 184... Communications Systems § 184.620 Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of...

46 CFR 184.620 - Propulsion engine control systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Propulsion engine control systems. 184.620 Section 184... Communications Systems § 184.620 Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of...

46 CFR 62.25-15 - Safety control systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

....35-50. Note: Safety control systems include automatic and manual safety trip controls and automatic... engines. (e) Automatic safety trip control systems must— (1) Be provided where there is an immediate... 46 Shipping 2 2011-10-01 2011-10-01 false Safety control systems. 62.25-15 Section 62.25-15...

40 CFR 63.749 - Compliance dates and determinations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... control system efficiency, Ek, as determined using the procedures specified in § 63.750(g) for control systems containing carbon adsorbers and in § 63.750(h) for control systems with other control devices, is... device is used, (A) The overall control system efficiency, Ek, as determined using the procedures...

49 CFR 229.13 - Control of locomotives.

Code of Federal Regulations, 2010 CFR

2010-10-01

... coupled in remote or multiple control, the propulsion system, the sanders, and the power brake system of each locomotive shall respond to control from the cab of the controlling locomotive. If a dynamic brake or regenerative brake system is in use, that portion of the system in use shall respond to control...

Development of a Self-Balancing Human Transportation Vehicle for the Teaching of Feedback Control

ERIC Educational Resources Information Center

Lin, Shui-Chun; Tsai, Ching-Chih

2009-01-01

Control systems education often needs to design interesting hands-on exercises that keep students interested in the control theory presented in lectures. These exercises include system modeling, system analyses, controller syntheses, implementation, experimentation, and performance evaluation of a control system. This paper presents an interesting…

49 CFR 236.1045 - Training specific to office control personnel.

Code of Federal Regulations, 2010 CFR

2010-10-01

... between the computer-aided dispatching system and the train control system, with respect to the safe... INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Positive Train Control Systems § 236.1045 Training specific to office control personnel. (a) Any person...

49 CFR 236.1045 - Training specific to office control personnel.

Code of Federal Regulations, 2014 CFR

2014-10-01

... between the computer-aided dispatching system and the train control system, with respect to the safe... INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Positive Train Control Systems § 236.1045 Training specific to office control personnel. (a) Any person...

49 CFR 236.925 - Training specific to control office personnel.

Code of Federal Regulations, 2013 CFR

2013-10-01

... concerning the interface between the computer-aided dispatching system and the train control system, with... INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Standards for Processor-Based Signal and Train Control Systems § 236.925 Training specific to control office...

49 CFR 236.1045 - Training specific to office control personnel.

Code of Federal Regulations, 2012 CFR

2012-10-01

... between the computer-aided dispatching system and the train control system, with respect to the safe... INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Positive Train Control Systems § 236.1045 Training specific to office control personnel. (a) Any person...

49 CFR 236.925 - Training specific to control office personnel.

Code of Federal Regulations, 2011 CFR

2011-10-01

... concerning the interface between the computer-aided dispatching system and the train control system, with... INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Standards for Processor-Based Signal and Train Control Systems § 236.925 Training specific to control office...

49 CFR 236.925 - Training specific to control office personnel.

Code of Federal Regulations, 2012 CFR

2012-10-01

... concerning the interface between the computer-aided dispatching system and the train control system, with... INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Standards for Processor-Based Signal and Train Control Systems § 236.925 Training specific to control office...

49 CFR 236.1045 - Training specific to office control personnel.

Code of Federal Regulations, 2011 CFR

2011-10-01

... between the computer-aided dispatching system and the train control system, with respect to the safe... INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Positive Train Control Systems § 236.1045 Training specific to office control personnel. (a) Any person...

49 CFR 236.925 - Training specific to control office personnel.

Code of Federal Regulations, 2010 CFR

2010-10-01

... concerning the interface between the computer-aided dispatching system and the train control system, with... INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Standards for Processor-Based Signal and Train Control Systems § 236.925 Training specific to control office...

49 CFR 236.1045 - Training specific to office control personnel.

Code of Federal Regulations, 2013 CFR

2013-10-01

... between the computer-aided dispatching system and the train control system, with respect to the safe... INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Positive Train Control Systems § 236.1045 Training specific to office control personnel. (a) Any person...

49 CFR 236.925 - Training specific to control office personnel.

Code of Federal Regulations, 2014 CFR

2014-10-01

... concerning the interface between the computer-aided dispatching system and the train control system, with... INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Standards for Processor-Based Signal and Train Control Systems § 236.925 Training specific to control office...

14 CFR 29.395 - Control system.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Control system. 29.395 Section 29.395... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Control Surface and System Loads § 29.395 Control system. (a) The reaction to the loads prescribed in § 29.397 must be provided by— (1) The control...

14 CFR 25.679 - Control system gust locks.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Control Systems § 25.679 Control system gust locks. (a) There must be a device to prevent damage to the control surfaces (including tabs... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Control system gust locks. 25.679 Section...

14 CFR 25.679 - Control system gust locks.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Control Systems § 25.679 Control system gust locks. (a) There must be a device to prevent damage to the control surfaces (including tabs... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Control system gust locks. 25.679 Section...

14 CFR 25.679 - Control system gust locks.

Code of Federal Regulations, 2011 CFR

2011-01-01

... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Control Systems § 25.679 Control system gust locks. (a) There must be a device to prevent damage to the control surfaces (including tabs... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Control system gust locks. 25.679 Section...

14 CFR 25.679 - Control system gust locks.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Control Systems § 25.679 Control system gust locks. (a) There must be a device to prevent damage to the control surfaces (including tabs... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Control system gust locks. 25.679 Section...

46 CFR 62.35-5 - Remote propulsion-control systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Remote propulsion-control systems. 62.35-5 Section 62.35... AUTOMATION Requirements for Specific Types of Automated Vital Systems § 62.35-5 Remote propulsion-control systems. (a) Manual propulsion control. All vessels having remote propulsion control from the navigating...

49 CFR 236.825 - System, automatic train control.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false System, automatic train control. 236.825 Section..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.825 System, automatic train control. A system so arranged that its operation will automatically...

49 CFR 236.825 - System, automatic train control.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false System, automatic train control. 236.825 Section..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.825 System, automatic train control. A system so arranged that its operation will automatically...

Adaptive Control for Autonomous Navigation of Mobile Robots Considering Time Delay and Uncertainty

NASA Astrophysics Data System (ADS)

Armah, Stephen Kofi

Autonomous control of mobile robots has attracted considerable attention of researchers in the areas of robotics and autonomous systems during the past decades. One of the goals in the field of mobile robotics is development of platforms that robustly operate in given, partially unknown, or unpredictable environments and offer desired services to humans. Autonomous mobile robots need to be equipped with effective, robust and/or adaptive, navigation control systems. In spite of enormous reported work on autonomous navigation control systems for mobile robots, achieving the goal above is still an open problem. Robustness and reliability of the controlled system can always be improved. The fundamental issues affecting the stability of the control systems include the undesired nonlinear effects introduced by actuator saturation, time delay in the controlled system, and uncertainty in the model. This research work develops robustly stabilizing control systems by investigating and addressing such nonlinear effects through analytical, simulations, and experiments. The control systems are designed to meet specified transient and steady-state specifications. The systems used for this research are ground (Dr Robot X80SV) and aerial (Parrot AR.Drone 2.0) mobile robots. Firstly, an effective autonomous navigation control system is developed for X80SV using logic control by combining 'go-to-goal', 'avoid-obstacle', and 'follow-wall' controllers. A MATLAB robot simulator is developed to implement this control algorithm and experiments are conducted in a typical office environment. The next stage of the research develops an autonomous position (x, y, and z) and attitude (roll, pitch, and yaw) controllers for a quadrotor, and PD-feedback control is used to achieve stabilization. The quadrotor's nonlinear dynamics and kinematics are implemented using MATLAB S-function to generate the state output. Secondly, the white-box and black-box approaches are used to obtain a linearized second-order altitude models for the quadrotor, AR.Drone 2.0. Proportional (P), pole placement or proportional plus velocity (PV), linear quadratic regulator (LQR), and model reference adaptive control (MRAC) controllers are designed and validated through simulations using MATLAB/Simulink. Control input saturation and time delay in the controlled systems are also studied. MATLAB graphical user interface (GUI) and Simulink programs are developed to implement the controllers on the drone. Thirdly, the time delay in the drone's control system is estimated using analytical and experimental methods. In the experimental approach, the transient properties of the experimental altitude responses are compared to those of simulated responses. The analytical approach makes use of the Lambert W function to obtain analytical solutions of scalar first-order delay differential equations (DDEs). A time-delayed P-feedback control system (retarded type) is used in estimating the time delay. Then an improved system performance is obtained by incorporating the estimated time delay in the design of the PV control system (neutral type) and PV-MRAC control system. Furthermore, the stability of a parametric perturbed linear time-invariant (LTI) retarded-type system is studied. This is done by analytically calculating the stability radius of the system. Simulation of the control system is conducted to confirm the stability. This robust control design and uncertainty analysis are conducted for first-order and second-order quadrotor models. Lastly, the robustly designed PV and PV-MRAC control systems are used to autonomously track multiple waypoints. Also, the robustness of the PV-MRAC controller is tested against a baseline PV controller using the payload capability of the drone. It is shown that the PV-MRAC offers several benefits over the fixed-gain approach of the PV controller. The adaptive control is found to offer enhanced robustness to the payload fluctuations.

Distributed Engine Control Empirical/Analytical Verification Tools

NASA Technical Reports Server (NTRS)

DeCastro, Jonathan; Hettler, Eric; Yedavalli, Rama; Mitra, Sayan

2013-01-01

NASA's vision for an intelligent engine will be realized with the development of a truly distributed control system featuring highly reliable, modular, and dependable components capable of both surviving the harsh engine operating environment and decentralized functionality. A set of control system verification tools was developed and applied to a C-MAPSS40K engine model, and metrics were established to assess the stability and performance of these control systems on the same platform. A software tool was developed that allows designers to assemble easily a distributed control system in software and immediately assess the overall impacts of the system on the target (simulated) platform, allowing control system designers to converge rapidly on acceptable architectures with consideration to all required hardware elements. The software developed in this program will be installed on a distributed hardware-in-the-loop (DHIL) simulation tool to assist NASA and the Distributed Engine Control Working Group (DECWG) in integrating DCS (distributed engine control systems) components onto existing and next-generation engines.The distributed engine control simulator blockset for MATLAB/Simulink and hardware simulator provides the capability to simulate virtual subcomponents, as well as swap actual subcomponents for hardware-in-the-loop (HIL) analysis. Subcomponents can be the communication network, smart sensor or actuator nodes, or a centralized control system. The distributed engine control blockset for MATLAB/Simulink is a software development tool. The software includes an engine simulation, a communication network simulation, control algorithms, and analysis algorithms set up in a modular environment for rapid simulation of different network architectures; the hardware consists of an embedded device running parts of the CMAPSS engine simulator and controlled through Simulink. The distributed engine control simulation, evaluation, and analysis technology provides unique capabilities to study the effects of a given change to the control system in the context of the distributed paradigm. The simulation tool can support treatment of all components within the control system, both virtual and real; these include communication data network, smart sensor and actuator nodes, centralized control system (FADEC full authority digital engine control), and the aircraft engine itself. The DECsim tool can allow simulation-based prototyping of control laws, control architectures, and decentralization strategies before hardware is integrated into the system. With the configuration specified, the simulator allows a variety of key factors to be systematically assessed. Such factors include control system performance, reliability, weight, and bandwidth utilization.

Renewal of the Control System and Reliable Long Term Operation of the LHD Cryogenic System

NASA Astrophysics Data System (ADS)

Mito, T.; Iwamoto, A.; Oba, K.; Takami, S.; Moriuchi, S.; Imagawa, S.; Takahata, K.; Yamada, S.; Yanagi, N.; Hamaguchi, S.; Kishida, F.; Nakashima, T.

The Large Helical Device (LHD) is a heliotron-type fusion plasma experimental machine which consists of a fully superconducting magnet system cooled by a helium refrigerator having a total equivalent cooling capacity of 9.2 kW@4.4 K. Seventeenplasma experimental campaigns have been performed successfully since1997 with high reliability of 99%. However, sixteen years have passed from the beginning of the system operation. Improvements are being implementedto prevent serious failures and to pursue further reliability.The LHD cryogenic control system was designed and developed as an open system utilizing latest control equipment of VME controllers and UNIX workstations at the construction time. Howeverthe generation change of control equipment has been advanced. Down-sizing of control deviceshas beenplanned from VME controllers to compact PCI controllers in order to simplify the system configuration and to improve the system reliability. The new system is composed of compact PCI controller and remote I/O connected with EtherNet/IP. Making the system redundant becomes possible by doubling CPU, LAN, and remote I/O respectively. The smooth renewal of the LHD cryogenic controlsystem and the further improvement of the cryogenic system reliability are reported.

Comparison of digital controllers used in magnetic suspension and balance systems

NASA Technical Reports Server (NTRS)

Kilgore, William A.

1990-01-01

Dynamic systems that were once controlled by analog circuits are now controlled by digital computers. Presented is a comparison of the digital controllers presently used with magnetic suspension and balance systems. The overall responses of the systems are compared using a computer simulation of the magnetic suspension and balance system and the digital controllers. The comparisons include responses to both simulated force and position inputs. A preferred digital controller is determined from the simulated responses.

3. EAGLE ROCK CONTROL CENTER, OPERATIONS CONTROL. AS SYSTEM BECOMES ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. EAGLE ROCK CONTROL CENTER, OPERATIONS CONTROL. AS SYSTEM BECOMES INCREASINGLY AUTOMATED, EAGLE ROCK WILL BECOME MORE AND MORE THE CENTRAL CONTROL SYSTEM OF THE METROPOLITAN WATER DISTRICT. - Eagle Rock Operations Control Center, Pasadena, Los Angeles County, CA

Intelligent on-line fault tolerant control for unanticipated catastrophic failures.

PubMed

Yen, Gary G; Ho, Liang-Wei

2004-10-01

As dynamic systems become increasingly complex, experience rapidly changing environments, and encounter a greater variety of unexpected component failures, solving the control problems of such systems is a grand challenge for control engineers. Traditional control design techniques are not adequate to cope with these systems, which may suffer from unanticipated dynamic failures. In this research work, we investigate the on-line fault tolerant control problem and propose an intelligent on-line control strategy to handle the desired trajectories tracking problem for systems suffering from various unanticipated catastrophic faults. Through theoretical analysis, the sufficient condition of system stability has been derived and two different on-line control laws have been developed. The approach of the proposed intelligent control strategy is to continuously monitor the system performance and identify what the system's current state is by using a fault detection method based upon our best knowledge of the nominal system and nominal controller. Once a fault is detected, the proposed intelligent controller will adjust its control signal to compensate for the unknown system failure dynamics by using an artificial neural network as an on-line estimator to approximate the unexpected and unknown failure dynamics. The first control law is derived directly from the Lyapunov stability theory, while the second control law is derived based upon the discrete-time sliding mode control technique. Both control laws have been implemented in a variety of failure scenarios to validate the proposed intelligent control scheme. The simulation results, including a three-tank benchmark problem, comply with theoretical analysis and demonstrate a significant improvement in trajectory following performance based upon the proposed intelligent control strategy.

Sliding Mode Thermal Control System for Space Station Furnace Facility

NASA Technical Reports Server (NTRS)

Jackson Mark E.; Shtessel, Yuri B.

1998-01-01

The decoupled control of the nonlinear, multiinput-multioutput, and highly coupled space station furnace facility (SSFF) thermal control system is addressed. Sliding mode control theory, a subset of variable-structure control theory, is employed to increase the performance, robustness, and reliability of the SSFF's currently designed control system. This paper presents the nonlinear thermal control system description and develops the sliding mode controllers that cause the interconnected subsystems to operate in their local sliding modes, resulting in control system invariance to plant uncertainties and external and interaction disturbances. The desired decoupled flow-rate tracking is achieved by optimization of the local linear sliding mode equations. The controllers are implemented digitally and extensive simulation results are presented to show the flow-rate tracking robustness and invariance to plant uncertainties, nonlinearities, external disturbances, and variations of the system pressure supplied to the controlled subsystems.

Advanced Ground Systems Maintenance Cryogenics Test Lab Control System Upgrade Project

NASA Technical Reports Server (NTRS)

Harp, Janice Leshay

2014-01-01

This project will outfit the Simulated Propellant Loading System (SPLS) at KSC's Cryogenics Test Laboratory with a new programmable logic control system. The control system upgrade enables the Advanced Ground Systems Maintenace Element Integration Team and other users of the SPLS to conduct testing in a controls environment similar to that used at the launch pad.

Nonlinear Control Systems

DTIC Science & Technology

2007-03-01

Finite -dimensional regulators for a class of infinite dimensional systems ,” Systems and Control Letters, 3 (1983), 7-12. [11] B...semiglobal stabilizability by encoded state feedback,” to appear in Systems and Control Letters. 22 29. C. De Persis, A. Isidori, “Global stabilization of...nonequilibrium setting, for both finite and infinite dimensional control systems . Our objectives for distributed parameter systems included

Hybrid Control for Multi-Agent Systems in Complex Sensing Environments

DTIC Science & Technology

2012-02-28

controllers , the overall closed-loop system is time -varying but can potentially exhibit better stability and performance... system is time -varying and yet, once 4 feedback-interconnected with a suitable controller , it can potentially yield better stability and performance...resolution Sensing, Control and Switched Systems 13 4 Metric-Based Receding Horizon Control 14 5 Decentralized Control and Finite Wordlength Channels 15

Microprocessor-based control systems application in nuclear power plant critical systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shah, M.R.; Nowak, J.B.

Microprocessor-based control systems have been used in fossil power plants and are receiving greater acceptance for application in nuclear plants. This technology is not new but it does require unique considerations when applied to nuclear power plants. Sargent and Lundy (S and L) has used a microprocessor-based component logic control system (interposing Logic System) for safety- and non-safety-related components in nuclear power plants under construction overseas. Currently, S and L is in the design stage to replace an existing analog control system with a microprocessor-based control system in the U.S. The trend in the industry is to replace systems inmore » existing plants or design new power plants with microprocessor-based control systems.« less

Minimal-Inversion Feedforward-And-Feedback Control System

NASA Technical Reports Server (NTRS)

Seraji, Homayoun

1990-01-01

Recent developments in theory of control systems support concept of minimal-inversion feedforward-and feedback control system consisting of three independently designable control subsystems. Applicable to the control of linear, time-invariant plant.

Application of a microcomputer-based system to control and monitor bacterial growth.

PubMed

Titus, J A; Luli, G W; Dekleva, M L; Strohl, W R

1984-02-01

A modular microcomputer-based system was developed to control and monitor various modes of bacterial growth. The control system was composed of an Apple II Plus microcomputer with 64-kilobyte random-access memory; a Cyborg ISAAC model 91A multichannel analog-to-digital and digital-to-analog converter; paired MRR-1 pH, pO(2), and foam control units; and in-house-designed relay, servo control, and turbidimetry systems. To demonstrate the flexibility of the system, we grew bacteria under various computer-controlled and monitored modes of growth, including batch, turbidostat, and chemostat systems. The Apple-ISAAC system was programmed in Labsoft BASIC (extended Applesoft) with an average control program using ca. 6 to 8 kilobytes of memory and up to 30 kilobytes for datum arrays. This modular microcomputer-based control system was easily coupled to laboratory scale fermentors for a variety of fermentations.

Application of a Microcomputer-Based System to Control and Monitor Bacterial Growth

PubMed Central

Titus, Jeffrey A.; Luli, Gregory W.; Dekleva, Michael L.; Strohl, William R.

1984-01-01

A modular microcomputer-based system was developed to control and monitor various modes of bacterial growth. The control system was composed of an Apple II Plus microcomputer with 64-kilobyte random-access memory; a Cyborg ISAAC model 91A multichannel analog-to-digital and digital-to-analog converter; paired MRR-1 pH, pO2, and foam control units; and in-house-designed relay, servo control, and turbidimetry systems. To demonstrate the flexibility of the system, we grew bacteria under various computer-controlled and monitored modes of growth, including batch, turbidostat, and chemostat systems. The Apple-ISAAC system was programmed in Labsoft BASIC (extended Applesoft) with an average control program using ca. 6 to 8 kilobytes of memory and up to 30 kilobytes for datum arrays. This modular microcomputer-based control system was easily coupled to laboratory scale fermentors for a variety of fermentations. PMID:16346462

An adaptive load-following control system for a space nuclear power system

NASA Astrophysics Data System (ADS)

Metzger, John D.; El-Genk, Mohamed S.

An adaptive load-following control system is proposed for a space nuclear power system. The conceptual design of the SP-100 space nuclear power system proposes operating the nuclear reactor at a base thermal power and accommodating changes in the electrical power demand with a shunt regulator. It is necessary to increase the reactor thermal power if the payload electrical demand exceeds the peak system electrical output for the associated reactor power. When it is necessary to change the nuclear reactor power to meet a change in the power demand, the power ascension or descension must be accomplished in a predetermined manner to avoid thermal stresses in the system and to achieve the desired reactor period. The load-following control system described has the ability to adapt to changes in the system and to changes in the satellite environment. The application is proposed of the model reference adaptive control (MRAC). The adaptive control system has the ability to control the dynamic response of nonlinear systems. Three basic subsets of adaptive control are: (1) gain scheduling, (2) self-tuning regulators, and (3) model reference adaptive control.

Investigation of energy management strategies for photovoltaic systems - A predictive control algorithm

NASA Technical Reports Server (NTRS)

Cull, R. C.; Eltimsahy, A. H.

1983-01-01

The present investigation is concerned with the formulation of energy management strategies for stand-alone photovoltaic (PV) systems, taking into account a basic control algorithm for a possible predictive, (and adaptive) controller. The control system controls the flow of energy in the system according to the amount of energy available, and predicts the appropriate control set-points based on the energy (insolation) available by using an appropriate system model. Aspects of adaptation to the conditions of the system are also considered. Attention is given to a statistical analysis technique, the analysis inputs, the analysis procedure, and details regarding the basic control algorithm.

Energy Efficient Engine: Control system preliminary definition report

NASA Technical Reports Server (NTRS)

Howe, David C.

1986-01-01

The object of the Control Preliminary Definition Program was to define a preliminary control system concept as a part of the Energy Efficient Engine program. The program was limited to a conceptual definition of a full authority digital electronic control system. System requirements were determined and a control system was conceptually defined to these requirements. Areas requiring technological development were identified and a plan was established for implementing the identified technological features, including a control technology demonstration. A significant element of this program was a study of the potential benefits of closed-loop active clearance control, along with laboratory tests of candidate clearance sensor elements for a closed loop system.

Advanced controls for light sources

NASA Astrophysics Data System (ADS)

Biedron, S. G.; Edelen, A. L.; Milton, S. V.

2016-09-01

We present a summary of our team's recent efforts in developing adaptive, artificial intelligence-inspired techniques specifically to address several control challenges that arise in machines/systems including those in particle accelerator systems. These techniques can readily be adapted to other systems such as lasers, beamline optics, etc… We are not at all suggesting that we create an autonomous system, but create a system with an intelligent control system, that can continually use operational data to improve itself and combines both traditional and advanced techniques. We believe that the system performance and reliability can be increased based on our findings. Another related point is that the controls sub-system of an overall system is usually not the heart of the system architecture or design process. More bluntly, often times all of the peripheral systems are considered as secondary to the main system components in the architecture design process because it is assumed that the controls system will be able to "fix" challenges found later with the sub-systems for overall system operation. We will show that this is not always the case and that it took an intelligent control application to overcome a sub-system's challenges. We will provide a recent example of such a "fix" with a standard controller and with an artificial intelligence-inspired controller. A final related point to be covered is that of system adaptation for requirements not original to a system's original design.

SP-100 Control System Design

NASA Astrophysics Data System (ADS)

Shukla, Jaikaran N.; Halfen, Frank J.; Brynsvold, Glen V.; Syed, Akbar; Jiang, Thomas J.; Wong, Kwok K.; Otwell, Robert L.

1994-07-01

Recent work in lower power generic early applications for the SP-100 have resulted in control system design simplification for a 20 kWe design with thermoelectric power conversion. This paper presents the non-mission-dependent control system features for this design. The control system includes a digital computer based controller, dual purpose control rods and drives, temperature sensors, and neutron flux monitors. The thaw system is mission dependent and can be either electrical or based on NaK trace lines. Key features of the control system and components are discussed. As was the case for higher power applications, the initial on-orbit approach to criticality involves the relatively fast withdrawal of the control-rods to a near-critical position followed by slower movement through critical and into the power range. The control system performs operating maneuvers as well as providing for automatic startup, shutdown, restart, and reactor protection.

Application of digital computer APU modeling techniques to control system design.

NASA Technical Reports Server (NTRS)

Bailey, D. A.; Burriss, W. L.

1973-01-01

Study of the required controls for a H2-O2 auxiliary power unit (APU) technology program for the Space Shuttle. A steady-state system digital computer program was prepared and used to optimize initial system design. Analytical models of each system component were included. The program was used to solve a nineteen-dimensional problem, and then time-dependent differential equations were added to the computer program to simulate transient APU system and control. Some system parameters were considered quasi-steady-state, and others were treated as differential variables. The dynamic control analysis proceeded from initial ideal control modeling (which considered one control function and assumed the others to be ideal), stepwise through the system (adding control functions), until all of the control functions and their interactions were considered. In this way, the adequacy of the final control design over the required wide range of APU operating conditions was established.

Pulse-density modulation control of chemical oscillation far from equilibrium in a droplet open-reactor system

PubMed Central

Sugiura, Haruka; Ito, Manami; Okuaki, Tomoya; Mori, Yoshihito; Kitahata, Hiroyuki; Takinoue, Masahiro

2016-01-01

The design, construction and control of artificial self-organized systems modelled on dynamical behaviours of living systems are important issues in biologically inspired engineering. Such systems are usually based on complex reaction dynamics far from equilibrium; therefore, the control of non-equilibrium conditions is required. Here we report a droplet open-reactor system, based on droplet fusion and fission, that achieves dynamical control over chemical fluxes into/out of the reactor for chemical reactions far from equilibrium. We mathematically reveal that the control mechanism is formulated as pulse-density modulation control of the fusion–fission timing. We produce the droplet open-reactor system using microfluidic technologies and then perform external control and autonomous feedback control over autocatalytic chemical oscillation reactions far from equilibrium. We believe that this system will be valuable for the dynamical control over self-organized phenomena far from equilibrium in chemical and biomedical studies. PMID:26786848

Pulse-density modulation control of chemical oscillation far from equilibrium in a droplet open-reactor system.

PubMed

Sugiura, Haruka; Ito, Manami; Okuaki, Tomoya; Mori, Yoshihito; Kitahata, Hiroyuki; Takinoue, Masahiro

2016-01-20

The design, construction and control of artificial self-organized systems modelled on dynamical behaviours of living systems are important issues in biologically inspired engineering. Such systems are usually based on complex reaction dynamics far from equilibrium; therefore, the control of non-equilibrium conditions is required. Here we report a droplet open-reactor system, based on droplet fusion and fission, that achieves dynamical control over chemical fluxes into/out of the reactor for chemical reactions far from equilibrium. We mathematically reveal that the control mechanism is formulated as pulse-density modulation control of the fusion-fission timing. We produce the droplet open-reactor system using microfluidic technologies and then perform external control and autonomous feedback control over autocatalytic chemical oscillation reactions far from equilibrium. We believe that this system will be valuable for the dynamical control over self-organized phenomena far from equilibrium in chemical and biomedical studies.

A discrete control model of PLANT

NASA Technical Reports Server (NTRS)

Mitchell, C. M.

1985-01-01

A model of the PLANT system using the discrete control modeling techniques developed by Miller is described. Discrete control models attempt to represent in a mathematical form how a human operator might decompose a complex system into simpler parts and how the control actions and system configuration are coordinated so that acceptable overall system performance is achieved. Basic questions include knowledge representation, information flow, and decision making in complex systems. The structure of the model is a general hierarchical/heterarchical scheme which structurally accounts for coordination and dynamic focus of attention. Mathematically, the discrete control model is defined in terms of a network of finite state systems. Specifically, the discrete control model accounts for how specific control actions are selected from information about the controlled system, the environment, and the context of the situation. The objective is to provide a plausible and empirically testable accounting and, if possible, explanation of control behavior.

Remote control of microcontroller-based infant stimulating system.

PubMed

Burunkaya, M; Güler, I

2000-04-01

In this paper, a remote-controlled and microcontroller-based cradle is designed and constructed. This system is also called Remote Control of Microcontroller-Based Infant Stimulation System or the RECOMBIS System. Cradle is an infant stimulating system that provides relaxation and sleeping for the baby. RECOMBIS system is designed for healthy full-term newborns to provide safe infant care and provide relaxation and sleeping for the baby. A microcontroller-based electronic circuit was designed and implemented for RECOMBIS system. Electromagnets were controlled by 8-bit PIC16F84 microcontroller, which is programmed using MPASM package. The system works by entering preset values from the keyboard, or pulse code modulated radio frequency remote control system. The control of the system and the motion range were tested. The test results showed that the system provided a good performance.

14 CFR 417.305 - Command control system testing.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Command control system testing. 417.305..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety System § 417.305 Command control system testing. (a) General. (1) A command control system, including its subsystems and components must undergo...

14 CFR 417.305 - Command control system testing.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Command control system testing. 417.305..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety System § 417.305 Command control system testing. (a) General. (1) A command control system, including its subsystems and components must undergo...

14 CFR 417.305 - Command control system testing.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Command control system testing. 417.305..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety System § 417.305 Command control system testing. (a) General. (1) A command control system, including its subsystems and components must undergo...

14 CFR 417.305 - Command control system testing.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Command control system testing. 417.305..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety System § 417.305 Command control system testing. (a) General. (1) A command control system, including its subsystems and components must undergo...

14 CFR 417.305 - Command control system testing.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Command control system testing. 417.305..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety System § 417.305 Command control system testing. (a) General. (1) A command control system, including its subsystems and components must undergo...

46 CFR 154.904 - Inert gas system: Controls.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Inert gas system: Controls. 154.904 Section 154.904... STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Atmospheric Control in Cargo Containment Systems § 154.904 Inert gas system: Controls. The inert gas system...

Controllable Grid Interface Test System | Energy Systems Integration

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Facility | NREL Controllable Grid Interface Test System Controllable Grid Interface Test System NREL's controllable grid interface (CGI) test system can reduce certification testing time and costs grid interface is the first test facility in the United States that has fault simulation capabilities

Decoupling control of vehicle chassis system based on neural network inverse system

NASA Astrophysics Data System (ADS)

Wang, Chunyan; Zhao, Wanzhong; Luan, Zhongkai; Gao, Qi; Deng, Ke

2018-06-01

Steering and suspension are two important subsystems affecting the handling stability and riding comfort of the chassis system. In order to avoid the interference and coupling of the control channels between active front steering (AFS) and active suspension subsystems (ASS), this paper presents a composite decoupling control method, which consists of a neural network inverse system and a robust controller. The neural network inverse system is composed of a static neural network with several integrators and state feedback of the original chassis system to approach the inverse system of the nonlinear systems. The existence of the inverse system for the chassis system is proved by the reversibility derivation of Interactor algorithm. The robust controller is based on the internal model control (IMC), which is designed to improve the robustness and anti-interference of the decoupled system by adding a pre-compensation controller to the pseudo linear system. The results of the simulation and vehicle test show that the proposed decoupling controller has excellent decoupling performance, which can transform the multivariable system into a number of single input and single output systems, and eliminate the mutual influence and interference. Furthermore, it has satisfactory tracking capability and robust performance, which can improve the comprehensive performance of the chassis system.

An Assessment of Vulnerabilities for Ship-based Control Systems

DTIC Science & Technology

2009-09-01

VULNERABILITIES FOR SHIP- BASED CONTROL SYSTEMS by Richard Bensing September 2009 Thesis Advisor: Karen Burke Co-Advisor: George Dinolt...COVERED Master’s Thesis 4. TITLE AND SUBTITLE: An Assessment of Vulnerabilities for Ship- based Control Systems 6. AUTHOR(S) Richard Bensing 5...soft underbelly. Computer- based control systems form the heart of the critical infrastructure, and these control systems are riddled with rampant

Flight-determined benefits of integrated flight-propulsion control systems

NASA Technical Reports Server (NTRS)

Stewart, James F.; Burcham, Frank W., Jr.; Gatlin, Donald H.

1992-01-01

The fundamentals of control integration for propulsion are reviewed giving practical illustrations of its use to demonstrate the advantages of integration. Attention is given to the first integration propulsion-control systems (IPCSs) which was developed for the F-111E, and the integrated controller design is described that NASA developed for the YF-12C aircraft. The integrated control systems incorporate a range of aircraft components including the engine, inlet controls, autopilot, autothrottle, airdata, navigation, and/or stability-augmentation systems. Also described are emergency-control systems, onboard engine optimization, and thrust-vectoring control technologies developed for the F-18A and the F-15. Integrated flight-propulsion control systems are shown to enhance the thrust, range, and survivability of the aircraft while reducing fuel consumption and maintenance.

Design of a powered elevator control system. [powered elevator system for modified C-8A aircraft for STOL operation

NASA Technical Reports Server (NTRS)

Glende, W. L. B.

1974-01-01

The design, fabrication and flight testing of a powered elevator system for the Augmentor Wing Jet STOL Research Aircraft (AWJSRA or Mod C-8A) are discussed. The system replaces a manual spring tab elevator control system that was unsatisfactory in the STOL flight regime. Pitch control in the AWJSRA is by means of a single elevator control surface. The elevator is used for both maneuver and trim control as the stabilizer is fixed. A fully powered, irreversible flight control system powered by dual hydraulic sources was designed. The existing control columns and single mechanical cable system of the AWJSRA have been retained as has been the basic elevator surface, except that the elevator spring tab is modified into a geared balance tab. The control surface is directly actuated by a dual tandem moving body actuator. Control signals are transmitted from the elevator aft quadrant to the actuator by a linkage system that includes a limited authority series servo actuator.

X-33 Attitude Control System Design for Ascent, Transition, and Entry Flight Regimes

NASA Technical Reports Server (NTRS)

Hall, Charles E.; Gallaher, Michael W.; Hendrix, Neal D.

1998-01-01

The Vehicle Control Systems Team at Marshall Space Flight Center, Systems Dynamics Laboratory, Guidance and Control Systems Division is designing under a cooperative agreement with Lockheed Martin Skunkworks, the Ascent, Transition, and Entry flight attitude control system for the X-33 experimental vehicle. Ascent flight control begins at liftoff and ends at linear aerospike main engine cutoff (NECO) while Transition and Entry flight control begins at MECO and concludes at the terminal area energy management (TAEM) interface. TAEM occurs at approximately Mach 3.0. This task includes not only the design of the vehicle attitude control systems but also the development of requirements for attitude control system components and subsystems. The X-33 attitude control system design is challenged by a short design cycle, the design environment (Mach 0 to about Mach 15), and the X-33 incremental test philosophy. The X-33 design-to-launch cycle of less than 3 years requires a concurrent design approach while the test philosophy requires design adaptation to vehicle variations that are a function of Mach number and mission profile. The flight attitude control system must deal with the mixing of aerosurfaces, reaction control thrusters, and linear aerospike engine control effectors and handle parasitic effects such as vehicle flexibility and propellant sloshing from the uniquely shaped propellant tanks. The attitude control system design is, as usual, closely linked to many other subsystems and must deal with constraints and requirements from these subsystems.

Phase Control in Nonlinear Systems

NASA Astrophysics Data System (ADS)

Zambrano, Samuel; Seoane, Jesús M.; Mariño, Inés P.; Sanjuán, Miguel A. F.; Meucci, Riccardo

The following sections are included: * Introduction * Phase Control of Chaos * Description of the model * Numerical exploration of phase control of chaos * Experimental evidence of phase control of chaos * Phase Control of Intermittency in Dynamical Systems * Crisis-induced intermittency and its control * Experimental setup and implementation of the phase control scheme * Phase control of the laser in the pre-crisis regime * Phase control of the intermittency after the crisis * Phase control of the intermittency in the quadratic map * Phase Control of Escapes in Open Dynamical Systems * Control of open dynamical systems * Model description * Numerical simulations and heuristic arguments * Experimental implementation in an electronic circuit * Conclusions and Discussions * Acknowledgments * References

A compound control strategy combining velocity compensation with ADRC of electro-hydraulic position servo control system.

PubMed

Gao, Bingwei; Shao, Junpeng; Yang, Xiaodong

2014-11-01

In order to enhance the anti-jamming ability of electro-hydraulic position servo control system at the same time improve the control precision of the system, a compound control strategy that combines velocity compensation with Active Disturbance Rejection Controller (ADRC) is proposed, and the working principle of the compound control strategy is given. ADRC controller is designed, and the extended state observer is used for observing internal parameters uncertainties and external disturbances, so that the disturbances of the system are suppressed effectively. Velocity compensation controller is designed and the compensation model is derived to further improve the positioning accuracy of the system and to achieve the velocity compensation without disturbance. The compound control strategy is verified by the simulation and experiment respectively, and the simulation and experimental results show that the electro-hydraulic position servo control system with ADRC controller can effectively inhibit the external disturbances, the precise positioning control is realized after introducing the velocity compensation controller, and verify that the compound control strategy is effective. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Fuzzy model-based servo and model following control for nonlinear systems.

PubMed

Ohtake, Hiroshi; Tanaka, Kazuo; Wang, Hua O

2009-12-01

This correspondence presents servo and nonlinear model following controls for a class of nonlinear systems using the Takagi-Sugeno fuzzy model-based control approach. First, the construction method of the augmented fuzzy system for continuous-time nonlinear systems is proposed by differentiating the original nonlinear system. Second, the dynamic fuzzy servo controller and the dynamic fuzzy model following controller, which can make outputs of the nonlinear system converge to target points and to outputs of the reference system, respectively, are introduced. Finally, the servo and model following controller design conditions are given in terms of linear matrix inequalities. Design examples illustrate the utility of this approach.

Motion control of musculoskeletal systems with redundancy.

PubMed

Park, Hyunjoo; Durand, Dominique M

2008-12-01

Motion control of musculoskeletal systems for functional electrical stimulation (FES) is a challenging problem due to the inherent complexity of the systems. These include being highly nonlinear, strongly coupled, time-varying, time-delayed, and redundant. The redundancy in particular makes it difficult to find an inverse model of the system for control purposes. We have developed a control system for multiple input multiple output (MIMO) redundant musculoskeletal systems with little prior information. The proposed method separates the steady-state properties from the dynamic properties. The dynamic control uses a steady-state inverse model and is implemented with both a PID controller for disturbance rejection and an artificial neural network (ANN) feedforward controller for fast trajectory tracking. A mechanism to control the sum of the muscle excitation levels is also included. To test the performance of the proposed control system, a two degree of freedom ankle-subtalar joint model with eight muscles was used. The simulation results show that separation of steady-state and dynamic control allow small output tracking errors for different reference trajectories such as pseudo-step, sinusoidal and filtered random signals. The proposed control method also demonstrated robustness against system parameter and controller parameter variations. A possible application of this control algorithm is FES control using multiple contact cuff electrodes where mathematical modeling is not feasible and the redundancy makes the control of dynamic movement difficult.

Control and optimization system and method for chemical looping processes

DOEpatents

Lou, Xinsheng; Joshi, Abhinaya; Lei, Hao

2014-06-24

A control system for optimizing a chemical loop system includes one or more sensors for measuring one or more parameters in a chemical loop. The sensors are disposed on or in a conduit positioned in the chemical loop. The sensors generate one or more data signals representative of an amount of solids in the conduit. The control system includes a data acquisition system in communication with the sensors and a controller in communication with the data acquisition system. The data acquisition system receives the data signals and the controller generates the control signals. The controller is in communication with one or more valves positioned in the chemical loop. The valves are configured to regulate a flow of the solids through the chemical loop.

Control and optimization system and method for chemical looping processes

DOEpatents

Lou, Xinsheng; Joshi, Abhinaya; Lei, Hao

2015-02-17

A control system for optimizing a chemical loop system includes one or more sensors for measuring one or more parameters in a chemical loop. The sensors are disposed on or in a conduit positioned in the chemical loop. The sensors generate one or more data signals representative of an amount of solids in the conduit. The control system includes a data acquisition system in communication with the sensors and a controller in communication with the data acquisition system. The data acquisition system receives the data signals and the controller generates the control signals. The controller is in communication with one or more valves positioned in the chemical loop. The valves are configured to regulate a flow of the solids through the chemical loop.

Coordinated joint motion control system with position error correction

DOEpatents

Danko, George [Reno, NV

2011-11-22

Disclosed are an articulated hydraulic machine supporting, control system and control method for same. The articulated hydraulic machine has an end effector for performing useful work. The control system is capable of controlling the end effector for automated movement along a preselected trajectory. The control system has a position error correction system to correct discrepancies between an actual end effector trajectory and a desired end effector trajectory. The correction system can employ one or more absolute position signals provided by one or more acceleration sensors supported by one or more movable machine elements. Good trajectory positioning and repeatability can be obtained. A two-joystick controller system is enabled, which can in some cases facilitate the operator's task and enhance their work quality and productivity.

Coordinated joint motion control system with position error correction

DOEpatents

Danko, George L.

2016-04-05

Disclosed are an articulated hydraulic machine supporting, control system and control method for same. The articulated hydraulic machine has an end effector for performing useful work. The control system is capable of controlling the end effector for automated movement along a preselected trajectory. The control system has a position error correction system to correct discrepancies between an actual end effector trajectory and a desired end effector trajectory. The correction system can employ one or more absolute position signals provided by one or more acceleration sensors supported by one or more movable machine elements. Good trajectory positioning and repeatability can be obtained. A two joystick controller system is enabled, which can in some cases facilitate the operator's task and enhance their work quality and productivity.

The semiotics of control and modeling relations in complex systems.

PubMed

Joslyn, C

2001-01-01

We provide a conceptual analysis of ideas and principles from the systems theory discourse which underlie Pattee's semantic or semiotic closure, which is itself foundational for a school of theoretical biology derived from systems theory and cybernetics, and is now being related to biological semiotics and explicated in the relational biological school of Rashevsky and Rosen. Atomic control systems and models are described as the canonical forms of semiotic organization, sharing measurement relations, but differing topologically in that control systems are circularly and models linearly related to their environments. Computation in control systems is introduced, motivating hierarchical decomposition, hybrid modeling and control systems, and anticipatory or model-based control. The semiotic relations in complex control systems are described in terms of relational constraints, and rules and laws are distinguished as contingent and necessary functional entailments, respectively. Finally, selection as a meta-level of constraint is introduced as the necessary condition for semantic relations in control systems and models.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Passerini, Stefano; Ponciroli, Roberto; Vilim, Richard B.

Here, the interaction of the active control system with passive safety behavior is investigated for sodium-cooled fast reactors. A claim often made of advanced reactors is that they are passively safe against unprotected upset events. In practice, such upset events are not analyzed in the context of the plant control system, but rather the analyses are performed without considering the normally programmed response of the control system (open-loop approach). This represents an oversimplification of the safety case. The issue of passive safety override arises since the control system commands actuators whose motions have safety consequences. Depending on the upset involvingmore » the control system ( operator error, active control system failure, or inadvertent control system override), an actuator does not necessarily go in the same direction as needed for safety. So neglecting to account for control system action during an unprotected upset is nonconservative from a safety standpoint. It is important then, during the design of the plant, to consider the potential for the control system to work against the inherent and safe regulating effects of purposefully engineered temperature feedbacks.« less

Development of autonomous controller system of high speed UAV from simulation to ready to fly condition

NASA Astrophysics Data System (ADS)

Yudhi Irwanto, Herma

2018-02-01

The development of autonomous controller system that is specially used in our high speed UAV, it’s call RKX-200EDF/TJ controlled vehicle needs to be continued as a step to mastery and to developt control system of LAPAN’s satellite launching rocket. The weakness of the existing control system in this high speed UAV needs to be repaired and replaced using the autonomous controller system. Conversion steps for ready-to-fly system involved controlling X tail fin, adjusting auto take off procedure by adding X axis sensor, procedure of way points reading and process of measuring distance and heading to the nearest way point, developing user-friendly ground station, and adding tools for safety landing. The development of this autonomous controller system also covered a real flying test in Pandanwangi, Lumajang in November 2016. Unfortunately, the flying test was not successful because the booster rocket was blown right after burning. However, the system could record the event and demonstrated that the controller system had worked according to plan.

CFAVC scheme for high frequency series resonant inverter-fed domestic induction heating system

NASA Astrophysics Data System (ADS)

Nagarajan, Booma; Reddy Sathi, Rama

2016-01-01

This article presents the investigations on the constant frequency asymmetric voltage cancellation control in the AC-AC resonant converter-fed domestic induction heating system. Conventional fixed frequency control techniques used in the high frequency converters lead to non-zero voltage switching operation and reduced output power. The proposed control technique produces higher output power than the conventional fixed-frequency control strategies. In this control technique, zero-voltage-switching operation is maintained during different duty cycle operation for reduction in the switching losses. Complete analysis of the induction heating power supply system with asymmetric voltage cancellation control is discussed in this article. Simulation and experimental study on constant frequency asymmetric voltage cancellation (CFAVC)-controlled full bridge series resonant inverter is performed. Time domain simulation results for the open and closed loop of the system are obtained using MATLAB simulation tool. The simulation results prove the control of voltage and power in a wide range. PID controller-based closed loop control system achieves the voltage regulation of the proposed system for the step change in load. Hardware implementation of the system under CFAVC control is done using the embedded controller. The simulation and experimental results validate the performance of the CFAVC control technique for series resonant-based induction cooking system.

Evolutionary game based control for biological systems with applications in drug delivery.

PubMed

Li, Xiaobo; Lenaghan, Scott C; Zhang, Mingjun

2013-06-07

Control engineering and analysis of biological systems have become increasingly important for systems and synthetic biology. Unfortunately, no widely accepted control framework is currently available for these systems, especially at the cell and molecular levels. This is partially due to the lack of appropriate mathematical models to describe the unique dynamics of biological systems, and the lack of implementation techniques, such as ultra-fast and ultra-small devices and corresponding control algorithms. This paper proposes a control framework for biological systems subject to dynamics that exhibit adaptive behavior under evolutionary pressures. The control framework was formulated based on evolutionary game based modeling, which integrates both the internal dynamics and the population dynamics. In the proposed control framework, the adaptive behavior was characterized as an internal dynamic, and the external environment was regarded as an external control input. The proposed open-interface control framework can be integrated with additional control algorithms for control of biological systems. To demonstrate the effectiveness of the proposed framework, an optimal control strategy was developed and validated for drug delivery using the pathogen Giardia lamblia as a test case. In principle, the proposed control framework can be applied to any biological system exhibiting adaptive behavior under evolutionary pressures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dynamic analysis of space robot remote control system

NASA Astrophysics Data System (ADS)

Kulakov, Felix; Alferov, Gennady; Sokolov, Boris; Gorovenko, Polina; Sharlay, Artem

2018-05-01

The article presents analysis on construction of two-stage remote control for space robots. This control ensures efficiency of the robot control system at large delays in transmission of control signals from the ground control center to the local control system of the space robot. The conditions for control stability of and high transparency are found.

46 CFR 58.30-50 - Requirements for miscellaneous fluid power and control systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-50 Requirements for miscellaneous fluid power and control systems. (a) All fluid power and control... 46 Shipping 2 2010-10-01 2010-10-01 false Requirements for miscellaneous fluid power and control...

46 CFR 58.30-50 - Requirements for miscellaneous fluid power and control systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

...) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-50 Requirements for miscellaneous fluid power and control systems. (a) All fluid power and control... 46 Shipping 2 2014-10-01 2014-10-01 false Requirements for miscellaneous fluid power and control...

21 CFR 870.3535 - Intra-aortic balloon and control system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... syndrome, cardiac and non-cardiac surgery, or complications of heart failure. The special controls for this... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Intra-aortic balloon and control system. 870.3535... balloon and control system. (a) Identification. An intra-aortic balloon and control system is a...

46 CFR 58.30-50 - Requirements for miscellaneous fluid power and control systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-50 Requirements for miscellaneous fluid power and control systems. (a) All fluid power and control... 46 Shipping 2 2013-10-01 2013-10-01 false Requirements for miscellaneous fluid power and control...

46 CFR 58.30-50 - Requirements for miscellaneous fluid power and control systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-50 Requirements for miscellaneous fluid power and control systems. (a) All fluid power and control... 46 Shipping 2 2011-10-01 2011-10-01 false Requirements for miscellaneous fluid power and control...

46 CFR 58.30-50 - Requirements for miscellaneous fluid power and control systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

...) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-50 Requirements for miscellaneous fluid power and control systems. (a) All fluid power and control... 46 Shipping 2 2012-10-01 2012-10-01 false Requirements for miscellaneous fluid power and control...

Stabilization of nonlinear systems using sampled-data output-feedback fuzzy controller based on polynomial-fuzzy-model-based control approach.

PubMed

Lam, H K

2012-02-01

This paper investigates the stability of sampled-data output-feedback (SDOF) polynomial-fuzzy-model-based control systems. Representing the nonlinear plant using a polynomial fuzzy model, an SDOF fuzzy controller is proposed to perform the control process using the system output information. As only the system output is available for feedback compensation, it is more challenging for the controller design and system analysis compared to the full-state-feedback case. Furthermore, because of the sampling activity, the control signal is kept constant by the zero-order hold during the sampling period, which complicates the system dynamics and makes the stability analysis more difficult. In this paper, two cases of SDOF fuzzy controllers, which either share the same number of fuzzy rules or not, are considered. The system stability is investigated based on the Lyapunov stability theory using the sum-of-squares (SOS) approach. SOS-based stability conditions are obtained to guarantee the system stability and synthesize the SDOF fuzzy controller. Simulation examples are given to demonstrate the merits of the proposed SDOF fuzzy control approach.

Neural-network hybrid control for antilock braking systems.

PubMed

Lin, Chih-Min; Hsu, C F

2003-01-01

The antilock braking systems are designed to maximize wheel traction by preventing the wheels from locking during braking, while also maintaining adequate vehicle steerability; however, the performance is often degraded under harsh road conditions. In this paper, a hybrid control system with a recurrent neural network (RNN) observer is developed for antilock braking systems. This hybrid control system is comprised of an ideal controller and a compensation controller. The ideal controller, containing an RNN uncertainty observer, is the principal controller; and the compensation controller is a compensator for the difference between the system uncertainty and the estimated uncertainty. Since for dynamic response the RNN has capabilities superior to the feedforward NN, it is utilized for the uncertainty observer. The Taylor linearization technique is employed to increase the learning ability of the RNN. In addition, the on-line parameter adaptation laws are derived based on a Lyapunov function, so the stability of the system can be guaranteed. Simulations are performed to demonstrate the effectiveness of the proposed NN hybrid control system for antilock braking control under various road conditions.

A reusable rocket engine intelligen control

NASA Technical Reports Server (NTRS)

Merrill, Walter C.; Lorenzo, Carl F.

1988-01-01

An intelligent control system for reusable space propulsion systems for future launch vehicles is described. The system description includes a framework for the design. The framework consists of an execution level with high-speed control and diagnostics, and a coordination level which marries expert system concepts with traditional control. A comparison is made between air breathing and rocket engine control concepts to assess the relative levels of development and to determine the applicability of air breathing control concepts to future reusable rocket engine systems.

A reusable rocket engine intelligent control

NASA Technical Reports Server (NTRS)

Merrill, Walter C.; Lorenzo, Carl F.

1988-01-01

An intelligent control system for reusable space propulsion systems for future launch vehicles is described. The system description includes a framework for the design. The framework consists of an execution level with high-speed control and diagnostics, and a coordination level which marries expert system concepts with traditional control. A comparison is made between air breathing and rocket engine control concepts to assess the relative levels of development and to determine the applicability of air breathing control concepts ot future reusable rocket engine systems.

Seasat-A attitude control system

NASA Technical Reports Server (NTRS)

Weiss, R.; Rodden, J. J.; Hendricks, R. J.

1977-01-01

The Seasat-A attitude control system controls the attitude of the satellite system during injection into final circular orbit after Atlas boost, during orbit adjust and trim phases, and throughout the 3-year mission. Ascent and injection guidance and attitude control are provided by the Agena spacecraft with a gyrocompassed mass expulsion system. On-orbit attitude control functions are performed by a system that has its functional roots in the gravity-gradient momentum bias technology. The paper discusses hardware, control laws, and simulation results.

Superconducting Coil Winding Machine Control System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nogiec, J. M.; Kotelnikov, S.; Makulski, A.

The Spirex coil winding machine is used at Fermilab to build coils for superconducting magnets. Recently this ma-chine was equipped with a new control system, which al-lows operation from both a computer and a portable remote control unit. This control system is distributed between three layers, implemented on a PC, real-time target, and FPGA, providing respectively HMI, operational logic and direct controls. The system controls motion of all mechan-ical components and regulates the cable tension. Safety is ensured by a failsafe, redundant system.

The frontoparietal control system: A central role in mental health

PubMed Central

Cole, Michael W.; Repovs, Grega; Anticevic, Alan

2014-01-01

Recent findings suggest the existence of a frontoparietal control system consisting of ‘flexible hubs’ that regulate distributed systems (e.g., visual, limbic, motor) according to current task goals. A growing number of studies are reporting alterations of this control system across a striking range of mental diseases. We suggest this may reflect a critical role for the control system in promoting and maintaining mental health. Specifically, we propose that this system implements feedback control to regulate symptoms as they arise (e.g., excessive anxiety reduced via regulation of amygdala), such that an intact control system is protective against a variety of mental illnesses. Consistent with this possibility, recent results indicate that several major mental illnesses involve altered brain-wide connectivity of the control system, likely altering its ability to regulate symptoms. These results suggest that this ‘immune system of the mind’ may be an especially important target for future basic and clinical research. PMID:24622818

Robust fast controller design via nonlinear fractional differential equations.

PubMed

Zhou, Xi; Wei, Yiheng; Liang, Shu; Wang, Yong

2017-07-01

A new method for linear system controller design is proposed whereby the closed-loop system achieves both robustness and fast response. The robustness performance considered here means the damping ratio of closed-loop system can keep its desired value under system parameter perturbation, while the fast response, represented by rise time of system output, can be improved by tuning the controller parameter. We exploit techniques from both the nonlinear systems control and the fractional order systems control to derive a novel nonlinear fractional order controller. For theoretical analysis of the closed-loop system performance, two comparison theorems are developed for a class of fractional differential equations. Moreover, the rise time of the closed-loop system can be estimated, which facilitates our controller design to satisfy the fast response performance and maintain the robustness. Finally, numerical examples are given to illustrate the effectiveness of our methods. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Application of programmable logic controllers to space simulation

NASA Technical Reports Server (NTRS)

Sushon, Janet

1992-01-01

Incorporating a state-of-the-art process control and instrumentation system into a complex system for thermal vacuum testing is discussed. The challenge was to connect several independent control systems provided by various vendors to a supervisory computer. This combination will sequentially control and monitor the process, collect the data, and transmit it to color a graphic system for subsequent manipulation. The vacuum system upgrade included: replacement of seventeen diffusion pumps with eight cryogenic pumps and one turbomolecular pump, replacing a relay based control system, replacing vacuum instrumentation, and upgrading the data acquisition system.

Comparative study between two different active flutter suppression systems

NASA Technical Reports Server (NTRS)

Nissim, E.

1978-01-01

An activated leading-edge (LE)-tailing-edge (TE) control system is applied to a drone aircraft with the objective of enabling the drone to fly subsonically at dynamic pressures which are 44% above the open-loop flutter dynamic pressure. The control synthesis approach is based on the aerodynamic energy concept and it incorporates recent developments in this area. A comparison is made between the performance of the activated LE-TE control system and the performance of a TE control system, analyzed in a previous work. The results obtained indicate that although all the control systems achieve the flutter suppression objectives, the TE control system appears to be somewhat superior to the LE-TE control system, in this specific application. This superiority is manifested through reduced values of control surface activity over a wide range of flight conditions.