Science.gov

Sample records for calibration laboratory sources

  1. NVLAP calibration laboratory program

    SciTech Connect

    Cigler, J.L.

    1993-12-31

    This paper presents an overview of the progress up to April 1993 in the development of the Calibration Laboratories Accreditation Program within the framework of the National Voluntary Laboratory Accreditation Program (NVLAP) at the National Institute of Standards and Technology (NIST).

  2. Design, fabrication, and calibration of curved integral coils for measuring transfer function, uniformity, and effective length of LBL ALS (Lawrence Berkeley Laboratory Advanced Light Source) Booster Dipole Magnets

    SciTech Connect

    Green, M.I.; Nelson, D.; Marks, S.; Gee, B.; Wong, W.; Meneghetti, J.

    1989-03-01

    A matched pair of curved integral coils has been designed, fabricated and calibrated at Lawrence Berkeley Laboratory for measuring Advanced Light Source (ALS) Booster Dipole Magnets. Distinctive fabrication and calibration techniques are described. The use of multifilar magnet wire in fabrication integral search coils is described. Procedures used and results of AC and DC measurements of transfer function, effective length and uniformity of the prototype booster dipole magnet are presented in companion papers. 8 refs.

  3. Calibrated vapor generator source

    DOEpatents

    Davies, J.P.; Larson, R.A.; Goodrich, L.D.; Hall, H.J.; Stoddard, B.D.; Davis, S.G.; Kaser, T.G.; Conrad, F.J.

    1995-09-26

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet. 10 figs.

  4. Calibrated vapor generator source

    DOEpatents

    Davies, John P.; Larson, Ronald A.; Goodrich, Lorenzo D.; Hall, Harold J.; Stoddard, Billy D.; Davis, Sean G.; Kaser, Timothy G.; Conrad, Frank J.

    1995-01-01

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet.

  5. Quality assurance programs at the PNL calibrations laboratory

    SciTech Connect

    Piper, R.K.; McDonald, J.C.; Fox, R.A.; Eichner, F.N.

    1993-03-01

    The calibrations laboratory at Pacific Northwest Laboratory (PNL) serves as a radiological standardization facility for personnel and environmental dosimetry and radiological survey instruments. As part of this function, the calibrations laboratory must maintain radiological reference fields with calibrations traceable to the National Institute of Standards and Technology (NIST). This task is accomplished by a combination of (1) sources or reference instruments calibrated at or by NIST, (2) measurement quality assurance (MQA) interactions with NIST, and (3) rigorous internal annual and quarterly calibration verifications. This paper describes a representative sample of the facilities, sources, and actions used to maintain accurate and traceable fields.

  6. Calibration of Photon Sources for Brachytherapy

    NASA Astrophysics Data System (ADS)

    Rijnders, Alex

    Source calibration has to be considered an essential part of the quality assurance program in a brachytherapy department. Not only it will ensure that the source strength value used for dose calculation agrees within some predetermined limits to the value stated on the source certificate, but also it will ensure traceability to international standards. At present calibration is most often still given in terms of reference air kerma rate, although calibration in terms of absorbed dose to water would be closer to the users interest. It can be expected that in a near future several standard laboratories will be able to offer this latter service, and dosimetry protocols will have to be adapted in this way. In-air measurement using ionization chambers (e.g. a Baldwin—Farmer ionization chamber for 192Ir high dose rate HDR or pulsed dose rate PDR sources) is still considered the method of choice for high energy source calibration, but because of their ease of use and reliability well type chambers are becoming more popular and are nowadays often recommended as the standard equipment. For low energy sources well type chambers are in practice the only equipment available for calibration. Care should be taken that the chamber is calibrated at the standard laboratory for the same source type and model as used in the clinic, and using the same measurement conditions and setup. Several standard laboratories have difficulties to provide these calibration facilities, especially for the low energy seed sources (125I and 103Pd). Should a user not be able to obtain properly calibrated equipment to verify the brachytherapy sources used in his department, then at least for sources that are replaced on a regular basis, a consistency check program should be set up to ensure a minimal level of quality control before these sources are used for patient treatment.

  7. Chromium-51 calibrating neutrino source

    SciTech Connect

    Demchenko, N.F.; Karasev, V.I.; Karelin, E.A.

    1993-12-31

    The problem for measurement of the sun neutrino flux is resolved at the specially made Baksansk neutrino telescope and calls for calibration of registration system. For this a man made neutrino source is required with the known yield of particles and intensity comparable with the intensity of the measured subject. The most suitable radionuclide for production of this source is chromium-51 the radionuclide decay of which is accompanied with neutrino radiation. At the Research Institute of Atomic Reactors (in Dimitrovgrad) the production technology is developed as well as the closed chromium-51 neutrino source is made of 4 x 10{sup 5} Ci activity. The parts of active source made in the form of core of metallic isotope-enriched chromium were irradiated in the high flux neutron trap of the SM-2 reactor. The sources were subsequently assembled at the shield cells with remote equipment application. The source was certificated as a special form radioactive material. Due to low half-life of chromium-51 (T 1/2 - 27 hours) all the operations on assembly, certification and delivery of source to the Baksansk Laboratory were performed at the earliest possible date (less than 3 days).

  8. Procedures for establishing and maintaining consistent air-kerma strength standards for low-energy, photon-emitting brachytherapy sources: recommendations of the Calibration Laboratory Accreditation Subcommittee of the American Association of Physicists in Medicine.

    PubMed

    DeWerd, Larry A; Huq, M Saiful; Das, Indra J; Ibbott, Geoffrey S; Hanson, William F; Slowey, Thomas W; Williamson, Jeffrey F; Coursey, Bert M

    2004-03-01

    Low dose rate brachytherapy is being used extensively for the treatment of prostate cancer. As of September 2003, there are a total of thirteen 125I and seven 103Pd sources that have calibrations from the National Institute of Standards and Technology (NIST) and the Accredited Dosimetry Calibration Laboratories (ADCLs) of the American Association of Physicists in Medicine (AAPM). The dosimetry standards for these sources are traceable to the NIST wide-angle free-air chamber. Procedures have been developed by the AAPM Calibration Laboratory Accreditation Subcommittee to standardize quality assurance and calibration, and to maintain the dosimetric traceability of these sources to ensure accurate clinical dosimetry. A description of these procedures is provided to the clinical users for traceability purposes as well as to provide guidance to the manufacturers of brachytherapy sources and ADCLs with regard to these procedures.

  9. NVLAP activities at Department of Defense calibration laboratories

    SciTech Connect

    Schaeffer, D.M.

    1993-12-31

    There are 367 active radiological instrument calibration laboratories within the U.S. Department of Defense (DoD). Each of the four services in DoD manages, operates, and certifies the technical proficiency and competency of those laboratories under their cognizance. Each service has designated secondary calibration laboratories to trace all calibration source standards to the National Institute of Standards and Technology. Individual service radiological calibration programs and capabilities, present and future, are described, as well as the measurement quality assurance (MQA) processes for their traceability. National Voluntary Laboratory Accreditation Program (NVLAP) programs for dosimetry systems are briefly summarized. Planned NVLAP accreditation of secondary laboratories is discussed in the context of current technical challenges and future efforts.

  10. HPS instrument calibration laboratory accreditation program

    SciTech Connect

    Masse, F.X; Eisenhower, E.H.; Swinth, K.L.

    1993-12-31

    The purpose of this paper is to provide an accurate overview of the development and structure of the program established by the Health Physics Society (HPS) for accrediting instrument calibration laboratories relative to their ability to accurately calibrate portable health physics instrumentation. The purpose of the program is to provide radiation protection professionals more meaningful direct and indirect access to the National Institute of Standards and Technology (NIST) national standards, thus introducing a means for improving the uniformity, accuracy, and quality of ionizing radiation field measurements. The process is designed to recognize and document the continuing capability of each accredited laboratory to accurately perform instrument calibration. There is no intent to monitor the laboratory to the extent that each calibration can be guaranteed by the program; this responsibility rests solely with the accredited laboratory.

  11. Requirements for Reference (Calibration) Laboratories in Laboratory Medicine

    PubMed Central

    Siekmann, Lothar

    2007-01-01

    In addition to reference measurement procedures and reference materials, reference or calibration laboratories play an integral role in the implementation of measurement traceability in routine laboratories. They provide results of measurements using higher-order methods, e.g. isotope dilution mass spectrometry and may assign values to materials to be used for external quality assessment programs and to secondary reference materials. The requirements for listing of laboratories that provide reference measurement services include a statement of the metrological level or principle of measurement, accreditation as a calibration laboratory according to ISO 15195 and the participation in a proficiency testing system (regular inter-laboratory comparisons) for reference laboratories. Ring trials are currently conducted for thirty well-defined measurands and the results are made available to all laboratories. Through the use of reference laboratory services that are listed by the Joint Committee for Traceability in Laboratory Medicine there is the opportunity to further promote traceability and standardisation of laboratory measurements. PMID:18392129

  12. Laboratory Calibration and Characterization of Video Cameras

    NASA Technical Reports Server (NTRS)

    Burner, A. W.; Snow, W. L.; Shortis, M. R.; Goad, W. K.

    1989-01-01

    Some techniques for laboratory calibration and characterization of video cameras used with frame grabber boards are presented. A laser-illuminated displaced reticle technique (with camera lens removed) is used to determine the camera/grabber effective horizontal and vertical pixel spacing as well as the angle of non-perpendicularity of the axes. The principal point of autocollimation and point of symmetry are found by illuminating the camera with an unexpanded laser beam, either aligned with the sensor or lens. Lens distortion and the principal distance are determined from images of a calibration plate suitable aligned with the camera. Calibration and characterization results for several video cameras are presented. Differences between these laboratory techniques and test range and plumb line calibration are noted.

  13. Laboratory calibration and characterization of video cameras

    NASA Astrophysics Data System (ADS)

    Burner, A. W.; Snow, W. L.; Shortis, M. R.; Goad, W. K.

    1990-08-01

    Some techniques for laboratory calibration and characterization of video cameras used with frame grabber boards are presented. A laser-illuminated displaced reticle technique (with camera lens removed) is used to determine the camera/grabber effective horizontal and vertical pixel spacing as well as the angle of nonperpendicularity of the axes. The principal point of autocollimation and point of symmetry are found by illuminating the camera with an unexpanded laser beam, either aligned with the sensor or lens. Lens distortion and the principal distance are determined from images of a calibration plate suitably aligned with the camera. Calibration and characterization results for several video cameras are presented. Differences between these laboratory techniques and test range and plumb line calibration are noted.

  14. RADCAL Operations Manual Radiation Calibration Laboratory Protocol

    SciTech Connect

    Bogard, J.S.

    1998-12-01

    The Life Sciences Division (LSD) of Oak Ridge National Laboratory (ORNL) has a long record of radiation dosimetry research, primarily using the Health Physics Research Reactor (HPRR) and the Radiation Calibration Laboratory (RADCAL) in its Dosimetry Applications Research (DOSAR) Program. These facilities have been used by a broad segment of the research community to perform a variety of experiments in areas including, but not limited to, radiobiology, radiation dosimeter and instrumentation development and calibration, and the testing of materials in a variety of radiation environments. Operations of the HPRR were terminated in 1987 and the reactor was moved to storage at the Oak Ridge Y-12 Plant; however, RADCAL will continue to be operated in accordance with the guidelines of the National Institute of Standards and Technology (NIST) Secondary Calibration Laboratory program and will meet all requirements for testing dosimeters under the National Voluntary Laboratory Accreditation Program (NVLAP). This manual is to serve as the primary instruction and operation manual for the Oak Ridge National Laboratory's RADCAL facility. Its purpose is to (1) provide operating protocols for the RADCAL facility, (2) outline the organizational structure, (3) define the Quality Assurance Action Plan, and (4) describe all the procedures, operations, and responsibilities for the safe and proper operation of all routine aspects of the calibration facility.

  15. Development of the PROSPECT Source Calibration System

    NASA Astrophysics Data System (ADS)

    Bykadorova, Arina; Prospect Collaboration

    2016-09-01

    PROSPECT, the Precision Reactor Oscillation and Spectrum Experiment, is a short-baseline antineutrino experiment consisting of a movable liquid scintillator detector operated near Oak Ridge National Laboratory's High Flux Isotope Reactor (HFIR). PROSPECT is designed to make a precise measurement of the antineutrino spectrum emitted from 235U fissions in a highly-enriched uranium reactor core, and to probe for eV-scale sterile neutrinos by examining neutrino oscillations at a distance of 7-12 m from the reactor. These measurements will address the observed reactor anomalies: the deficit in the reactor flux and the deviation in the spectral shape. PROSPECT consists of a 2-ton segmented liquid scintillator detector. Each segment is read out with two photomultipliers. Energy response and position reconstruction are calibrated using radioactive gamma and neutron sources. We have developed a retractable source deployment system that allows the placement of sources along the length of the detector segments and tested it using PROSPECT-50, a 50-liter detector prototype consisting of two segments. We will present the design of the PROSPECT source calibration system and results from PROSPECT-50. Wright Laboratory, Department of Physics, Yale University, New Haven, CT, USA.

  16. Multigamma-ray calibration sources

    SciTech Connect

    Meyer, R.A.; Massey, T.N.

    1983-05-01

    We have calibrated a self-consistent set of multigamma-ray standards using the automated multi-spectrometry ..gamma..-ray counting facility at LLNL's Nuclear Chemistry Division. Pure sources of long-lived activity were produced by mass separation and/or chemical purification. The sources were counted individually and in combination on several different calibrated spectrometer systems. These systems utilize various detectors ranging from small (x-ray) detectors to large volume high-purity Ge detectors. This has allowed the use of the most ideal individual detector-efficiency characteristics for the determination of the relative ..gamma..-ray intensities. Precise energy measurements, reported earlier (Meyer, 1976) have been performed by an independent method. Both the energy and ..gamma..-ray-emission probabilities determined compare well with independently established values such as the recent ICRM intercomparison of /sup 152/Eu. We discuss our investigations aimed at resolving the shape of the efficiency response function up to 10 MeV for large volume Ge(Li) and high-purity Ge detectors. Recent results on the ..gamma..-ray-emission probabilities per decay for /sup 149/Gd and /sup 168/Tm multigamma-ray sources are discussed. For /sup 168/Tm, we deduce a 0.01% ..beta../sup -/ branch to the 87.73-keV level in /sup 168/Yb rather than the previous value which was a factor of 200 greater. In addition, we describe current cooperative efforts aimed at establishing a consistent set of data for short-lived fission products. Included are recent measurements on the bromine fission products with ..gamma.. rays up to 7 MeV.

  17. Spectrally and Radiometrically Stable, Wideband, Onboard Calibration Source

    NASA Technical Reports Server (NTRS)

    Coles, James B.; Richardson, Brandon S.; Eastwood, Michael L.; Sarture, Charles M.; Quetin, Gregory R.; Porter, Michael D.; Green, Robert O.; Nolte, Scott H.; Hernandez, Marco A.; Knoll, Linley A.

    2013-01-01

    The Onboard Calibration (OBC) source incorporates a medical/scientific-grade halogen source with a precisely designed fiber coupling system, and a fiber-based intensity-monitoring feedback loop that results in radiometric and spectral stabilities to within less than 0.3 percent over a 15-hour period. The airborne imaging spectrometer systems developed at the Jet Propulsion Laboratory incorporate OBC sources to provide auxiliary in-use system calibration data. The use of the OBC source will provide a significant increase in the quantitative accuracy, reliability, and resulting utility of the spectral data collected from current and future imaging spectrometer instruments.

  18. Construction and operation of an improved radiation calibration facility at Brookhaven National Laboratory. Environmental assessment

    SciTech Connect

    1994-10-01

    Calibration of instruments used to detect and measure ionizing radiation has been conducted over the last 20 years at Brookhaven National Laboratory`s (BNL) Radiation Calibration Facility, Building 348. Growth of research facilities, projects in progress, and more stringent Department of Energy (DOE) orders which involve exposure to nuclear radiation have placed substantial burdens on the existing radiation calibration facility. The facility currently does not meet the requirements of DOE Order 5480.4 or American National Standards Institute (ANSI) N323-1978, which establish calibration methods for portable radiation protection instruments used in the detection and measurement of levels of ionizing radiation fields or levels of radioactive surface contaminations. Failure to comply with this standard could mean instrumentation is not being calibrated to necessary levels of sensitivity. The Laboratory has also recently obtained a new neutron source and gamma beam irradiator which can not be made operational at existing facilities because of geometry and shielding inadequacies. These sources are needed to perform routine periodic calibrations of radiation detecting instruments used by scientific and technical personnel and to meet BNL`s substantial increase in demand for radiation monitoring capabilities. To place these new sources into operation, it is proposed to construct an addition to the existing radiation calibration facility that would house all calibration sources and bring BNL calibration activities into compliance with DOE and ANSI standards. The purpose of this assessment is to identify potential significant environmental impacts associated with the construction and operation of an improved radiation calibration facility at BNL.

  19. Artificial calibration source for ALMA radio interferometer

    NASA Astrophysics Data System (ADS)

    Kiuchi, Hitoshi; Hills, Richard; Whyborn, Nicholas D.; Asayama, Shinichiro; Sakamoto, Seiichi; Iguchi, Satoru; Corder, Stuartt A.

    2016-07-01

    The ALMA (Atacama Large Millimeter/submillimeter Array) radio interferometer has some different types of antennas which have a variation of gain and leakages across the primary beam of an individual antenna. We have been developing an artificial calibration source which is used for compensation of individual difference of antennas. In a high-frequency antenna, using astronomical sources to do calibration measurement would be extremely time consuming, whereas with the artificial calibration source becomes a realistic possibility. Photonic techniques are considered to be superior to conventional techniques based on electronic devices in terms of wide bandwidth and high-frequency signals. Conversion from an optical signal to a millimeter/sub-millimeter wave signal is done by a photo-mixer.

  20. The Mars Science Laboratory APXS calibration target: Comparison of Martian measurements with the terrestrial calibration

    NASA Astrophysics Data System (ADS)

    Campbell, J. L.; King, P. L.; Burkemper, L.; Berger, J. A.; Gellert, R.; Boyd, N. I.; Perrett, G. M.; Pradler, I.; Thompson, L.; Edgett, K. S.; Yingst, R. A.

    2014-03-01

    The Mars Science Laboratory Curiosity rover carries a basalt calibration target for monitoring the performance of the alpha particle X-ray spectrometer. The spectrum acquired on Sol 34 shows increased contributions from Mg, S, Cl and Fe relative to laboratory spectra recorded before launch. Mars Hand Lens Imager images confirm changes in the appearance of the surface. Spectra taken on Sols 179 and 411 indicate some loss of the deposited material. The observations suggest deposition of a surface film likely consisting of dust mobilized by impingement of the sky crane's terminal descent engine plumes with surface fines during Curiosity's landing. New APXS software has been used to model the thin film that coated the calibration target on landing. The results suggest that a film of about 100 nm thickness, and containing predominantly MgO, Fe2O3, SO3, Cl and Na2O could give rise to the observed spectral changes. If this film is also present on the alpha particle sources within the APXS, then its effect is negligible and the terrestrial calibration remains appropriate.

  1. Design, manufacture, and calibration of infrared radiometric blackbody sources

    SciTech Connect

    Byrd, D.A.; Michaud, F.D.; Bender, S.C.

    1996-04-01

    A Radiometric Calibration Station (RCS) is being assembled at the Los Alamos National Laboratories (LANL) which will allow for calibration of sensors with detector arrays having spectral capability from about 0.4-15 {mu}m. The configuration of the LANL RCS. Two blackbody sources have been designed to cover the spectral range from about 3-15 {mu}m, operating at temperatures ranging from about 180-350 K within a vacuum environment. The sources are designed to present a uniform spectral radiance over a large area to the sensor unit under test. The thermal uniformity requirement of the blackbody cavities has been one of the key factors of the design, requiring less than 50 mK variation over the entire blackbody surface to attain effective emissivity values of about 0.999. Once the two units are built and verified to the level of about 100 mK at LANL, they will be sent to the National Institute of Standards and Technology (NIST), where at least a factor of two improvement will be calibrated into the blackbody control system. The physical size of these assemblies will require modifications of the existing NIST Low Background Infrared (LBIR) Facility. LANL has constructed a bolt-on addition to the LBIR facility that will allow calibration of our large aperture sources. Methodology for attaining the two blackbody sources at calibrated levels of performance equivalent to present state of the art will be explained in the following.

  2. Source Code Analysis Laboratory (SCALe)

    DTIC Science & Technology

    2012-04-01

    revenue. Among respondents to the IAAR survey, 86% of companies certified in quality management realized a positive return on investment (ROI). An...SCALe undertakes. Testing and calibration laboratories that comply with ISO /IEC 17025 also operate in accordance with ISO 9001 . • NIST National...17025:2005 accredited and ISO 9001 :2008 registered. 4.3 SAIC Accreditation and Certification Services SAIC (Science Applications International

  3. Criteria for the operation of federally-owned secondary calibration laboratories (ionizing radiation). Special pub. (Final)

    SciTech Connect

    Eisenhower, E.H.

    1991-08-01

    The document contains standards of performance for laboratories that calibrate instrumentation used to measure ionizing radiation. Such standards are useful for the development of a secondary level of calibration laboratories that can provide a high-quality link between the National Institute of Standards and Technology and those who make routine measurements at the field level. The standards may also be used as criteria on which a decision is based regarding accreditation of a particular laboratory. They were developed by representatives of federally-owned laboratories that perform calibrations of the type addressed by the document. The first major part contains general criteria that must be satisfied by all laboratories seeking accreditation. It includes requirements relating to management and staff, physical aspects of the laboratory, calibrations facilities and equipment, operational procedures, accuracy and quality assurance, and records and reports. Five subsequent major parts establish criteria for calibration of survey instruments, irradiation of personnel dosimeters, calibration of sources, calibration of instruments for diagnostic levels, and calibration of reference-class instruments. The types of radiation covered include gamma rays, x rays, beta particles, neutrons, and alpha particles. An appendix describes the proficiency tests administered by NIST to secondary laboratories as a prerequisite for their accreditation.

  4. High-dose secondary calibration laboratory accreditation program

    SciTech Connect

    Humphreys, J.C.

    1993-12-31

    There is a need for high-dose secondary calibration laboratories to serve the multi-billion dollar radiation processing industry. This need is driven by the desires of industry for less costly calibrations and faster calibration-cycle response time. Services needed include calibration irradiations of routine processing dosimeters and the supply of reference standard transfer dosimeters for irradiation in the production processing facility. In order to provide measurement quality assurance and to demonstrate consistency with national standards, the high-dose secondary laboratories would be accredited by means of an expansion of an existing National Voluntary Laboratory Accreditation Program. A laboratory performance criteria document is under development to implement the new program.

  5. Secondary calibration laboratory for ionizing radiation laboratory accreitation program National Institute of Standards and Technology National Voluntary Laboratory Accreditation Program

    SciTech Connect

    Martin, P.R.

    1993-12-31

    This paper presents an overview of the procedures and requirements for accreditation under the Secondary Calibration Laboratory for Ionizing Radiation Program (SCLIR LAP). The requirements for a quality system, proficiency testing and the onsite assessment are discussed. The purpose of the accreditation program is to establish a network of secondary calibration laboratories that can provide calibrations traceable to the primary national standards.

  6. Immediate needs for MQA testing at state secondary calibration laboratories

    SciTech Connect

    Cline, R.

    1993-12-31

    The Calibration Laboratory attempts to provide services that satisfy the needs and requests for a variety of customers. New needs and requests have resulted in calibration of instrumentation outside the original laboratory designs. These tasks require several changes at the laboratory and a need for new support services, especially measurement quality assurance (MQA). The MQA tests are gamma (Cs-137) below 0.5 mrem (5{mu}Sv) per hour and x-ray kVp. Modification to the current gamma (Cs-137) MQA test is recommended because lower intensity fields are commonly measured.

  7. 21 CFR 892.1400 - Nuclear sealed calibration source.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nuclear sealed calibration source. 892.1400... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1400 Nuclear sealed calibration source. (a) Identification. A nuclear sealed calibration source is a device that consists of an...

  8. 21 CFR 892.1400 - Nuclear sealed calibration source.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nuclear sealed calibration source. 892.1400... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1400 Nuclear sealed calibration source. (a) Identification. A nuclear sealed calibration source is a device that consists of an...

  9. 21 CFR 892.1400 - Nuclear sealed calibration source.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nuclear sealed calibration source. 892.1400... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1400 Nuclear sealed calibration source. (a) Identification. A nuclear sealed calibration source is a device that consists of an...

  10. 21 CFR 892.1400 - Nuclear sealed calibration source.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nuclear sealed calibration source. 892.1400... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1400 Nuclear sealed calibration source. (a) Identification. A nuclear sealed calibration source is a device that consists of an...

  11. 21 CFR 892.1400 - Nuclear sealed calibration source.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nuclear sealed calibration source. 892.1400... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1400 Nuclear sealed calibration source. (a) Identification. A nuclear sealed calibration source is a device that consists of an...

  12. Five Proficiency Testing Programs for the Jcss Weight Calibration Laboratories

    NASA Astrophysics Data System (ADS)

    Ueki, Masaaki; Sun, Jianxin; Ueda, Kazunaga

    The Japan Calibration Service System (JCSS) organized in 1993 accredits the measurement capability of calibration laboratories and ensures the traceability to the national measurement standards. As an essential part of accreditation of the measurement capability of calibration laboratories for the weights, the International Accreditation Japan (IAJapan) of National Institute of Technology and Evaluation has been operating the JCSS proficiency testing programs with the technical support of the National Metrology Institute of Japan (NMIJ/AIST). Up to now, five proficiency testing programs have been carried out for the JCSS weight calibration laboratories in the range of 2 mg to 10 kg. The proficiency testing programs organized by the IAJapan were carried out in accordance with ISO/IEC Guide 43 (JIS Q 17043), and the NMIJ was responsible for the technical aspect as a reference laboratory. This paper describes the methods of the five proficiency testing programs during the period from 1997 to 2009, and outlines assessment of the measurement capability of the JCSS weight calibration laboratories.

  13. A calibration service for biomedical instrumentation maintenance laboratories.

    PubMed

    Barnes, A; Evans, A L; Job, H M; Laing, R; Smith, D C

    1999-01-01

    An in-house calibration laboratory for the Biomedical Instrumentation Maintenance Services of the hospitals in the West of Scotland was established in 1993. This paper describes the development of this calibration service in the context of an overall quality system and also estimates its costs. Not only does the in-house service have many advantages but it is shown to be cost effective for workloads exceeding 260 items per annum.

  14. The Euclid near-infrared calibration source

    NASA Astrophysics Data System (ADS)

    Holmes, Rory; Bizenberger, Peter; Krause, Oliver; Schweitzer, Mario; Glauser, Adrian M.

    2010-07-01

    The Euclid dark energy mission is currently competing in ESA's Cosmic Vision program. Its imaging instrument, which has one visible and one infrared channel, will survey the entire extragalactic sky during the 5 year mission. The near-infrared imaging photometer (NIP) channel, operating in the ~0.92 - 2.0 μm spectral range, will be used in conjunction with the visible imaging channel (VIS) to constrain the nature of dark energy and dark matter. To meet the stringent overall photometric requirement, the NIP channel requires a dedicated on-board flat-field source to calibrate the large, 18 detector focal plane. In the baseline concept a 170 mm Spectralon diffuser plate, mounted to a pre-existing shutter mechanism outside the channel, is used as a flat-field calibration target, negating the need for an additional single-point-failure mechanism. The 117 × 230 mm focal plane will therefore be illuminated through all of the channel's optical elements and will allow flat-field measurements to be taken in all wavelength bands. A ring of low power tungsten lamps, with custom reflecting elements optimized for optical performance, will be used to illuminate the diffuser plate. This paper details the end-to-end optical simulations of this concept, a potential mechanical implementation and the initial tests of the proposed key components.

  15. Thermocouple Calibration and Accuracy in a Materials Testing Laboratory

    NASA Technical Reports Server (NTRS)

    Lerch, B. A.; Nathal, M. V.; Keller, D. J.

    2002-01-01

    A consolidation of information has been provided that can be used to define procedures for enhancing and maintaining accuracy in temperature measurements in materials testing laboratories. These studies were restricted to type R and K thermocouples (TCs) tested in air. Thermocouple accuracies, as influenced by calibration methods, thermocouple stability, and manufacturer's tolerances were all quantified in terms of statistical confidence intervals. By calibrating specific TCs the benefits in accuracy can be as great as 6 C or 5X better compared to relying on manufacturer's tolerances. The results emphasize strict reliance on the defined testing protocol and on the need to establish recalibration frequencies in order to maintain these levels of accuracy.

  16. High dose calibrations at the pacific northwest laboratory

    NASA Astrophysics Data System (ADS)

    McDonald, J. C.; Fox, R. A.

    1989-04-01

    he need is increasing for both high radiation exposures and calibration measurements that provide traceability of such exposures to national standards. The applications of high exposures include: electronic component damage studies, sterilization of medical products and food irradiation. Accurate high exposure measurements are difficult to obtain and cannot, in general, be carried out with a single dose measurement system or technique because of the wide range of doses and the variety of materials involved. This paper describes the dosimetric measurement and calibration techniques used at the Pacific Northwest Laboratory (PNL) that make use of radiochromic dye films, thermoluminescence dosimeters (TLDs), ionization chambers and calorimetric dosimeters. The methods used to demonstrate the consistency of PNL calibrations with national standards will also be discussed.

  17. Effect of calibration on dispersion of glycohemoglobin values determined by 111 laboratories using 21 methods.

    PubMed

    Weykamp, C W; Penders, T J; Muskiet, F A; van der Slik, W

    1994-01-01

    One hundred eleven laboratories, using 21 different methods based on five different principles, determined glycohemoglobin (GHb) percentages in two identical series of six lyophilized hemolysates and three similarly processed calibrators, distributed 3 months apart. To assign GHb percentages to calibrators, we used HbA1c results from nine participants who used the Bio-Rad Diamat high-performance liquid chromatographic method. Three-point calibration with assigned values improved mean intralaboratory variation (CV) from 6.6% to 3.5%. For samples with low (5.5%) and high (14.1%) GHb percentages, respectively, calibration decreased interlaboratory variation per method (from 10% to 4% and from 6% to 3%), inter-method variation (from 18% to 4% and from 16% to 3%), and overall interlaboratory variation (from 25% to 7% and from 15% to 4%). Without calibration, 71% of the laboratories did not meet the clinically desirable intralaboratory CV of 3.5%; calibration reduced this proportion to 39%. We conclude that, irrespective of the analytical method used, calibration greatly reduces all sources of GHb variation.

  18. Dynamic size spectrometry of airborne microorganisms: Laboratory evaluation and calibration

    NASA Astrophysics Data System (ADS)

    Qian, Yinge; Willeke, Klaus; Ulevicius, Vidmantas; Grinshpun, Sergey A.; Donnelly, Jean

    Bioaerosol samplers need to be calibrated for the microorganisms of interest. The Aerosizer, a relatively new aerodynamic size spectrometer, is shown to be a suitable dynamic instrument for the evaluation and calibration of such samplers in the laboratory, prior to their use in the field. It provides the necessary reference count against which the microbiological response of the sampler can be compared. It measures the health-significant aerodynamic diameters of microorganisms down to 0.5 μm, thus including most of the bacteria, fungi and pollen found in outdoor and indoor air environments. Comparison tests with a laser size spectrometer indicate that the suspension of microorganisms needs to be washed several times before aerosolization to avoid coating of the airborne microorganisms with nutrients and microbial slime from the suspension, and to reduce the residue particles to sizes below the lowest size of the aerosolized microorganisms.

  19. The Herschel-PACS photometer calibration. Point-source flux calibration for scan maps

    NASA Astrophysics Data System (ADS)

    Balog, Zoltan; Müller, Thomas; Nielbock, Markus; Altieri, Bruno; Klaas, Ulrich; Blommaert, Joris; Linz, Hendrik; Lutz, Dieter; Moór, Attila; Billot, Nicolas; Sauvage, Marc; Okumura, Koryo

    2014-07-01

    This paper provides an overview of the PACS photometer flux calibration concept, in particular for the principal observation mode, the scan map. The absolute flux calibration is tied to the photospheric models of five fiducial stellar standards ( α Boo, α Cet, α Tau, β And, γ Dra). The data processing steps to arrive at a consistent and homogeneous calibration are outlined. In the current state the relative photometric accuracy is ˜2 % in all bands. Starting from the present calibration status, the characterization and correction for instrumental effects affecting the relative calibration accuracy is described and an outlook for the final achievable calibration numbers is given. After including all the correction for the instrumental effects, the relative photometric calibration accuracy (repeatability) will be as good as 0.5 % in the blue and green band and 2 % in the red band. This excellent calibration starts to reveal possible inconsistencies between the models of the K-type and the M-type stellar calibrators. The absolute calibration accuracy is therefore mainly limited by the 5 % uncertainty of the celestial standard models in all three bands. The PACS bolometer response was extremely stable over the entire Herschel mission and a single, time-independent response calibration file is sufficient for the processing and calibration of the science observations. The dedicated measurements of the internal calibration sources were needed only to characterize secondary effects. No aging effects of the bolometer or the filters have been found. Also, we found no signs of filter leaks. The PACS photometric system is very well characterized with a constant energy spectrum νF ν = λF λ = const as a reference. Colour corrections for a wide range of sources SEDs are determined and tabulated.

  20. Portable Remote Imaging Spectrometer (PRISM): Laboratory and Field Calibration Results

    NASA Astrophysics Data System (ADS)

    Mccubbin, I. B.; Green, R. O.; Mouroulis, P.; Van Gorp, B.; Dierssen, H. M.

    2012-12-01

    The Portable Remote Imaging Spectrometer (PRISM) is an airborne sensor tailored specifically for the challenges of coastal ocean research. PRISM has high throughput, high-uniformity and low polarization sensitivity. PRISM is an airborne imaging spectrometer sensor that has been developed by the Jet Propulsion Laboratory (JPL) with funding from NASA's Earth Science and Technology Office, Airborne Science Office, and Ocean Biology and Biogeochemistry Office. Development of PRISM started in August 2009. Laboratory measurements of the sensor characteristics as well as measurements over land and water calibration sites will be reported. The objective of the PRISM program is to provide a facility instrument for the community of coastal ocean scientists in order to address specific science questions that have been identified by NASA as critical to the understanding of terrestrial processes. PRISM is a push-broom sensor, and utilizes a Dyson spectrometer, which has 3-nm spectral resolution from 350-1000 nm. The objective of the PRISM 2012 airborne campaign was to a) provide instrument calibration data by overflying specific well-characterized ground targets, and b) perform an investigation into the health of specific seagrass types as indicative of coastal habitat health in the Elkhorn Slough region of Monterey Bay, CA. In May and July of 2012 PRISM flew engineering test flights and an initial science campaign. The initial results from the May and July 2012 flight campaigns will be presented.

  1. Characterisation of a protection level Am-241 calibration source

    NASA Astrophysics Data System (ADS)

    Bass, G. A.; Rossiter, M. J.; Williams, T. T.

    1992-11-01

    The various measurements involved in the commissioning process of an Am-241 radioactive source and transport mechanisms to be used for protection level calibration work are detailed. The source and its handling mechanisms are described and measurements to characterize the resultant gamma ray beam are described. For the beam measurements, the inverse square law is investigated and beam uniformity is assessed. A trial calibration of ionization chambers is described. The Am-241 irradiation facility is concluded to be suitable for calibrating secondary standards as part of the calibration service offered for protection level instruments. The umbra part of beam is acceptably uniform for a range of chambers and the measurements obtained were predictable and consistent. This quality will be added to the range of qualities offered as part of the protection level secondary standard calibration service.

  2. Common Calibration Source for Monitoring Long-term Ozone Trends

    NASA Technical Reports Server (NTRS)

    Kowalewski, Matthew

    2004-01-01

    Accurate long-term satellite measurements are crucial for monitoring the recovery of the ozone layer. The slow pace of the recovery and limited lifetimes of satellite monitoring instruments demands that datasets from multiple observation systems be combined to provide the long-term accuracy needed. A fundamental component of accurately monitoring long-term trends is the calibration of these various instruments. NASA s Radiometric Calibration and Development Facility at the Goddard Space Flight Center has provided resources to minimize calibration biases between multiple instruments through the use of a common calibration source and standardized procedures traceable to national standards. The Facility s 50 cm barium sulfate integrating sphere has been used as a common calibration source for both US and international satellite instruments, including the Total Ozone Mapping Spectrometer (TOMS), Solar Backscatter Ultraviolet 2 (SBUV/2) instruments, Shuttle SBUV (SSBUV), Ozone Mapping Instrument (OMI), Global Ozone Monitoring Experiment (GOME) (ESA), Scanning Imaging SpectroMeter for Atmospheric ChartographY (SCIAMACHY) (ESA), and others. We will discuss the advantages of using a common calibration source and its effects on long-term ozone data sets. In addition, sphere calibration results from various instruments will be presented to demonstrate the accuracy of the long-term characterization of the source itself.

  3. Results from source-based and detector-based calibrations of a CLARREO calibration demonstration system

    NASA Astrophysics Data System (ADS)

    Angal, Amit; McCorkel, Joel; Thome, Kurt

    2016-09-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission is formulated to determine long-term climate trends using SI-traceable measurements. The CLARREO mission will include instruments operating in the reflected solar (RS) wavelength region from 320 nm to 2300 nm. The Solar, Lunar for Absolute Reflectance Imaging Spectroradiometer (SOLARIS) is the calibration demonstration system (CDS) for the reflected solar portion of CLARREO and facilitates testing and evaluation of calibration approaches. The basis of CLARREO and SOLARIS calibration is the Goddard Laser for Absolute Measurement of Response (GLAMR) that provides a radiance-based calibration at reflective solar wavelengths using continuously tunable lasers. SI-traceability is achieved via detector-based standards that, in GLAMR's case, are a set of NIST-calibrated transfer radiometers. A portable version of the SOLARIS, Suitcase SOLARIS is used to evaluate GLAMR's calibration accuracies. The calibration of Suitcase SOLARIS using GLAMR agrees with that obtained from source-based results of the Remote Sensing Group (RSG) at the University of Arizona to better than 5% (k=2) in the 720-860 nm spectral range. The differences are within the uncertainties of the NIST-calibrated FEL lamp-based approach of RSG and give confidence that GLAMR is operating at <5% (k=2) absolute uncertainties. Limitations of the Suitcase SOLARIS instrument also discussed and the next edition of the SOLARIS instrument (Suitcase SOLARIS- 2) is expected to provide an improved mechanism to further assess GLAMR and CLARREO calibration approaches.

  4. Ceramic ChemCam Calibration Targets on Mars Science Laboratory

    NASA Astrophysics Data System (ADS)

    Vaniman, D.; Dyar, M. D.; Wiens, R.; Ollila, A.; Lanza, N.; Lasue, J.; Rhodes, J. M.; Clegg, S.; Newsom, H.

    2012-09-01

    The ChemCam instrument on the Mars Science Laboratory rover Curiosity will use laser-induced breakdown spectroscopy (LIBS) to analyze major and minor element chemistry from sub-millimeter spot sizes, at ranges of ˜1.5-7 m. To interpret the emission spectra obtained, ten calibration standards will be carried on the rover deck. Graphite, Ti metal, and four glasses of igneous composition provide primary, homogeneous calibration targets for the laser. Four granular ceramic targets have been added to provide compositions closer to soils and sedimentary materials like those expected at the Gale Crater field site on Mars. Components used in making these ceramics include basalt, evaporite, and phyllosilicate materials that approximate the chemical compositions of detrital and authigenic constituents of clastic and evaporite sediments, including the elevated sulfate contents present in many Mars sediments and soils. Powdered components were sintered at low temperature (800 °C) with a small amount (9 wt.%) of lithium tetraborate flux to produce ceramics that retain volatile sulfur yet are durable enough for the mission. The ceramic targets are more heterogeneous than the pure element and homogenous glass standards but they provide standards with compositions more similar to the sedimentary rocks that will be Curiosity's prime targets at Gale Crater.

  5. Neutron calibration sources in the Daya Bay experiment

    DOE PAGES

    Liu, J.; Carr, R.; Dwyer, D. A.; ...

    2015-07-09

    We describe the design and construction of the low rate neutron calibration sources used in the Daya Bay Reactor Anti-neutrino Experiment. Such sources are free of correlated gamma-neutron emission, which is essential in minimizing induced background in the anti-neutrino detector. Thus, the design characteristics have been validated in the Daya Bay anti-neutrino detector.

  6. A dynamic pressure source for the calibration of pressure transducers

    NASA Technical Reports Server (NTRS)

    Vezzetti, C. F.; Hilten, J. S.; Mayo-Wells, J. F.; Lederer, P. S.

    1976-01-01

    A dynamic pressure source is described for producing sinusoidally varying pressures of up to 34 kPa zero to peak, over the frequency range of approximately 50 Hz to 2 kHz. The source is intended for the dynamic calibration of pressure transducers. The transducer to be calibrated is mounted near the base of the thick walled aluminum tube forming the vessel so that the pressure sensitive element is in contact with the liquid in the tube. A section of the tube is filled with small steel balls to damp the motion of the 10-St dimethyl siloxane working fluid in order to extend the useful frquency range to higher frequencies than would be provided by an undamped system. The dynamic response of six transducers provided by the sponsor was evaluated using the pressure sources; the results of these calibrations are given.

  7. Active radiometric calorimeter for absolute calibration of radioactive sources

    SciTech Connect

    Stump, K.E.; DeWerd, L.A.; Rudman, D.A.; Schima, S.A.

    2005-03-01

    This report describes the design and initial noise floor measurements of a radiometric calorimeter designed to measure therapeutic medical radioactive sources. The instrument demonstrates a noise floor of approximately 2 nW. This low noise floor is achieved by using high temperature superconducting (HTS) transition edge sensor (TES) thermometers in a temperature-control feedback loop. This feedback loop will be used to provide absolute source calibrations based upon the electrical substitution method. Other unique features of the calorimeter are (a) its ability to change sources for calibration without disrupting the vacuum of the instrument, and (b) the ability to measure the emitted power of a source in addition to the total contained source power.

  8. Absolute calorimetric calibration of low energy brachytherapy sources

    NASA Astrophysics Data System (ADS)

    Stump, Kurt E.

    In the past decade there has been a dramatic increase in the use of permanent radioactive source implants in the treatment of prostate cancer. A small radioactive source encapsulated in a titanium shell is used in this type of treatment. The radioisotopes used are generally 125I or 103Pd. Both of these isotopes have relatively short half-lives, 59.4 days and 16.99 days, respectively, and have low-energy emissions and a low dose rate. These factors make these sources well suited for this application, but the calibration of these sources poses significant metrological challenges. The current standard calibration technique involves the measurement of ionization in air to determine the source air-kerma strength. While this has proved to be an improvement over previous techniques, the method has been shown to be metrologically impure and may not be the ideal means of calbrating these sources. Calorimetric methods have long been viewed to be the most fundamental means of determining source strength for a radiation source. This is because calorimetry provides a direct measurement of source energy. However, due to the low energy and low power of the sources described above, current calorimetric methods are inadequate. This thesis presents work oriented toward developing novel methods to provide direct and absolute measurements of source power for low-energy low dose rate brachytherapy sources. The method is the first use of an actively temperature-controlled radiation absorber using the electrical substitution method to determine total contained source power of these sources. The instrument described operates at cryogenic temperatures. The method employed provides a direct measurement of source power. The work presented here is focused upon building a metrological foundation upon which to establish power-based calibrations of clinical-strength sources. To that end instrument performance has been assessed for these source strengths. The intent is to establish the limits of

  9. Laboratory-Based BRDF Calibration of Radiometric Tarps

    NASA Technical Reports Server (NTRS)

    Georgiev, Georgi T.; Butler, James J.

    2007-01-01

    The current study provides the remote sensing community with important high accuracy laboratory-based BRDF calibration of radiometric tarps. The results illustrate the dependence of tarps' weft and warp threads orientation on BRDF. The study was done at incident angles of 0deg, 10deg, and 30deg; scatter zenith angles from 0deg to 60deg, and scatter azimuth angles of 0deg, 45deg, 90deg, 135deg, and 180deg. The wavelengths were 485nm, 550nm, 633nm and 800nm. The dependence is well defined at all measurement geometries and wavelengths. It can be as high as 8% at 0deg incident angle and 2% at 30deg incident angle. The fitted BRDF data show a very small discrepancy from the measured ones. New data on the forward and backscatter properties of radiometric tarps is reported. The backward scatter is well pronounced for the white samples. The black sample has well pronounced forward scatter. The BRDF characterization of radiometric tarps can be successfully extended to other structured surface fabric samples. The results are NIST traceable.

  10. 10 CFR 35.432 - Calibration measurements of brachytherapy sources.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Calibration measurements of brachytherapy sources. 35.432 Section 35.432 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy... Association of Physicists in Medicine that are made in accordance with paragraph (a) of this section. (c)...

  11. 10 CFR 35.432 - Calibration measurements of brachytherapy sources.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Calibration measurements of brachytherapy sources. 35.432 Section 35.432 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy... Association of Physicists in Medicine that are made in accordance with paragraph (a) of this section. (c)...

  12. 10 CFR 35.432 - Calibration measurements of brachytherapy sources.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Calibration measurements of brachytherapy sources. 35.432 Section 35.432 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy... Association of Physicists in Medicine that are made in accordance with paragraph (a) of this section. (c)...

  13. 10 CFR 35.432 - Calibration measurements of brachytherapy sources.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Calibration measurements of brachytherapy sources. 35.432 Section 35.432 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy... Association of Physicists in Medicine that are made in accordance with paragraph (a) of this section. (c)...

  14. 10 CFR 35.432 - Calibration measurements of brachytherapy sources.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Calibration measurements of brachytherapy sources. 35.432 Section 35.432 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy... Association of Physicists in Medicine that are made in accordance with paragraph (a) of this section. (c)...

  15. Comparison of pencil-type ionization chamber calibration results and methods between dosimetry laboratories.

    PubMed

    Hourdakis, Costas J; Büermann, Ludwig; Ciraj-Bjelac, Olivera; Csete, Istvan; Delis, Harry; Gomola, Igor; Persson, Linda; Novak, Leos; Petkov, Ivailo; Toroi, Paula

    2016-01-01

    A comparison of calibration results and procedures in terms of air kerma length product, PKL, and air kerma, K, was conducted between eight dosimetry laboratories. A pencil-type ionization chamber (IC), generally used for computed tomography dose measurements, was calibrated according to three calibration methods, while its residual signal and other characteristics (sensitivity profile, active length) were assessed. The results showed that the "partial irradiation method" is the preferred method for the pencil-type IC calibration in terms of PKL and it could be applied by the calibration laboratories successfully. Most of the participating laboratories achieved high level of agreement (>99%) for both dosimetry quantities (PKL and K). Estimated relative standard uncertainties of comparison results vary among laboratories from 0.34% to 2.32% depending on the quantity, beam quality and calibration method applied. Detailed analysis of the assigned uncertainties have been presented and discussed.

  16. Calibration of a time-resolved hard-x-ray detector using radioactive sources

    NASA Astrophysics Data System (ADS)

    Stoeckl, C.; Theobald, W.; Regan, S. P.; Romanofsky, M. H.

    2016-11-01

    A four-channel, time-resolved, hard x-ray detector (HXRD) has been operating at the Laboratory for Laser Energetics for more than a decade. The slope temperature of the hot-electron population in direct-drive inertial confinement fusion experiments is inferred by recording the hard x-ray radiation generated in the interaction of the electrons with the target. Measuring the energy deposited by hot electrons requires an absolute calibration of the hard x-ray detector. A novel method to obtain an absolute calibration of the HXRD using single photons from radioactive sources was developed, which uses a thermoelectrically cooled, low-noise, charge-sensitive amplifier.

  17. Primary calibrations of radionuclide solutions and sources for the EML quality assessment program

    SciTech Connect

    Fisenne, I.M.

    1993-12-31

    The quality assurance procedures established for the operation of the U.S. Department of Energy`s Environmental Measurements Laboratory (DOE-EML`s) Quality Assessment Program (QAP) are essentially the same as those that are in effect for any EML program involving radiometric measurements. All these programs have at their core the use of radionuclide standards for their instrument calibration. This paper focuses on EML`s approach to the acquisition, calibration and application of a wide range of radionuclide sources that are required to meet its programmatic needs.

  18. Development of a quality assurance program for ionizing radiation secondary calibration laboratories

    SciTech Connect

    Heaton, H.T. II; Taylor, A.R. Jr.

    1993-12-31

    For calibration laboratories, routine calibrations of instruments meeting stated accuracy goals are important. One method of achieving the accuracy goals is to establish and follow a quality assurance program designed to monitor all aspects of the calibration program and to provide the appropriate feedback mechanism if adjustments are needed. In the United States there are a number of organizations with laboratory accreditation programs. All existing accreditation programs require that the laboratory implement a quality assurance program with essentially the same elements in all of these programs. Collectively, these elements have been designated as a Measurement Quality Assurance (MQA) program. This paper will briefly discuss the interrelationship of the elements of an MQA program. Using the Center for Devices and Radiological Health (CDRH) X-ray Calibration Laboratory (XCL) as an example, it will focus on setting up a quality control program for the equipment in a Secondary Calibration Laboratory.

  19. Development of a photochemical source for the production and calibration of acyl peroxynitrate compounds

    NASA Astrophysics Data System (ADS)

    Veres, P. R.; Roberts, J. M.

    2015-02-01

    A dynamic system for the calibration of acyl peroxynitrate compounds (APNs) has been developed in the laboratory to reduce the difficulty, required time, and stability of laboratory produced standards for difficult to synthesize APN species. In this work we present a photochemical source for the generation of APN standards: acetyl peroxynitrate (PAN), propionyl peroxynitrate (PPN), acryloyl peroxynitrate (APAN), methacryloyl peroxynitrate (MPAN) and crotonyl peroxynitrate (CPAN). APNs are generated via photolysis of a mixture of acyl chloride (RC(O)Cl) and ketone (RC(=O)R) precursor compounds in the presence of O2 and NO2. Subsequent separation by a prep-scale gas chromatograph and detection with a total NOy instrument serves to quantify the output of the APN source. Validation of the APN products was performed using iodide ion chemical ionization mass spectroscopy (I- CIMS). This method of standard production is an efficient and accurate technique for the calibration of instrumentation used to measure PAN, PPN, APAN, MPAN, and CPAN.

  20. Brookhaven National Laboratory meteorological services instrument calibration plan and procedures

    SciTech Connect

    Heiser .

    2013-02-16

    This document describes the Meteorological Services (Met Services) Calibration and Maintenance Schedule and Procedures, The purpose is to establish the frequency and mechanism for the calibration and maintenance of the network of meteorological instrumentation operated by Met Services. The goal is to maintain the network in a manner that will result in accurate, precise and reliable readings from the instrumentation.

  1. Laboratory source of synchrotron radiation: TROLL-2

    NASA Astrophysics Data System (ADS)

    Anevsky, S. I.; Vernyi, A. E.; Panasjuk, V. S.; Khromchenko, V. B.

    1987-11-01

    A laboratory synchrotron radiation (SR) source TROLL-2 is described. Its main parameters are as follows: the energy of the accelerated particles = 24 MeV; the orbit radius = 20 mm; the SR pulse half-width = 2 ms, the maximum spectral radiant power (at λ = 350 nm) = 1.2×10 6 W/m.

  2. Two laboratory methods for the calibration of GPS speed meters

    NASA Astrophysics Data System (ADS)

    Bai, Yin; Sun, Qiao; Du, Lei; Yu, Mei; Bai, Jie

    2015-01-01

    The set-ups of two calibration systems are presented to investigate calibration methods of GPS speed meters. The GPS speed meter calibrated is a special type of high accuracy speed meter for vehicles which uses Doppler demodulation of GPS signals to calculate the measured speed of a moving target. Three experiments are performed: including simulated calibration, field-test signal replay calibration, and in-field test comparison with an optical speed meter. The experiments are conducted at specific speeds in the range of 40-180 km h-1 with the same GPS speed meter as the device under calibration. The evaluation of measurement results validates both methods for calibrating GPS speed meters. The relative deviations between the measurement results of the GPS-based high accuracy speed meter and those of the optical speed meter are analyzed, and the equivalent uncertainty of the comparison is evaluated. The comparison results justify the utilization of GPS speed meters as reference equipment if no fewer than seven satellites are available. This study contributes to the widespread use of GPS-based high accuracy speed meters as legal reference equipment in traffic speed metrology.

  3. Comparison of Blackbody Sources for Low-Temperature IR Calibration

    NASA Astrophysics Data System (ADS)

    Ljungblad, S.; Holmsten, M.; Josefson, L. E.; Klason, P.

    2015-12-01

    Radiation thermometers are traditionally mostly used in high-temperature applications. They are, however, becoming more common in different applications at room temperature or below, in applications such as monitoring frozen food and evaluating heat leakage in buildings. To measure temperature accurately with a pyrometer, calibration is essential. A problem with traditional, commercially available, blackbody sources is that ice is often formed on the surface when measuring temperatures below 0°C. This is due to the humidity of the surrounding air and, as ice does not have the same emissivity as the blackbody source, it biases the measurements. An alternative to a traditional blackbody source has been tested by SP Technical Research Institute of Sweden. The objective is to find a cost-efficient method of calibrating pyrometers by comparison at the level of accuracy required for the intended use. A disc-shaped blackbody with a surface pyramid pattern is placed in a climatic chamber with an opening for field of view of the pyrometer. The temperature of the climatic chamber is measured with two platinum resistance thermometers in the air in the vicinity of the disc. As a rule, frost will form only if the deposition surface is colder than the surrounding air, and, as this is not the case when the air of the climatic chamber is cooled, there should be no frost or ice formed on the blackbody surface. To test the disc-shaped blackbody source, a blackbody cavity immersed in a conventional stirred liquid bath was used as a reference blackbody source. Two different pyrometers were calibrated by comparison using the two different blackbody sources, and the results were compared. The results of the measurements show that the disc works as intended and is suitable as a blackbody radiation source.

  4. Characteristics of the Neutron Irradiation Facilities of the PSI Calibration Laboratory

    SciTech Connect

    Hoedlmoser, H.; Schuler, Ch.; Butterweck, G.; Mayer, S.

    2011-12-13

    The neutron radiation fields of the Calibration Laboratory at Paul Scherrer Institute (PSI) are traceable to the national standards of the Physikalisch-Technische Bundesanstalt (PTB) in Germany. A Berthold LB6411 neutron dose rate meter for neutron radiation is used as a secondary standard. Recently, a thorough characterization of the neutron irradiation fields of the {sup 241}Am-Be and {sup 252}Cf sources by means of reference measurements and a detailed MCNPX simulation of the irradiation facility has been initiated. In this work, the characteristics of the neutron radiation fields are summarized and presented together with model equations and an uncertainty analysis. MCNPX results are shown for the {sup 241}Am-Be source. A comparison of measured and simulated data shows an excellent agreement. From the simulation, valuable information about the neutron fields like the contribution of scattered neutrons in the fields and the energy spectra could be obtained.

  5. A report from the AVS Standards Committee - Comparison of ion gauge calibrations by several standards laboratories

    NASA Technical Reports Server (NTRS)

    Warshawsky, I.

    1982-01-01

    Calibrations by four U.S. laboratories of four hot-cathode ion gauges, in the range 0.07-13 mPa, showed systematic differences among laboratories that were much larger than the expected error of any one calibration. They also suggested that any of the four gauges tested, if properly packaged and shipped, was able to serve as a transfer standard with probable error of 2%. A second comparison was made of the calibrations by two U.S. laboratories of some other gauges that had also been calibrated by the National Physical Laboratory, England. Results did not permit conclusive determination of whether differences were due to the laboratories or to changes in the gauges.

  6. Status of the laboratory infrastructure for detector calibration and characterization at the European XFEL

    NASA Astrophysics Data System (ADS)

    Raab, N.; Ballak, K.-E.; Dietze, T.; Ekmedzič, M.; Hauf, S.; Januschek, F.; Kaukher, A.; Kuster, M.; Lang, P. M.; Münnich, A.; Schmitt, R.; Sztuk-Dambietz, J.; Turcato, M.

    2016-12-01

    The European X-ray Free Electron Laser (XFEL.EU) will provide unprecedented peak brilliance and ultra-short and spatially coherent X-ray pulses in an energy range of 0.25 to 25 keV . The pulse timing structure is unique with a burst of 2700 pulses of 100 fs length at a temporal distance of 220 ns followed by a 99.4 ms gap. To make optimal use of this timing structure and energy range a great variety of detectors are being developed for use at XFEL.EU, including 2D X-ray imaging cameras that are able to detect images at a rate of 4.5 MHz, provide dynamic ranges up to 105 photons per pulse per pixel under different operating conditions and covering a large range of angular resolution \\cite{requirements,Markus}. In order to characterize, commission and calibrate this variety of detectors and for testing of detector prototypes the XFEL.EU detector group is building up an X-ray test laboratory that allows testing of detectors with X-ray photons under conditions that are as similar to the future beam line conditions at the XFEL.EU as is possible with laboratory sources [1]. A total of four test environments provide the infrastructure for detector tests and calibration: two portable setups that utilize low power X-ray sources and radioactive isotopes, a test environment where a commercial high power X-ray generator is in use, and a pulsed X-ray/electron source which will provide pulses as short as 25 ns in XFEL.EU burst mode combined with target anodes of different materials. The status of the test environments, three of which are already in use while one is in commissioning phase, will be presented as well as first results from performance tests and characterization of the sources.

  7. Multi-source self-calibration: Unveiling the microJy population of compact radio sources

    NASA Astrophysics Data System (ADS)

    Radcliffe, J. F.; Garrett, M. A.; Beswick, R. J.; Muxlow, T. W. B.; Barthel, P. D.; Deller, A. T.; Middelberg, E.

    2016-03-01

    Context. Very long baseline interferometry (VLBI) data are extremely sensitive to the phase stability of the VLBI array. This is especially important when we reach μJy rms sensitivities. Calibration using standard phase-referencing techniques is often used to improve the phase stability of VLBI data, but the results are often not optimal. This is evident in blank fields that do not have in-beam calibrators. Aims: We present a calibration algorithm termed multi-source self-calibration (MSSC) which can be used after standard phase referencing on wide-field VLBI observations. This is tested on a 1.6 GHz wide-field VLBI data set of the Hubble Deep Field North and the Hubble Flanking Fields. Methods: MSSC uses multiple target sources that are detected in the field via standard phase referencing techniques and modifies the visibilities so that each data set approximates to a point source. These are combined to increase the signal to noise and permit self-calibration. In principle, this should allow residual phase changes caused by the troposphere and ionosphere to be corrected. By means of faceting, the technique can also be used for direction-dependent calibration. Results: Phase corrections, derived using MSSC, were applied to a wide-field VLBI data set of the HDF-N, which comprises of 699 phase centres. MSSC was found to perform considerably better than standard phase referencing and single source self-calibration. All detected sources exhibited dramatic improvements in dynamic range. Using MSSC, one source reached the detection threshold, taking the total detected sources to twenty. This means 60% of these sources can now be imaged with uniform weighting, compared to just 45% with standard phase referencing. In principle, this technique can be applied to any future VLBI observations. The Parseltongue code, which implements MSSC, has been released and made publicly available to the astronomical community (http://https://github.com/jradcliffe5/multi_self_cal).

  8. A Penning discharge source for extreme ultraviolet calibration

    NASA Technical Reports Server (NTRS)

    Finley, David S.; Jelinsky, Patrick; Bowyer, Stuart; Malina, Roger F.

    1986-01-01

    A Penning discharge lamp for use in the calibration of instruments and components for the extreme ultraviolet has been developed. This source is sufficiently light and compact to make it suitable for mounting on the movable slit assembly of a grazing incidence Rowland circle monochromator. Because this is a continuous discharge source, it is suitable for use with photon counting detectors. Line radiation is provided both by the gas and by atoms sputtered off the interchangeable metal cathodes. Usable lines are produced by species as highly ionized as Ne IV and Al V. The wavelength coverage provided is such that a good density of emission lines is available down to wavelengths as short as 100A. This source fills the gap between 100 and 300A, which is inadequately covered by the other available compact continuous radiation sources.

  9. Primary calibration of coiled {sup 103}Pd brachytherapy sources

    SciTech Connect

    Paxton, Adam B.; Culberson, Wesley S.; DeWerd, Larry A.; Micka, John A.

    2008-01-15

    Coiled {sup 103}Pd brachytherapy sources have been developed by RadioMed Corporation for use as low-dose-rate (LDR) interstitial implants. The coiled sources are provided in integer lengths from 1 to 6 cm and address many common issues seen with traditional LDR brachytherapy sources. The current standard for determining the air-kerma strength (S{sub K}) of low-energy LDR brachytherapy sources is the National Institute of Standards and Technology's Wide-Angle Free-Air Chamber (NIST WAFAC). Due to geometric limitations, however, the NIST WAFAC is unable to determine the S{sub K} of sources longer than 1 cm. This project utilized the University of Wisconsin's Variable-Aperture Free-Air Chamber (UW VAFAC) to determine the S{sub K} of the longer coiled sources. The UW VAFAC has shown agreement in S{sub K} values of 1 cm length coils to within 1% of those determined with the NIST WAFAC, but the UW VAFAC does not share the same geometric limitations as the NIST WAFAC. A new source holder was constructed to hold the coiled sources in place during measurements with the UW VAFAC. Correction factors for the increased length of the sources have been determined and applied to the measurements. Using the new source holder and corrections, the S{sub K} of 3 and 6 cm coiled sources has been determined. Corrected UW VAFAC data and ionization current measurements from well chambers have been used to determine calibration coefficients for use in the measurement of 3 and 6 cm coiled sources in well chambers. Thus, the UW VAFAC has provided the first transferable, primary measurement of low-energy LDR brachytherapy sources with lengths greater than 1 cm.

  10. Estimating the precision of serial dilutions and colony counts: contribution of laboratory re-calibration of pipettes.

    PubMed

    Hedges, A J

    2003-10-15

    The basic (inherent) precision of serial dilutions and of colony counts made from them may be reliably estimated by reference solely to the pipette-manufacturer's specifications. Such estimates do not include external sources of variation and may be regarded as minima. The quality of estimation can be improved by using information gained by laboratory ('in-house') re-calibration of the pipettes. The degree of improvement was assessed by comparison with similar series made without re-calibration. It was found that improvement was minimal for colony counts but worthwhile for homogeneous solutions.

  11. Laboratory test simulation for non-flat response calibration of global Earth albedo monitor

    NASA Astrophysics Data System (ADS)

    Seong, Sehyun; Kim, Sug-Whan; Ryu, Dongok; Hong, Jinsuk; Lockwood, Mike

    2012-09-01

    In this report, we present laboratory test simulation for directional responsivity of a global Earth albedo monitoring instrument. The sensor is to observe the Sun and the Earth, alternately, and measure their shortwave (<4μm) radiations around the L1 halo orbit to obtain global Earth albedo. The instrument consists of a broadband scanning radiometer (energy channel instrument) and an imager (visible channel instrument) with ±2° field-of-view. In the case of the energy channel instrument, radiations arriving at the viewing ports from the Sun and the Earth are directed toward the pyroelectric detector via two spherical folding mirrors and a 3D compound parabolic concentrator (CPC). The instrument responsivity is defined by the ratio of the incident radiation input to the instrument output signal. The radiometer's relative directional responsivity needs to be characterized across the field-of-view to assist output signal calibration. For the laboratory test, the distant small source configuration consists of an off-axis collimator and the instrument with adjustable mounts. Using reconstructed 3D CPC surface, the laboratory test simulation for predicting the instrument directional responsivity was conducted by a radiative transfer computation with ray tracing technique. The technical details of the laboratory test simulation are presented together with future plan.

  12. QA experience at the University of Wisconsin accredited dosimetry calibration laboratory

    SciTech Connect

    DeWard, L.A.; Micka, J.A.

    1993-12-31

    The University of Wisconsin Accredited Dosimetry Calibration Laboratory (UW ADCL) employs procedure manuals as part of its Quality Assurance (QA) program. One of these manuals covers the QA procedures and results for all of the UW ADCL measurement equipment. The QA procedures are divided into two main areas: QA for laboratory equipment and QA for external chambers sent for calibration. All internal laboratory equipment is checked and recalibrated on an annual basis, after establishing its consistency on a 6-month basis. QA for external instruments involves checking past calibration history as well as comparing to a range of calibration values for specific instrument models. Generally, the authors find that a chamber will have a variation of less than 0.5 % from previous Co-60 calibration factors, and falls within two standard deviations of previous calibrations. If x-ray calibrations are also performed, the energy response of the chamber is plotted and compared to previous instruments of the same model. These procedures give the authors confidence in the transfer of calibration values from National Institute of Standards and Technology (NIST).

  13. Implementation of ISO guide 25 in a medical dosimetry secondary standards calibration laboratory

    SciTech Connect

    DeWerd, L.A.

    1995-12-31

    Currently, there is a great deal of discussion among industry and government agencies about ISO 9000 accreditation. U.S. manufacturers with ISO 9000 accreditation are regarded more favorably by European countries. The principles behind the ISO 9000 accreditation are based on the Total Quality Management (TQM) principles that are being implemented in many U.S. industries. This paper will deal only with the calibration issue. There is a difference in the areas covered by ISO 9000 and ISO Guide 25 documents. ISO 9000, in particular ISO 9001 - ISO 9003, cover the {open_quotes}calibration{close_quotes} of inspection, measuring and test equipment. This equipment is basically used for {open_quotes}factory calibrations{close_quotes} to determine that equipment is performing within manufacturer specifications. ISO Guide 25 is specifically for {open_quotes}calibration and testing laboratories,{close_quotes} generally laboratories that have painstaking procedures to reduce uncertainties and establish high accuracy of the transfer of calibration. The experience of the University of Wisconsin Accredited Dosimetry Calibration Laboratory in conforming to ISO Guide 25 will be outlined. The entire laboratory staff must become familiar with the process and an individual with direct authority must become the one to maintain the quality of equipment and calibrations in the role of {open_quotes}quality-assurance manager.{close_quotes}

  14. Services of the CDRH X-ray calibration laboratory and their traceability to National Standards

    SciTech Connect

    Cerra, F.; Heaton, H.T.

    1993-12-31

    The X-ray Calibration Laboratory (XCL) of the Center for Devices and Radiological Health (CDRH) provides calibration services for the Food and Drug Administration (FDA). The instruments calibrated are used by FDA and contract state inspectors to verify compliance with federal x-ray performance standards and for national surveys of x-ray trends. In order to provide traceability of measurements, the CDRH XCL is accredited by the National Voluntary Laboratory Accreditation Program (NVLAP) for reference, diagnostic, and x-ray survey instrument calibrations. In addition to these accredited services, the CDRH XCL also calibrates non-invasive kVp meters in single- and three-phase x-ray beams, and thermoluminescent dosimeter (TLD) chips used to measure CT beam profiles. The poster illustrates these services and shows the traceability links back to the National Standards.

  15. RADBALL TECHNOLOGY TESTING IN THE SAVANNAH RIVER SITE HEALTH PHYSICS INSTRUMENT CALIBRATION LABORATORY

    SciTech Connect

    Farfan, E.

    2010-07-08

    The United Kingdom's National Nuclear Laboratory (NNL) has developed a radiation-mapping device that can locate and quantify radioactive hazards within contaminated areas of the nuclear industry. The device, known as RadBall{trademark}, consists of a colander-like outer collimator that houses a radiation-sensitive polymer sphere. The collimator has over two hundred small holes; thus, specific areas of the polymer sphere are exposed to radiation becoming increasingly more opaque in proportion to the absorbed dose. The polymer sphere is imaged in an optical-CT scanner that produces a high resolution 3D map of optical attenuation coefficients. Subsequent analysis of the optical attenuation data provides information on the spatial distribution of sources in a given area forming a 3D characterization of the area of interest. The RadBallTM technology has been deployed in a number of technology trials in nuclear waste reprocessing plants at Sellafield in the United Kingdom and facilities of the Savannah River National Laboratory (SRNL). This paper summarizes the tests completed at SRNL Health Physics Instrument Calibration Laboratory (HPICL).

  16. Calibration of the Mars Science Laboratory Alpha Particle X-Ray Spectrometer

    NASA Astrophysics Data System (ADS)

    Perrett, G. M.; Campbell, J. L.; Gellert, R.; King, P. L.; Maxwell, J. A.; Andrushenko, S. M.

    2011-12-01

    We have used a suite of over 60 geochemical reference standards for the calibration of the Mars Science Laboratory (MSL) Alpha Particle X-ray Spectrometer (APXS). For the elements P, S, Cl and Br we have supplemented this suite by adding various amounts of relevant chemical compounds to a powdered basalt standard. Special attention has been paid to include phyllosilicates, sulphates and a broad selection of igneous basalts as these are predicted key deposits at the MSL landing site, Gale Crater. The calibration is performed from first principles using x-ray excitation cross sections for the alpha particle and x-ray radiation source and an assumed homogeneous sample matrix. Remaining deviations indicate significant influences of mineral phases especially for light elements in basalts, ultra-mafic rocks and trachytes. Supporting x-ray diffraction work has helped to derive empirical, iterative corrections for distinct rock types, based on the first APXS analysis, assuming a homogeneous sample. These corrections have the potential to significantly improve the accuracy of APXS analyses, especially when other MSL instrument results, such as x-ray diffraction data from ChemMin, are included in the overall analysis process.

  17. Laboratory calibration of AAFE radiometer/scatterometer (RADSCAT)

    NASA Technical Reports Server (NTRS)

    Schroeder, L. C.; Jones, W. L., Jr.; Mitchell, J. L.

    1976-01-01

    A brief description of the electrical and mechanical instrument configuration, followed by an extensive discussion of laboratory tests and results are contained herein. This information is required to provide parameters for data reduction, and a basis for analysis of the measurement errors in data taken with this instrument.

  18. Calibration of R/V Marcus G. Langseth Seismic Sources

    NASA Astrophysics Data System (ADS)

    Diebold, J.; Tolstoy, M.; Webb, S.; Doermann, L.; Bohenstihl, D.; Nooner, S.; Crone, T.; Holmes, R. C.

    2008-12-01

    NSF-owned Research Vessel Marcus G. Langseth is operated by Lamont-Doherty Earth Observatory, providing the tools for full-scale marine seismic surveys to the academic community. Since inauguration of science operations, Langseth has successfully supported 2D and 3D seismic operations, including offshore- onshore and OBS refraction profiling A significant component of Langseths equipage is the seismic source, comprising four identical linear subarrays which can be combined in a number of configurations according to the needs of each scientific mission. To ensure a full understanding of the acoustic levels of these sources and in order to mitigate their possible impact upon marine life through accurate determination of safety radii, an extensive program of acoustic calibration was carried out in 2007 and 2008, during Langseths shakedown exercises. A total of 14000+ airgun array discharges were recorded in three separate locations with water depths varying from 1750 to 45 meters and at source-receiver offsets between near-zero and 17 km. The quantity of data recorded allows significant quantitative analysis of the sound levels produced by the Langseth seismic sources. A variety of acoustic metrics will be presented and compared, including peak levels and energy-based measures such as RMS, Energy Flux Density and its equivalent, Sound Exposure Level. It is clearly seen that water depth exerts a fundamental control on received sound levels, but also that these effects can be predicted with reasonable accuracy.

  19. A useful formula for the radiological calibration laboratory.

    PubMed

    Cummings, F M

    2005-03-01

    A useful technique for determining the relationships between irradiation position and air kerma or neutron dose equivalent rate is presented. The standard geometric model (1/r2) is expanded allowing the user to include curvature in the model caused by scattered radiation. This technique applies to clean irradiation geometries that are well modeled by the standard geometric model, high-scatter geometries encountered in well irradiators, and neutron irradiation fields used to calibrate health physics instruments and personnel dosimeters. The technique, with slight modification, is also useful for determining the quality of x-ray beams. The basic equations and the implementing Excel functions are listed. In addition, several examples are presented to demonstrate the application of the technique.

  20. Modeling Study of a Proposed Field Calibration Source Using K-40 and High-Z Targets for Sodium Iodide Detectors.

    PubMed

    Rogers, Jeremy; Marianno, Craig; Kallenbach, Gene; Trevino, Jose

    2016-06-01

    Calibration sources based on the primordial isotope potassium-40 (K) have reduced controls on the source's activity due to its terrestrial ubiquity and very low specific activity. Potassium-40's beta emissions and 1,460.8 keV gamma ray can be used to induce K-shell fluorescence x rays in high-Z metals between 60 and 80 keV. A gamma ray calibration source that uses potassium chloride salt and a high-Z metal to create a two-point calibration for a sodium iodide field gamma spectroscopy instrument is thus proposed. The calibration source was designed in collaboration with the Sandia National Laboratory using the Monte Carlo N-Particle eXtended (MCNPX) transport code. Two methods of x-ray production were explored. First, a thin high-Z layer (HZL) was interposed between the detector and the potassium chloride-urethane source matrix. Second, bismuth metal powder was homogeneously mixed with a urethane binding agent to form a potassium chloride-bismuth matrix (KBM). The bismuth-based source was selected as the development model because it is inexpensive, nontoxic, and outperforms the high-Z layer method in simulation. Based on the MCNPX studies, sealing a mixture of bismuth powder and potassium chloride into a thin plastic case could provide a light, inexpensive field calibration source.

  1. Calibration of a microchannel plate based extreme ultraviolet grazing incident spectrometer at the Advanced Light Source.

    PubMed

    Bakeman, M S; van Tilborg, J; Sokollik, T; Baum, D; Ybarrolaza, N; Duarte, R; Toth, C; Leemans, W P

    2010-10-01

    We present the design and calibration of a microchannel plate based extreme ultraviolet spectrometer. Calibration was performed at the Advance Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBNL). This spectrometer will be used to record the single shot spectrum of radiation emitted by the tapered hybrid undulator (THUNDER) undulator installed at the LOASIS GeV-class laser-plasma-accelerator. The spectrometer uses an aberration-corrected concave grating with 1200 lines/mm covering 11-62 nm and a microchannel plate detector with a CsI coated photocathode for increased quantum efficiency in the extreme ultraviolet. A touch screen interface controls the grating angle, aperture size, and placement of the detector in vacuum, allowing for high-resolution measurements over the entire spectral range.

  2. Calibration of a microchannel plate based extreme ultraviolet grazing incident spectrometer at the Advanced Light Source

    SciTech Connect

    Bakeman, M. S.; Tilborg, J. van; Sokollik, T.; Baum, D.; Ybarrolaza, N.; Duarte, R.; Toth, C.; Leemans, W. P.

    2010-10-15

    We present the design and calibration of a microchannel plate based extreme ultraviolet spectrometer. Calibration was performed at the Advance Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBNL). This spectrometer will be used to record the single shot spectrum of radiation emitted by the tapered hybrid undulator (THUNDER) undulator installed at the LOASIS GeV-class laser-plasma-accelerator. The spectrometer uses an aberration-corrected concave grating with 1200 lines/mm covering 11-62 nm and a microchannel plate detector with a CsI coated photocathode for increased quantum efficiency in the extreme ultraviolet. A touch screen interface controls the grating angle, aperture size, and placement of the detector in vacuum, allowing for high-resolution measurements over the entire spectral range.

  3. Aqueous blackbody calibration source for millimeter-wave/terahertz metrology

    SciTech Connect

    Dietlein, Charles; Popovic, Zoya; Grossman, Erich N

    2008-10-20

    This paper describes a calibrated broadband emitter for the millimeter-wave through terahertz frequency regime, called the aqueous blackbody calibration source. Due to its extremely high absorption, liquid water is chosen as the emitter on the basis of reciprocity. The water is constrained to a specific shape (an optical trap geometry) in an expanded polystyrene (EPS) container and maintained at a selected, uniform temperature. Uncertainty in the selected radiometric temperature due to the undesirable reflectance present at a water interface is minimized by the trap geometry, ensuring that radiation incident on the entrance aperture encounters a pair of s and a pair of p reflections at 45 deg. . For water reflectance Rw of 40% at 45 deg. in W-band, this implies a theoretical effective aperture emissivity of (1-R{sup 2}wsR{sup 2}wp)>98.8%. From W-band to 450 GHz, the maximum radiometric temperature uncertainty is {+-}0.40 K, independent of water temperature. Uncertainty from 450 GHz to 1 THz is increased due to EPS scattering and absorption, resulting in a maximum uncertainty of -3 K at 1 THz.

  4. Modeling study of a proposed field calibration source using K-40 and high-Z targets for sodium iodide detectors

    DOE PAGES

    Rogers, Jeremy; Marianno, Craig; Kallenbach, Gene; ...

    2016-06-01

    Calibration sources based on the primordial isotope potassium-40 (40K) have reduced controls on the source’s activity due to its terrestrial ubiquity and very low specific activity. Potassium–40’s beta emissions and 1,460.8 keV gamma ray can be used to induce K-shell fluorescence x rays in high-Z metals between 60 and 80 keV. A gamma ray calibration source that uses potassium chloride salt and a high-Z metal to create a two-point calibration for a sodium iodide field gamma spectroscopy instrument is thus proposed. The calibration source was designed in collaboration with the Sandia National Laboratory using the Monte Carlo N-Particle eXtended (MCNPX)more » transport code. Two methods of x-ray production were explored. First, a thin high-Z layer (HZL) was interposed between the detector and the potassium chloride-urethane source matrix. Second, bismuth metal powder was homogeneously mixed with a urethane binding agent to form a potassium chloride-bismuth matrix (KBM). The bismuth-based source was selected as the development model because it is inexpensive, nontoxic, and outperforms the high-Z layer method in simulation. As a result, based on the MCNPX studies, sealing a mixture of bismuth powder and potassium chloride into a thin plastic case could provide a light, inexpensive field calibration source.« less

  5. Modeling study of a proposed field calibration source using K-40 and high-Z targets for sodium iodide detectors

    SciTech Connect

    Rogers, Jeremy; Marianno, Craig; Kallenbach, Gene; Trevino, Jose

    2016-06-01

    Calibration sources based on the primordial isotope potassium-40 (40K) have reduced controls on the source’s activity due to its terrestrial ubiquity and very low specific activity. Potassium–40’s beta emissions and 1,460.8 keV gamma ray can be used to induce K-shell fluorescence x rays in high-Z metals between 60 and 80 keV. A gamma ray calibration source that uses potassium chloride salt and a high-Z metal to create a two-point calibration for a sodium iodide field gamma spectroscopy instrument is thus proposed. The calibration source was designed in collaboration with the Sandia National Laboratory using the Monte Carlo N-Particle eXtended (MCNPX) transport code. Two methods of x-ray production were explored. First, a thin high-Z layer (HZL) was interposed between the detector and the potassium chloride-urethane source matrix. Second, bismuth metal powder was homogeneously mixed with a urethane binding agent to form a potassium chloride-bismuth matrix (KBM). The bismuth-based source was selected as the development model because it is inexpensive, nontoxic, and outperforms the high-Z layer method in simulation. As a result, based on the MCNPX studies, sealing a mixture of bismuth powder and potassium chloride into a thin plastic case could provide a light, inexpensive field calibration source.

  6. Energy calibration of energy-resolved photon-counting pixel detectors using laboratory polychromatic x-ray beams

    NASA Astrophysics Data System (ADS)

    Youn, Hanbean; Han, Jong Chul; Kam, Soohwa; Yun, Seungman; Kim, Ho Kyung

    2014-10-01

    Recently, photon-counting detectors capable of resolving incident x-ray photon energies have been considered for use in spectral x-ray imaging applications. For reliable use of energy-resolved photon-counting detectors (ERPCDs), energy calibration is an essential procedure prior to their use because variations in responses from each pixel of the ERPCD for incident photons, even at the same energy, are inevitable. Energy calibration can be performed using a variety of methods. In all of these methods, the photon spectra with well-defined peak energies are recorded. Every pixel should be calibrated on its own. In this study, we suggest the use of a conventional polychromatic x-ray source (that is typically used in laboratories) for energy calibration. The energy calibration procedure mainly includes the determination of the peak energies in the spectra, flood-field irradiation, determination of peak channels, and determination of calibration curves (i.e., the slopes and intercepts of linear polynomials). We applied a calibration algorithm to a CdTe ERPCD comprised of 128×128 pixels with a pitch of 0.35 mm using highly attenuated polychromatic x-ray beams to reduce the pulse pile-up effect, and to obtain a narrow-shaped spectrum due to beam hardening. The averaged relative error in calibration curves obtained from 16,384 pixels was about 0.56% for 59.6 keV photons from an Americium radioisotope. This pixel-by-pixel energy calibration enhanced the signal- and contrast-to-noise ratios in images, respectively, by a factor of ~5 and 3 due to improvement in image homogeneity, compared to those obtained without energy calibration. One secondary finding of this study was that the x-ray photon spectra obtained using a common algorithm for computing x-ray spectra reasonably described the peaks in the measured spectra, which implies easier peak detection without the direct measurement of spectra using a separate spectrometer. The proposed method will be a useful alternative to

  7. R/V EWING seismic source array calibrations: 2003

    NASA Astrophysics Data System (ADS)

    Diebold, J.; Webb, S.; Tolstoy, M.; Rawson, M.; Holmes, C.; Bohnenstiehl, D.; Chapp, E.

    2003-12-01

    In the Northern Gulf of Mexico, May, 2003, an NSF-funded effort was carried out to obtain calibrated measurements of the various airgun arrays deployed by R/V EWING during its seismic surveys. The motivations for this were several: to ground-truth the modeling upon which safety radii for marine mammal mitigation are established; to obtain broadband digitized signals which will accurately define the full spectral content of airgun signatures; to investigate the effects of seafloor interactions and their contribution to the acoustic noise levels from seismic sources. For this purpose, a digital, remotely telemetering spar buoy was designed and assembled; affording interactive control over the choice of two hydrophone channels, four fixed gain settings and four digitizing rates [6,250 - 50,000 Hz.] Three deployments were planned: a deep-water site, suitable for comparison of actual signals with modeled results; a shallow-water [25 - 50m] site where the effects of bottom interaction would be strongest; and a continental-slope site, which represents the favored habitat of many cetacean species. Methodology was developed which enabled the sequential discharge of four subarrays of 6, 10, 12 and 20 airguns. A separate run was made with two "GI" airguns, the favored high resolution survey source. An Incidental Harassment Authorization and a Biological Opinion, including an Incidental Take Statement were issued for the project by National Marine Fisheries, and a suite of marine mammal observation and mitigation procedures was followed. The deep and shallow water sites were occupied, and some 440 airgun signals were recorded. The slope site work was cancelled due to weather too poor for accurate marine mammal observation, but calibration was subsequently carried out with an exploration industry source vessel in a similar environment. Preliminary results indicate that the mitigation modeling is accurate, though somewhat conservative; that the radiated energy from airgun arrays

  8. Development of a photochemical source for the production and calibration of acyl peroxynitrate compounds

    NASA Astrophysics Data System (ADS)

    Veres, P. R.; Roberts, J. M.

    2015-05-01

    A dynamic system for the calibration of acyl peroxynitrate compounds (APNs) has been developed in the laboratory to reduce the difficulty, required time, and instability of laboratory-produced standards for difficult-to-synthesize APN species. In this work we present a photochemical source for the generation of APN standards: acetyl peroxynitrate (PAN), propionyl peroxynitrate (PPN), acryloyl peroxynitrate (APAN), methacryloyl peroxynitrate (MPAN), and crotonyl peroxynitrate (CPAN). APNs are generated via photolysis of a mixture of acyl chloride (RC(O)Cl) and ketone (RC(=O)R) precursor compounds in the presence of O2 and NO2. Subsequent separation by a prep-scale gas chromatograph and detection with a total NOy instrument serve to quantify the output of the APN source. Validation of the APN products was performed using iodide ion chemical ionization mass spectroscopy (I- CIMS). This method of standard production is an efficient and accurate technique for the calibration of instrumentation used to measure PAN, PPN, APAN, MPAN, and CPAN.

  9. Angular response calibration of the burst and transient source experiment

    NASA Technical Reports Server (NTRS)

    Lestrade, John Patrick

    1988-01-01

    The Gamma Ray Observatory includes four experiments designed to observe the gamma-ray universe. Laboratory measurements to test the response the Burst and Transient Source Experiment (BATSE) modules to gamma-ray sources that are non-axial were recently completed. The results of these observations are necessary for the correct interpretation of BATSE data obtained after it is put in Earth orbit. The launch is planned for March, 1900. Preliminary analyses of these test data show the presence of a radial dependence to the detector's light collection efficiency. It is proposed to evaluate the importance of this radial response, analyze future experimental data to derive the actual functional dependence on radius, and calculate the net effect on the output spectrum as a function of the angle of incidence.

  10. Dealing with the size-of-source effect in the calibration of direct-reading radiation thermometer

    SciTech Connect

    Saunders, P.

    2013-09-11

    The majority of general-purpose low-temperature handheld radiation thermometers are severely affected by the size-of-source effect (SSE). Calibration of these instruments is pointless unless the SSE is accounted for in the calibration process. Traditional SSE measurement techniques, however, are costly and time consuming, and because the instruments are direct-reading in temperature, traditional SSE results are not easily interpretable, particularly by the general user. This paper describes a simplified method for measuring the SSE, suitable for second-tier calibration laboratories and requiring no additional equipment, and proposes a means of reporting SSE results on a calibration certificate that should be easily understood by the non-specialist user.

  11. History, organization, and oversight of the accredited dosimetry calibration laboratories by the AAPM

    SciTech Connect

    Rozenfeld, M.

    1993-12-31

    For more than 20 years, the American Association of Physicists in Medicine (AAPM) has operated an accreditation program for secondary standards laboratories that calibrate radiation measuring instruments. Except for one short period, that program has been able to provide the facilities to satisfy the national need for accurate calibrations of such instruments. That exception, in 1981, due to the combination of the U.S. Nuclear Regulatory Commission (NRC) requiring instrument calibrations by users of cobalt-60 teletherapy units and the withdrawal of one of the three laboratories accredited at that time. However, after successful operation as a Task Group of the Radiation Therapy Committee (RTC) of the AAPM for two decades, a reorganization of this structure is now under serious consideration by the administration of the AAPM.

  12. Laboratory Calibration of the Optical Transient Detector (OTD) and the Lightning Imaging Sensor (LIS)

    NASA Technical Reports Server (NTRS)

    Koshak, William J.; Stewart, Mike F.; Christian, Hugh J.; Bergstrom, James W.; Hall, John M.; Solakiewicz, Richard J.

    1994-01-01

    We present in detail the laboratory apparatus and techniques that were used to complete a full radiometric calibration of two space-based lightning detectors developed at NASA Marshall Space Flight Center (MSFC). A discussion of the methods applied to geolocate lightning and to estimate lightning detection efficiency are provided.

  13. Inter-Laboratory Comparison for Calibration of Relative Humidity Devices Among Accredited Laboratories in Malaysia

    NASA Astrophysics Data System (ADS)

    Hussain, F.; Khairuddin, S.; Othman, H.

    2017-01-01

    An inter-laboratory comparison in relative humidity measurements among accredited laboratories has been coordinated by the National Metrology Institute of Malaysia. It was carried out to determine the performance of the participating laboratories. The objective of the comparison was to acknowledge the participating laboratories competencies and to verify the level of accuracies declared in their scope of accreditation, in accordance with the MS ISO/IEC 17025 accreditation. The measurement parameter involved was relative humidity for the range of 30-90 %rh at a nominal temperature of 50°C. Eight accredited laboratories participated in the inter-laboratory comparison. Two units of artifacts have been circulated among the participants as the transfer standards.

  14. Characterization and Calibration of the CheMin Mineralogical Instrument on Mars Science Laboratory

    NASA Astrophysics Data System (ADS)

    Blake, David; Vaniman, David; Achilles, Cherie; Anderson, Robert; Bish, David; Bristow, Tom; Chen, Curtis; Chipera, Steve; Crisp, Joy; Des Marais, David; Downs, Robert T.; Farmer, Jack; Feldman, Sabrina; Fonda, Mark; Gailhanou, Marc; Ma, Hongwei; Ming, Doug W.; Morris, Richard V.; Sarrazin, Philippe; Stolper, Ed; Treiman, Allan; Yen, Albert

    2012-09-01

    A principal goal of the Mars Science Laboratory (MSL) rover Curiosity is to identify and characterize past habitable environments on Mars. Determination of the mineralogical and chemical composition of Martian rocks and soils constrains their formation and alteration pathways, providing information on climate and habitability through time. The CheMin X-ray diffraction (XRD) and X-ray fluorescence (XRF) instrument on MSL will return accurate mineralogical identifications and quantitative phase abundances for scooped soil samples and drilled rock powders collected at Gale Crater during Curiosity's 1-Mars-year nominal mission. The instrument has a Co X-ray source and a cooled charge-coupled device (CCD) detector arranged in transmission geometry with the sample. CheMin's angular range of 5∘ to 50∘ 2 θ with <0.35∘ 2 θ resolution is sufficient to identify and quantify virtually all minerals. CheMin's XRF requirement was descoped for technical and budgetary reasons. However, X-ray energy discrimination is still required to separate Co K α from Co K β and Fe K α photons. The X-ray energy-dispersive histograms (EDH) returned along with XRD for instrument evaluation should be useful in identifying elements Z>13 that are contained in the sample. The CheMin XRD is equipped with internal chemical and mineralogical standards and 27 reusable sample cells with either Mylar® or Kapton® windows to accommodate acidic-to-basic environmental conditions. The CheMin flight model (FM) instrument will be calibrated utilizing analyses of common samples against a demonstration-model (DM) instrument and CheMin-like laboratory instruments. The samples include phyllosilicate and sulfate minerals that are expected at Gale crater on the basis of remote sensing observations.

  15. 10 CFR 35.2432 - Records of calibration measurements of brachytherapy sources.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Records of calibration measurements of brachytherapy sources. 35.2432 Section 35.2432 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL... manufacturer's name, model number, and serial number for the source and the instruments used to calibrate...

  16. 10 CFR 35.2432 - Records of calibration measurements of brachytherapy sources.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Records of calibration measurements of brachytherapy sources. 35.2432 Section 35.2432 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL... last use of the source. (b) The record must include— (1) The date of the calibration; (2)...

  17. Ultra-Compact Imaging Spectrometer (UCIS) for In-Situ Planetary Mineralogy: Laboratory and Field Calibration

    NASA Technical Reports Server (NTRS)

    Van Gorp, Byron; Mouroulis, Pantazis; Green, Robert O.; Rodriguez, Jose I.; Blaney, Diana; Wilson, Daniel W.; Sellar, R. Glenn; Richardson, Brandon S.

    2012-01-01

    The Ultra-Compact Imaging Spectrometer (UCIS) is a miniature telescope and spectrometer system intended for mapping terrain mineralogy over distances from 1.5 m to infinity with spatial sampling of 1.35 mrad over a 33 deg field, and spectral sampling of 10 nm in the 600-2500 nm range. The core of the system has been designed for operation in a Martian environment, but can also be used in a terrestrial environment when placed inside a vacuum vessel. We report the laboratory and field calibration data that include spatial and spectral calibration, and demonstrate the use of the system.

  18. 10 CFR 70.19 - General license for calibration or reference sources.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... section, plutonium in the form of calibration or reference sources: (1) Any person in a non-agreement... plutonium in such sources; (2) Shall not receive, possess, use or transfer such source unless the source, or... regulatory authority. Do not remove this label. caution—radioactive material—this source contains...

  19. 10 CFR 70.19 - General license for calibration or reference sources.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... section, plutonium in the form of calibration or reference sources: (1) Any person in a non-agreement... plutonium in such sources; (2) Shall not receive, possess, use or transfer such source unless the source, or... regulatory authority. Do not remove this label. caution—radioactive material—this source contains...

  20. 10 CFR 70.19 - General license for calibration or reference sources.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... section, plutonium in the form of calibration or reference sources: (1) Any person in a non-agreement... plutonium in such sources; (2) Shall not receive, possess, use or transfer such source unless the source, or... regulatory authority. Do not remove this label. caution—radioactive material—this source contains...

  1. 10 CFR 70.19 - General license for calibration or reference sources.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... section, plutonium in the form of calibration or reference sources: (1) Any person in a non-agreement... plutonium in such sources; (2) Shall not receive, possess, use or transfer such source unless the source, or... regulatory authority. Do not remove this label. caution—radioactive material—this source contains...

  2. 10 CFR 70.19 - General license for calibration or reference sources.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... section, plutonium in the form of calibration or reference sources: (1) Any person in a non-agreement... plutonium in such sources; (2) Shall not receive, possess, use or transfer such source unless the source, or... regulatory authority. Do not remove this label. caution—radioactive material—this source contains...

  3. A new facility for the synchrotron radiation-based calibration of transfer radiation sources in the ultraviolet and vacuum ultraviolet spectral range

    SciTech Connect

    Thornagel, Reiner; Fliegauf, Rolf; Klein, Roman Kroth, Simone; Paustian, Wolfgang; Richter, Mathias

    2015-01-15

    The Physikalisch-Technische Bundesanstalt (PTB) has a long tradition in the calibration of radiation sources in the ultraviolet and vacuum ultraviolet spectral range, with traceability to calculable synchrotron radiation. Within this context, new instrumentation in the PTB laboratory at the Metrology Light Source (MLS) has been put into operation that opens up extended and improved calibration possibilities. A new facility for radiation source calibrations has been set up in the spectral range from 7 nm to 400 nm based on a combined normal incidence-grazing incidence monochromator. The facility can be used for the calibration of transfer sources in terms of spectral radiant intensity or mean spectral radiance, with traceability to the MLS primary source standard. We describe the design and performance of the experimental station and give examples of some commissioning results.

  4. Phased Array Radiometer Calibration Using a Radiated Noise Source

    NASA Technical Reports Server (NTRS)

    Srinivasan, Karthik; Limaye, Ashutoch S.; Laymon, Charles A.; Meyer, Paul J.

    2010-01-01

    Electronic beam steering capability of phased array antenna systems offer significant advantages when used in real aperture imaging radiometers. The sensitivity of such systems is limited by the ability to accurately calibrate variations in the antenna circuit characteristics. Passive antenna systems, which require mechanical rotation to scan the beam, have stable characteristics and the noise figure of the antenna can be characterized with knowledge of its physical temperature [1],[2]. Phased array antenna systems provide the ability to electronically steer the beam in any desired direction. Such antennas make use of active components (amplifiers, phase shifters) to provide electronic scanning capability while maintaining a low antenna noise figure. The gain fluctuations in the active components can be significant, resulting in substantial calibration difficulties [3]. In this paper, we introduce two novel calibration techniques that provide an end-to-end calibration of a real-aperture, phased array radiometer system. Empirical data will be shown to illustrate the performance of both methods.

  5. A database of phase calibration sources and their radio spectra for the Giant Metrewave Radio Telescope

    NASA Astrophysics Data System (ADS)

    Lal, Dharam V.; Dubal, Shilpa S.; Sherkar, Sachin S.

    2016-12-01

    We are pursuing a project to build a database of phase calibration sources suitable for Giant Metrewave Radio Telescope (GMRT). Here we present the first release of 45 low frequency calibration sources at 235 MHz and 610 MHz. These calibration sources are broadly divided into quasars, radio galaxies and unidentified sources. We provide their flux densities, models for calibration sources, ( u, v) plots, final deconvolved restored maps and clean-component lists/files for use in the Astronomical Image Processing System ( aips) and the Common Astronomy Software Applications ( casa). We also assign a quality factor to each of the calibration sources. These data products are made available online through the GMRT observatory website. In addition we find that (i) these 45 low frequency calibration sources are uniformly distributed in the sky and future efforts to increase the size of the database should populate the sky further, (ii) spectra of these calibration sources are about equally divided between straight, curved and complex shapes, (iii) quasars tend to exhibit flatter radio spectra as compared to the radio galaxies or the unidentified sources, (iv) quasars are also known to be radio variable and hence possibly show complex spectra more frequently, and (v) radio galaxies tend to have steeper spectra, which are possibly due to the large redshifts of distant galaxies causing the shift of spectrum to lower frequencies.

  6. Investigation of Phototriangulation Accuracy with Using of Various Techniques Laboratory and Field Calibration

    NASA Astrophysics Data System (ADS)

    Chibunichev, A. G.; Kurkov, V. M.; Smirnov, A. V.; Govorov, A. V.; Mikhalin, V. A.

    2016-10-01

    Nowadays, aerial survey technology using aerial systems based on unmanned aerial vehicles (UAVs) becomes more popular. UAVs physically can not carry professional aerocameras. Consumer digital cameras are used instead. Such cameras usually have rolling, lamellar or global shutter. Quite often manufacturers and users of such aerial systems do not use camera calibration. In this case self-calibration techniques are used. However such approach is not confirmed by extensive theoretical and practical research. In this paper we compare results of phototriangulation based on laboratory, test-field or self-calibration. For investigations we use Zaoksky test area as an experimental field provided dense network of target and natural control points. Racurs PHOTOMOD and Agisoft PhotoScan software were used in evaluation. The results of investigations, conclusions and practical recommendations are presented in this article.

  7. Calibration of a laboratory spectrophotometer for specular light by means of stacked glass plates.

    NASA Technical Reports Server (NTRS)

    Allen, W. A.; Richardson, A. J.

    1971-01-01

    Stacked glass plates have been used to calibrate a laboratory spectrophotometer, over the spectral range 0.5-2.5 microns, for specular light. The uncalibrated instrument was characterized by systematic errors when used to measure the reflectance and transmittance of stacked glass plates. Calibration included first, a determination of the reflectance of a standard composed of barium sulfate paint deposited on an aluminum plate; second, the approximation of the reflectance and transmittance residuals between observed and computed values by means of cubic equations; and, finally, the removal of the systematic errors by a computer. The instrument, after calibration, was accurate to 1% when used to measure the reflectance and transmittance of stacked glass plates.

  8. Comparison of CNES spherical and NASA hemispherical large aperture integrating sources. I - Using a laboratory transfer spectroradiometer. II - Using the SPOT-2 satellite instruments

    NASA Technical Reports Server (NTRS)

    Guenther, B.; Mclean, J.; Leroy, M.; Henry, P.

    1990-01-01

    CNES spherical and NASA hemispherical large aperture calibration sources are examined using a laboratory transfer spectroradiometer and SPOT-2 instruments. The sources, collected at Matra in France during October 1987, are compared in terms of absolute calibration, linearity, and uniformity. The laboratory transfer spectroradiometer data reveal that the calibration results correspond to within about 7 percent absolute accuracy level and the linearity of the CNES source with lamp level is good. It is observed using the satellite data that both sources have an excellent uniformity over a 4 deg field of view.

  9. Power source evaluation capabilities at Sandia National Laboratories

    SciTech Connect

    Doughty, D.H.; Butler, P.C.

    1996-04-01

    Sandia National Laboratories maintains one of the most comprehensive power source characterization facilities in the U.S. National Laboratory system. This paper describes the capabilities for evaluation of fuel cell technologies. The facility has a rechargeable battery test laboratory and a test area for performing nondestructive and functional computer-controlled testing of cells and batteries.

  10. FOUR PI CALIBRATION AND MODELING OF A BARE GERMANIUM DETECTOR IN A CYLINDRICAL FIELD SOURCE

    SciTech Connect

    Dewberry, R.; Young, J.

    2011-04-29

    from an axially symmetric cylindrical shell. Subsequent to publication of 1, the theoretical treatment of the cylindrical shell and disk source acquisition sources was recognized by the Los Alamos National Laboratory as suitable for including in the Safeguards Training Program.8 Therefore, we felt it was important to accurately demonstrate the calculus describing the cylindrical shell configuration for the HpGe detector and to theoretically account for the observed bare-detector efficiencies measured in references (3-6). In this paper we demonstrate the applicability of the cylindrical shell derivation to a flexible planar sheet of known Am-241, Eu-152, and Cs-137 activity that we rolled into a symmetrical cylindrical shell of radioactivity. Using the geometry correction equation of reference 1, we calculate geometry correction values using the known detector and source dimensions combined with source to detector distances. We then compare measured detection efficiencies from a cylindrical shell of activity for the 185.7-keV photon (U-235) and for the 414.3-keV photon (Pu-239) with those determined for a 12-inch point source(2,7) to demonstrate agreement between experiment and the theoretically calculated values derived by the Savannah River National Laboratory (SRNL) authors of reference 1. We demonstrate this geometry correction first for the 185.7- and 414.3-keV {gamma}-rays. But because the detector was point source calibrated at 12 inches for the energy range (60 -1700) keV (using two distinct sources) to map its intrinsic efficiency, the geometry correction for any acquisition configuration holds for all photon energies.2 We demonstrate that for ten photon energies in the range 121 keV to 967 keV. The good agreement between experiment and calculation is demonstrated at five source to detector distances using the identical shielded HpGe detector of references 4-7 as well as with a separate HpGe detector. We then extend the measurement to include a single

  11. Heavy ion beams from an Alphatross source for use in calibration and testing of diagnostics

    NASA Astrophysics Data System (ADS)

    Ward, R. J.; Brown, G. M.; Ho, D.; Stockler, B. F. O. F.; Freeman, C. G.; Padalino, S. J.; Regan, S. P.

    2016-10-01

    Ion beams from the 1.7 MV Pelletron Accelerator at SUNY Geneseo have been used to test and calibrate many inertial confinement fusion (ICF) diagnostics and high energy density physics (HEDP) diagnostics used at the Laboratory for Laser Energetics (LLE). The ion source on this accelerator, a radio-frequency (RF) alkali-metal charge exchange source called an Alphatross, is designed to produce beams of hydrogen and helium isotopes. There is interest in accelerating beams of carbon, oxygen, argon, and other heavy ions for use in testing several diagnostics, including the Time Resolved Tandem Faraday Cup (TRTF). The feasibility of generating these heavy ion beams using the Alphatross source will be reported. Small amounts of various gases are mixed into the helium plasma in the ion source bottle. A velocity selector is used to allow the desired ions to pass into the accelerator. As the heavy ions pass through the stripper canal of the accelerator, they emerge in a variety of charge states. The energy of the ion beam at the high-energy end of the accelerator will vary as a function of the charge state, however the maximum energy deliverable to target is limited by the maximum achievable magnetic field produced by the accelerator's steering magnet. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  12. Source-based calibration of space instruments using calculable synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Klein, Roman; Fliegauf, Rolf; Kroth, Simone; Paustian, Wolfgang; Reichel, Thomas; Richter, Mathias; Thornagel, Reiner

    2016-10-01

    Physikalisch-Technische Bundesanstalt (PTB) has more than 20 years of experience in the calibration of space-based instruments using synchrotron radiation to cover the ultraviolet (UV), vacuum UV (VUV), and x-ray spectral range. Over the past decades, PTB has performed calibrations for numerous space missions within scientific collaborations and has become an important partner for activities in this field. New instrumentation at the electron storage ring, metrology light source, creates additional calibration possibilities within this framework. A new facility for the calibration of radiation transfer source standards with a considerably extended spectral range has been put into operation. The commissioning of a large vacuum vessel that can accommodate entire space instruments opens up new prospects. Finally, an existing VUV transfer calibration source was upgraded to increase the spectral range coverage to a band from 15 to 350 nm.

  13. Air kerma standard for calibration of well-type chambers in Brazil using {sup 192}Ir HDR sources and its traceability

    SciTech Connect

    Di Prinzio, Renato; Almeida, Carlos Eduardo de

    2009-03-15

    In Brazil there are over 100 high dose rate (HDR) brachytherapy facilities using well-type chambers for the determination of the air kerma rate of {sup 192}Ir sources. This paper presents the methodology developed and extensively tested by the Laboratorio de Ciencias Radiologicas (LCR) and presently in use to calibrate those types of chambers. The system was initially used to calibrate six well-type chambers of brachytherapy services, and the maximum deviation of only 1.0% was observed between the calibration coefficients obtained and the ones in the calibration certificate provided by the UWADCL. In addition to its traceability to the Brazilian National Standards, the whole system was taken to University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL) for a direct comparison and the same formalism to calculate the air kerma was used. The comparison results between the two laboratories show an agreement of 0.9% for the calibration coefficients. Three Brazilian well-type chambers were calibrated at the UWADCL, and by LCR, in Brazil, using the developed system and a clinical HDR machine. The results of the calibration of three well chambers have shown an agreement better than 1.0%. Uncertainty analyses involving the measurements made both at the UWADCL and LCR laboratories are discussed.

  14. A Portable Ultra-Stable Calibration Source for Precision RV Measurements in NIR

    NASA Astrophysics Data System (ADS)

    Wang, Ji; Ge, J.; Wan, X.; Delgado, A.; Jakeman, H.

    2011-09-01

    In the next decade, astronomers are aiming at reaching 0.1 m/s RV precision, which will enable discoveries of Earth-like planets around solar-type stars. However, the RV precision is currently limited by stellar activity, the stability and bandwidth of RV calibration sources. We proposed to use an ultra-stable monolithic Michelson interferometer as an RV calibration source. This monolithic interferometer source has several advantages over the conventional RV calibration sources: (1), it produces sinusoidal spectral features which can be easily processed, unlike gas absorption cells or emission lamps, which spectral line distributions are extremely nonuniform; (2), it has a wide spectral coverage from visible to near infrared (NIR); (3), it is designed to be thermal-stable (thermally compensated) so that the thermal induced RV drift is very small; (4), it is also field compensated to ensure a high optical efficiency so that a spatially incoherent continuum light source is suitable for producing bright calibration light (unlike the faint ThAr emission lamp); (5). it is extremely compact ( 10x10x10 cm3) and low cost compared to the bulky (more than 1x1x1 m3) and extremely high cost laser frequency combs. With the help of the proposed RV calibration source, the search of exoplanets around M dwarfs or even L, T dwarfs can be extended to the NIR band. The predicted sub m/s RV calibration precision will enable the discovery of Earth-like planets in the habitable zone around M dwarfs. The proposed calibration source may be quite useful for calibrating future space instruments for possible space RV exoplanet searches in the IR region where RV measurements are free of contamination of the Earth's telluric lines, which is a serious issue for ground-based IR RV observations. We will present our latest results of the calibration source on its application for both Echelle spectrograph and the instrument adopting DFDI method.

  15. Radio Astronomical Polarimetry and Point-Source Calibration

    NASA Astrophysics Data System (ADS)

    van Straten, W.

    2004-05-01

    A mathematical framework is presented for use in the experimental determination of the polarimetric response of observatory instrumentation. Elementary principles of linear algebra are applied to model the full matrix description of the polarization measurement equation by least-squares estimation of nonlinear, scalar parameters. The formalism is applied to calibrate the center element of the Parkes Multibeam receiver using observations of the millisecond pulsar PSR J0437-4715 and the radio galaxy 3C 218 (Hydra A).

  16. Photovoltaic Calibrations at the National Renewable Energy Laboratory and Uncertainty Analysis Following the ISO 17025 Guidelines

    SciTech Connect

    Emery, Keith

    2016-09-01

    The measurement of photovoltaic (PV) performance with respect to reference conditions requires measuring current versus voltage for a given tabular reference spectrum, junction temperature, and total irradiance. This report presents the procedures implemented by the PV Cell and Module Performance Characterization Group at the National Renewable Energy Laboratory (NREL) to achieve the lowest practical uncertainty. A rigorous uncertainty analysis of these procedures is presented, which follows the International Organization for Standardization (ISO) Guide to the Expression of Uncertainty in Measurement. This uncertainty analysis is required for the team’s laboratory accreditation under ISO standard 17025, “General Requirements for the Competence of Testing and Calibration Laboratories.” The report also discusses additional areas where the uncertainty can be reduced.

  17. Laboratory robotics -- An automated tool for preparing ion chromatography calibration standards

    SciTech Connect

    Chadwick, J.L.

    1995-04-01

    This paper describes the use of a laboratory robot as an automated tool for preparing multi-level calibration standards for On-Line Ion Chromatography (IC) Systems. The robot is designed for preparation of up to six levels of standards, with each level containing up to eleven ionic species in aqueous solution. The robot is required to add the standards` constituents as both a liquid and solid additions and to keep a record of exactly what goes into making up every standard. Utilizing a laboratory robot to prepare calibration standards provides significant benefits to the testing environment. These benefits include: accurate and precise calibration standards in individually capped containers with preparation traceability; automated and unattended multi-specie preparation for both anion and cation analytical channels; the ability to free up a test operator from a repetitive routine and re-apply those efforts to test operations; The robot uses a single channel IC to analyze each prepared standard for specie content and concentration. Those results are later used as a measure of quality control. System requirements and configurations, robotic operations, manpower requirements, analytical verification, accuracy and precision of prepared solutions, and robotic downtime are discussed in detail.

  18. A Bayesian approach to calibrating apatite fission track annealing models for laboratory and geological timescales

    NASA Astrophysics Data System (ADS)

    Stephenson, John; Gallagher, Kerry; Holmes, Chris

    2006-10-01

    We present a new approach for modelling annealing of fission tracks in apatite, aiming to address various problems with existing models. We cast the model in a fully Bayesian context, which allows us explicitly to deal with data and parameter uncertainties and correlations, and also to deal with the predictive uncertainties. We focus on a well-known annealing algorithm [Laslett, G.M., Green, P.F., Duddy, I.R., Gleadow. A.J.W., 1987. Thermal annealing of fission tracks in apatite. 2. A quantitative-analysis. Chem. Geol., 65 (1), 1-13], and build a hierachical Bayesian model to incorporate both laboratory and geological timescale data as direct constraints. Relative to the original model calibration, we find a better (in terms of likelihood) model conditioned just on the reported laboratory data. We then include the uncertainty on the temperatures recorded during the laboratory annealing experiments. We again find a better model, but the predictive uncertainty when extrapolated to geological timescales is increased due to the uncertainty on the laboratory temperatures. Finally, we explictly include a data set [Vrolijk, P., Donelick, R.A., Quenq, J., Cloos. M., 1992. Testing models of fission track annealing in apatite in a simple thermal setting: site 800, leg 129. In: Larson, R., Lancelet, Y. (Eds.), Proceedings of the Ocean Drilling Program, Scientific Results, vol. 129, pp. 169-176] which provides low-temperature geological timescale constraints for the model calibration. When combined with the laboratory data, we find a model which satisfies both the low-temperature and high-temperature geological timescale benchmarks, although the fit to the original laboratory data is degraded. However, when extrapolated to geological timescales, this combined model significantly reduces the well-known rapid recent cooling artifact found in many published thermal models for geological samples.

  19. Toward Improvements in Inter-laboratory Calibration of Argon Isotope Measurements

    NASA Astrophysics Data System (ADS)

    Hemming, S. R.; Deino, A. L.; Heizler, M. T.; Hodges, K. V.; McIntosh, W. C.; Renne, P. R.; Swisher, C. C., III; Turrin, B. D.; Van Soest, M. C.

    2015-12-01

    It is important to continue to develop strategies to improve our ability to compare results between laboratories chronometers. The U-Pb community has significantly reduced inter-laboratory biases with the application of a community tracer solution and the distribution of synthetic zircon solutions. Inevitably sample selection and processing and even biases in interpretations will still lead to some disagreements in the assignment of ages. Accordingly natural samples that are shared will be important for achievement of the highest levels of agreement. Analogous improvements in quality and inter-laboratory agreement of analytical aspects of Ar-Ar can be achieved through development of synthetic age standards in gas canisters with multiple pipettes to deliver various controlled amounts of argon to the mass spectrometer. A preliminary proof-of concept comes from the inter-laboratory calibration experiment for the 40Ar/39Ar community. This portable Argon Pipette Intercalibration System (APIS) consists of three 2.7 L canisters each equipped with three pipettes of 0.1, 0.2 and 0.4 cc volumes. The currently traveling APIS has the three canisters filled with air and 40Ar*/39Ar of 1.73 and canister 2 has a 40Ar*/39Ar of 40.98 (~ Alder Creek and Fish Canyon in the same irradiation). With these pipettes it is possible to combine them to provide 0.1, 0.2, 0.3 (0.1+0.2), 0.4, 0.5 (0.1+0.4), 0.6 (0.2+0.4), and 0.7 (0.1+0.2+0.4) cc. The configuration allows a simple test for inter-laboratory biases and for volume/pressure dependent mass fractionation on the measured ratios for a gas with a single argon isotope composition. Although not yet tested, it is also possible to mix gas from any one of the three canisters in proportions of these increments, allowing even more tightly controlled calibration of measurements. We suggest that ultimately each EARTHTIME lab should be equipped with such a system permanently, with a community plan for a traveling system to periodically repeat the

  20. Ka-Band Monopulse Antenna Pointing Calibration Using Wideband Radio Sources

    NASA Astrophysics Data System (ADS)

    Buu, C.; Calvo, J.; Cheng, T.-H.; Vazquez, M.

    2010-08-01

    A new method of performing a system end-to-end monopulse antenna calibration using widely available wideband astronomical radio sources is presented as an alternative to the current method of using a spacecraft signal. Current monopulse calibration requires a spacecraft carrier signal to measure amplitude and phase differences in the monopulse feed and low-noise amplifiers (LNAs). The alternative method presented here will allow the ground station to perform monopulse calibrations during maintenance periods instead of spacecraft track time, and provide an end-to-end system check-out capability without requiring a spacecraft signal. In this article, we give an overview of the current calibration approach, describe a new method for calibrating with radio sources, and present results from field testing of this new method.

  1. The Laboratory Radiometric Calibration of the CCD Stereo Camera for the Optical Payload of the Lunar Explorer Project

    NASA Astrophysics Data System (ADS)

    Wang, Jue; Li, Chun-Lai; Zhao, Bao-Chang

    2007-03-01

    The system of the optical payload for the Lunar Explorer includes a CCD stereo camera and an imaging interferometer. The former is devised to get the solid images of the lunar surface with a laser altimeter. The camera working principle, calibration purpose, and content, nude chip detection, and the process of the relative and absolute calibration in the laboratory are introduced.

  2. Feasibility of calibrating elongated brachytherapy sources using a well-type ionization chamber

    SciTech Connect

    Meigooni, Ali S.; Awan, Shahid B.; Dou, Kai

    2006-11-15

    Recently, elongated brachytherapy sources (active length >1 cm) have become commercially available for interstitial prostate implants. These sources were introduced to improve the quality of brachytherapy procedures by eliminating the migration and seed bunching associated with loose seed-type implants. However, the inability to calibrate elongated brachytherapy sources with the Wide-Angle Free-Air Chamber (WAFAC) used by the National Institute of Standards and Technology (NIST) hinders the experimental determination of dosimetric parameters of these source types. In order to resolve this shortcoming, an interim solution has been introduced for calibration of elongated brachytherapy sources using a commercially available well-type ionization chamber. The feasibility of this procedure was examined by calibrating RadioCoil{sup Tm} {sup 103}Pd sources with active lengths ranging from 1 to 7 cm.

  3. On-sky calibration performance of a monolithic Michelson interferometer filtered source

    NASA Astrophysics Data System (ADS)

    Ge, Jian; Ma, Bo; Powell, Scott; Varosi, Frank; Schofield, Sidney; Grieves, Nolan; Liu, Jian

    2014-07-01

    In the new era of searching for Earth-like planets, new generation radial velocity (RV) high resolution spectrographs requires ~0.1 m/s Doppler calibration accuracy in the visible band and a similar calibration precision in the near infrared. The patented stable monolithic Michelson interferometer filtered source called the Sine source emerges as a very promising calibration device. This Sine source has the potential of covering the practical working wavelengths (~0.38- 2.5 μm) for Doppler measurements with high resolution optical and near infrared high resolution spectrographs at the ground-based telescopes. The single frame calibration precision can reach < 0.1 m/s for the state of the art spectrographs, and it can be easily designed to match the intrinsic sensitivities of future Doppler instruments. The Sine source also has the great practical advantages in compact (portable) size and low cost. Here we report early results from on-sky calibration of a Sine source measured with two state-of-the-art TOU optical high resolution spectrograph (R=100,000, 0.38-0.9 microns) and FIRST near infrared spectrograph (R=50,000, 0.8-1.8 microns) at a 2 meter robotic telescope at Fairborn Observatory in Arizona. The results with the TOU spectrograph monitoring over seven days show that the Sine source has produced ~3 times better calibration precision than the ThAr calibration (RMS = 2.7m/s vs. 7.4m/s) at 0.49-0.62 microns where calibration data have been processed by our preliminary data pipeline and ~1.4 times better than the iodine absorption spectra (RMS=3.6 m/s) at the same wavelength region. As both ThAr and Iodine have reached sub m/s calibration accuracy with existing Doppler instruments (such as HARPS and HIRES), it is likely that the sine source would provide similar improvement once a better data pipeline and an upgraded version of a Sine source are developed. It is totally possible to reach ~0.1 m/s in the optical wavelength region. In addition, this Sine source

  4. Radiometric absolute noise-temperature measurement system features improved accuracy and calibration ease

    NASA Technical Reports Server (NTRS)

    Brown, W.; Ewen, H.; Haroules, G.

    1970-01-01

    Radiometric receiver system, which measures noise temperatures in degrees Kelvin, does not require cryogenic noise sources for routine operation. It eliminates radiometer calibration errors associated with RF attenuation measurements. Calibrated noise source is required only for laboratory adjustment and calibration.

  5. Development of a low energy ion source for ROSINA ion mode calibration

    SciTech Connect

    Rubin, Martin; Altwegg, Kathrin; Jaeckel, Annette; Balsiger, Hans

    2006-10-15

    The European Rosetta mission on its way to comet 67P/Churyumov-Gerasimenko will remain for more than a year in the close vicinity (1 km) of the comet. The two ROSINA mass spectrometers on board Rosetta are designed to analyze the neutral and ionized volatile components of the cometary coma. However, the relative velocity between the comet and the spacecraft will be minimal and also the velocity of the outgassing particles is below 1 km/s. This combination leads to very low ion energies in the surrounding plasma of the comet, typically below 20 eV. Additionally, the spacecraft may charge up to a few volts in this environment. In order to simulate such plasma and to calibrate the mass spectrometers, a source for ions with very low energies had to be developed for the use in the laboratory together with the different gases expected at the comet. In this paper we present the design of this ion source and we discuss the physical parameters of the ion beam like sensitivity, energy distribution, and beam shape. Finally, we show the first ion measurements that have been performed together with one of the two mass spectrometers.

  6. Calibration of the NPL secondary standard radionuclide calibrator for 125I seeds used for prostate brachytherapy. National Physical Laboratory.

    PubMed

    Baker, M; Bass, G A; Woods, M J

    2002-01-01

    In the therapeutic use of radionuclides, by far the most rapid growth in recent years is that of 125I seeds used for the treatment of prostate cancer. Large numbers of these seeds are used in each treatment and there is a need for a simple but accurate means of confirming their dose rates. This mechanism requires a transfer device for which the calibration factors are traceable to national standards. The NPL secondary standard radionuclide calibrator, because of its guaranteed reproducibility and traceable calibration procedure, is ideally suited for this purpose. A series of characterisation measurements have been performed on the NPL radionuclide calibrator in order to estimate the uncertainty levels that can be achieved and these are presented together with the relevant calibration factors for some typical seeds.

  7. Photometric Calibration of an EUV Flat Field Spectrometer at the Advanced Light Source

    SciTech Connect

    May, M; Lepson, J; Beiersdorfer, P; Thorn, D; Chen, H; Hey, D; Smith, A

    2002-07-03

    The photometric calibration of ail extreme ultraviolet flat field spectrometer has been done at the Advanced Light Source at LBNL. This spectrometer is used to record spectrum for atomic physics research from highly charged ions in plasmas created in the Livermore electron beam ion traps EBIT-I and SUPEREBIT. Two calibrations were done each with a different gold-coated grating, a 1200 {ell}/mm and a 2400 {ell}/mm, that covered 75-300{angstrom} and 15-160{angstrom}, respectively. The detector for this calibration was a back thinned CCD. The relative calibration was determined for several different incident angles for both gratings. Within the scatter of the data, the calibration was roughly insensitive to the incidence angle for the range of angles investigated.

  8. 10 CFR 31.8 - Americium-241 and radium-226 in the form of calibration or reference sources.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Americium-241 and radium-226 in the form of calibration or... BYPRODUCT MATERIAL § 31.8 Americium-241 and radium-226 in the form of calibration or reference sources. (a..., americium-241 or radium-226 in the form of calibration or reference sources: (1) Any person in a...

  9. 10 CFR 31.8 - Americium-241 and radium-226 in the form of calibration or reference sources.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Americium-241 and radium-226 in the form of calibration or... BYPRODUCT MATERIAL § 31.8 Americium-241 and radium-226 in the form of calibration or reference sources. (a..., americium-241 or radium-226 in the form of calibration or reference sources: (1) Any person in a...

  10. 10 CFR 31.8 - Americium-241 and radium-226 in the form of calibration or reference sources.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Americium-241 and radium-226 in the form of calibration or... BYPRODUCT MATERIAL § 31.8 Americium-241 and radium-226 in the form of calibration or reference sources. (a..., americium-241 or radium-226 in the form of calibration or reference sources: (1) Any person in a...

  11. 10 CFR 31.8 - Americium-241 and radium-226 in the form of calibration or reference sources.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Americium-241 and radium-226 in the form of calibration or... BYPRODUCT MATERIAL § 31.8 Americium-241 and radium-226 in the form of calibration or reference sources. (a..., americium-241 or radium-226 in the form of calibration or reference sources: (1) Any person in a...

  12. 10 CFR 31.8 - Americium-241 and radium-226 in the form of calibration or reference sources.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Americium-241 and radium-226 in the form of calibration or... BYPRODUCT MATERIAL § 31.8 Americium-241 and radium-226 in the form of calibration or reference sources. (a..., americium-241 or radium-226 in the form of calibration or reference sources: (1) Any person in a...

  13. Isotherm Sensor Calibration Program for Mars Science Laboratory Heat Shield Flight Data Analysis

    NASA Technical Reports Server (NTRS)

    Santos, Jose A.; Oishi, Tomo; Martinez, Ed R.

    2011-01-01

    Seven instrumented sensor plugs were installed on the Mars Science Laboratory heat shield in December 2008 as part of the Mars Science Laboratory Entry, Descent, and Landing Instrumentation (MEDLI) project. These sensor plugs contain four in-depth thermocouples and one Hollow aErothermal Ablation and Temperature (HEAT) sensor. The HEAT sensor follows the time progression of a 700 C isotherm through the thickness of a thermal protection system (TPS) material. The data can be used to infer char depth and, when analyzed in conjunction with the thermocouple data, the thermal gradient through the TPS material can also be determined. However, the uncertainty on the isotherm value is not well defined. To address this uncertainty, a team at NASA Ames Research Center is carrying out a HEAT sensor calibration test program. The scope of this test program is described, and initial results from experiments conducted in the laboratory to study the isotherm temperature of the HEAT sensor are presented. Data from the laboratory tests indicate an isotherm temperature of 720 C 60 C. An overview of near term arc jet testing is also given, including preliminary data from 30.48cm 30.48cm PICA panels instrumented with two MEDLI sensor plugs and tested in the NASA Ames Panel Test Facility. Forward work includes analysis of the arc jet test data, including an evaluation of the isotherm value based on the instant in time when it reaches a thermocouple depth.

  14. Progress in photovoltaic module calibration: results of a worldwide intercomparison between four reference laboratories

    NASA Astrophysics Data System (ADS)

    Dirnberger, D.; Kräling, U.; Müllejans, H.; Salis, E.; Emery, K.; Hishikawa, Y.; Kiefer, K.

    2014-10-01

    Measurement results from a worldwide intercomparison of photovoltaic module calibrations are presented. Four photovoltaic reference laboratories in the USA, Japan and Europe with different traceability chains, measurement equipment and procedures, and uncertainty estimation concepts, participated. Seven photovoltaic modules of different technologies were measured (standard and high-efficiency crystalline silicon, cadmium telluride, single and double-junction amorphous and micromorph silicon). The measurement results from all laboratories and for all devices agreed well. Maximum power for the crystalline silicon samples was within ±1.3% for all thin-film modules roughly within ±3%, which is an improvement compared to past intercomparisons. The agreement between the results was evaluated using a weighted mean as a reference value, which considers results-specific uncertainty, instead of the widely used unweighted arithmetic mean. A further statistical analysis of all deviations between results and the corresponding reference mean showed that the uncertainties estimated by the participating laboratories were realistic, with a slight tendency towards being too conservative. The observed deviations of results from the reference mean concerned mainly short-circuit current and fill factor. Module stability was monitored through repeated measurements at Fraunhofer ISE before and after measurements at each of the other participating laboratories. Based on these re-measurements, stability problems that occurred for some thin-film modules and influenced the results were analyzed and explained in detail.

  15. High-Precision Calibration of Electron Beam Energy from the Hefei Light Source Using Spin Resonant Depolarization

    NASA Astrophysics Data System (ADS)

    Lan, Jie-Qin; Xu, Hong-Liang

    2014-12-01

    The electron beam energy at the Hefei Light Source (HLS) in the National Synchrotron Radiation Laboratory is highly precisely calibrated by using the method of spin resonant depolarization for the first time. The spin tune and the beam energy are determined by sweeping the frequency of a radial rf stripline oscillating magnetic field to artificially excite a spin resonance and depolarize the beam. The resonance signal is recognized by observing the sudden change of the Touschek loss counting rate of the beam. The possible systematic errors of the experiment are presented and the accuracy of the calibrated energy is shown to be about 10-4. A series of measurements show that the energy stability of the machine is of the order of 9 × 10-3.

  16. SOLAR/SOLSPEC: Scientific Objectives, Instrument Performance and Its Absolute Calibration Using a Blackbody as Primary Standard Source

    NASA Astrophysics Data System (ADS)

    Thuillier, G.; Foujols, T.; Bolsée, D.; Gillotay, D.; Hersé, M.; Peetermans, W.; Decuyper, W.; Mandel, H.; Sperfeld, P.; Pape, S.; Taubert, D. R.; Hartmann, J.

    2009-06-01

    SOLAR is a set of three solar instruments measuring the total and spectral absolute irradiance from 16 nm to 3080 nm for solar, atmospheric and climatology physics. It is an external payload for the COLUMBUS laboratory launched on 7 February 2008. The mission’s primary objective is the measurement of the solar irradiance with the highest possible accuracy, and its variability using the following instruments: SOL-ACES (SOLar Auto-Calibrating EUV/UV Spectrophotometers) consists of four grazing incidence planar gratings measuring from 16 nm to 220 nm; SOLSPEC (SOLar SPECtrum) consists of three double gratings spectrometers, covering the range 165 nm to 3080 nm; and SOVIM (SOlar Variability Irradiance Monitor) is combining two types of absolute radiometers and three-channel filter - radiometers. SOLSPEC and SOL-ACES have been calibrated by primary standard radiation sources of the Physikalisch-Technische Bundesanstalt (PTB). Below we describe SOLSPEC, and its performance.

  17. Calibration of time of flight detectors using laser-driven neutron source

    SciTech Connect

    Mirfayzi, S. R.; Kar, S. Ahmed, H.; Green, A.; Alejo, A.; Jung, D.; Krygier, A. G.; Freeman, R. R.; Clarke, R.; Fuchs, J.; Vassura, L.; Kleinschmidt, A.; Roth, M.; Morrison, J. T.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Oliver, M.; Zepf, M.; Borghesi, M.

    2015-07-15

    Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

  18. Calibration of time of flight detectors using laser-driven neutron source

    NASA Astrophysics Data System (ADS)

    Mirfayzi, S. R.; Kar, S.; Ahmed, H.; Krygier, A. G.; Green, A.; Alejo, A.; Clarke, R.; Freeman, R. R.; Fuchs, J.; Jung, D.; Kleinschmidt, A.; Morrison, J. T.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Oliver, M.; Roth, M.; Vassura, L.; Zepf, M.; Borghesi, M.

    2015-07-01

    Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

  19. The biochemical estimation of age in Euphausiids: Laboratory calibration and field comparisons

    NASA Astrophysics Data System (ADS)

    Harvey, H. R.; Ju, Se-J.; Son, S.-K.; Feinberg, L. R.; Shaw, C. T.; Peterson, W. T.

    2010-04-01

    Euphausiids play a key role in many marine ecosystems as a link between primary producers and top predators. Understanding their demographic (i.e. age) structure is an essential tool to assess growth and recruitment as well as to determine how changes in environmental conditions might alter their condition and distribution. Age determination of crustaceans cannot be accomplished using traditional approaches, and here we evaluate the potential for biochemical products of tissue metabolism (termed lipofuscins) to determine the demographic structure of euphausiids in field collections . Lipofuscin was extracted from krill neural tissues (eye and eye-stalk), quantified using fluorescent intensity and normalized to tissue protein content to allow comparisons across animal sizes. Multiple fluorescent components from krill were observed, with the major product having a maximum fluorescence at excitation of 355 nm and emission of 510 nm. Needed age calibration of lipofuscin accumulation in Euphausia pacifica was accomplished using known-age individuals hatched and reared in the laboratory for over one year. Lipofuscin content extracted from neural tissues of laboratory-reared animals was highly correlated with the chronological age of animals ( r=0.87). Calibrated with laboratory lipofuscin accumulation rates, field-collected sub-adult and adult E. pacifica in the Northeast Pacific were estimated to be older than 100 days and younger than 1year. Comparative data for the Antarctic krill, E. superba showed much higher lipofuscin values suggesting a much longer lifespan than the more temperate species, E. pacifica. These regional comparisons suggest that biochemical indices allow a practical approach to estimate population age structure of diverse populations, and combined with other measurements can provide estimates of vital rates (i.e. longevity, mortality, growth) for krill populations in dynamic environments.

  20. Augmenting watershed model calibration with incorporation of ancillary data sources and qualitative soft data sources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Watershed simulation models can be calibrated using “hard data” such as temporal streamflow observations; however, users may find upon examination of detailed outputs that some of the calibrated models may not reflect summative actual watershed behavior. Thus, it is necessary to use “soft data” (i....

  1. Results from the intercalibration of optical low-light calibration sources 2011

    NASA Astrophysics Data System (ADS)

    Brändström, B. U. E.; Enell, C.-F.; Widell, O.; Hansson, T.; Whiter, D.; Mäkinen, S.; Mikhaylova, D.; Axelsson, K.; Sigernes, F.; Gulbrandsen, N.; Schlatter, N. M.; Gjendem, A. G.; Cai, L.; Reistad, J. P.; Daae, M.; Demissie, T. D.; Andalsvik, Y. L.; Roberts, O.; Poluyanov, S.; Chernouss, S.

    2011-12-01

    Following the 38th Annual Meeting on Atmospheric studies by Optical methods at Siuntio in Finland, an intercalibration workshop for optical low-light calibration sources was held in Sodankylä, Finland. The main purpose of this workshop was to provide a comparable scale for absolute measurements of aurora and airglow. All sources brought to the intercalibration workshop were compared to an international standard source (Fritz-Peak) using the Lindau Calibration Photometer built by Wilhelm Barke and Hans Lauche in 1984. The international standard source is on loan from Michael Gadsden, Aberdeen. The results were compared to several earlier intercalibration workshops. It was found that most sources were fairly stable over time with errors in the range of 5-20%. To further validate the results, two sources were also intercalibrated at UNIS, Longyearbyen, Svalbard. Preliminary analysis indicate good agreement with the intercalibration in Sodankylä.

  2. Metrology laboratory requirements for third-generation synchrotron radiation sources

    SciTech Connect

    Takacs, P.Z.; Quian, Shinan

    1997-11-01

    New third-generation synchrotron radiation sources that are now, or will soon, come on line will need to decide how to handle the testing of optical components delivered for use in their beam lines. In many cases it is desirable to establish an in-house metrology laboratory to do the work. We review the history behind the formation of the Optical Metrology Laboratory at Brookhaven National Laboratory and the rationale for its continued existence. We offer suggestions to those who may be contemplating setting up similar facilities, based on our experiences over the past two decades.

  3. A Volt Second Source for Calibration of Integrator in a Pulsed Field Magnetometer

    NASA Astrophysics Data System (ADS)

    Lin, An-Li; He, Jian; Zhang, Yue; John, Dudding; Michael, Hall

    2007-11-01

    A volt-second (Vs) source intended for absolutely calibrating the integrator in a pulsed field magnetometer (PFM) is designed and proven to be with accurate rising and falling edges and reasonable lower uncertainty. A comparison experiment shows that the difference between the magnetic fluxes generated respectively by the Vs source and the mutual inductor is within ±0.04%. The PFM is then calibrated in an absolute way of the Vs source. The calibrated PFM gives the measured results in good agreement with a static BH tracer supplied by National Institute of Metrology of China and provides a convenient way of studying the effect of mathematic process on the dynamic measuring curve of PFMs.

  4. Wideband spherically focused PVDF acoustic sources for calibration of ultrasound hydrophone probes.

    PubMed

    Selfridge, A; Lewin, P A

    2000-01-01

    Several broadband sources have been developed for the purpose of calibrating hydrophones. The specific configuration described is intended for the calibration of hydrophones In a frequency range of 1 to 40 MHz. All devices used 25 /spl mu/m film of PVDF bonded to a matched backing. Two had radii of curvatures (ROC) of 25.4 and 127 mm with f numbers of 3.8 and 19, respectively. Their active element diameter was 0.28 in (6.60 mm). The active diameter of the third source used was 25 mm, and it had an ROC of 254 mm and an f number of 10. The use of a focused element minimized frequency-dependent diffraction effects, resulting in a smooth variation of acoustic pressure at the focus from 1 to 40 MHz. Also, using a focused PVDF source permitted calibrations above 20 MHz without resorting to harmonic generation via nonlinear propagation.

  5. Point-source calibration of a segmented gamma-ray scanner

    SciTech Connect

    Sheppard, G.A.; Piquette, E.C.

    1994-08-01

    For a conventional segmented gamma-ray scanner (SGS) in which the sample is rotated continuously within a fixed detector field of view, the data will not support alternatives to the assumption that the gamma-emitting nuclides and the matrix in which they reside are uniformly distributed. This homogeneity assumption permits the geometry of samples and calibration standards to be approximated by that of a non attenuating line source on the axis of rotation. Other common SGS assumptions are that the detector is perfectly collimated, that its response is flat over its field of view, and that it can be approximated adequately by a line. All of these assumption have led to a preference for homogeneous calibration standards. Preparation and certification of such calibration standards are usually difficult and expensive. Storage and transportation of SGS standards can be inconvenient or even quite troublesome. The authors have proposed and tested an alternative method of SGS calibration that only requires a point-source standard. The proposed technique relies on the empirical determination of a normalized two-dimensional detector response and the measurement of the count rate from a point-source standard located at the response apex. With these data, the system`s response to a distributed, homogeneous samples can be predicted using numerical integration. Typical biases measured using a commercially available SGS calibrated with a point source have been less than 2%.

  6. Characteristics of Cometary Dust Tracks in Stardust Aerogel and Laboratory Calibrations

    NASA Technical Reports Server (NTRS)

    Burchell, M. J.; Fairey, S. A. J.; Wozniakiewicz, P.; Brownlee, D. E.; Hoerz, F.; Kearsley, A. T.; See, T. H.; Tsou, P.; Westphal, A.; Green, S. F.; Trigo-Rodriguez, J. M.; Dominguez, G.

    2007-01-01

    The cometary tray of the NASA Stardust spacecraft s aerogel collector has been examined to study the dust that was captured during the 2004 fly by of comet 81P/Wild-2. An optical scan of the entire collector surface revealed 256 impact features in the aerogel (width > 100 microns). 20 aerogel blocks (out of a total of 132) were removed from the collector tray for a higher resolution optical scan and 186 tracks were observed (track length > 50 microns and width > 8 microns). The impact features were classified into three types based on their morphology. Laboratory calibrations were conducted which reproduce all three types. This work suggests that the cometary dust consisted of some cohesive, relatively strong particles as well as particles with a more friable or low cohesion matrix containing smaller strong grains. The calibrations also permitted a particle size distribution to be estimated for the cometary dust. We estimate that approximately 1200 particles bigger than 1 micron struck the aerogel. The cumulative size distribution of the captured particles was obtained and compared with observations made by active dust detectors during the encounter. At large sizes (>20 microns) all measures of the dust are compatible, but at micrometer scales and smaller discrepancies exist between the various measurement systems which may reflect structure in the dust flux (streams, clusters etc.) along with some possible instrument effects.

  7. An automated calibration laboratory for flight research instrumentation: Requirements and a proposed design approach

    NASA Technical Reports Server (NTRS)

    Oneill-Rood, Nora; Glover, Richard D.

    1990-01-01

    NASA's Dryden Flight Research Facility (Ames-Dryden), operates a diverse fleet of research aircraft which are heavily instrumented to provide both real time data for in-flight monitoring and recorded data for postflight analysis. Ames-Dryden's existing automated calibration (AUTOCAL) laboratory is a computerized facility which tests aircraft sensors to certify accuracy for anticipated harsh flight environments. Recently, a major AUTOCAL lab upgrade was initiated; the goal of this modernization is to enhance productivity and improve configuration management for both software and test data. The new system will have multiple testing stations employing distributed processing linked by a local area network to a centralized database. The baseline requirements for the new AUTOCAL lab and the design approach being taken for its mechanization are described.

  8. Open Source Software Licenses for Livermore National Laboratory

    SciTech Connect

    Busby, L.

    2000-08-10

    This paper attempts to develop supporting material in an effort to provide new options for licensing Laboratory-created software. Where employees and the Lab wish to release software codes as so-called ''Open Source'', they need, at a minimum, new licensing language for their released products. Several open source software licenses are reviewed to understand their common elements, and develop recommendations regarding new language.

  9. Behaviour of mudflows realized in a laboratory apparatus and relative numerical calibration

    NASA Astrophysics Data System (ADS)

    Brezzi, Lorenzo; Gabrieli, Fabio; Kaitna, Roland; Cola, Simonetta

    2016-04-01

    Nowadays, numerical simulations are indispensable allies for the researchers to reproduce phenomena such as earth-flows, debris-flows and mudflows. One of the most difficult and problematic phases is about the choice and the calibration of the parameters to be included in the model at the real scale. Surely, it can be useful to start from laboratory experiment that simplify as much as possible the case study with the aim of reducing uncertainties related to the trigger and the propagation of a real flow. In this way, geometry of the problem, identification of the triggering mass, are well known and constrained in the experimental tests as in the numerical simulations and the focus of the study may be moved to the material parameters. This article wants to analyze the behavior of different mixtures of water and kaolin, which flow in a laboratory channel. A 10 dm3 prismatic container that discharges the material into a channel 2m long and 0.16 m wide composes the simple experimental apparatus. The chute base was roughened by glued sand and inclined with a 21° angle. Initially, we evaluated the lengths of run-out, the spread and shape of the deposit for five different mixtures. A huge quantity of information were obtained by 3 laser sensors attached to the channel and by photogrammetry, that gives out a 3D model of the deposit shape at the end of the flow. Subsequently, we reproduced these physical phenomena by using the numerical model Geoflow-SPH (Pastor et al., 2008; 2014) , governed by a Bingham rheological law (O'Brien & Julien, 1988), and we calibrated the different tests by back-analysis to assess optimum parameters. The final goal was the comprehension of the relationship that characterizes the parameters with the variation of the kaolin content in the mixtures.

  10. Results from the intercalibration of optical low light calibration sources 2011

    NASA Astrophysics Data System (ADS)

    Brändström, B. U. E.; Enell, C.-F.; Widell, O.; Hansson, T.; Whiter, D.; Mäkinen, S.; Mikhaylova, D.; Axelsson, K.; Sigernes, F.; Gulbrandsen, N.; Schlatter, N. M.; Gjendem, A. G.; Cai, L.; Reistad, J. P.; Daae, M.; Demissie, T. D.; Andalsvik, Y. L.; Roberts, O.; Poluyanov, S.; Chernouss, S.

    2012-05-01

    Following the 38th Annual European Meeting on Atmospheric Studies by Optical Methods in Siuntio in Finland, an intercalibration workshop for optical low light calibration sources was held in Sodankylä, Finland. The main purpose of this workshop was to provide a comparable scale for absolute measurements of aurora and airglow. All sources brought to the intercalibration workshop were compared to the Fritz Peak reference source using the Lindau Calibration Photometer built by Wilhelm Barke and Hans Lauche in 1984. The results were compared to several earlier intercalibration workshops. It was found that most sources were fairly stable over time, with errors in the range of 5-25%. To further validate the results, two sources were also intercalibrated at UNIS, Longyearbyen, Svalbard. Preliminary analysis indicates agreement with the intercalibration in Sodankylä within about 15-25%.

  11. Spectral phase-based automatic calibration scheme for swept source-based optical coherence tomography systems

    NASA Astrophysics Data System (ADS)

    Ratheesh, K. M.; Seah, L. K.; Murukeshan, V. M.

    2016-11-01

    The automatic calibration in Fourier-domain optical coherence tomography (FD-OCT) systems allows for high resolution imaging with precise depth ranging functionality in many complex imaging scenarios, such as microsurgery. However, the accuracy and speed of the existing automatic schemes are limited due to the functional approximations and iterative operations used in their procedures. In this paper, we present a new real-time automatic calibration scheme for swept source-based optical coherence tomography (SS-OCT) systems. The proposed automatic calibration can be performed during scanning operation and does not require an auxiliary interferometer for calibration signal generation and an additional channel for its acquisition. The proposed method makes use of the spectral component corresponding to the sample surface reflection as the calibration signal. The spectral phase function representing the non-linear sweeping characteristic of the frequency-swept laser source is determined from the calibration signal. The phase linearization with improved accuracy is achieved by normalization and rescaling of the obtained phase function. The fractional-time indices corresponding to the equidistantly spaced phase intervals are estimated directly from the resampling function and are used to resample the OCT signals. The proposed approach allows for precise calibration irrespective of the path length variation induced by the non-planar topography of the sample or galvo scanning. The conceived idea was illustrated using an in-house-developed SS-OCT system by considering the specular reflection from a mirror and other test samples. It was shown that the proposed method provides high-performance calibration in terms of axial resolution and sensitivity without increasing computational and hardware complexity.

  12. Fast calibration of SPECT monolithic scintillation detectors using un-collimated sources

    NASA Astrophysics Data System (ADS)

    España, Samuel; Deprez, Karel; Van Holen, Roel; Vandenberghe, Stefaan

    2013-07-01

    Monolithic scintillation detectors for positron emission tomography and single-photon emission computed tomography (SPECT) imaging have many advantages over pixelated detectors. The use of monolithic crystals allows for reducing the scintillator cost per unit volume and increasing the sensitivity along with the energy and timing resolution of the detector. In addition, on thick detectors the depth-of-interaction can be determined without additional hardware. However, costly and complex calibration procedures have been proposed to achieve optimal detector performance for monolithic detectors. This hampers their use in commercial systems. There is thus, a need for simple calibration routines that can be performed on assembled systems. The main goal of this work is to develop a simplified calibration procedure based on acquired training data. In comparison with other methods that use training data acquired with beam sources attached to robotic stages, the proposed method uses a static un-collimated activity source with simple geometry acquiring in a reasonable time. Once the data are acquired, the calibration of the detector is accomplished in three steps: energy calibration based on the k-means clustering method, self-organization based on the self-organizing maps algorithm, and distortion correction based on the Monge-Kantorovich grid adaptation. The proposed calibration method was validated for 2D positioning using a SPECT detector. Similar results were obtained by comparison with an existing calibration method (maximum likelihood estimation). In conclusion, we proposed a novel calibration method for monolithic scintillation detectors that greatly simplifies their use with optimal performance in SPECT systems.

  13. Suppression of fiber modal noise induced radial velocity errors for bright emission-line calibration sources

    SciTech Connect

    Mahadevan, Suvrath; Halverson, Samuel; Ramsey, Lawrence; Venditti, Nick

    2014-05-01

    Modal noise in optical fibers imposes limits on the signal-to-noise ratio (S/N) and velocity precision achievable with the next generation of astronomical spectrographs. This is an increasingly pressing problem for precision radial velocity spectrographs in the near-infrared (NIR) and optical that require both high stability of the observed line profiles and high S/N. Many of these spectrographs plan to use highly coherent emission-line calibration sources like laser frequency combs and Fabry-Perot etalons to achieve precision sufficient to detect terrestrial-mass planets. These high-precision calibration sources often use single-mode fibers or highly coherent sources. Coupling light from single-mode fibers to multi-mode fibers leads to only a very low number of modes being excited, thereby exacerbating the modal noise measured by the spectrograph. We present a commercial off-the-shelf solution that significantly mitigates modal noise at all optical and NIR wavelengths, and which can be applied to spectrograph calibration systems. Our solution uses an integrating sphere in conjunction with a diffuser that is moved rapidly using electrostrictive polymers, and is generally superior to most tested forms of mechanical fiber agitation. We demonstrate a high level of modal noise reduction with a narrow bandwidth 1550 nm laser. Our relatively inexpensive solution immediately enables spectrographs to take advantage of the innate precision of bright state-of-the art calibration sources by removing a major source of systematic noise.

  14. Design of spectrally tunable calibration source based on Digital Micromirror Device (DMD)

    NASA Astrophysics Data System (ADS)

    Zhai, Wenchao; Zhang, Meng; Meng, Fangang; Zheng, Xiaobing

    2016-10-01

    A kind of novel calibration source with dual output modes, namely, narrow-band and broadband, was designed. The optical system of the source is refractive, in spectrometer-like optical configurations using a prism as the dispersion device. The Digital Micromirror Device (DMD) is used as the spatial light modulator, which locates at the focal plane of the dispersion unit. The dispersive wavelengths are located at the active area of DMD, every column of the DMD corresponds to a different wavelength and the rows of each DMD column correspond to the intensity of that wavelength. With the modulation of the DMD, it can produce narrow-band/monochromatic output like a monochromator by switching the corresponding columns on, and broadband output by switching several different columns on. The source's operating band spans 450 2250nm, consisting of two independent parts which span 450 1000nm and 1000 2250nm, respectively. The narrow-band bandwidths spans 5 28nm for VIS-NIR and 20 40nm for SWIR subsystems. Several broadband target spectra, including sea water, plants and sun, were simulated by this source through spectral simulation algorithm. The source's radiometric metrics are suitable to be traced to the absolute cryogenic radiometer (ACR), the most accurate optical power standard at present, which is helpful to improve the calibration accuracy for remote sensors at the beginning. The capability of simulating target spectra will reduce the calibration uncertainties caused by the spectral mismatch between calibration sources and targets viewed by the remote sensors. Based on the considerations above, the source is very appropriate and applicable for remote sensor's calibration.

  15. Crowd-Sourced Calibration: The GEDI Strategy for Empirical Biomass Estimation Using Spaceborne Lidar

    NASA Astrophysics Data System (ADS)

    Dubayah, R.

    2015-12-01

    The central task in estimating forest biomass from spaceborne sensors is the development of calibration equations that relate observed forest structure to biomass at a variety of spatial scales. Empirical methods generally rely on statistical estimation or machine learning techniques where field-based estimates of biomass at the plot level are associated with post-launch observations of variables such as canopy height and cover. For global-scale mapping the process is complex and leads to a number of questions: How many calibrations are required to capture non-stationarity in the relationships? Where does one calibration begin and another end? Should calibrations be conditioned by biome? Vegetation type? Land-use? Post-launch calibrations lead to further complications, such as the requirement to have sufficient field plot data underneath potentially sparse satellite observations, spatial and temporal mismatches in scale between field plots and pixels, and geolocation uncertainty, both in the plots and the satellite data. The Global Ecosystem Dynamics Investigation (GEDI) is under development by NASA to estimate forest biomass. GEDI will deploy a multi-beam lidar on the International Space Station and provide billions of observations of forest structure per year. Because GEDI uses relatively small footprints, about 25 m diameter, post-launch calibration is exceptionally problematic for the reasons listed earlier. Instead, GEDI will use a kind of "crowd-sourced" calibration strategy where existing lidar observations and the corresponding plot biomass will be assembled from data contributed by the science community. Through a process of continuous updating, calibrations will be refined as more data is ingested. This talk will focus on the GEDI pre-launch calibration strategy and present initial progress on its development, and how it forms the basis for meeting mission biomass requirements.

  16. 10 CFR 35.65 - Authorization for calibration, transmission, and reference sources.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Authorization for calibration, transmission, and reference sources. 35.65 Section 35.65 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL.... Any person authorized by § 35.11 for medical use of byproduct material may receive, possess, and...

  17. 10 CFR 35.65 - Authorization for calibration, transmission, and reference sources.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Authorization for calibration, transmission, and reference sources. 35.65 Section 35.65 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL.... Any person authorized by § 35.11 for medical use of byproduct material may receive, possess, and...

  18. 10 CFR 35.65 - Authorization for calibration, transmission, and reference sources.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Authorization for calibration, transmission, and reference sources. 35.65 Section 35.65 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL.... Any person authorized by § 35.11 for medical use of byproduct material may receive, possess, and...

  19. 10 CFR 35.65 - Authorization for calibration, transmission, and reference sources.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Authorization for calibration, transmission, and reference sources. 35.65 Section 35.65 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL.... Any person authorized by § 35.11 for medical use of byproduct material may receive, possess, and...

  20. 10 CFR 35.65 - Authorization for calibration, transmission, and reference sources.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Authorization for calibration, transmission, and reference sources. 35.65 Section 35.65 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL.... Any person authorized by § 35.11 for medical use of byproduct material may receive, possess, and...

  1. THE SUN AS A CALIBRATION SIGNAL SOURCE FOR L- AND S-BAND TELEMETRY

    DTIC Science & Technology

    performance at all times. The sun provides sufficient signal strength in these bands, and its subtended angle of 0.5 deg from the earth is small enough to...communications link the sun could be used as a signal source for calibration purposes. Characteristics of solar emission are reviewed briefly, and the methods of determining receiving system noise temperature are developed.

  2. NPL secondary standard radionuclide calibrator. Syringe calibration factors for radionuclides used in nuclear medicine. National Physical Laboratory.

    PubMed

    Tyler, D K; Baker, M; Woods, M J

    2002-01-01

    The measurement of the activity of a radiopharmaceutical administration to a patient is normally achieved via the use of a radionuclide calibrator. Although these radionuclides are normally measured initially in a standard glass vial, an aliquot of the solution is then usually withdrawn into a syringe prior to the administration. Both for general quality assurance good practice and for additional guarantees for patient safety, a confirmatory measurement of the syringe is almost obligatory Because of the different geometries and elemental compositions between plastic syringes and glass vials, the calibration factors for syringes may well be significantly different from those for the glass containers. The magnitude of these differences depends on the energies of the emitted photons. A variety of syringes typically used in hospital administrations, and covering a range of volumes and manufacturers, were obtained. The results obtained were compared to those for glass vials and show the large errors that can be produced by ignoring these differences in container format.

  3. Clarity: an open-source manager for laboratory automation.

    PubMed

    Delaney, Nigel F; Rojas Echenique, José I; Marx, Christopher J

    2013-04-01

    Software to manage automated laboratories, when interfaced with hardware instruments, gives users a way to specify experimental protocols and schedule activities to avoid hardware conflicts. In addition to these basics, modern laboratories need software that can run multiple different protocols in parallel and that can be easily extended to interface with a constantly growing diversity of techniques and instruments. We present Clarity, a laboratory automation manager that is hardware agnostic, portable, extensible, and open source. Clarity provides critical features including remote monitoring, robust error reporting by phone or email, and full state recovery in the event of a system crash. We discuss the basic organization of Clarity, demonstrate an example of its implementation for the automated analysis of bacterial growth, and describe how the program can be extended to manage new hardware. Clarity is mature, well documented, actively developed, written in C# for the Common Language Infrastructure, and is free and open-source software. These advantages set Clarity apart from currently available laboratory automation programs. The source code and documentation for Clarity is available at http://code.google.com/p/osla/.

  4. LED based powerful nanosecond light sources for calibration systems of deep underwater neutrino telescopes

    NASA Astrophysics Data System (ADS)

    Lubsandorzhiev, B. K.; Poleshuk, R. V.; Shaibonov, B. A. J.; Vyatchin, Y. E.

    2009-04-01

    Powerful nanosecond light sources based on LEDs have been developed for use in calibration systems of deep underwater neutrino telescopes. The light sources use either matrixes of ultra bright blue InGaN LEDs or new generation high power blue LEDs. It is shown that such light sources have light yield of up to 1010-1012 photons per pulse with very fast light emission kinetics. The developed light sources are currently used in a number of astroparticle physics experiments, namely: the lake Baikal neutrino experiment, the TUNKA EAS experiment, etc.

  5. Sources and assumptions for the vicarious calibration of ocean color satellite observations

    SciTech Connect

    Bailey, Sean W.; Hooker, Stanford B.; Antoine, David; Franz, Bryan A.; Werdell, P. Jeremy

    2008-04-20

    Spaceborne ocean color sensors require vicarious calibration to sea-truth data to achieve accurate water-leaving radiance retrievals. The assumed requirements of an in situ data set necessary to achieve accurate vicarious calibration were set forth in a series of papers and reports developed nearly a decade ago, which were embodied in the development and site location of the Marine Optical BuoY (MOBY). Since that time, NASA has successfully used data collected by MOBY as the sole source of sea-truth data for vicarious calibration of the Sea-viewing Wide field-of-view Sensor (SeaWiFS) and Moderate Resolution Imaging Spectroradiometer instruments. In this paper, we make use of the 10-year, global time series of SeaWiFS measurements to test the sensitivity of vicarious calibration to the assumptions inherent in the in situ requirements (e.g., very low chlorophyll waters, hyperspectral measurements). Our study utilized field measurements from a variety of sources with sufficient diversity in data collection methods and geophysical variability to challenge those in situ restrictions. We found that some requirements could be relaxed without compromising the ability to vicariously calibrate to the level required for accurate water-leaving radiance retrievals from satellite-based sensors.

  6. X-ray intensity and source size characterizations for the 25 kV upgraded Manson source at Sandia National Laboratories

    NASA Astrophysics Data System (ADS)

    Loisel, G.; Lake, P.; Gard, P.; Dunham, G.; Nielsen-Weber, L.; Wu, M.; Norris, E.

    2016-11-01

    At Sandia National Laboratories, the x-ray generator Manson source model 5 was upgraded from 10 to 25 kV. The purpose of the upgrade is to drive higher characteristics photon energies with higher throughput. In this work we present characterization studies for the source size and the x-ray intensity when varying the source voltage for a series of K-, L-, and M-shell lines emitted from Al, Y, and Au elements composing the anode. We used a 2-pinhole camera to measure the source size and an energy dispersive detector to monitor the spectral content and intensity of the x-ray source. As the voltage increases, the source size is significantly reduced and line intensity is increased for the three materials. We can take advantage of the smaller source size and higher source throughput to effectively calibrate the suite of Z Pulsed Power Facility crystal spectrometers.

  7. X-ray intensity and source size characterizations for the 25 kV upgraded Manson source at Sandia National Laboratories.

    PubMed

    Loisel, G; Lake, P; Gard, P; Dunham, G; Nielsen-Weber, L; Wu, M; Norris, E

    2016-11-01

    At Sandia National Laboratories, the x-ray generator Manson source model 5 was upgraded from 10 to 25 kV. The purpose of the upgrade is to drive higher characteristics photon energies with higher throughput. In this work we present characterization studies for the source size and the x-ray intensity when varying the source voltage for a series of K-, L-, and M-shell lines emitted from Al, Y, and Au elements composing the anode. We used a 2-pinhole camera to measure the source size and an energy dispersive detector to monitor the spectral content and intensity of the x-ray source. As the voltage increases, the source size is significantly reduced and line intensity is increased for the three materials. We can take advantage of the smaller source size and higher source throughput to effectively calibrate the suite of Z Pulsed Power Facility crystal spectrometers.

  8. The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) 2005: Calibration and Targeted Sources

    NASA Astrophysics Data System (ADS)

    Truch, M. D. P.; Ade, P. A. R.; Bock, J. J.; Chapin, E. L.; Devlin, M. J.; Dicker, S.; Griffin, M.; Gundersen, J. O.; Halpern, M.; Hargrave, P. C.; Hughes, D. H.; Klein, J.; Marsden, G.; Martin, P. G.; Mauskopf, P.; Netterfield, C. B.; Olmi, L.; Pascale, E.; Patanchon, G.; Rex, M.; Scott, D.; Semisch, C.; Tucker, C.; Tucker, G. S.; Viero, M. P.; Wiebe, D. V.

    2008-07-01

    The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) operated successfully during a 100 hr flight from northern Sweden in 2005 June (BLAST05). As part of the calibration and pointing procedures, several compact sources were mapped, including solar system, Galactic, and extragalactic targets, specifically Pallas, CRL 2688, LDN 1014, IRAS 20126+4104, IRAS 21078+5211, IRAS 21307+5049, IRAS 22134+5834, IRAS 23011+6126, K3-50, W75N, and Mrk 231. One additional source, Arp 220, was observed and used as our primary calibrator. Details of the overall BLAST05 calibration procedure are discussed here. The BLAST observations of each compact source are described, flux densities and spectral energy distributions are reported, and these are compared with previous measurements at other wavelengths. The 250, 350, and 500 μm BLAST data can provide useful constraints to the amplitude and slope of the submillimeter continuum, which in turn may be useful for the improved calibration of other submillimeter instruments.

  9. Narrow Line X-Ray Calibration Source for High Resolution Microcalorimeters

    NASA Technical Reports Server (NTRS)

    Hokin, M.S.; McCammon, D.; Morgan, K.M.; Bandler, Simon Richard; Lee, S.J.; Moseley, S.H.; Smith, S.J.

    2013-01-01

    We are developing a narrow line calibration source for use with X-ray microcalorimeters. At energies below 300 electronvolts fluorescent lines are intrinsically broad, making calibration of high resolution detectors difficult. This source consists of a 405 nanometers (3 electronvolts) laser diode coupled to an optical fiber. The diode is pulsed to create approximately one hundred photons in a few microseconds. If the pulses are short compared to the rise time of the detector, they will be detected as single events with a total energy in the soft X-ray range. Poisson fluctuations in photon number per pulse create a comb of X-ray lines with 3 electronvolts spacing, so detectors with energy resolution better than 2 electronvolts are required to resolve the individual lines. Our currently unstabilized diode has a multimode width less than 1 nanometer, giving a 300 electronvolt event a Full width at half maximum (FWHM) less than 0.1 electronvolts. By varying the driving voltage, or pulse width, the source can produce a comb centered on a wide range of energies. The calibration events are produced at precisely known times. This allows continuous calibration of a flight mission without contaminating the observed spectrum and with minimal deadtime.

  10. Non-matrix Matched Glass Disk Calibration Standards Improve XRF Micronutrient Analysis of Wheat Grain across Five Laboratories in India.

    PubMed

    Guild, Georgia E; Stangoulis, James C R

    2016-01-01

    Within the HarvestPlus program there are many collaborators currently using X-Ray Fluorescence (XRF) spectroscopy to measure Fe and Zn in their target crops. In India, five HarvestPlus wheat collaborators have laboratories that conduct this analysis and their throughput has increased significantly. The benefits of using XRF are its ease of use, minimal sample preparation and high throughput analysis. The lack of commercially available calibration standards has led to a need for alternative calibration arrangements for many of the instruments. Consequently, the majority of instruments have either been installed with an electronic transfer of an original grain calibration set developed by a preferred lab, or a locally supplied calibration. Unfortunately, neither of these methods has been entirely successful. The electronic transfer is unable to account for small variations between the instruments, whereas the use of a locally provided calibration set is heavily reliant on the accuracy of the reference analysis method, which is particularly difficult to achieve when analyzing low levels of micronutrient. Consequently, we have developed a calibration method that uses non-matrix matched glass disks. Here we present the validation of this method and show this calibration approach can improve the reproducibility and accuracy of whole grain wheat analysis on 5 different XRF instruments across the HarvestPlus breeding program.

  11. Non-matrix Matched Glass Disk Calibration Standards Improve XRF Micronutrient Analysis of Wheat Grain across Five Laboratories in India

    PubMed Central

    Guild, Georgia E.; Stangoulis, James C. R.

    2016-01-01

    Within the HarvestPlus program there are many collaborators currently using X-Ray Fluorescence (XRF) spectroscopy to measure Fe and Zn in their target crops. In India, five HarvestPlus wheat collaborators have laboratories that conduct this analysis and their throughput has increased significantly. The benefits of using XRF are its ease of use, minimal sample preparation and high throughput analysis. The lack of commercially available calibration standards has led to a need for alternative calibration arrangements for many of the instruments. Consequently, the majority of instruments have either been installed with an electronic transfer of an original grain calibration set developed by a preferred lab, or a locally supplied calibration. Unfortunately, neither of these methods has been entirely successful. The electronic transfer is unable to account for small variations between the instruments, whereas the use of a locally provided calibration set is heavily reliant on the accuracy of the reference analysis method, which is particularly difficult to achieve when analyzing low levels of micronutrient. Consequently, we have developed a calibration method that uses non-matrix matched glass disks. Here we present the validation of this method and show this calibration approach can improve the reproducibility and accuracy of whole grain wheat analysis on 5 different XRF instruments across the HarvestPlus breeding program. PMID:27375644

  12. The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) 2005: Calibration and Targeted Sources

    NASA Astrophysics Data System (ADS)

    Truch, Matthew; BLAST Collaboration

    2007-12-01

    The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) operated successfully during a 100-hour flight from northern Sweden in June 2005 (BLAST05). As part of the calibration and pointing procedures, several compact sources were mapped, including solar system, Galactic, and extragalactic targets, specifically Pallas, CRL 2688, LDN 1014, IRAS 20126+4104, IRAS 21078+5211, IRAS 21307+5049, IRAS 22134+5834, IRAS 23011+6126, K3-50, W 75N, Mrk 231, NGC 4565, and Arp 220 (this last source being our primary calibrator). The BLAST observations of each compact source are described, flux densities and spectral energy distributions are reported, and these are compared with previous measurements at other wavelengths. BLAST was particularly useful for constraining the slope of the submillimeter continuum.

  13. Comparison of Continuous Wave CO2 Doppler Lidar Calibration Using Earth Surface Targets in Laboratory and Airborne Measurements

    NASA Technical Reports Server (NTRS)

    Jarzembski, Maurice A.; Srivastava, Vandana

    1999-01-01

    Routine backscatter, beta, measurements by an airborne or space-based lidar from designated earth surfaces with known and fairly uniform beta properties can potentially offer lidar calibration opportunities. This can in turn be used to obtain accurate atmospheric aerosol and cloud beta measurements on large spatial scales. This is important because achieving a precise calibration factor for large pulsed lidars then need not rest solely on using a standard hard target procedure. Furthermore, calibration from designated earth surfaces would provide an inflight performance evaluation of the lidar. Hence, with active remote sensing using lasers with high resolution data, calibration of a space-based lidar using earth's surfaces will be extremely useful. The calibration methodology using the earth's surface initially requires measuring beta of various earth surfaces simulated in the laboratory using a focused continuous wave (CW) CO2 Doppler lidar and then use these beta measurements as standards for the earth surface signal from airborne or space-based lidars. Since beta from the earth's surface may be retrieved at different angles of incidence, beta would also need to be measured at various angles of incidences of the different surfaces. In general, Earth-surface reflectance measurements have been made in the infrared, but the use of lidars to characterize them and in turn use of the Earth's surface to calibrate lidars has not been made. The feasibility of this calibration methodology is demonstrated through a comparison of these laboratory measurements with actual earth surface beta retrieved from the same lidar during the NASA/Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS) mission on NASA's DC8 aircraft from 13 - 26 September, 1995. For the selected earth surface from the airborne lidar data, an average beta for the surface was established and the statistics of lidar efficiency was determined. This was compared with the actual lidar efficiency

  14. Clarity: An Open Source Manager for Laboratory Automation

    PubMed Central

    Delaney, Nigel F.; Echenique, José Rojas; Marx, Christopher J.

    2013-01-01

    Software to manage automated laboratories interfaces with hardware instruments, gives users a way to specify experimental protocols, and schedules activities to avoid hardware conflicts. In addition to these basics, modern laboratories need software that can run multiple different protocols in parallel and that can be easily extended to interface with a constantly growing diversity of techniques and instruments. We present Clarity: a laboratory automation manager that is hardware agnostic, portable, extensible and open source. Clarity provides critical features including remote monitoring, robust error reporting by phone or email, and full state recovery in the event of a system crash. We discuss the basic organization of Clarity; demonstrate an example of its implementation for the automated analysis of bacterial growth; and describe how the program can be extended to manage new hardware. Clarity is mature; well documented; actively developed; written in C# for the Common Language Infrastructure; and is free and open source software. These advantages set Clarity apart from currently available laboratory automation programs. PMID:23032169

  15. Laser ion source with solenoid for Brookhaven National Laboratory-electron beam ion source.

    PubMed

    Kondo, K; Yamamoto, T; Sekine, M; Okamura, M

    2012-02-01

    The electron beam ion source (EBIS) preinjector at Brookhaven National Laboratory (BNL) is a new heavy ion-preinjector for relativistic heavy ion collider (RHIC) and NASA Space Radiation Laboratory (NSRL). Laser ion source (LIS) is a primary ion source provider for the BNL-EBIS. LIS with solenoid at the plasma drift section can realize the low peak current (∼100 μA) with high charge (∼10 nC) which is the BNL-EBIS requirement. The gap between two solenoids does not cause serious plasma current decay, which helps us to make up the BNL-EBIS beamline.

  16. New detections of Galactic molecular absorption systems toward ALMA calibrator sources

    NASA Astrophysics Data System (ADS)

    Ando, Ryo; Kohno, Kotaro; Tamura, Yoichi; Izumi, Takuma; Umehata, Hideki; Nagai, Hiroshi

    2016-02-01

    We report on Atacama Large Millimeter/submillimeter Array (ALMA) detections of molecular absorption lines in Bands 3, 6, and 7 toward four radio-loud quasars, which were observed as the bandpass and complex gain calibrators. The absorption systems, three of which are newly detected, are found to be Galactic origin. Moreover, HCO absorption lines toward two objects are detected, which almost doubles the number of HCO absorption samples in the Galactic diffuse medium. In addition, high HCO-to-H13CO+ column density ratios are found, suggesting that the interstellar media (ISM) observed toward the two calibrators are in photodissociation regions, which observationally illustrates the chemistry of diffuse ISM driven by ultraviolet (UV) radiation. These results demonstrate that calibrators in the ALMA Archive are potential sources for the quest for new absorption systems and for detailed investigation of the nature of the ISM.

  17. A method for the temperature calibration of an infrared camera using water as a radiative source

    SciTech Connect

    Bower, S. M.; Kou, J.; Saylor, J. R.

    2009-09-15

    Presented here is an effective low-cost method for the temperature calibration of infrared cameras, for applications in the 0-100 deg. C range. The calibration of image gray level intensity to temperature is achieved by imaging an upwelling flow of water, the temperature of which is measured with a thermistor probe. The upwelling flow is created by a diffuser located below the water surface of a constant temperature water bath. The thermistor probe is kept immediately below the surface, and the distance from the diffuser outlet to the surface is adjusted so that the deformation of the water surface on account of the flow is small, yet the difference between the surface temperature seen by the camera and the bulk temperature measured by the thermistor is also small. The benefit of this method compared to typical calibration procedures is that, without sacrificing the quality of the calibration, relatively expensive commercial blackbodies are replaced by water as the radiative source ({epsilon}{approx_equal}0.98 for the wavelengths considered here). A heat transfer analysis is provided, which improves the accuracy of the calibration method and also provides the user with guidance to further increases in accuracy of the method.

  18. A practical implementation of the 2010 IPEM high dose rate brachytherapy code of practice for the calibration of 192Ir sources

    NASA Astrophysics Data System (ADS)

    Awunor, O. A.; Lecomber, A. R.; Richmond, N.; Walker, C.

    2011-08-01

    This paper details a practical method for deriving the reference air kerma rate calibration coefficient for Farmer NE2571 chambers using the UK Institute of Physics and Engineering in Medicine (IPEM) code of practice for the determination of the reference air kerma rate for HDR 192Ir brachytherapy sources based on the National Physical Laboratory (NPL) air kerma standard. The reference air kerma rate calibration coefficient was derived using pressure, temperature and source decay corrected ionization chamber response measurements over three successive 192Ir source clinical cycles. A secondary standard instrument (a Standard Imaging 1000 Plus well chamber) and four tertiary standard instruments (one additional Standard Imaging 1000 Plus well chamber and three Farmer NE2571 chambers housed in a perspex phantom) were used to provide traceability to the NPL primary standard and enable comparison of performance between the chambers. Conservative and optimized estimates on the expanded uncertainties (k = 2) associated with chamber response, ion recombination and reference air kerma rate calibration coefficient were determined. This was seen to be 2.3% and 0.4% respectively for chamber response, 0.2% and 0.08% respectively for ion recombination and 2.6% and 1.2% respectively for the calibration coefficient. No significant change in ion recombination with source decay was observed over the duration of clinical use of the respective 192Ir sources.

  19. A practical implementation of the 2010 IPEM high dose rate brachytherapy code of practice for the calibration of 192Ir sources.

    PubMed

    Awunor, O A; Lecomber, A R; Richmond, N; Walker, C

    2011-08-21

    This paper details a practical method for deriving the reference air kerma rate calibration coefficient for Farmer NE2571 chambers using the U.K. Institute of Physics and Engineering in Medicine (IPEM) code of practice for the determination of the reference air kerma rate for HDR (192)Ir brachytherapy sources based on the National Physical Laboratory (NPL) air kerma standard. The reference air kerma rate calibration coefficient was derived using pressure, temperature and source decay corrected ionization chamber response measurements over three successive (192)Ir source clinical cycles. A secondary standard instrument (a Standard Imaging 1000 Plus well chamber) and four tertiary standard instruments (one additional Standard Imaging 1000 Plus well chamber and three Farmer NE2571 chambers housed in a perspex phantom) were used to provide traceability to the NPL primary standard and enable comparison of performance between the chambers. Conservative and optimized estimates on the expanded uncertainties (k = 2) associated with chamber response, ion recombination and reference air kerma rate calibration coefficient were determined. This was seen to be 2.3% and 0.4% respectively for chamber response, 0.2% and 0.08% respectively for ion recombination and 2.6% and 1.2% respectively for the calibration coefficient. No significant change in ion recombination with source decay was observed over the duration of clinical use of the respective 192Ir sources.

  20. Absolute flux density calibrations of radio sources: 2.3 GHz

    NASA Technical Reports Server (NTRS)

    Freiley, A. J.; Batelaan, P. D.; Bathker, D. A.

    1977-01-01

    A detailed description of a NASA/JPL Deep Space Network program to improve S-band gain calibrations of large aperture antennas is reported. The program is considered unique in at least three ways; first, absolute gain calibrations of high quality suppressed-sidelobe dual mode horns first provide a high accuracy foundation to the foundation to the program. Second, a very careful transfer calibration technique using an artificial far-field coherent-wave source was used to accurately obtain the gain of one large (26 m) aperture. Third, using the calibrated large aperture directly, the absolute flux density of five selected galactic and extragalactic natural radio sources was determined with an absolute accuracy better than 2 percent, now quoted at the familiar 1 sigma confidence level. The follow-on considerations to apply these results to an operational network of ground antennas are discussed. It is concluded that absolute gain accuracies within + or - 0.30 to 0.40 db are possible, depending primarily on the repeatability (scatter) in the field data from Deep Space Network user stations.

  1. Laboratory Calibration of Density-Dependent Lines in the EUV and Soft X-Ray Regions

    SciTech Connect

    Lepson, J K; Beiersdorfer, P; Gu, M F; Desai, P

    2010-12-09

    We analyzed spectral data of Fe XXII and Ar XIV from laboratory sources in which the electron density varies by several orders of magnitude to help benchmark density-sensitive emission lines useful for astrophysics and to test the atomic models underlying the diagnostic line ratios. We found excellent agreement for Fe XXII, but poorer agreement for Ar XIV. A number of astrophysically important emission lines are sensitive to electron density in the EUV and soft X-ray regions. Lines from Fe XXII, for example, have been used in recent years as diagnostics of stellar coronae, such as the active variable AB Dor, Capella, and EX Hya (Sanz-Forcada et al. 2003, Mewe et al. 2001, Mauche et al. 2003). Here we report spectral data of Fe XXII and Ar XIV from laboratory sources in which the electron density is known from either K-shell density diagnostics (for electron beam ion traps) or from non-spectroscopic means (tokamaks), ranging from 5 x 10{sup 10} cm{sup -3} to 5 x 10{sup 14} cm{sup -3}. These measurements were used to test the atomic data underlying the density diagnostic line ratios, complementing earlier work (Chen et al. 2004).

  2. The Use of Transfer Radiometers in Validating the Visible through Shortwave Infrared Calibrations of Radiance Sources Used by Instruments in NASA's Earth Observing System

    NASA Technical Reports Server (NTRS)

    Butler, James J.; Barnes, Robert A.

    2002-01-01

    The detection and study of climate change over a time frame of decades requires successive generations of satellite, airborne, and ground-based instrumentation carefully calibrated against a common radiance scale. In NASA s Earth Observing System (EOS) program, the pre-launch radiometric calibration of these instruments in the wavelength region from 400 nm to 2500 nm is accomplished using internally illuminated integrating spheres and diffuse reflectance panels illuminated by irradiance standard lamps. Since 1995, the EOS Calibration Program operating within the EOS Project Science Office (PSO) has enlisted the expertise of national standards laboratories and government and university metrology laboratories in an effort to validate the radiance scales assigned to sphere and panel radiance sources by EOS instrument calibration facilities. This state-of-the-art program has been accomplished using ultra-stable transfer radiometers independently calibrated by the above participating institutions. In ten comparisons since February 1995, the agreement between the radiance measurements of the transfer radiometers is plus or minus 1.80% at 411 nm, plus or minus 1.31% at 552.5 nm, plus or minus 1.32% at 868.0 nm, plus or minus 2.54% at 1622nm, and plus or minus 2.81% at 2200nm (sigma =1).

  3. Lunar Reconnaissance Orbiter Camera Narrow Angle Cameras: Laboratory and Initial Flight Calibration

    NASA Astrophysics Data System (ADS)

    Humm, D. C.; Tschimmel, M.; Denevi, B. W.; Lawrence, S.; Mahanti, P.; Tran, T. N.; Thomas, P. C.; Eliason, E.; Robinson, M. S.

    2009-12-01

    The Lunar Reconnaissance Orbiter Camera (LROC) has two identical Narrow Angle Cameras (NACs). Each NAC is a monochrome pushbroom scanner, providing images with a pixel scale of 50 cm from a 50-km orbit. A single NAC image has a swath width of 2.5 km and a length of up to 26 km. The NACs are mounted to acquire side-by-side imaging for a combined swath width of 5 km. The NAC is designed to fully characterize future human and robotic landing sites in terms of scientific and resource merit, trafficability, and hazards. The North and South poles will be mapped at 1-meter-scale poleward of 85.5 degrees latitude. Stereo coverage is achieved by pointing the NACs off-nadir, which requires planning in advance. Read noise is 91 and 93 e- and the full well capacity is 334,000 and 352,000 e- for NAC-L and NAC-R respectively. Signal-to-noise ranges from 42 for low-reflectance material with 70 degree illumination to 230 for high-reflectance material with 0 degree illumination. Longer exposure times and 2x binning are available to further increase signal-to-noise with loss of spatial resolution. Lossy data compression from 12 bits to 8 bits uses a companding table selected from a set optimized for different signal levels. A model of focal plane temperatures based on flight data is used to command dark levels for individual images, optimizing the performance of the companding tables and providing good matching of the NAC-L and NAC-R images even before calibration. The preliminary NAC calibration pipeline includes a correction for nonlinearity at low signal levels with an offset applied for DN>600 and a logistic function for DN<600. Flight images taken on the limb of the Moon provide a measure of stray light performance. Averages over many lines of images provide a measure of flat field performance in flight. These are comparable with laboratory data taken with a diffusely reflecting uniform panel.

  4. Preliminary Calibration Report of an Apparatus to Measure Vibration Characteristics of Low Frequency Disturbance Source Devices

    NASA Technical Reports Server (NTRS)

    Russell, James W.; Marshall, Robert A.; Finley, Tom D.; Lawrence, George F.

    1994-01-01

    This report presents a description of the test apparatus and the method of testing the low frequency disturbance source characteristics of small pumps, fans, camera motors, and recorders that are typical of those used in microgravity science facilities. The test apparatus will allow both force and acceleration spectra of these disturbance devices to be obtained from acceleration measurements over the frequency range from 2 to 300 Hz. Some preliminary calibration results are presented.

  5. Use of INR calibrator plasmas in the routine coagulation laboratory: a study of two thrombolastin reagents.

    PubMed

    Fattorini, Annalisa; Pattarini, Elisabetta; Viganò, Silvana; Crippa, Luciano; D'Angelo, Armando

    2012-09-01

    INR values may be either calculated with the ISI values supplied by thromboplastin manufacturers or are directly extrapolated from certified INR calibrator plasmas. We tested the principle of local INR calibration using INR calibrator plasmas (PT-Multi Calibrator, Siemens), two thromboplastin reagents (Neoplastin Plus, rabbit brain, Stago, coagulometer-specific ISI 1.31, and Innovin, recombinant human tissue factor, Siemens) and the same coagulometer (STA-R, Stago) in 100 patients on warfarin. Using a ISI value of 0.77 with Tomenson correction for Innovin (correction factor=1.09), INR values of patients were similar with the two reagents, with a bias of 0.03 INR units and no significant regression of the difference over the average INR by method comparison analysis. With the INR calibrator plasmas, INR values with Neoplastin Plus were lower than Innovin values with an average bias of 0.39 INR units and a significant regression of the difference over the average INR (r=-0.91). Significant bias (0.16 INR units, p<0.00001) and regression (r=-0.77) was also observed by comparison of Neoplastin Plus INRs with Innovin calibrated INRs. Based on a therapeutic INR interval of 2.0 to 3.5, discordance in warfarin dosing was approximately 3 times higher with INR calibration (27% vs 11%). Because of non commutability with fresh plasma samples, local INR calibration with lyophilized calibrator plasmas may not be valid for some reagent-instrument combinations.

  6. Development of a compact 20 MeV gamma-ray source for energy calibration at the Sudbury Neutrino Observatory

    SciTech Connect

    Poon, A.W.P.; Browne, M.C.; Robertson, R.G.H.; Waltham, C.E.; Kherani, N.P.

    1995-12-31

    The Sudbury Neutrino Observatory (SNO) is a real-time neutrino detector under construction near Sudbury, Ontario, Canada. SNO collaboration is developing various calibration sources in order to determine the detector response completely. This paper describes briefly the calibration sources being developed by the collaboration. One of these, a compact {sup 3}H(p,{gamma}){sup 4}He source, which produces 20-MeV {gamma}-rays, is described.

  7. Development of pyroelectric neutron source for calibration of neutrino and dark matter detectors

    NASA Astrophysics Data System (ADS)

    Chepurnov, A. S.; Ionidi, V. Y.; Gromov, M. B.; Kirsanov, M. A.; Klyuyev, A. S.; Kubankin, A. S.; Oleinik, A. N.; Shchagin, A. V.; Vokhmyanina, K. A.

    2017-01-01

    The laboratory experimental setup for development of pyroelectric neutron generator for calibration of neutrino and dark matter detectors for direct search of Weakly Interacting Massive Particles (WIMP) has been developed. The setup allows providing and controlling the neutrons generation process realized during d-d nuclear fusion. It is shown that the neutrons with energy 2.45 MeV can be generated starting from a level of electric potential generated by pyroelectric crystal about 30 kV, in contrast to the typical neutron tubes which need the applied outer high voltage level about 100 kV.

  8. Calibration of the CDF tile-fiber endplug calorimeters using moving radioactive sources

    SciTech Connect

    Barnes, V.; Laasanen, A.; Pompos, A.; Wilson, M.

    1998-11-01

    The use of moving radioactive gamma sources to assess, calibrate and monitor scintillating tile calorimeters is discussed, and the techniques and equipment are described. The capabilities of the technique are illustrated using Cs{sup 137} sources with the CDF Endplug Upgrade EM and Hadron calorimeters at testbeams and at a cosmic ray test stand. Source measurements of all the tiles in testbeam modules which are exact replicas of the calorimeters, predict the relative responses of EM towers to 50 GeV positrons and muons, and of Hadron towers to 50 GeV pions, with RMS accuracies of 1.3{percent}, 1.8{percent} and 2.0{percent}, respectively. Source measurements will be used in lieu of testbeam measurements for the initial calibration of all towers in the final calorimeters. Source measurements of single tiles are reproducible to 0.4{percent} and will be used to monitor gain changes of the photomultiplier tubes. {copyright} {ital 1998 American Institute of Physics.}

  9. A 220Rn source for the calibration of low-background experiments

    NASA Astrophysics Data System (ADS)

    Lang, R. F.; Brown, A.; Brown, E.; Cervantes, M.; Macmullin, S.; Masson, D.; Schreiner, J.; Simgen, H.

    2016-04-01

    We characterize two 40 kBq sources of electrodeposited 228Th for use in low-background experiments. The sources efficiently emanate 220Rn, a noble gas that can diffuse in a detector volume. 220Rn and its daughter isotopes produce α-, β-, and γ-radiation, which may used to calibrate a variety of detector responses and features, before decaying completely in only a few days. We perform various tests to place limits on the release of other long-lived isotopes. In particular, we find an emanation of < 0.008 atoms/min/kBq (90% CL) for 228Th and (1.53 ± 0.04) atoms/min/kBq for 224Ra. The sources lend themselves in particular to the calibration of detectors employing liquid noble elements such as argon and xenon. With the source mounted in a noble gas system, we demonstrate that filters are highly efficient in reducing the activity of these longer-lived isotopes further. We thus confirm the suitability of these sources even for use in next-generation experiments, such as XENON1T/XENONnT, LZ, and nEXO.

  10. The advanced light source at the Lawrence Berkeley laboratory

    NASA Astrophysics Data System (ADS)

    Jackson, Alan

    1991-05-01

    The Advanced Light Source (ALS), a national facility currently under construction at the Lawrence Berkeley Laboratory (LBL), is a third-generation synchrotron light source designed to produce extremely bright beams of synchrotron radiation, in the energy range from a few eV to 10 keV. The design is based on a 1-1.9 GeV electron storage ring (optimized at 1.5 GeV), and utilizes special magnets, known as undulators and wigglers (collectively referred to as insertion devices), to generate the radiation. In this paper we describe the main accelerator components of the ALS, the variety of insertion devices, the radiation spectra expected from these devices, and the complement of experiments that have been approved for initial operation, starting in April 1993.

  11. The Advanced Light Source at Lawrence Berkeley Laboratory

    NASA Astrophysics Data System (ADS)

    Robinson, A. L.; Perera, R. C. C.; Schlachter, A. S.

    1992-01-01

    The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL), scheduled to be operational in the spring of 1993 as a U.S. Department of Energy national user facility, will be a next-generation source of soft x-ray and ultraviolet (XUV) synchrotron radiation. Undulators will provide the world's brightest synchrotron radiation at photon energies from below 10 eV to above 2 keV; wiggler and bend-magnet radiation will extend the spectral coverage with high fluxes above 10 keV. These capabilities will support an extensive research program in a broad spectrum of scientific and technological areas in which XUV radiation is used to study and manipulate matter in all its varied gaseous, liquid, and solid forms. The ALS will also serve those interested in developing the fabrication technology for microstructures and nanostructures, as well as for characterizing them.

  12. Laboratory calibration of the calcium carbonate clumped isotope thermometer in the 25-250 °C temperature range

    NASA Astrophysics Data System (ADS)

    Kluge, Tobias; John, Cédric M.; Jourdan, Anne-Lise; Davis, Simon; Crawshaw, John

    2015-05-01

    Many fields of Earth sciences benefit from the knowledge of mineral formation temperatures. For example, carbonates are extensively used for reconstruction of the Earth's past climatic variations by determining ocean, lake, and soil paleotemperatures. Furthermore, diagenetic minerals and their formation or alteration temperature may provide information about the burial history of important geological units and can have practical applications, for instance, for reconstructing the geochemical and thermal histories of hydrocarbon reservoirs. Carbonate clumped isotope thermometry is a relatively new technique that can provide the formation temperature of carbonate minerals without requiring a priori knowledge of the isotopic composition of the initial solution. It is based on the temperature-dependent abundance of the rare 13C-18O bonds in carbonate minerals, specified as a Δ47 value. The clumped isotope thermometer has been calibrated experimentally from 1 °C to 70 °C. However, higher temperatures that are relevant to geological processes have so far not been directly calibrated in the laboratory. In order to close this calibration gap and to provide a robust basis for the application of clumped isotopes to high-temperature geological processes we precipitated CaCO3 (mainly calcite) in the laboratory between 23 and 250 °C. We used two different precipitation techniques: first, minerals were precipitated from a CaCO3 supersaturated solution at atmospheric pressure (23-91 °C), and, second, from a solution resulting from the mixing of CaCl2 and NaHCO3 in a pressurized reaction vessel at a pressure of up to 80 bar (25-250 °C). The calibration lines of both experimental approaches overlap and agree in the slopes with theoretical estimates and with other calibration experiments in which carbonates were reacted with phosphoric acid at temperatures above 70 °C. Our study suggests a universal Δ47-T calibration (T in K, Δ47 in ‰):

  13. SU-E-T-155: Calibration of Variable Longitudinal Strength 103Pd Brachytherapy Sources

    SciTech Connect

    Reed, J; Radtke, J; Micka, J; Culberson, W; DeWerd, L

    2015-06-15

    Purpose: Brachytherapy sources with variable longitudinal strength (VLS) allow for a customized intensity along the length of the source. These have applications in focal brachytherapy treatments of prostate cancer where dose boosting can be achieved through modulation of intra-source strengths. This work focused on development of a calibration methodology for VLS sources based on measurements and Monte Carlo (MC) simulations of five 1 cm {sup 10} {sup 3}Pd sources each containing four regions of variable {sup 103}Pd strength. Methods: The air-kerma strengths of the sources were measured with a variable-aperture free-air chamber (VAFAC). Source strengths were also measured using a well chamber. The in-air azimuthal and polar anisotropy of the sources were measured by rotating them in front of a NaI scintillation detector and were calculated with MC simulations. Azimuthal anisotropy results were normalized to their mean intensity values. Polar anisotropy results were normalized to their average transverse axis intensity values. The relative longitudinal strengths of the sources were measured via on-contact irradiations with radiochromic film, and were calculated with MC simulations. Results: The variable {sup 103}Pd loading of the sources was validated by VAFAC and well chamber measurements. Ratios of VAFAC air-kerma strengths and well chamber responses were within ±1.3% for all sources. Azimuthal anisotropy results indicated that ≥95% of the normalized values for all sources were within ±1.7% of the mean values. Polar anisotropy results indicated variations within ±0.3% for a ±7.6° angular region with respect to the source transverse axis. Locations and intensities of the {sup 103}Pd regions were validated by radiochromic film measurements and MC simulations. Conclusion: The calibration methodology developed in this work confirms that the VLS sources investigated have a high level of polar uniformity, and that the strength and longitudinal intensity can be

  14. The Idaho National Engineering and Environmental Laboratory Source Water Assessment

    SciTech Connect

    Sehlke, G.

    2003-03-17

    The Idaho National Engineering and Environmental Laboratory (INEEL) covers approximately 890 square miles and includes 12 public water systems that must be evaluated for Source water protection purposes under the Safe Drinking Water Act. Because of its size and location, six watersheds and five aquifers could potentially affect the INEEL's drinking water sources. Based on a preliminary evaluation of the available information, it was determined that the Big Lost River, Birch Creek, and Little Lost River Watersheds and the eastern Snake River Plain Aquifer needed to be assessed. These watersheds were delineated using the United States Geologic Survey's Hydrological Unit scheme. Well capture zones were originally estimated using the RESSQC module of the Environmental Protection Agency's Well Head Protection Area model, and the initial modeling assumptions and results were checked by running several scenarios using Modflow modeling. After a technical review, the resulting capture zones were expanded to account for the uncertainties associated with changing groundwater flow directions, a this vadose zone, and other data uncertainties. Finally, all well capture zones at a given facility were merged to a single wellhead protection area at each facility. A contaminant source inventory was conducted, and the results were integrated with the well capture zones, watershed and aquifer information, and facility information using geographic information system technology to complete the INEEL's Source Water Assessment. Of the INEEL's 12 public water systems, three systems rated as low susceptibility (EBR-1, Main Gate, and Gun Range), and the remainder rated as moderate susceptibility. No INEEL public water system rated as high susceptibility. We are using this information to develop a source water management plan from which we will subsequently implement an INEEL-wide source water management program. The results are a very robust set of wellhead protection areas that will protect

  15. Validation Tests of Open-Source Procedures for Digital Camera Calibration and 3d Image-Based Modelling

    NASA Astrophysics Data System (ADS)

    Toschi, I.; Rivola, R.; Bertacchini, E.; Castagnetti, C.; Dubbini, M.; Capra, A.

    2013-07-01

    Among the many open-source software solutions recently developed for the extraction of point clouds from a set of un-oriented images, the photogrammetric tools Apero and MicMac (IGN, Institut Géographique National) aim to distinguish themselves by focusing on the accuracy and the metric content of the final result. This paper firstly aims at assessing the accuracy of the simplified and automated calibration procedure offered by the IGN tools. Results obtained with this procedure were compared with those achieved with a test-range calibration approach using a pre-surveyed laboratory test-field. Both direct and a-posteriori validation tests turned out successfully showing the stability and the metric accuracy of the process, even when low textured or reflective surfaces are present in the 3D scene. Afterwards, the possibility of achieving accurate 3D models from the subsequently extracted dense point clouds is also evaluated. Three different types of sculptural elements were chosen as test-objects and "ground-truth" data were acquired with triangulation laser scanners. 3D models derived from point clouds oriented with a simplified relative procedure show a suitable metric accuracy: all comparisons delivered a standard deviation of millimeter-level. The use of Ground Control Points in the orientation phase did not improve significantly the accuracy of the final 3D model, when a small figure-like corbel was used as test-object.

  16. Calibration and Laboratory Test of the Department of Energy Cloud Particle Imager

    SciTech Connect

    McFarquhar, GM; Um, J

    2012-02-17

    Calibration parameters from the Connolly et al. (2007) algorithm cannot be applied to the Department of Energy's (DOE) CPI because the DOE CPI is version 2.0. Thus, Dr. Junshik Um and Prof. Greg McFarquhar brought the DOE CPI to the University of Manchester, UK, where facilities for calibrating it were available. In addition, two other versions of CPIs (1.0 and 1.5) were available on-site at the University of Manchester so that an intercomparison of three different versions of the CPI was possible. The three CPIs (versions 1.0, 1.5, and 2.0) were calibrated by moving glass calibration beads and ice analogues of known size parallel to the object plane. The distance between the object plane and a particle, the particle's focus, its apparent maximum dimension, and a background image were measured in order to derive calibration parameters for each CPI version. The calibration parameters are used in two empirical equations that are applied to in situ CPI data to determine particle size and depth of field, and hence particle size distributions (PSDs). After the tests with the glass calibration beads to derive the calibration parameters, the three CPIs were installed at the base of the Manchester Ice Cloud Chamber and connected to air pumps that drew cloud through the sample volume. Warm liquid clouds at a temperature of 1-2 C and ice clouds at a temperature of -5 C were generated, and the resulting PSDs for each of the CPIs were determined by applying the results of each calibration.

  17. Laboratory Plasma Source as an MHD Model for Astrophysical Jets

    NASA Technical Reports Server (NTRS)

    Mayo, Robert M.

    1997-01-01

    The significance of the work described herein lies in the demonstration of Magnetized Coaxial Plasma Gun (MCG) devices like CPS-1 to produce energetic laboratory magneto-flows with embedded magnetic fields that can be used as a simulation tool to study flow interaction dynamic of jet flows, to demonstrate the magnetic acceleration and collimation of flows with primarily toroidal fields, and study cross field transport in turbulent accreting flows. Since plasma produced in MCG devices have magnetic topology and MHD flow regime similarity to stellar and extragalactic jets, we expect that careful investigation of these flows in the laboratory will reveal fundamental physical mechanisms influencing astrophysical flows. Discussion in the next section (sec.2) focuses on recent results describing collimation, leading flow surface interaction layers, and turbulent accretion. The primary objectives for a new three year effort would involve the development and deployment of novel electrostatic, magnetic, and visible plasma diagnostic techniques to measure plasma and flow parameters of the CPS-1 device in the flow chamber downstream of the plasma source to study, (1) mass ejection, morphology, and collimation and stability of energetic outflows, (2) the effects of external magnetization on collimation and stability, (3) the interaction of such flows with background neutral gas, the generation of visible emission in such interaction, and effect of neutral clouds on jet flow dynamics, and (4) the cross magnetic field transport of turbulent accreting flows. The applicability of existing laboratory plasma facilities to the study of stellar and extragalactic plasma should be exploited to elucidate underlying physical mechanisms that cannot be ascertained though astrophysical observation, and provide baseline to a wide variety of proposed models, MHD and otherwise. The work proposed herin represents a continued effort on a novel approach in relating laboratory experiments to

  18. Characterization of BT-2: Calibration Target for Mars Science Laboratory Alpha Particle X-Ray Spectrometer

    NASA Astrophysics Data System (ADS)

    Thompson, L. M.; King, P. L.; Spray, J. G.; Elliott, B. E.; Gellert, R.

    2012-03-01

    This work describes the ongoing effort to fully characterize BT-2 (the calibration standard for the APXS instrument onboard MSL) using a variety of techniques and instrumentation to aid in the interpretation of APXS data.

  19. The Add-A-Source Matrix Calibration of a Large Neutron Box Counter

    SciTech Connect

    Bosko, A.; Croft, S.; Philips, S.; McElroy, R.D.

    2008-07-01

    A general purpose passive neutron box counter has been designed, constructed and factory calibrated. The instrument is intended to sort and assay Transuranic Uranium (TRU) waste according to the Waste Isolation Pilot Plant (WIPP) criteria in containers ranging from drums to large boxes and crates. A multi-position Cf Add-A-Source (AAS) capability has been built into the system to determine gross matrix correction factors. The Cf source capsule runs in a U-shaped guide tube beneath the powered roller conveyor used to move the containers into the assay cavity from the loading station. The factory calibration involved measuring a wide range of matrix materials and densities in 208-liter (55 US-gal.) barrels, Standard Waste Box (SWB), Standard Large Box (SLB-2), and Ten Drum Overpack (TDOP) containers. For each container a Volume Weighted Average (VWA) rate and an AAS perturbation factor was determined and the relationship between them was established for the full range of conditions expected to be encountered operationally. In this paper we describe the calibration procedure which used Cf-252 as a surrogate for Pu-240 to map out the spatial responses for the various container-matrix combinations. A particular challenge was the scale of the measurement campaign which was directly related to the large volume of some of the containers. The reduction of the data was also challenging because for the larger items with high concentrations of hydrogen steep spatial gradients were observed in the response. For this reason simple volume-element averaging of the data to derive VWA quantities was inadequate and numerical-integration approaches of the 3-dimensional maps were explored. The response maps were also used to create point-source contributions to the Total Measurement Uncertainty (TMU), but this work is not the subject of this paper. The wide range in container size also required varying numbers of AAS interrogation position. For the drums a single AAS position was used

  20. Preliminary designs for X-ray source modifications for the Marshall Space Flight Center's X-ray calibration facility

    NASA Technical Reports Server (NTRS)

    Croft, W. L.

    1986-01-01

    The objective of this investigation is to develop preliminary designs for modifications to the X-ray source of the MSFC X-Ray Calibration Facility. Recommendations are made regarding: (1) the production of an unpolarized X-ray beam, (2) modification of the source to provide characteristic X-rays with energies up to 40 keV, and (3) addition of the capability to calibrate instruments in the extreme ultraviolet wavelength region.

  1. Rapid calibrated high-resolution hyperspectral imaging using tunable laser source

    NASA Astrophysics Data System (ADS)

    Nguyen, Lam K.; Margalith, Eli

    2009-05-01

    We present a novel hyperspectral imaging technique based on tunable laser technology. By replacing the broadband source and tunable filters of a typical NIR imaging instrument, several advantages are realized, including: high spectral resolution, highly variable field-of-views, fast scan-rates, high signal-to-noise ratio, and the ability to use optical fiber for efficient and flexible sample illumination. With this technique, high-resolution, calibrated hyperspectral images over the NIR range can be acquired in seconds. The performance of system features will be demonstrated on two example applications: detecting melamine contamination in wheat gluten and separating bovine protein from wheat protein in cattle feed.

  2. SQUID (Superconducting Quantum Interference Device) Arrays for Simultaneous Magnetic Measurements: Calibration and Source Localization Performance.

    DTIC Science & Technology

    1988-02-29

    Calibration & Source Localization 12. PERSONAL AUTHOR(S) Lloyd Kaufman, Samuel J. Williamson, and P. Costa Ribeiro 13a. TYPE OF REPORT 13b. TIME COVERED 14...Ribelro et d . 4 January 1968 SQUID Arrays Page 7 4. A Method of Verification Another way to measure the field imbalance correction ti, which at the...voltage VC for a displacement d from the detection coil’s center will be: AV ( d ) = (BclK) [ Tj - (5/2)( d /Sc)2 + (225/8)(bdSc2) 2 (6) The two unknowns in

  3. Laser ion source activities at Brookhaven National Laboratory

    DOE PAGES

    Kanesue, Takeshi; Okamura, Masahiro

    2015-07-31

    In Brookhaven National Laboratory (BNL), we have been developing laser ion sources for diverse accelerators. Tabletop Nd:YAG lasers with up to several Joules of energy are mainly used to create ablation plasmas for stable operations. The obtained charge states depend on laser power density and target species. Two types of ion extraction schemes, Direct Plasma Injection Scheme (DPIS) and conventional static extraction, are used depending on application. We optimized and select a suitable laser irradiation condition and a beam extraction scheme to meet the requirement of the following accelerator system. We have demonstrated to accelerate more than 5 x 1010more » of C6+ ions using the DPIS. We successfully commissioned low charge ion beam provider to the user facilities in BNL. As a result, to achieve higher current, higher charge state and lower emittance, further studies will continue.« less

  4. Laser ion source activities at Brookhaven National Laboratory

    SciTech Connect

    Kanesue, Takeshi; Okamura, Masahiro

    2015-07-31

    In Brookhaven National Laboratory (BNL), we have been developing laser ion sources for diverse accelerators. Tabletop Nd:YAG lasers with up to several Joules of energy are mainly used to create ablation plasmas for stable operations. The obtained charge states depend on laser power density and target species. Two types of ion extraction schemes, Direct Plasma Injection Scheme (DPIS) and conventional static extraction, are used depending on application. We optimized and select a suitable laser irradiation condition and a beam extraction scheme to meet the requirement of the following accelerator system. We have demonstrated to accelerate more than 5 x 1010 of C6+ ions using the DPIS. We successfully commissioned low charge ion beam provider to the user facilities in BNL. As a result, to achieve higher current, higher charge state and lower emittance, further studies will continue.

  5. The moon as a radiometric reference source for on-orbit sensor stability calibration

    USGS Publications Warehouse

    Stone, T.C.

    2009-01-01

    The wealth of data generated by the world's Earth-observing satellites, now spanning decades, allows the construction of long-term climate records. A key consideration for detecting climate trends is precise quantification of temporal changes in sensor calibration on-orbit. For radiometer instruments in the solar reflectance wavelength range (near-UV to shortwave-IR), the Moon can be viewed as a solar diffuser with exceptional stability properties. A model for the lunar spectral irradiance that predicts the geometric variations in the Moon's brightness with ???1% precision has been developed at the U.S. Geological Survey in Flagstaff, AZ. Lunar model results corresponding to a series of Moon observations taken by an instrument can be used to stabilize sensor calibration with sub-percent per year precision, as demonstrated by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS). The inherent stability of the Moon and the operational model to utilize the lunar irradiance quantity provide the Moon as a reference source for monitoring radiometric calibration in orbit. This represents an important capability for detecting terrestrial climate change from space-based radiometric measurements.

  6. Calibration of the Regional Crustal Waveguide and the Retrieval of Source Parameters Using Waveform Modeling

    NASA Astrophysics Data System (ADS)

    Saikia, C. K.; Woods, B. B.; Thio, H. K.

    - Regional crustal waveguide calibration is essential to the retrieval of source parameters and the location of smaller (M<4.8) seismic events. This path calibration of regional seismic phases is strongly dependent on the accuracy of hypocentral locations of calibration (or master) events. This information can be difficult to obtain, especially for smaller events. Generally, explosion or quarry blast generated travel-time data with known locations and origin times are useful for developing the path calibration parameters, but in many regions such data sets are scanty or do not exist. We present a method which is useful for regional path calibration independent of such data, i.e. with earthquakes, which is applicable for events down to Mw = 4 and which has successfully been applied in India, central Asia, western Mediterranean, North Africa, Tibet and the former Soviet Union. These studies suggest that reliably determining depth is essential to establishing accurate epicentral location and origin time for events. We find that the error in source depth does not necessarily trade-off only with the origin time for events with poor azimuthal coverage, but with the horizontal location as well, thus resulting in poor epicentral locations. For example, hypocenters for some events in central Asia were found to move from their fixed-depth locations by about 20km. Such errors in location and depth will propagate into path calibration parameters, particularly with respect to travel times. The modeling of teleseismic depth phases (pP, sP) yields accurate depths for earthquakes down to magnitude Mw = 4.7. This Mwthreshold can be lowered to four if regional seismograms are used in conjunction with a calibrated velocity structure model to determine depth, with the relative amplitude of the Pnl waves to the surface waves and the interaction of regional sPmP and pPmP phases being good indicators of event depths. We also found that for deep events a seismic phase which follows an S

  7. Radio Frequency Plasma Discharge Lamps for Use as Stable Calibration Light Sources

    NASA Technical Reports Server (NTRS)

    McAndrew, Brendan; Cooper, John; Arecchi, Angelo; McKee, Greg; Durell, Christopher

    2012-01-01

    Stable high radiance in visible and near-ultraviolet wavelengths is desirable for radiometric calibration sources. In this work, newly available electrodeless radio-frequency (RF) driven plasma light sources were combined with research grade, low-noise power supplies and coupled to an integrating sphere to produce a uniform radiance source. The stock light sources consist of a 28 VDC power supply, RF driver, and a resonant RF cavity. The RF cavity includes a small bulb with a fill gas that is ionized by the electric field and emits light. This assembly is known as the emitter. The RF driver supplies a source of RF energy to the emitter. In commercial form, embedded electronics within the RF driver perform a continual optimization routine to maximize energy transfer to the emitter. This optimization routine continually varies the light output sinusoidally by approximately 2% over a several-second period. Modifying to eliminate this optimization eliminates the sinusoidal variation but allows the output to slowly drift over time. This drift can be minimized by allowing sufficient warm-up time to achieve thermal equilibrium. It was also found that supplying the RF driver with a low-noise source of DC electrical power improves the stability of the lamp output. Finally, coupling the light into an integrating sphere reduces the effect of spatial fluctuations, and decreases noise at the output port of the sphere.

  8. Spectral Irradiance Calibration in the Infrared 11: Comparison of (alpha) Boo and 1 Ceres with a Laboratory Standard

    NASA Technical Reports Server (NTRS)

    Witteborn, Fred C.; Cohen, Martin; Bregman, Jess D.; Wooden, Diane; Heere, Karen; Shirley, Eric L.

    1998-01-01

    Infrared spectra of two celestial objects frequently used as flux standards are calibrated against an absolute laboratory flux standard at a spectral resolving power of 100 to 200. The spectrum of the K1.5III star, alpha Boo, is measured from 3 microns to 30 microns and that of the C-type asteroid, 1 Ceres, from 5 microns to 30 microns. While these 'standard' spectra do not have the apparent precision of those based on calculated models, they do not require the assumptions involved in theoretical models of stars and asteroids. Specifically they provide a model-independent means of calibrating celestial flux in the spectral range from 12 microns to 30 microns where accurate absolute photometry is not available. The agreement found between the spectral shapes of alpha Boo and Ceres based on laboratory standards, and those based on observed ratios to alpha CMa (Sirius) and alpha Lyr (Vega), flux calibrated by theoretical modeling of these hot stars strengthens our confidence in the applicability of the stellar models as primary irradiance standards.

  9. Radiation Measurements Laboratory (RML) calibration and assessment of the ATR SPING-3 stack effluent monitor

    SciTech Connect

    Koeppen, L.D.; Rogers, J.W.; Simpson, O.D.

    1983-12-01

    An evaluation, calibration and assessment of the Eberline SPING-3 ATR stack effluent monitor was conducted. This unit which monitors particulate, iodine and noble gas effluents was producing abnormal results following the initial installation and operational testing. The purposes of this work were to find the causes of the abnormal results and correct them if possible; check the calibrations and adjust them if necessary; and to provide a better in-depth understanding of what the unit is monitoring and how well it performs under this application. Results have shown that there were some problems associated with the unit as initially installed and tested. These problems have been identified and suggested alternatives shown, the monitor was found to be applicable to some extent under the current conditions. The calibrations have been checked and adjustments made. More operation testing and evaluation is needed to assess how well this works under a variety of ATR operating conditions. 2 references, 10 figures, 3 tables. (ACR)

  10. Innovative methodology for intercomparison of radionuclide calibrators using short half-life in situ prepared radioactive sources

    SciTech Connect

    Oliveira, P. A.; Santos, J. A. M.

    2014-07-15

    Purpose: An original radionuclide calibrator method for activity determination is presented. The method could be used for intercomparison surveys for short half-life radioactive sources used in Nuclear Medicine, such as{sup 99m}Tc or most positron emission tomography radiopharmaceuticals. Methods: By evaluation of the resulting net optical density (netOD) using a standardized scanning method of irradiated Gafchromic XRQA2 film, a comparison of the netOD measurement with a previously determined calibration curve can be made and the difference between the tested radionuclide calibrator and a radionuclide calibrator used as reference device can be calculated. To estimate the total expected measurement uncertainties, a careful analysis of the methodology, for the case of{sup 99m}Tc, was performed: reproducibility determination, scanning conditions, and possible fadeout effects. Since every factor of the activity measurement procedure can influence the final result, the method also evaluates correct syringe positioning inside the radionuclide calibrator. Results: As an alternative to using a calibrated source sent to the surveyed site, which requires a relatively long half-life of the nuclide, or sending a portable calibrated radionuclide calibrator, the proposed method uses a source preparedin situ. An indirect activity determination is achieved by the irradiation of a radiochromic film using {sup 99m}Tc under strictly controlled conditions, and cumulated activity calculation from the initial activity and total irradiation time. The irradiated Gafchromic film and the irradiator, without the source, can then be sent to a National Metrology Institute for evaluation of the results. Conclusions: The methodology described in this paper showed to have a good potential for accurate (3%) radionuclide calibrators intercomparison studies for{sup 99m}Tc between Nuclear Medicine centers without source transfer and can easily be adapted to other short half-life radionuclides.

  11. Source spectra, moment, and energy for recent eastern mediterranean earthquakes: calibration of international monitoring system stations

    SciTech Connect

    Mayeda, K M; Hofstetter, A; Rodgers, A J; Walter, W R

    2000-07-26

    In the past several years there have been several large (M{sub w} > 7.0) earthquakes in the eastern Mediterranean region (Gulf of Aqaba, Racha, Adana, etc.), many of which have had aftershock deployments by local seismological organizations. In addition to providing ground truth data (GT << 5 km) that is used in regional location calibration and validation, the waveform data can be used to aid in calibrating regional magnitudes, seismic discriminants, and velocity structure. For small regional events (m{sub b} << 4.5), a stable, accurate magnitude is essential in the development of realistic detection threshold curves, proper magnitude and distance amplitude correction processing, formation of an M{sub s}:m{sub b} discriminant, and accurate yield determination of clandestine nuclear explosions. Our approach provides a stable source spectra from which M{sub w} and m{sub b} can be obtained without regional magnitude biases. Once calibration corrections are obtained for earthquakes, the coda-derived source spectra exhibit strong depth-dependent spectral peaking when the same corrections are applied to explosions at the Nevada Test Site (Mayeda and Walter, 1996), chemical explosions in the recent ''Depth of Burial'' experiment in Kazahkstan (Myers et al., 1999), and the recent nuclear test in India. For events in the western U.S. we found that total seismic energy, E, scales as M{sub o}{sup 0.25} resulting in more radiated energy than would be expected under the assumptions of constant stress-drop scaling. Preliminary results for events in the Middle East region also show this behavior, which appears to be the result of intermediate spectra fall-off (f{sup 1.5}) for frequencies ranging between {approx}0.1 and 0.8 Hz for the larger events. We developed a Seismic Analysis Code (SAC) coda processing command that reads in an ASCII flat file that contains calibration information specific for a station and surrounding region, then outputs a coda-derived source spectra

  12. Calibration and Sequence Development Status for the Sample Analysis at Mars Investigation on the Mars Science Laboratory

    NASA Technical Reports Server (NTRS)

    Mahaffy, Paul R.

    2012-01-01

    The measurement goals of the Sample Analysis at Mars (SAM) instrument suite on the "Curiosity" Rover of the Mars Science Laboratory (MSL) include chemical and isotopic analysis of organic and inorganic volatiles for both atmospheric and solid samples [1,2]. SAM directly supports the ambitious goals of the MSL mission to provide a quantitative assessment of habitability and preservation in Gale crater by means of a range of chemical and geological measurements [3]. The SAM FM combined calibration and environmental testing took place primarily in 2010 with a limited set of tests implemented after integration into the rover in January 2011. The scope of SAM FM testing was limited both to preserve SAM consumables such as life time of its electromechanical elements and to minimize the level of terrestrial contamination in the SAM instrument. A more comprehensive calibration of a SAM-like suite of instruments will be implemented in 2012 with calibration runs planned for the SAM testbed. The SAM Testbed is nearly identical to the SAM FM and operates in a ambient pressure chamber. The SAM Instrument Suite: SAM's instruments are a Quadrupole Mass Spectrometer (QMS), a 6-column Gas Chromatograph (GC), and a 2-channel Tunable Laser Spectrometer (TLS). Gas Chromatography Mass Spectrometry is designed for identification of even trace organic compounds. The TLS [5] secures the C, H, and O isotopic composition in carbon dioxide, water, and methane. Sieved materials are delivered from the MSL sample acquisition and processing system to one of68 cups of the Sample Manipulation System (SMS). 59 of these cups are fabricated from inert quartz. After sample delivery, a cup is inserted into one of 2 ovens for evolved gas analysis (EGA ambient to >9500C) by the QMS and TLS. A portion of the gas released can be trapped and subsequently analyzed by GCMS. Nine sealed cups contain liquid solvents and chemical derivatization or thermochemolysis agents to extract and transform polar molecules

  13. CBF/CMRO2 Coupling Measured with Calibrated-BOLD fMRI: Sources of Bias

    PubMed Central

    Leontiev, Oleg; Dubowitz, David J.; Buxton, Richard B.

    2007-01-01

    The coupling between cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) during brain activation can be characterized by an empirical index n, the ratio of fractional CBF changes to fractional CMRO2 changes. Measurements of n have yielded varying results, and it is not known if the observed variability is due to measurement techniques or underlying physiology. The calibrated BOLD approach using hypercapnia offers a promising tool for assessing changes in CBF/CMRO2 coupling in health and disease, but potential systematic errors have not yet been characterized. The goal of this study was to experimentally evaluate the magnitude of bias in the estimate of n that arises from the way in which a region of interest (ROI) is chosen for averaging data, and to relate this potential bias to a more general theoretical consideration of the sources of systematic errors in the calibrated BOLD experiment. Results were compared for different approaches for defining an ROI within the visual cortex based on: 1) retinotopically-defined V1; 2) a functional CBF localizer; and 3) a functional BOLD localizer. Data in V1 yielded a significantly lower estimate of n (2.45) compared to either CBF (n = 3.45) or BOLD (n = 3.18) localizers. Different statistical thresholds produced biases in estimates of n with values ranging from 3.01 (low threshold) to 4.37 (high threshold). Possible sources of the observed biases are discussed. These results underscore the importance of a critical evaluation of the methodology, and the adoption of consistent standards for applying the calibrated BOLD approach to the evaluation of CBF/CMRO2 coupling. PMID:17524665

  14. CBF/CMRO2 coupling measured with calibrated BOLD fMRI: sources of bias.

    PubMed

    Leontiev, Oleg; Dubowitz, David J; Buxton, Richard B

    2007-07-15

    The coupling between cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) during brain activation can be characterized by an empirical index n, the ratio of fractional CBF changes to fractional CMRO2 changes. Measurements of n have yielded varying results, and it is not known if the observed variability is due to measurement techniques or underlying physiology. The calibrated BOLD approach using hypercapnia offers a promising tool for assessing changes in CBF/CMRO2 coupling in health and disease, but potential systematic errors have not yet been characterized. The goal of this study was to experimentally evaluate the magnitude of bias in the estimate of n that arises from the way in which a region of interest (ROI) is chosen for averaging data and to relate this potential bias to a more general theoretical consideration of the sources of systematic errors in the calibrated BOLD experiment. Results were compared for different approaches for defining an ROI within the visual cortex based on: (1) retinotopically defined V1; (2) a functional CBF localizer; and (3) a functional BOLD localizer. Data in V1 yielded a significantly lower estimate of n (2.45) compared to either CBF (n=3.45) or BOLD (n=3.18) localizers. Different statistical thresholds produced biases in estimates of n with values ranging from 3.01 (low threshold) to 4.37 (high threshold). Possible sources of the observed biases are discussed. These results underscore the importance of a critical evaluation of the methodology, and the adoption of consistent standards for applying the calibrated BOLD approach to the evaluation of CBF/CMRO2 coupling.

  15. Calibration of Seismic Sources during a Test Cruise with the new RV SONNE

    NASA Astrophysics Data System (ADS)

    Engels, M.; Schnabel, M.; Damm, V.

    2015-12-01

    During autumn 2014, several test cruises of the brand new German research vessel SONNE were carried out before the first official scientific cruise started in December. In September 2014, BGR conducted a seismic test cruise in the British North Sea. RV SONNE is a multipurpose research vessel and was also designed for the mobile BGR 3D seismic equipment, which was tested successfully during the cruise. We spend two days for calibration of the following seismic sources of BGR: G-gun array (50 l @ 150 bar) G-gun array (50 l @ 207 bar) single GI-gun (3.4 l @ 150 bar) For this experiment two hydrophones (TC4042 from Reson Teledyne) sampling up to 48 kHz were fixed below a drifting buoy at 20 m and 60 m water depth - the sea bottom was at 80 m depth. The vessel with the seismic sources sailed several up to 7 km long profiles around the buoy in order to cover many different azimuths and distances. We aimed to measure sound pressure level (SPL) and sound exposure level (SEL) under the conditions of the shallow North Sea. Total reflections and refracted waves dominate the recorded wave field, enhance the noise level and partly screen the direct wave in contrast to 'true' deep water calibration based solely on the direct wave. Presented are SPL and RMS power results in time domain, the decay with distance along profiles, and the somehow complicated 2D sound radiation pattern modulated by topography. The shading effect of the vessel's hull is significant. In frequency domain we consider 1/3 octave levels and estimate the amount of energy in frequency ranges not used for reflection seismic processing. Results are presented in comparison of the three different sources listed above. We compare the measured SPL decay with distance during this experiment with deep water modeling of seismic sources (Gundalf software) and with published results from calibrations with other marine seismic sources under different conditions: E.g. Breitzke et al. (2008, 2010) with RV Polarstern

  16. SATELLITE-MOUNTED LIGHT SOURCES AS PHOTOMETRIC CALIBRATION STANDARDS FOR GROUND-BASED TELESCOPES

    SciTech Connect

    Albert, J.

    2012-01-15

    A significant and growing portion of systematic error on a number of fundamental parameters in astrophysics and cosmology is due to uncertainties from absolute photometric and flux standards. A path toward achieving major reduction in such uncertainties may be provided by satellite-mounted light sources, resulting in improvement in the ability to precisely characterize atmospheric extinction, and thus helping to usher in the coming generation of precision results in astronomy. Using a campaign of observations of the 532 nm pulsed laser aboard the CALIPSO satellite, collected using a portable network of cameras and photodiodes, we obtain initial measurements of atmospheric extinction, which can apparently be greatly improved by further data of this type. For a future satellite-mounted precision light source, a high-altitude balloon platform under development (together with colleagues) can provide testing as well as observational data for calibration of atmospheric uncertainties.

  17. SEVEN-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE (WMAP ) OBSERVATIONS: PLANETS AND CELESTIAL CALIBRATION SOURCES

    SciTech Connect

    Weiland, J. L.; Odegard, N.; Hill, R. S.; Greason, M. R.; Wollack, E.; Hinshaw, G.; Kogut, A.; Bennett, C. L.; Gold, B.; Larson, D.; Dunkley, J.; Halpern, M.; Komatsu, E.; Limon, M.; Meyer, S. S.; Nolta, M. R.; Smith, K. M.; Spergel, D. N.

    2011-02-01

    We present WMAP seven-year observations of bright sources which are often used as calibrators at microwave frequencies. Ten objects are studied in five frequency bands (23-94 GHz): the outer planets (Mars, Jupiter, Saturn, Uranus, and Neptune) and five fixed celestial sources (Cas A, Tau A, Cyg A, 3C274, and 3C58). The seven-year analysis of Jupiter provides temperatures which are within 1{sigma} of the previously published WMAP five-year values, with slightly tighter constraints on variability with orbital phase (0.2% {+-} 0.4%), and limits (but no detections) on linear polarization. Observed temperatures for both Mars and Saturn vary significantly with viewing geometry. Scaling factors are provided which, when multiplied by the Wright Mars thermal model predictions at 350 {mu}m, reproduce WMAP seasonally averaged observations of Mars within {approx}2%. An empirical model is described which fits brightness variations of Saturn due to geometrical effects and can be used to predict the WMAP observations to within 3%. Seven-year mean temperatures for Uranus and Neptune are also tabulated. Uncertainties in Uranus temperatures are 3%-4% in the 41, 61, and 94 GHz bands; the smallest uncertainty for Neptune is 8% for the 94 GHz band. Intriguingly, the spectrum of Uranus appears to show a dip at {approx}30 GHz of unidentified origin, although the feature is not of high statistical significance. Flux densities for the five selected fixed celestial sources are derived from the seven-year WMAP sky maps and are tabulated for Stokes I, Q, and U, along with polarization fraction and position angle. Fractional uncertainties for the Stokes I fluxes are typically 1% to 3%. Source variability over the seven-year baseline is also estimated. Significant secular decrease is seen for Cas A and Tau A: our results are consistent with a frequency-independent decrease of about 0.53% per year for Cas A and 0.22% per year for Tau A. We present WMAP polarization data with uncertainties of a

  18. Performance of thin CaSO4:Dy pellets for calibration of a Sr90+Y90 source

    NASA Astrophysics Data System (ADS)

    Oliveira, M. L.; Caldas, L. V. E.

    2007-09-01

    Because of the radionuclide long half-life, Sr90+Y90, plane or concave sources, utilized in brachytherapy, have to be calibrated initially by the manufacturer and then routinely while they are utilized. Plane applicators can be calibrated against a conventional extrapolation chamber, but concave sources, because of their geometry, should be calibrated using relative dosimeters, as thermoluminescent (TL) materials. Thin CaSO4:Dy pellets are produced at IPEN specially for beta radiation detection. Previous works showed the feasibility of this material in the dosimetry of Sr90+Y90 sources in a wide range of absorbed dose in air. The aim of this work was to study the usefulness of these pellets for the calibration of a Sr90+Y90 concave applicator. To reach this objective, a special phantom was designed and manufactured in PTFE with semi spherical geometry. Because of the dependence of the TL response on the mass of the pellet, the response of each pellet was normalized by its mass in order to reduce the dispersion on TL response. Important characteristics of this material were obtained in reference of a standard Sr90+Y90 source, and the pellets were calibrated against a plane applicator; then they were utilized to calibrate the concave applicator.

  19. Exploring a Black Body Source as an Absolute Radiometric Calibration Standard and Comparison with a NIST Traced Lamp Standard

    NASA Technical Reports Server (NTRS)

    Green, Robert O.; Chrien, Thomas; Sarture, Chuck

    2001-01-01

    Radiometric calibration of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) is required for the scientific research and application objectives pursued with the spectroscopic measurements. Specifically calibration is required for: inter-comparison of AVIRIS data measured at different locations and at different times; analysis of AVIRIS data with data measured by other instruments; and analysis of AVIRIS data in conjunction with computer models. The primary effect of radiometric calibration is conversion of AVIRIS instrument response values (digitized numbers, or DN) to units of absolute radiance. For example, a figure shows the instrument response spectrum measured by AVIRIS over a portion of Rogers Dry Lake, California, and another figure shows the same spectrum calibrated to radiance. Only the calibrated spectrum may be quantitatively analyzed for science research and application objectives. Since the initial development of the AVIRIS instrument-radiometric calibration has been based upon a 1000-W irradiance lamp with a calibration traced to the National Institute of Standards and Technology (NIST). There are several advantages to this irradiance-lamp calibration approach. First, the considerable effort of NIST backs up the calibration. Second, by changing the distance to the lamp, the output can closely span the radiance levels measured by AVIRIS. Third, this type of standard is widely used. Fourth, these calibrated lamps are comparatively inexpensive. Conversely, there are several disadvantages to this approach as well. First, the lamp is not a primary standard. Second, the lamp output characteristics may change in an unknown manner through time. Third, it is difficult to assess, constrain, or improve the calibration uncertainty delivered with the lamp. In an attempt to explore the effect and potentially address some of these disadvantages a set of analyses and measurements comparing an irradiance lamp with a black-body source have been completed

  20. Standardisation of elemental analytical techniques applied to provenance studies of archaeological ceramics: an inter laboratory calibration study.

    PubMed

    Hein, A; Tsolakidou, A; Iliopoulos, I; Mommsen, H; Buxeda i Garrigós, J; Montana, G; Kilikoglou, V

    2002-04-01

    Chemical analysis is a well-established procedure for the provenancing of archaeological ceramics. Various analytical techniques are routinely used and large amounts of data have been accumulated so far in data banks. However, in order to exchange results obtained by different laboratories, the respective analytical procedures need to be tested in terms of their inter-comparability. In this study, the schemes of analysis used in four laboratories that are involved in archaeological pottery studies on a routine basis were compared. The techniques investigated were neutron activation analysis (NAA), X-ray fluorescence analysis (XRF), inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). For this comparison series of measurements on different geological standard reference materials (SRM) were carried out and the results were statistically evaluated. An attempt was also made towards the establishment of calibration factors between pairs of analytical setups in order to smooth the systematic differences among the results.

  1. Analysis and Calibration of Sources of Electronic Error in PSD Sensor Response

    PubMed Central

    Rodríguez-Navarro, David; Lázaro-Galilea, José Luis; Bravo-Muñoz, Ignacio; Gardel-Vicente, Alfredo; Tsirigotis, Georgios

    2016-01-01

    In order to obtain very precise measurements of the position of agents located at a considerable distance using a sensor system based on position sensitive detectors (PSD), it is necessary to analyze and mitigate the factors that generate substantial errors in the system’s response. These sources of error can be divided into electronic and geometric factors. The former stem from the nature and construction of the PSD as well as the performance, tolerances and electronic response of the system, while the latter are related to the sensor’s optical system. Here, we focus solely on the electrical effects, since the study, analysis and correction of these are a prerequisite for subsequently addressing geometric errors. A simple calibration method is proposed, which considers PSD response, component tolerances, temperature variations, signal frequency used, signal to noise ratio (SNR), suboptimal operational amplifier parameters, and analog to digital converter (ADC) quantitation SNRQ, etc. Following an analysis of these effects and calibration of the sensor, it was possible to correct the errors, thus rendering the effects negligible, as reported in the results section. PMID:27136562

  2. Study for the analysis of the observations, and numerical data representing the planets as far-infrared calibration sources

    NASA Technical Reports Server (NTRS)

    Wu, Shi Tsan; Zhou, Minggang

    1994-01-01

    The existing radiative transfer and inversion programs will be modified for application to the atmospheres of Uranus, Neptune, and Jupiter. The programs will be employed for analysis of KAO planetary observations in order to develop far infrared photometric calibration standards. This work will be carried out on MSFC computers. The expected end product of this task is a working program for analysis of the observations, and numerical data representing the planets as far-infrared calibration sources.

  3. Laboratory calibration of a POCIS-like sampler based on molecularly imprinted polymers for glyphosate and AMPA sampling in water.

    PubMed

    Berho, Catherine; Claude, Bérengère; Coisy, Emeline; Togola, Anne; Bayoudh, Sami; Morin, Philippe; Amalric, Laurence

    2017-03-01

    For more than 15 years, integrative passive sampling has been successfully used for monitoring contaminants in water, but no passive sampling device exists for strongly polar organic compounds, such as glyphosate. We thus propose a polar organic chemical integrative sampler (POCIS)-like tool dedicated to glyphosate and its main degradation product aminomethylphosphonic acid (AMPA), and describe the laboratory calibration of such a tool for calculating the sampling rates of glyphosate and AMPA. This passive sampler consists of a POCIS with molecularly imprinted polymer as a receiving phase and a polyethersulfone diffusion membrane. The calibration experiment for the POCIS was conducted for 35 days in a continuous water-flow-through exposure system. The calibration results show that the sampling rates are 111 and 122 mL day(-1) for glyphosate and AMPA respectively, highlighting the potential interest in and the applicability of this method for environmental monitoring. The influence of membrane porosity on the glyphosate sampling rate was also tested. Graphical Abstract ᅟ.

  4. Dual-channel photoacoustic hygrometer for airborne measurements: background, calibration, laboratory and in-flight intercomparison tests

    NASA Astrophysics Data System (ADS)

    Tátrai, D.; Bozóki, Z.; Smit, H.; Rolf, C.; Spelten, N.; Krämer, M.; Filges, A.; Gerbig, C.; Gulyás, G.; Szabó, G.

    2015-01-01

    This paper describes a tunable diode laser-based dual-channel photoacoustic (PA) humidity measuring system primarily designed for aircraft-based environment research. It is calibrated for total pressure and water vapor (WV) volume mixing ratios (VMRs) possible during airborne applications. WV VMR is calculated by using pressure-dependent calibration curves and a cubic spline interpolation method. Coverage of the entire atmospheric humidity concentration range that might be encountered during airborne measurements is facilitated by applying an automated sensitivity mode switching algorithm. The calibrated PA system was validated through laboratory and airborne intercomparisons, which proved that the repeatability, the estimated accuracy and the response time of the system are 0.5 ppmV or 0.5% of the actual reading (whichever value is the greater), 5% of the actual reading within the VMR range of 1-12 000 ppmV and 2 s, respectively. The upper detection limit of the system is theoretically about 85 000 ppmV, limited only by condensation of water vapor on the walls of the 318 K heated PA cells and inlet lines, and was experimentally verified up to 20 000 ppmV. The unique advantage of the presented system is its applicability for simultaneous water vapor and total water volume mixing ratio measurements.

  5. GOSAT-OCO-2 synergetic CO2 observations over calibration & validation sites and large emission sources

    NASA Astrophysics Data System (ADS)

    Kuze, A.; Shiomi, K.; Suto, H.; Kataoka, F.; Crisp, D.; Schwandner, F. M.; Bruegge, C. J.; Taylor, T.; Kawakami, S.

    2015-12-01

    GOSAT and OCO-2 have different observation strategies. TANSO-FTS onboard GOSAT has wide spectral coverage from SWIR to TIR and an agile pointing system at the expense of spatial context, while OCO-2 targets CO2with higher spatial resolution using imaging grating spectrometers. Since the early phase of the two projects, both teams have worked in calibration and validation to demonstrate the effectiveness of satellite greenhouse gases observation. In 2008, the pre-launch cross-calibration agreement between GOSAT and OCO radiometers was better than 2% when measuring the traceable GOSAT calibration sphere (Sakuma et. al, 2010). Since GOSAT's launch in 2009, annual joint vicarious calibration campaigns at the Railroad Valley (RRV) playa have estimated radiometric degradation factors with time at an uncertainty of 7%. (Kuze et al., 2014). After OCO-2 launch, two independent measurements can now be compared to distinguish common forward calculation errors such as molecule absorption line parameters, solar lines and light-path modification by aerosol scattering from instrument-specific errors. On 25 Mach 2015, both GOSAT and OCO-2 targeted RRV simultaneously. The measured radiance spectra at the top of the atmosphere agree within 5% for all common bands. On June 29 and July 1 during the 7th RRV campaign, coincidence observation of GOSAT, OCO-2, AJAX airplane, radiosonde, and FTS and radiometers on the ground, provided surface albedo, BRDF, temperature, humidity CO2 and CH4 density to demonstrate consistency between forward radiative transfer calculation and satellite measured data. Both GOSAT and OCO-2 have been regularly targeting the TCCON site at Lamont and large emission sources such as mega cities and oil fields and glint over the ocean. Retrieved parameters such as surface albedo, pressure, column averaged mole fraction and aerosol related parameters can be compared firstly where aerosol optical thickness is low and topography is flat, and then over aerosol

  6. Medicina array demonstrator: calibration and radiation pattern characterization using a UAV-mounted radio-frequency source

    NASA Astrophysics Data System (ADS)

    Pupillo, G.; Naldi, G.; Bianchi, G.; Mattana, A.; Monari, J.; Perini, F.; Poloni, M.; Schiaffino, M.; Bolli, P.; Lingua, A.; Aicardi, I.; Bendea, H.; Maschio, P.; Piras, M.; Virone, G.; Paonessa, F.; Farooqui, Z.; Tibaldi, A.; Addamo, G.; Peverini, O. A.; Tascone, R.; Wijnholds, S. J.

    2015-06-01

    One of the most challenging aspects of the new-generation Low-Frequency Aperture Array (LFAA) radio telescopes is instrument calibration. The operational LOw-Frequency ARray (LOFAR) instrument and the future LFAA element of the Square Kilometre Array (SKA) require advanced calibration techniques to reach the expected outstanding performance. In this framework, a small array, called Medicina Array Demonstrator (MAD), has been designed and installed in Italy to provide a test bench for antenna characterization and calibration techniques based on a flying artificial test source. A radio-frequency tone is transmitted through a dipole antenna mounted on a micro Unmanned Aerial Vehicle (UAV) (hexacopter) and received by each element of the array. A modern digital FPGA-based back-end is responsible for both data-acquisition and data-reduction. A simple amplitude and phase equalization algorithm is exploited for array calibration owing to the high stability and accuracy of the developed artificial test source. Both the measured embedded element patterns and calibrated array patterns are found to be in good agreement with the simulated data. The successful measurement campaign has demonstrated that a UAV-mounted test source provides a means to accurately validate and calibrate the full-polarized response of an antenna/array in operating conditions, including consequently effects like mutual coupling between the array elements and contribution of the environment to the antenna patterns. A similar system can therefore find a future application in the SKA-LFAA context.

  7. GT0 Explosion Sources for IMS Infrasound Calibration: Charge Design and Yield Estimation from Near-source Observations

    NASA Astrophysics Data System (ADS)

    Gitterman, Y.; Hofstetter, R.

    2014-03-01

    Three large-scale on-surface explosions were conducted by the Geophysical Institute of Israel (GII) at the Sayarim Military Range, Negev desert, Israel: about 82 tons of strong high explosives in August 2009, and two explosions of about 10 and 100 tons of ANFO explosives in January 2011. It was a collaborative effort between Israel, CTBTO, USA and several European countries, with the main goal to provide fully controlled ground truth (GT0) infrasound sources, monitored by extensive observations, for calibration of International Monitoring System (IMS) infrasound stations in Europe, Middle East and Asia. In all shots, the explosives were assembled like a pyramid/hemisphere on dry desert alluvium, with a complicated explosion design, different from the ideal homogenous hemisphere used in similar experiments in the past. Strong boosters and an upward charge detonation scheme were applied to provide more energy radiated to the atmosphere. Under these conditions the evaluation of the actual explosion yield, an important source parameter, is crucial for the GT0 calibration experiment. Audio-visual, air-shock and acoustic records were utilized for interpretation of observed unique blast effects, and for determination of blast wave parameters suited for yield estimation and the associated relationships. High-pressure gauges were deployed at 100-600 m to record air-blast properties, evaluate the efficiency of the charge design and energy generation, and provide a reliable estimation of the charge yield. The yield estimators, based on empirical scaled relations for well-known basic air-blast parameters—the peak pressure, impulse and positive phase duration, as well as on the crater dimensions and seismic magnitudes, were analyzed. A novel empirical scaled relationship for the little-known secondary shock delay was developed, consistent for broad ranges of ANFO charges and distances, which facilitates using this stable and reliable air-blast parameter as a new potential

  8. Preparation and characterisation of ceramic-based thoron sources for thoron calibration chamber.

    PubMed

    Csordás, A; Fábián, F; Horváth, M; Hegedűs, M; Somlai, J; Kovács, T

    2015-11-01

    The aim of this study is to explore the correlations between the properties of the source's material and the thoron flux produced. This means a complex procedure that involves morphological characterisation (the determination of specific surface area and pore size distribution) and thoron emanation and exhalation measurements as well. In this work, the preparation of 27 thoron sources has been carried out. Three types of ceramics with different morphological properties were used as a matrix material with three different thorium contents. Spheres were formed from the dollop, and they were fired at different temperatures (200, 600 and 900°C). The phase analysis of the samples was performed by powder X-ray diffraction. The pore size distribution was determined by mercury penetration. The thoron emanation was measured using an accumulation chamber; the measured thoron emanation coefficients were from 0.34 ± 0.03 to 7.69 ± 0.13 %. Based on the results, the preparation parameters of the thoron source optimised for the calibration procedure have been given.

  9. Broadband calibration of the R/V Marcus G. Langseth four-string seismic sources

    NASA Astrophysics Data System (ADS)

    Tolstoy, M.; Diebold, J.; Doermann, L.; Nooner, S.; Webb, S. C.; Bohnenstiehl, D. R.; Crone, T. J.; Holmes, R. C.

    2009-08-01

    The R/V Marcus G. Langseth is the first 3-D seismic vessel operated by the U.S. academic community. With up to a four-string, 36-element source and four 6-km-long solid state hydrophone arrays, this vessel promises significant new insights into Earth science processes. The potential impact of anthropogenic sound sources on marine life is an important topic to the marine seismic community. To ensure that operations fully comply with existing and future marine mammal permitting requirements, a calibration experiment was conducted in the Gulf of Mexico in 2007-2008. Results are presented from deep (˜1.6 km) and shallow (˜50 m) water sites, obtained using the full 36-element (6600 cubic inches) seismic source. This array configuration will require the largest safety radii, and the deep and shallow sites provide two contrasting operational environments. Results show that safety radii and the offset between root-mean-square and sound exposure level measurements were highly dependent on water depth.

  10. Pt/Pd thermocouple resilience over 327 operating hours in an industrial calibration laboratory

    NASA Astrophysics Data System (ADS)

    Elliott, C. J.; Pearce, J. V.; Machin, G.; Ford, T.; Hicks, K.

    2013-09-01

    Two Pt/Pd thermocouples have been manufactured industrially at CCPI-Europe to a robust design optimised by NPL. The first has been exposed to temperatures up to 1000 °C for 93 operating hours and the second exposed to higher temperatures (up to 1300 °C) for 327 operating hours, over the course of a year. No significant drift is observed in the temperature measurement for either Pt/Pd thermocouple, when compared against reference Type R thermocouples. This work demonstrates the long-term stability and reliability of Pt/Pd thermocouples in use within an industrial calibration environment with this optimised, robust design.

  11. Pinon Pine Tree Study, Los Alamos National Laboratory: Source document

    SciTech Connect

    P. R. Fresquez; J. D. Huchton; M. A. Mullen; L. Naranjo, Jr.

    2000-01-01

    One of the dominant tree species growing within and around Los Alamos National Laboratory (LANL), Los Alamos, NM, lands is the pinon pine (Pinus edulis) tree. Pinon pine is used for firewood, fence posts, and building materials and is a source of nuts for food--the seeds are consumed by a wide variety of animals and are also gathered by people in the area and eaten raw or roasted. This study investigated the (1) concentration of {sup 3}H, {sup 137}Cs, {sup 90}Sr, {sup tot}U, {sup 238}Pu, {sup 239,240}Pu, and {sup 241}Am in soils (0- to 12-in. [31 cm] depth underneath the tree), pinon pine shoots (PPS), and pinon pine nuts (PPN) collected from LANL lands and regional background (BG) locations, (2) concentrations of radionuclides in PPN collected in 1977 to present data, (3) committed effective dose equivalent (CEDE) from the ingestion of nuts, and (4) soil to PPS to PPN concentration ratios (CRs). Most radionuclides, with the exception of {sup 3}H in soils, were not significantly higher (p < 0.10) in soils, PPS, and PPN collected from LANL as compared to BG locations, and concentrations of most radionuclides in PPN from LANL have decreased over time. The maximum net CEDE (the CEDE plus two sigma minus BG) at the most conservative ingestion rate (10 lb [4.5 kg]) was 0.0018 mrem (0.018 {micro}Sv). Soil-to-nut CRs for most radionuclides were within the range of default values in the literature for common fruits and vegetables.

  12. Laboratory calibrations of the PP-SESAME instrument on Philae for measuring the cometary surface permittivity

    NASA Astrophysics Data System (ADS)

    Hamelin, M.; Le Gall, A.; Caujolle-Bert, S.; Schmidt, W.; Grard, R.; Laasko, H.; Ciarletti, V.; Seidensticker, K.

    2013-09-01

    The complex permittivity of terrestrial and planetary grounds can be derived from Mutual Impedance (MI) measurements using a four-electrode array [1]; the system is working at a fixed frequency with the electrodes not necessarily in contact with the ground and with a dedicated electronic system. This concept was used to build the Permittivity Probe (PP) as part of the SESAME experiment of the Philae Rosetta cometary lander. However severe constraints due to the payload facilities and to the particular environment lead to the actual design of the instrument. Unfortunately it was not possible to perform calibrations of the full system before lauch and the ground model consists of several parts used by various instruments. Here we report the results of basic calibration tests performed with a model of the Philae Landing Gear built in DLR. These tests involve only the three feet electrodes and a mockup of the the Philae body with very simple and well defined targets for characterizing the instrument. Further measurements on natural targets would be the next step.

  13. Laboratory data on coarse-sediment transport for bedload-sampler calibrations

    USGS Publications Warehouse

    Hubbell, David Wellington; Stevens, H.H.; Skinner, J.V.; Beverage, J.P.

    1987-01-01

    A unique facility capable of recirculating and continuously measuring the transport rates of sediment particles ranging in size from about 1 to 75 millimeters in diameter was designed and used in an extensive program involving the calibration of bedload samplers. The facility consisted of a 9-footwide by 6-foot-deep by 272-foot-long rectangular channel that incorporated seven automated collection pans and a sedimentreturn system. The collection pans accumulated, weighed, and periodically dumped bedload falling through a slot in the channel floor. Variations of the Helley-Smith bedload sampler, an Arnhem sampler, and two VUV-type samplers were used to obtain transport rates for comparison with rates measured at the bedload slot (trap). Tests were conducted under 20 different hydraulic and sedimentologic conditions (runs) with 3 uniform-size bed materials and a bed-material mixture. Hydraulic and sedimentologic data collected concurrently with the calibration measurements are described and, in part, summarized in tabular and graphic form. Tables indicate the extent of the data, which are available on magnetic media. The information includes sediment-transport rates; particle-size distributions; water discharges, depths, and slopes; longitudinal profiles of streambed-surface elevations; and temporal records of streambed-surface elevations at fixed locations.

  14. Laboratory Testing and Calibration of the Nuclei-Mode Aerosol Size Spectrometer

    NASA Technical Reports Server (NTRS)

    Brock, Charles A.

    1999-01-01

    This grant was awarded to complete testing and calibration of a new instrument, the nuclei-mode aerosol size spectrometer (N-MASS), following its use in the WB-57F Aerosol Measurement (WAM) campaign in early 1998. The N-MASS measures the size distribution of particles in the 4-60 nm diameter range with 1-Hz response at typical free tropospheric conditions. Specific tasks to have been completed under the auspices of this award were: 1) to experimentally determine the instrumental sampling efficiency; 2) to determine the effects of varying temperatures and flows on N-MASS performance; and 3) to calibrate the N-MASS at typical flight conditions as operated in WAM. The work outlined above has been completed, and a journal manuscript based on this work and that describes the performance of the N-MASS is in preparation. Following a brief description of the principles of operation of the instrument, the major findings of this study are described.

  15. Global Inter-Laboratory Fecal Source Identification Methods Comparison Study

    EPA Science Inventory

    Source tracking is key to identifying sources of fecal contamination for remediation as well as risk assessment. Previous intra- and inter-lab studies have investigated the performance of human and cow-associated source tracking markers, as well as library-dependent fecal source ...

  16. Importance of Temperature Calibration for Sunset Laboratory Carbon Analyzer: NIOSH and IMPROVE Temperature Protocols

    EPA Science Inventory

    The Sunset Laboratory Dual-Optical Carbonaceous Analyzer that simultaneously measures transmission and reflectance signals is widely used in thermal-optical analysis of particulate matter samples. Most often it is used to measure total carbon (TC), organic carbon (OC), and eleme...

  17. A calibrator based on the use of low-coherent light source straightness interferometer and compensation method.

    PubMed

    Lin, Shyh-Tsong; Yeh, Sheng-Lih; Chiu, Chi-Shang; Huang, Mou-Shan

    2011-10-24

    A calibrator utilizing a low-coherent light source straightness interferometer and a compensation method is introduced for straightness measurements in this paper. Where the interference pattern, which is modulated by an envelope function, generated by the interferometer undergoes a shifting as the Wolaston prism of the interferometer experiences a lateral displacement, and the compensation method senses the displacement by driving the prism back to the position to restore the pattern. A setup, which is with a measurement sensitivity of 36.6°/μm, constructed for realizing the calibrator is demonstrated. The experimental results from the uses of the setup reveal that the setup is with a measurement resolution and stability of 0.019 and 0.08 μm, respectively, validate the calibrator, and confirm the calibrator's applicability of straightness measurements and advantage of extensible working distance.

  18. Neutron Arm Study and Calibration for the GEn Experiment at Thomas Jefferson National Laboratory

    SciTech Connect

    Ngo, Timothy

    2007-07-01

    The measurement of the neutron electric form factor, G$n\\atop{e}$, will allow us to solve indirectly for the quark charge distribution inside of the neutron. With the equipment at Jefferson Lab we have measured G$n\\atop{e}$ at four momentum transfer values of Q2 at 1.3, 2.4 and 3.4 (GeV/c)2 using a polarized electron beam and polarized Helium target. The scattered electrons off of the Helium target are detected in the BigBite spectrometer and the recoiling neutrons from the Helium are detected in the Neutron Arm, which is composed of an array of scintillators. The main focus of this thesis will be devoted to the geometry, timing and energy calibrations of the Neutron Arm.

  19. A radio telescope for the calibration of radio sources at 32 gigahertz

    NASA Technical Reports Server (NTRS)

    Gatti, M. S.; Stewart, S. R.; Bowen, J. G.; Paulsen, E. B.

    1994-01-01

    A 1.5-m-diameter radio telescope has been designed, developed, and assembled to directly measure the flux density of radio sources in the 32-GHz (Ka-band) frequency band. The main goal of the design and development was to provide a system that could yield the greatest absolute accuracy yet possible with such a system. The accuracy of the measurements have a heritage that is traceable to the National Institute of Standards and Technology. At the present time, the absolute accuracy of flux density measurements provided by this telescope system, during Venus observations at nearly closest approach to Earth, is plus or minus 5 percent, with an associated precision of plus or minus 2 percent. Combining a cooled high-electron mobility transistor low-noise amplifier, twin-beam Dicke switching antenna, and accurate positioning system resulted in a state-of-the-art system at 32 GHz. This article describes the design and performance of the system as it was delivered to the Owens Valley Radio Observatory to support direct calibrations of the strongest radio sources at Ka-band.

  20. Dust Impact Monitor DIM onboard Rosetta/Philae: Laboratory Calibration with Impact Experiments

    NASA Astrophysics Data System (ADS)

    Krüger, H.; Ossowski, T.; Seidensticker, K.; Apathy, I.; Fischer, H.-H.; Hirn, A.; Jünemann, M.; Loose, A.; Peter, A.; Sperl, M.

    2011-10-01

    The Rosetta lander spacecraft Philae, which will land on the surface of comet 67P/Churyumov- Gerasimenko in late 2014, is equipped with the Dust Impact Monitor instrument (DIM). The DIM sensor, which is part of the SESAME instrument package [Seidensticker et al., 2007], consists of three piezoelectric detectors, each one mounted on the outer side of a cube facing in three orthogonal directions. The total sensor area is approximately 70 cm2. DIM will measure impacts of sub-millimeter and millimeter sized ice and dust particles that are emitted from the nucleus and transported into the cometary coma by the escaping gas flow. A grain-size dependent fraction of the emitted grains is expected to fall back to the nucleus surface due to gravity. DIM will be able to detect both these components, the backfalling particles as well as the grains hitting the detector on direct trajectories from the surface. With DIM we will be able to measure fluxes, impact directions as well as the speed and size of the impacting cometary particles. Two particle acceleration devices for impact calibration experiments are presently available at Max- Planck-Institut für Sonnensystemforschung (MPS), Katlenburg-Lindau: With (a) a dedicated dropping device and (b) a small air gun we can simulate impacts with particles of different materials (steel, glass, ruby, polyethylen, etc.), radii between 0.2 and 1mm and impact speeds up to 2msec-1. We have performed a large number of impact experiments with two flight spare units of the DIM sensor at MPS. We present the results from our impact experiments and discuss their implications for the calibration of the DIM flight instrument.

  1. Students as Signal Sources in the Biomedical Engineering Laboratory

    DTIC Science & Technology

    2007-11-02

    Laboratory courses are used throughout Biomedical Engineering curriculum to give students hands-on, practical experience in scientific, computing and... biomedical engineering principles as well as increase student appreciation of the scientific process.

  2. Laboratory Simulation of Impacts upon Aluminum Foils of the Stardust Spacecraft: Calibration of Dust Particle Size from Comet Wild 2

    NASA Technical Reports Server (NTRS)

    Kearsley, A. T.; Burchell, M. J.; Horz, F.; Cole, M. J.; Schwandt, C. S.

    2006-01-01

    Metallic aluminium alloy foils exposed on the forward, comet-facing surface of the aerogel tray on the Stardust spacecraft are likely to have been impacted by the same cometary particle population as the dedicated impact sensors and the aerogel collector. The ability of soft aluminium alloy to record hypervelocity impacts as bowl-shaped craters offers an opportunistic substrate for recognition of impacts by particles of a wide potential size range. In contrast to impact surveys conducted on samples from low Earth orbit, the simple encounter geometry for Stardust and Wild 2, with a known and constant spacecraft-particle relative velocity and effective surface-perpendicular impact trajectories, permits closely comparable simulation in laboratory experiments. For a detailed calibration programme we have selected a suite of spherical glass projectiles of uniform density and hardness characteristics, with well-documented particle size range from 10 microns to nearly 100 microns. Light gas gun buckshot firings of these particles at approximately 6km s)exp -1) onto samples of the same foil as employed on Stardust have yielded large numbers of craters. Scanning electron microscopy of both projectiles and impact features has allowed construction of a calibration plot, showing a linear relationship between impacting particle size and impact crater diameter. The close match between our experimental conditions and the Stardust mission encounter parameters should provide another opportunity to measure particle size distributions and fluxes close to the nucleus of Wild 2, independent of the active impact detector instruments aboard the Stardust spacecraft.

  3. Polar organic chemical integrative sampler (POCIS) uptake rates for 17 polar pesticides and degradation products: laboratory calibration.

    PubMed

    Ibrahim, Imtiaz; Togola, Anne; Gonzalez, Catherine

    2013-06-01

    Polar organic chemical integrative samplers (POCIS) are useful for monitoring a wide range of chemicals, including polar pesticides, in water bodies. However, few calibration data are available, which limits the use of these samplers for time-weighted average concentration measurements in an aquatic medium. This work deals with the laboratory calibration of the pharmaceutical configuration of a polar organic chemical integrative sampler (pharm-POCIS) for calculating the sampling rates of 17 polar pesticides (1.15 ≤  logK(ow) ≤ 3.71) commonly found in water. The experiment, conducted for 21 days in a continuous water flow-through exposure system, showed an integrative accumulation of all studied pesticides for 15 days. Three compounds (metalaxyl, azoxystrobine, and terbuthylazine) remained integrative for the 21-day experiment. The sampling rates measured ranged from 67.9 to 279 mL day(-1) and increased with the hydrophobicity of the pesticides until reaching a plateau where no significant variation in sampling rate is observed when increasing the hydrophobicity.

  4. Calibrating nonlinear volcano deformation source parameters in FEMs: The pinned mesh perturbation method. (Invited)

    NASA Astrophysics Data System (ADS)

    Masterlark, T.; Stone, J.; Feigl, K.

    2010-12-01

    The internal structure, loading processes, and effective boundary conditions of a volcano control the deformation that we observe at the Earth’s surface. Forward models of these internal structures and processes allow us to predict the surface deformation. In practice, we are faced with the inverse situation of using surface observations (e.g., InSAR and GPS) to characterize the inaccessible internal structures and processes. Distortions of these characteristics are tied to our ability to: 1) identify and resolve the internal structure; 2) simulate the internal processes over a problem domain having this internal structure; and 3) calibrate parameters that describe these internal processes to the observed deformation. Relatively simple analytical solutions for deformation sources (such as a pressurized magma chamber) embedded in a homogeneous, elastic half-space are commonly used to simulate observed volcano deformation, because they are computationally inexpensive, and thus easily integrated into inverse analyses that seek to characterize the source position and magnitude. However, the half-space models generally do not adequately represent internal distributions of material properties and complex geometric configurations, such as topography, of volcano deformational systems. These incompatibilities are known to severely bias both source parameter estimations and forward model calculations of deformation and stress. Alternatively, a Finite Element Model (FEM) can simulate the elastic response to a pressurized magma chamber over a domain having arbitrary geometry and distribution of material properties. However, the ability to impose perturbations of the source position parameters and automatically reconstruct an acceptable mesh has been an obstacle to implementing FEM-based nonlinear inverse methods to estimate the position of a deformation source. Using InSAR-observed deflation of Okmok volcano, Alaska, during its 1997 eruption as an example, we present the

  5. Metrological tests of a 200 L calibration source for HPGE detector systems for assay of radioactive waste drums.

    PubMed

    Boshkova, T; Mitev, K

    2016-03-01

    In this work we present test procedures, approval criteria and results from two metrological inspections of a certified large volume (152)Eu source (drum about 200L) intended for calibration of HPGe gamma assay systems used for activity measurement of radioactive waste drums. The aim of the inspections was to prove the stability of the calibration source during its working life. The large volume source was designed and produced in 2007. It consists of 448 identical sealed radioactive sources (modules) apportioned in 32 transparent plastic tubes which were placed in a wooden matrix which filled the drum. During the inspections the modules were subjected to tests for verification of their certified characteristics. The results show a perfect compliance with the NIST basic guidelines for the properties of a radioactive certified reference material (CRM) and demonstrate the stability of the large volume CRM-drum after 7 years of operation.

  6. Laboratory investigation of drinking water sources of Kangra, Himachal Pradesh.

    PubMed

    Thakur, S D; Panda, A K

    2012-06-01

    A total of 70 drinking water sources including piped water supply (n = 36), ground water sources (n = 24, hand pumps and bore wells) and natural water sources (n = 10, springs/step-wells) from various parts of district Kangra, Himachal Pradesh were investigated for their suitability for drinking purpose by presumptive coliform test. Three samples were collected from each source during different parts of the year. Piped water sources (91.7%) were most contaminated followed by natural water sources (90%) and ground water sources (62.5%). 70.5% of the total water samples (n = 210) were positive for coliforms. All the three samples from 8.3% (n = 3), 37.5% (n = 9) and 10% (n = 1) piped water, ground water and natural sources respectively, were negative for coliform organisms. A variety of organisms including Proteus, Klebsiella, Citrobacter, Escherichia coli (E. coli), Pasteurella, Enterobacter and Serratia liquefaciens were isolated from water samples positive for coliforms in presumptive coliform test. Thermo-tolerant coliform organisms; Escherichia coli, Citrobacter, Klebsiella and Enterobacter were 71.2% (n = 52) of the total bacterial isolations. These findings suggest absence of adequate treatment and disinfection of the water sources supplying drinking water in district Kangra.

  7. Improvement of the WBC calibration of the Internal Dosimetry Laboratory of the CDTN/CNEN using the physical phantom BOMAB and MCNPX code.

    PubMed

    Paiva, Fernanda Guerra; Oliveira, Arno Heeren de; Mendes, Bruno Melo; Pinto, Jacqueline Rosária; Filho, Nelson do Nascimento A; Dantas, Bernardo Maranhão; Dantas, Ana Letícia A; Silva, Teógenes Augusto da; Lacerda, Marco Aurélio de Sousa; Fonseca, Telma Cristina Ferreira

    2016-11-01

    The Laboratory of Internal Dosimetry of the Center for Development of Nuclear Technology (LDI/CDTN) is responsible for routine internal monitoring of occupationally exposed individuals. The determination of photon emitting radionuclides in the human body requires calibration of the detector in specific counting geometries. The calibration process uses physical phantoms containing certified activities of the radionuclides of interest. The objective of this work was to obtain calibration efficiency curves of the Whole Body Counter in operation at the LDI/CDTN using a BOMAB physical phantom and Monte Carlo simulations.

  8. Dissolved plume attenuation with DNAPL source remediation, aqueous decay and volatilization — Analytical solution, model calibration and prediction uncertainty

    NASA Astrophysics Data System (ADS)

    Parker, Jack C.; Park, Eungyu; Tang, Guoping

    2008-11-01

    A vertically-integrated analytical model for dissolved phase transport is described that considers a time-dependent DNAPL source based on the upscaled dissolution kinetics model of Parker and Park with extensions to consider time-dependent source zone biodecay, partial source mass reduction, and remediation-enhanced source dissolution kinetics. The model also considers spatial variability in aqueous plume decay, which is treated as the sum of aqueous biodecay and volatilization due to diffusive transport and barometric pumping through the unsaturated zone. The model is implemented in Excel/VBA coupled with (1) an inverse solution that utilizes prior information on model parameters and their uncertainty to condition the solution, and (2) an error analysis module that computes parameter covariances and total prediction uncertainty due to regression error and parameter uncertainty. A hypothetical case study is presented to evaluate the feasibility of calibrating the model from limited noisy field data. The results indicate that prediction uncertainty increases significantly over time following calibration, primarily due to propagation of parameter uncertainty. However, differences between the predicted performance of source zone partial mass reduction and the known true performance were reasonably small. Furthermore, a clear difference is observed between the predicted performance for the remedial action scenario versus that for a no-action scenario, which is consistent with the true system behavior. The results suggest that the model formulation can be effectively utilized to assess monitored natural attenuation and source remediation options if careful attention is given to model calibration and prediction uncertainty issues.

  9. Close-geometry efficiency calibration of p-type HPGe detectors with a Cs-134 point source.

    PubMed

    DeFelice, P; Fazio, A; Vidmar, T; Korun, M

    2006-01-01

    When close-geometry detector calibration is required in gamma-ray spectrometry, single-line emitters are usually used in order to avoid true coincidence summing effects. We managed to overcome this limitation by developing a method for the determination of the efficiency of p-type HPGe detectors in close-geometry with a calibrated Cs-134 point source. No separate determination of coincidence summing correction factors is required and a single measurement furnishes the full-energy-peak efficiencies in the 475-1365 keV energy range.

  10. SU-F-BRA-09: New Efficient Method for Xoft Axxent Electronic Brachytherapy Source Calibration by Pre-Characterizing Surface Applicators

    SciTech Connect

    Pai, S

    2015-06-15

    Purpose: The objective is to improve the efficiency and efficacy of Xoft™ Axxent™ electronic brachytherapy (EBT) calibration of the source & surface applicator using AAPM TG-61 formalism. Methods: Current method of Xoft EBT source calibration involves determination of absolute dose rate of the source in each of the four conical surface applicators using in-air chamber measurements & TG61 formalism. We propose a simplified TG-61 calibration methodology involving initial characterization of surface cone applicators. This is accomplished by calibrating dose rates for all 4 surface applicator sets (for 10 sources) which establishes the “applicator output ratios” with respect to the selected reference applicator (20 mm applicator). After the initial time, Xoft™ Axxent™ source TG61 Calibration is carried out only in the reference applicator. Using the established applicator output ratios, dose rates for other applicators will be calculated. Results: 200 sources & 8 surface applicator sets were calibrated cumulatively using a Standard Imaging A20 ion-chamber in accordance with manufacturer-recommended protocols. Dose rates of 10, 20, 35 & 50mm applicators were normalized to the reference (20mm) applicator. The data in Figure 1 indicates that the normalized dose rate variation for each applicator for all 200 sources is better than ±3%. The average output ratios are 1.11, 1.02 and 0.49 for the 10 mm,35 mm and 50 mm applicators, respectively, which are in good agreement with the manufacturer’s published output ratios of 1.13, 1.02 and 0.49. Conclusion: Our measurements successfully demonstrate the accuracy of a new calibration method using a single surface applicator for Xoft EBT sources and deriving the dose rates of other applicators. The accuracy of the calibration is improved as this method minimizes the source position variation inside the applicator during individual source calibrations. The new method significantly reduces the calibration time to less

  11. Sandia National Laboratories` high power electromagnetic impulse sources

    SciTech Connect

    Rinehart, L.F.; Buttram, M.T.; Denison, G.J.; Lundstrom, J.M.; Crowe, W.R.; Aurand, J.F.; Patterson, P.E.

    1994-10-01

    Three impulse sources have been developed to cover a wide range of peak power, bandwidth and center frequency requirements. Each of the sources can operate in single shot, rep-rate, or burst modes. These devices are of rugged construction and are suitable for field use. This paper will describe the specifications and principals of operation for each source. The sources to be described are: SNIPER (Sub-Nanosecond ImPulsE Radiator), a coaxial Blumlein pulser with an in-line (series) peaking switch; EMBL (EnantioMorphic BLurfflein), a bipolar parallel plate Blumlein with a crowbar type (parallel) peaking switch; and the LCO (L-C Oscillator) a spark-switched L-C oscillator with damped sinusoidal output. SNIPER and EMBL are ultra-wideband (UWB) sources which produce a very fast high voltage transition. When differentiated by the antenna, an impulse whose width corresponds to the transition time is radiated. The LCO operates with a center frequency up to 800 MHz and up to 100 MHz bandwidth. Because the LCO output is relatively narrow band, high gain antennas may be employed to produce very high radiated field strengths.

  12. Sandia National Laboratories' high power electromagnetic impulse sources

    NASA Astrophysics Data System (ADS)

    Rinehart, L. F.; Buttram, M. T.; Denison, G. J.; Lundstrom, J. M.; Crowe, W. R.; Aurand, J. F.; Patterson, P. E.

    1994-05-01

    Three impulse sources have been developed to cover a wide range of peak power, bandwidth and center frequency requirements. Each of the sources can operate in single shot, rep-rate, or burst modes. These devices are of rugged construction and are suitable for field use. This paper will describe the specifications and principals of operation for each source. The sources to be described are: SNIPER (Sub-Nanosecond ImPulsE Radiator), a coaxial Blumlein pulser with an in-line (series) peaking switch; EMBL (EnantioMorphic BLurfflein), a bipolar parallel plate Blumlein with a crowbar type (parallel) peaking switch; and the LCO (L-C Oscillator) a spark-switched L-C oscillator with damped sinusoidal output. SNIPER and EMBL are ultra-wideband (UWB) sources which produce a very fast high voltage transition. When differentiated by the antenna, an impulse whose width corresponds to the transition time is radiated. The LCO operates with a center frequency up to 800 MHz and up to 100 MHz bandwidth. Because the LCO output is relatively narrow band, high gain antennas may be employed to produce very high radiated field strengths.

  13. Infrared Measurements of AFGL (Air Force Geophysics Laboratory) Sources.

    DTIC Science & Technology

    1983-06-07

    of sources brighter than magnitude [ X ] is plotted against [ X ] in figures 3 and 4. The LL source counts are plotted as dots in these two figu re s. From...radiation is from, a cir- cumstellar dust shell. The characteristic temperature of these shells 21 *~** * * ** X ...scale height. We find: N([4)) = 3 x 10 -7 pc -3 and N(L1Q]) = 9 x 10 .8 pc 3 . Kirton and Fitzgerald (1974) found the density of late M stars (M5-9) to

  14. VIEW OF BUILDING 126, LOOKING NORTH. BUILDING 126, THE SOURCE ...

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

    VIEW OF BUILDING 126, LOOKING NORTH. BUILDING 126, THE SOURCE CALIBRATION LABORATORY, WAS USED TO EXPOSE AND CALIBRATE RADIATION DETECTION DEVICES, INCLUDING THERMOLUMINESCENT DOSIMETERS, WORN BY EMPLOYEES TO DETECT RADIATION EXPOSURE - Rocky Flats Plant, Source Calibration Laboratory, Between Second & Third Streets & Central & Cedar Avenues, Golden, Jefferson County, CO

  15. A comparison of absolute calibrations of a radiation thermometer based on a monochromator and a tunable source

    NASA Astrophysics Data System (ADS)

    Keawprasert, T.; Anhalt, K.; Taubert, D. R.; Sperling, A.; Schuster, M.; Nevas, S.

    2013-09-01

    An LP3 radiation thermometer was absolutely calibrated at a newly developed monochromator-based set-up and the TUneable Lasers in Photometry (TULIP) facility of PTB in the wavelength range from 400 nm to 1100 nm. At both facilities, the spectral radiation of the respective sources irradiates an integrating sphere, thus generating uniform radiance across its precision aperture. The spectral irradiance of the integrating sphere is determined via an effective area of a precision aperture and a Si trap detector, traceable to the primary cryogenic radiometer of PTB. Due to the limited output power from the monochromator, the absolute calibration was performed with the measurement uncertainty of 0.17 % (k = 1), while the respective uncertainty at the TULIP facility is 0.14 %. Calibration results obtained by the two facilities were compared in terms of spectral radiance responsivity, effective wavelength and integral responsivity. It was found that the measurement results in integral responsivity at the both facilities are in agreement within the expanded uncertainty (k = 2). To verify the calibration accuracy, the absolutely calibrated radiation thermometer was used to measure the thermodynamic freezing temperatures of the PTB gold fixed-point blackbody.

  16. A comparison of absolute calibrations of a radiation thermometer based on a monochromator and a tunable source

    SciTech Connect

    Keawprasert, T.; Anhalt, K.; Taubert, D. R.; Sperling, A.; Schuster, M.; Nevas, S.

    2013-09-11

    An LP3 radiation thermometer was absolutely calibrated at a newly developed monochromator-based set-up and the TUneable Lasers in Photometry (TULIP) facility of PTB in the wavelength range from 400 nm to 1100 nm. At both facilities, the spectral radiation of the respective sources irradiates an integrating sphere, thus generating uniform radiance across its precision aperture. The spectral irradiance of the integrating sphere is determined via an effective area of a precision aperture and a Si trap detector, traceable to the primary cryogenic radiometer of PTB. Due to the limited output power from the monochromator, the absolute calibration was performed with the measurement uncertainty of 0.17 % (k= 1), while the respective uncertainty at the TULIP facility is 0.14 %. Calibration results obtained by the two facilities were compared in terms of spectral radiance responsivity, effective wavelength and integral responsivity. It was found that the measurement results in integral responsivity at the both facilities are in agreement within the expanded uncertainty (k= 2). To verify the calibration accuracy, the absolutely calibrated radiation thermometer was used to measure the thermodynamic freezing temperatures of the PTB gold fixed-point blackbody.

  17. Developing Biofuel in the Teaching Laboratory: Ethanol from Various Sources

    ERIC Educational Resources Information Center

    Epstein, Jessica L.; Vieira, Matthew; Aryal, Binod; Vera, Nicolas; Solis, Melissa

    2010-01-01

    In this series of experiments, we mimic a small-scale ethanol plant. Students discover that the practical aspects of ethanol production are determined by the quantity of biomass produced per unit land, rather than the volume of ethanol produced per unit of biomass. These experiments explore the production of ethanol from different sources: fruits,…

  18. Laboratory calibration of the seismo-acoustic response of CO2 saturated sandstones

    NASA Astrophysics Data System (ADS)

    Siggins, A. F.; Lwin, M.; Wisman, P.

    2009-04-01

    Geological sequestration can be regarded as one of the promising mitigation strategies against the negative effects of atmospheric carbon dioxide on global climate change. Injection of CO2into depleted natural gas reservoirs in particular, sandstone formations at depth with suitable porosity and seals, seems to be a promising scenario for on-land storage. In fact, a demonstration project is currently underway in the Otway Basin in South Eastern Australia under the auspices of the Australian CO2CRC. One of the most useful geophysical remote sensing tools for monitoring sub surface CO2 injection is seismic imaging. Interpretation of seismic data for the quantitative measurement of the distribution and saturations of CO2 in the subsurface requires a knowledge of the effects of CO2as a pore fluid on the seismo-acoustic response of the reservoir rocks. This report describes some recent experiments that we have conducted to investigate this aspect under controlled laboratory conditions at pressures representative of in-situ reservoir conditions. Prior to the availability of core from the actual Otway injection site, two synthetic sandstones were tested ultrasonically in a computer controlled triaxial testing rig under a range of confining pressures and pore pressures representative of in-situ reservoir pressures. These sandstones comprised; (1) a synthetic material with calcite intergranular cement (CIPS) and (2), a synthetic sandstone with silica intergranular cement. Porosities of the sandstones were respectively, 32%,and 33%. Initial testing was carried on the cores at room temperature-dried condition with confining pressures up to 65MPa in steps of 5 MPa. Cores were then flooded with CO2, initially at 6MPa, 22 degrees C, then with liquid phase CO2at pressures from 7MPa to 17 MPa in steps of 5 MPa. Confining pressures varied from 10 MPa to 65 MPa. A limited number of experiments were also conducted in an additional rig at 50oC with supercritical phase CO2. Ultrasonic

  19. Compact plasma focus devices: Flexible laboratory sources for applications

    SciTech Connect

    Lebert, R.; Engel, A.; Bergmann, K.; Treichel, O.; Gavrilescu, C.; Neff, W.

    1997-05-05

    Small pinch plasma devices are intense sources of pulsed XUV-radiation. Because of their low costs and their compact sizes pinch plasmas seem well suited to supplement research activities based on synchrotrons. With correct optimisation, both continuous radiation and narrowband line radiation can be tailored for specific applications. For the special demand of optimising narrowband emission from these plasmas the scaling of K-shell line emission of intermediate atomic number pinch plasmas with respect to device parameters has been studied. Scaling laws, especially taking into account the transient behaviour of the pinch plasma, give design criteria. Investigations of the transition between column and micropinch mode offer predictable access to shorter wavelengths and smaller source sizes. Results on proximity x-ray lithography, imaging and contact x-ray microscopy, x-ray fluorescence (XFA) microscopy and photo-electron spectroscopy (XPS) were achieved.

  20. Laboratory study of PCB transport from primary sources to ...

    EPA Pesticide Factsheets

    Transport of house dust and Arizona Test Dust on polychlorinated biphenyl (PCB)-containing panels and PCB-free panels was investigated in a 30-m3 stainless steel chamber. The PCB-containing panels were aluminum sheets coated with a PCB-spiked, oil-based primer or two-part polysulfide caulk. The PCB-free panels were coated with the same materials but they were not spiked with PCBs. The dust was weighed and spread on the panels as evenly as possible. The dust on each panel was collected at different times to determine its PCB content. The dust data collected from the PCB panels were used to evaluate the PCB migration from the source to the dust through direct contact, and the data from the PCB-free panels were used to evaluate the sorption of PCBs through the dust/air partition. Settled dust can adsorb PCBs from air. The sorption concentration was dependent on the congener concentration in the air and favored less volatile congeners. When the house dust was in direct contact with a primary source, PCBs migrated into the dust at a much faster rate than the PCB transfer rate due to the dust/air partition. Unlike the dust/air partition, the dust/source partition was not significantly affected by the volatility of the congener. This research is important to decision makers, environmental engineers, and researchers who are concerned with risk assessment and risk management for PCB contamination.

  1. Sensitivity calibration of an imaging extreme ultraviolet spectrometer-detector system for determining the efficiency of broadband extreme ultraviolet sources

    NASA Astrophysics Data System (ADS)

    Fuchs, S.; Rödel, C.; Krebs, M.; Hädrich, S.; Bierbach, J.; Paz, A. E.; Kuschel, S.; Wünsche, M.; Hilbert, V.; Zastrau, U.; Förster, E.; Limpert, J.; Paulus, G. G.

    2013-02-01

    We report on the absolute sensitivity calibration of an extreme ultraviolet (XUV) spectrometer system that is frequently employed to study emission from short-pulse laser experiments. The XUV spectrometer, consisting of a toroidal mirror and a transmission grating, was characterized at a synchrotron source in respect of the ratio of the detected to the incident photon flux at photon energies ranging from 15.5 eV to 99 eV. The absolute calibration allows the determination of the XUV photon number emitted by laser-based XUV sources, e.g., high-harmonic generation from plasma surfaces or in gaseous media. We have demonstrated high-harmonic generation in gases and plasma surfaces providing 2.3 μW and μJ per harmonic using the respective generation mechanisms.

  2. ENHANCED BIOREMEDIATION UTILIZING HYDROGEN PEROXIDE AS A SUPPLEMENTAL SOURCE OF OXYGEN: A LABORATORY AND FIELD STUDY

    EPA Science Inventory

    Laboratory and field scale studies were conducted to investigate the feasibility of using hydrogen peroxide as a supplemental source of oxygen for bioremediation of an aviation gasoline fuel spill. Field samples of aviation gasoline contaminated aquifer material were artificially...

  3. [Laser-based radiometric calibration].

    PubMed

    Li, Zhi-gang; Zheng, Yu-quan

    2014-12-01

    Increasingly higher demands are put forward to spectral radiometric calibration accuracy and the development of new tunable laser based spectral radiometric calibration technology is promoted, along with the development of studies of terrestrial remote sensing, aeronautical and astronautical remote sensing, plasma physics, quantitative spectroscopy, etc. Internationally a number of national metrology scientific research institutes have built tunable laser based spectral radiometric calibration facilities in succession, which are traceable to cryogenic radiometers and have low uncertainties for spectral responsivity calibration and characterization of detectors and remote sensing instruments in the UK, the USA, Germany, etc. Among them, the facility for spectral irradiance and radiance responsivity calibrations using uniform sources (SIRCCUS) at the National Institute of Standards and Technology (NIST) in the USA and the Tunable Lasers in Photometry (TULIP) facility at the Physikalisch-Technische Bundesanstalt (PTB) in Germany have more representatives. Compared with lamp-monochromator systems, laser based spectral radiometric calibrations have many advantages, such as narrow spectral bandwidth, high wavelength accuracy, low calibration uncertainty and so on for radiometric calibration applications. In this paper, the development of laser-based spectral radiometric calibration and structures and performances of laser-based radiometric calibration facilities represented by the National Physical Laboratory (NPL) in the UK, NIST and PTB are presented, technical advantages of laser-based spectral radiometric calibration are analyzed, and applications of this technology are further discussed. Laser-based spectral radiometric calibration facilities can be widely used in important system-level radiometric calibration measurements with high accuracy, including radiance temperature, radiance and irradiance calibrations for space remote sensing instruments, and promote the

  4. CONSTRUCTION OF A CALIBRATED PROBABILISTIC CLASSIFICATION CATALOG: APPLICATION TO 50k VARIABLE SOURCES IN THE ALL-SKY AUTOMATED SURVEY

    SciTech Connect

    Richards, Joseph W.; Starr, Dan L.; Miller, Adam A.; Bloom, Joshua S.; Brink, Henrik; Crellin-Quick, Arien; Butler, Nathaniel R.

    2012-12-15

    With growing data volumes from synoptic surveys, astronomers necessarily must become more abstracted from the discovery and introspection processes. Given the scarcity of follow-up resources, there is a particularly sharp onus on the frameworks that replace these human roles to provide accurate and well-calibrated probabilistic classification catalogs. Such catalogs inform the subsequent follow-up, allowing consumers to optimize the selection of specific sources for further study and permitting rigorous treatment of classification purities and efficiencies for population studies. Here, we describe a process to produce a probabilistic classification catalog of variability with machine learning from a multi-epoch photometric survey. In addition to producing accurate classifications, we show how to estimate calibrated class probabilities and motivate the importance of probability calibration. We also introduce a methodology for feature-based anomaly detection, which allows discovery of objects in the survey that do not fit within the predefined class taxonomy. Finally, we apply these methods to sources observed by the All-Sky Automated Survey (ASAS), and release the Machine-learned ASAS Classification Catalog (MACC), a 28 class probabilistic classification catalog of 50,124 ASAS sources in the ASAS Catalog of Variable Stars. We estimate that MACC achieves a sub-20% classification error rate and demonstrate that the class posterior probabilities are reasonably calibrated. MACC classifications compare favorably to the classifications of several previous domain-specific ASAS papers and to the ASAS Catalog of Variable Stars, which had classified only 24% of those sources into one of 12 science classes.

  5. Instrument study of the Lunar Dust eXplorer (LDX) for a lunar lander mission II: Laboratory model calibration

    NASA Astrophysics Data System (ADS)

    Li, Yanwei; Strack, Heiko; Bugiel, Sebastian; Wu, Yiyong; Srama, Ralf

    2015-10-01

    A dust trajectory detector placed on the lunar surface is exposed to extend people's knowledge on the dust environment above the lunar surface. The new design of Lunar Dust eXplorer (LDX) is well suited for lunar or asteroid landers with a broad range of particle charges (0.1-10 fC), speeds (few m s-1 to few km s-1) and sizes (0.1-10 μ m). The calibration of dust trajectory detector is important for the detector development. We do present experimental results to characterize the accuracy of the newly developed LDX laboratory model. Micron sized iron particles were accelerated to speed between 0.5 and 20 km s-1 with primary charges larger than 1 fC. The achieved accuracies of the detector are ± 5 % and ± 7 % for particle charge and speed, respectively. Dust trajectories can be determined with measurement accuracy better than ± 2°. A dust sensor of this type is suited for the exploration of the surface of small bodies without an atmosphere like the Earth's moon or asteroids in future, and the minisatellites are also suitable carriers for the study of interplanetary dust and manned debris on low Earth orbits.

  6. Francium sources at Laboratori Nazionali di Legnaro: Design and performance

    SciTech Connect

    Stancari, G.; Veronesi, S.; Corradi, L.; Atutov, S.N.; Calabrese, R.; Dainelli, A.; Mariotti, E.; Moi, L.; Sanguinetti, S.; Tomassetti, L.

    2006-03-15

    A facility for the production of radioactive francium is operating at the laboratories of the Istituto Nazionale di Fisica Nucleare (INFN) in Legnaro, Italy. The goal is to collect a cold sample of radioactive atoms in a magneto-optical trap for studies in atomic, nuclear, and particle physics. Production of francium is achieved via the fusion-evaporation reaction {sup 197}Au({sup 18}O,kn){sup 215-k}Fr generated by a {approx}100-MeV {sup 18}O{sup 6+} beam on a thick gold target. The production target is heated to {approx}1200 K and kept at a potential of +3 kV to enhance Fr diffusion and surface desorption. Average production rates are 0.7x10{sup 6} ions/s for {sup 210}Fr with a primary beam flux of 10{sup 12} particles/s, with peaks of 2x10{sup 6} ions/s. Details are given on the design and construction of the production targets and on the measurements that characterize their performance.

  7. Laboratory Reproduction of Auroral Magnetospheric Radio Wave Sources

    SciTech Connect

    Ronald, K.; Speirs, D. C.; McConville, S. L.; Gillespie, K. M.; Phelps, A. D. R.; Cross, A. W.; Robertson, C. W.; Whyte, C. G.; He, W.; Bingham, R.; Vorgul, I.; Cairns, R. A.; Kellett, B. J.

    2008-10-15

    Auroral Kilometric Radiation, AKR, occurs naturally in the polar regions of the Earth's magnetosphere where electrons are accelerated by electric fields into the increasing planetary magnetic dipole. Here conservation of the magnetic moment converts axial to rotational momentum forming a horseshoe distribution in velocity phase space. This distribution is unstable to cyclotron emissions and radiation is emitted in the X-mode. In the laboratory a 75-85kV electron beam of 5-40A was magnetically compressed by a system of solenoids. Results are presented for an electron beam gyrating at cyclotron frequencies of 4.42GHz and 11.7GHz resonating with near cut-off TE01 and TE03 modes respectively. Measurements of the electron transport combined with numerical simulations demonstrated that a horseshoe distribution function was formed in electron velocity space. Analysis of the experimental measurements allowed the inference of the 1D number density as a function of the electron beam pitch angle. The total power emitted experimentally was {approx}19-35 kW with a maximum RF emission efficiency of {approx}2%. These results were compared to those obtained numerically using a 2D PiC code KARAT with a maximum efficiency of 2% predicted for the same mode and frequency, consistent with astrophysical and theoretical results.

  8. Pre-flight calibration and initial data processing for the ChemCam laser-induced breakdown spectroscopy instrument on the Mars Science Laboratory rover

    USGS Publications Warehouse

    Wiens, R.C.; Maurice, S.; Lasue, J.; Forni, O.; Anderson, R.B.; Clegg, S.; Bender, S.; Blaney, D.; Barraclough, B.L.; Cousin, A.; DeFlores, L.; Delapp, D.; Dyar, M.D.; Fabre, C.; Gasnault, O.; Lanza, N.; Mazoyer, J.; Melikechi, N.; Meslin, P.-Y.; Newsom, H.; Ollila, A.; Perez, R.; Tokar, R.; Vaniman, D.

    2013-01-01

    The ChemCam instrument package on the Mars Science Laboratory rover, Curiosity, is the first planetary science instrument to employ laser-induced breakdown spectroscopy (LIBS) to determine the compositions of geological samples on another planet. Pre-processing of the spectra involves subtracting the ambient light background, removing noise, removing the electron continuum, calibrating for the wavelength, correcting for the variable distance to the target, and applying a wavelength-dependent correction for the instrument response. Further processing of the data uses multivariate and univariate comparisons with a LIBS spectral library developed prior to launch as well as comparisons with several on-board standards post-landing. The level-2 data products include semi-quantitative abundances derived from partial least squares regression. A LIBS spectral library was developed using 69 rock standards in the form of pressed powder disks, glasses, and ceramics to minimize heterogeneity on the scale of the observation (350–550 μm dia.). The standards covered typical compositional ranges of igneous materials and also included sulfates, carbonates, and phyllosilicates. The provenance and elemental and mineralogical compositions of these standards are described. Spectral characteristics of this data set are presented, including the size distribution and integrated irradiances of the plasmas, and a proxy for plasma temperature as a function of distance from the instrument. Two laboratory-based clones of ChemCam reside in Los Alamos and Toulouse for the purpose of adding new spectra to the database as the need arises. Sensitivity to differences in wavelength correlation to spectral channels and spectral resolution has been investigated, indicating that spectral registration needs to be within half a pixel and resolution needs to match within 1.5 to 2.6 pixels. Absolute errors are tabulated for derived compositions of each major element in each standard using PLS regression

  9. A derivative standard for polarimeter calibration

    SciTech Connect

    Mulhollan, G.; Clendenin, J.; Saez, P.

    1996-10-01

    A long-standing problem in polarized electron physics is the lack of a traceable standard for calibrating electron spin polarimeters. While several polarimeters are absolutely calibrated to better than 2%, the typical instrument has an inherent accuracy no better than 10%. This variability among polarimeters makes it difficult to compare advances in polarized electron sources between laboratories. The authors have undertaken an effort to establish 100 nm thick molecular beam epitaxy grown GaAs(110) as a material which may be used as a derivative standard for calibrating systems possessing a solid state polarized electron source. The near-bandgap spin polarization of photoelectrons emitted from this material has been characterized for a variety of conditions and several laboratories which possess well calibrated polarimeters have measured the photoelectron polarization of cathodes cut from a common wafer. Despite instrumentation differences, the spread in the measurements is sufficiently small that this material may be used as a derivative calibration standard.

  10. Advanced light source at Lawrence Berkeley Laboratory (invited)

    NASA Astrophysics Data System (ADS)

    Cornacchia, M.

    1989-07-01

    The 1-2-GeV synchrotron radiation source will be a national user-based facility providing photon beams of unprecedented brightness in the ultraviolet and soft x-ray region of the electromagnetic spectrum. The facility design is optimized to emphasize the use of undulators to provide high-spectral brilliance in the few electron volt to 1-keV spectral range; wigglers provide high flux up to approximately 10 keV. Beam structure of a few tens of picoseconds will be available for time-resolved experiments. The facility is designed for operational flexibility and to assure rapid commissioning. The initial complement of experimental stations consists of five insertion devices (four undulators and our wiggler) and associated beamlines, and two white light beams from bend magnets. Six other straight sections are available for additional insertion devices, and the design provides for up to 48 ports for beams from bending magnets. The storage ring is optimized for operation at 1.5 GeV with a maximum energy of 1.9 GeV. The injection system includes a 1-Hz, 1.5-GeV booster synchrotron for full energy injection at the nominal operating energy of the storage ring. Filling time for the maximum stored current of 400 mA is expected to be 2 min, and the beam half-life will be about 6 h. Attention is being given to the severe requirements for beam stability and the need to independently control photon beam alignment. We describe the important characteristics of the facility, significant aspects of the technical design of accelerator systems, insertion devices and photon beamlines, and considerations related to addressing projected user needs in the development of the project.

  11. Laser ion source with solenoid for Brookhaven National Laboratory-electron beam ion sourcea)

    NASA Astrophysics Data System (ADS)

    Kondo, K.; Yamamoto, T.; Sekine, M.; Okamura, M.

    2012-02-01

    The electron beam ion source (EBIS) preinjector at Brookhaven National Laboratory (BNL) is a new heavy ion-preinjector for relativistic heavy ion collider (RHIC) and NASA Space Radiation Laboratory (NSRL). Laser ion source (LIS) is a primary ion source provider for the BNL-EBIS. LIS with solenoid at the plasma drift section can realize the low peak current (˜100 μA) with high charge (˜10 nC) which is the BNL-EBIS requirement. The gap between two solenoids does not cause serious plasma current decay, which helps us to make up the BNL-EBIS beamline.

  12. PLACE: an open-source python package for laboratory automation, control, and experimentation.

    PubMed

    Johnson, Jami L; Tom Wörden, Henrik; van Wijk, Kasper

    2015-02-01

    In modern laboratories, software can drive the full experimental process from data acquisition to storage, processing, and analysis. The automation of laboratory data acquisition is an important consideration for every laboratory. When implementing a laboratory automation scheme, important parameters include its reliability, time to implement, adaptability, and compatibility with software used at other stages of experimentation. In this article, we present an open-source, flexible, and extensible Python package for Laboratory Automation, Control, and Experimentation (PLACE). The package uses modular organization and clear design principles; therefore, it can be easily customized or expanded to meet the needs of diverse laboratories. We discuss the organization of PLACE, data-handling considerations, and then present an example using PLACE for laser-ultrasound experiments. Finally, we demonstrate the seamless transition to post-processing and analysis with Python through the development of an analysis module for data produced by PLACE automation.

  13. Radiative transfer modeling of dust-coated Pancam calibration target materials: Laboratory visible/near-infrared spectrogoniometry

    USGS Publications Warehouse

    Johnson, J. R.; Sohl-Dickstein, J.; Grundy, W.M.; Arvidson, R. E.; Bell, J.F.; Christensen, P.R.; Graff, T.; Guinness, E.A.; Kinch, K.; Morris, Robert; Shepard, M.K.

    2006-01-01

    Laboratory visible/near-infrared multispectral observations of Mars Exploration Rover Pancam calibration target materials coated with different thicknesses of Mars spectral analog dust were acquired under variable illumination geometries using the Bloomsburg University Goniometer. The data were fit with a two-layer radiative transfer model that combines a Hapke formulation for the dust with measured values of the substrate interpolated using a He-Torrance approach. We first determined the single-scattering albedo, phase function, opposition effect width, and amplitude for the dust using the entire data set (six coating thicknesses, three substrates, four wavelengths, and phase angles 3??-117??). The dust exhibited single-scattering albedo values similar to other Mars analog soils and to Mars Pathfinder dust and a dominantly forward scattering behavior whose scattering lobe became narrower at longer wavelengths. Opacity values for each dust thickness corresponded well to those predicted from the particles sizes of the Mars analog dust. We then restricted the number of substrates, dust thicknesses, and incidence angles input to the model. The results suggest that the dust properties are best characterized when using substrates whose reflectances are brighter and darker than those of the deposited dust and data that span a wide range of dust thicknesses. The model also determined the dust photometric properties relatively well despite limitations placed on the range of incidence angles. The model presented here will help determine the photometric properties of dust deposited on the MER rovers and to track the multiple episodes of dust deposition and erosion that have occurred at both landing sites. Copyright 2006 by the American Geophysical Union.

  14. Calibration services for medical applications of radiation

    SciTech Connect

    DeWerd, L.A.

    1993-12-31

    Calibration services for the medical community applications of radiation involve measuring radiation precisely and having traceability to the National Institute of Standards and Technology (NIST). Radiation therapy applications involve the use of ionization chambers and electrometers for external beams and well-type ionization chamber systems as well as radioactive sources for brachytherapy. Diagnostic x-ray applications involve ionization chamber systems and devices to measure other parameters of the x-ray machine, such as non-invasive kVp meters. Calibration laboratories have been established to provide radiation calibration services while maintaining traceability to NIST. New radiation applications of the medical community spur investigation to provide the future calibration needs.

  15. WE-D-9A-06: Open Source Monitor Calibration and Quality Control Software for Enterprise Display Management

    SciTech Connect

    Bevins, N; Vanderhoek, M; Lang, S; Flynn, M

    2014-06-15

    Purpose: Medical display monitor calibration and quality control present challenges to medical physicists. The purpose of this work is to demonstrate and share experiences with an open source package that allows for both initial monitor setup and routine performance evaluation. Methods: A software package, pacsDisplay, has been developed over the last decade to aid in the calibration of all monitors within the radiology group in our health system. The software is used to calibrate monitors to follow the DICOM Grayscale Standard Display Function (GSDF) via lookup tables installed on the workstation. Additional functionality facilitates periodic evaluations of both primary and secondary medical monitors to ensure satisfactory performance. This software is installed on all radiology workstations, and can also be run as a stand-alone tool from a USB disk. Recently, a database has been developed to store and centralize the monitor performance data and to provide long-term trends for compliance with internal standards and various accrediting organizations. Results: Implementation and utilization of pacsDisplay has resulted in improved monitor performance across the health system. Monitor testing is now performed at regular intervals and the software is being used across multiple imaging modalities. Monitor performance characteristics such as maximum and minimum luminance, ambient luminance and illuminance, color tracking, and GSDF conformity are loaded into a centralized database for system performance comparisons. Compliance reports for organizations such as MQSA, ACR, and TJC are generated automatically and stored in the same database. Conclusion: An open source software solution has simplified and improved the standardization of displays within our health system. This work serves as an example method for calibrating and testing monitors within an enterprise health system.

  16. A millisecond-risetime sub-millimeter light source for lab and in flight bolometer calibration

    NASA Astrophysics Data System (ADS)

    Abbon, Ph.; Delbart, A.; Fesquet, M.; Magneville, C.; Mazeau, B.; Pansart, J.-P.; Yvon, D.; Dumoulin, L.; Marnieros, S.; Camus, Ph.; Durand, T.; Hoffmann, Ch.

    2007-06-01

    The Olimpo balloon project will use a 120 bolometer camera to observe the sky at four frequencies (143, 217, 385 and 600 GHz) with a resolution of 3 to 2 arc-minute. This paper presents the sub-millimeter calibration "lamp" developed for ground testing and in-flight secondary calibration of bolometric detectors. By design, main features of the device are reproducibility and stability of light flux and millisecond rise time. The radiative device will be placed inside the bolometer camera and will illuminate the bolometer array through a hole in the last 2 K mirror. Operation, readout, and monitoring of the device is ensured by warm electronics. Light output flux and duration is programmable, triggered and monitored from a simple computer RS232 interface. It was tested to be reliable in ballooning temperature conditions from -80 to 50C. Design and test's results are explained.

  17. New analytical approach to calibrate the co-axial HPGe detectors including correction for source matrix self-attenuation.

    PubMed

    Badawi, Mohamed S; Gouda, Mona M; Nafee, Sherif S; El-Khatib, Ahmed M; El-Mallah, Ekram A

    2012-12-01

    To calibrate the co-axial HPGe semiconductor detectors, we introduce a new theoretical approach based on the Direct Statistical method proposed by Selim and Abbas (1995, 1996) to calculate the full-energy peak efficiency for cylindrical detectors. The present method depends on the accurate analytical calculation of the average path length covered by the photon inside the detector active volume and the geometrical solid angle Ω, to obtain a simple formula for the efficiency. In addition, the self attenuation coefficient of the source matrix (with a radius greater than the detector's radius), the attenuation factors of the source container and the detector housing materials are also treated by calculating the average path length within these materials. (152)Eu aqueous radioactive sources covering the energy range from 121 to 1408 keV were used. Remarkable agreement between the measured and the calculated efficiencies was achieved with discrepancies less than 2%.

  18. Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). A description of the sensor, ground data processing facility, laboratory calibration, and first results

    NASA Technical Reports Server (NTRS)

    Vane, Gregg (Editor)

    1987-01-01

    The papers in this document were presented at the Imaging Spectroscopy 2 Conference of the 31st International Symposium on Optical and Optoelectronic Applied Science and Engineering, in San Diego, California, on 20 and 21 August 1987. They describe the design and performance of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) sensor and its subsystems, the ground data processing facility, laboratory calibration, and first results.

  19. Comparison of Continuous-Wave CO2 Lidar Calibration by use of Earth-Surface Targets in Laboratory and Airborne Measurements

    NASA Technical Reports Server (NTRS)

    Jarzembski, Maurice A.; Srivastava, Vandana

    1998-01-01

    Backscatter of several Earth surfaces was characterized in the laboratory as a function of incidence angle with a focused continuous-wave 9.1 micro meter CO2 Doppler lidar for use as possible calibration targets. Some targets showed negligible angular dependence, while others showed a slight increase with decreasing angle. The Earth-surface signal measured over the complex Californian terrain during a 1995 NASA airborne mission compared well with laboratory data. Distributions of the Earth's surface signal shows that the lidar efficiency can be estimated with a fair degree of accuracy, preferably with uniform Earth-surface targets during flight for airborne or space-based lidar.

  20. TU-AB-201-09: Calibration of An Element of a New Directional Pd-103 Planar Source Array

    SciTech Connect

    Aima, M; Culberson, W; Reed, J; DeWerd, L

    2015-06-15

    Purpose: The CivaSheet™ is a new directional Pd-103 planar source array, with a variable number of discrete source elements referred to as “dots”. Each dot consists of a polymer capsule containing {sup 103}Pd and a gold shield that attenuates radiation on one side of the device to define hot and cold dose regions. Fluorescence from the gold shield is observed in the dot spectrum. Since CivaSheet™ is a planar directional source, conventional methods used for calibration of azimuthally symmetric sources are not applicable. The purpose of this work is to establish an air-kerma-strength standard and a transfer to a well chamber for clinical calibration. Methods: Primary air-kerma strength measurement of the dots was performed using a variable-aperture free-air chamber (VAFAC). Charge measurements were recorded using a well chamber with a custom insert. Anisotropy measurements were performed using a Sodium-Iodide detector. Spectral measurements were performed using a low-energy germanium detector and compared to a source without gold. The dot geometry was modeled using the MCNP6 radiation transport code. Results: Air-kerma strength measurements of a batch of four dots performed with the VAFAC were within ±1.5% of the average measured value and the measurement precision was within ±0.5%. Anisotropy measurements indicated uniform emission within the measurement uncertainty for the solid angle defining the VAFAC aperture used. Charge measurements of each dot using the well chamber in four cardinal angle source orientations were within ±1.5% of the average measured values. The spectral study of a dot resulted in identification of fluorescence from the gold shield and primary spectral energies that were compared to MCNP6 simulations. Conclusion: Calibration procedures for the new directional Pd-103 source dot were established for future clinical use, based on the results of experimental and Monte Carlo investigations. This work was partially supported by NCI

  1. Low-level measuring techniques for neutrons: High accuracy neutron source strength determination and fluence rate measurement at an underground laboratory

    SciTech Connect

    Zimbal, Andreas; Reginatto, Marcel; Schuhmacher, Helmut; Wiegel, Burkhard; Degering, Detlev; Zuber, Kai

    2013-08-08

    We report on measuring techniques for neutrons that have been developed at the Physikalisch-Technische Bundesanstalt (PTB), the German National Metrology Institute. PTB has characterized radioactive sources used in the BOREXINO and XENON100 experiments. For the BOREXINO experiment, a {sup 228}Th gamma radiation source was required which would not emit more than 10 neutrons per second. The determination of the neutron emission rate of this specially designed {sup 228}Th source was challenging due to the low neutron emission rate and because the ratio of neutron to gamma radiation was expected to be extremely low, of the order of 10{sup −6}. For the XENON100 detector, PTB carried out a high accuracy measurement of the neutron emission rate of an AmBe source. PTB has also done measurements in underground laboratories. A two month measurement campaign with a set of {sup 3}He-filled proportional counters was carried out in PTB's former UDO underground laboratory at the Asse salt mine. The aim of the campaign was to determine the intrinsic background of detectors, which is needed for the analysis of data taken in lowintensity neutron fields. At a later time, PTB did a preliminary measurement of the neutron fluence rate at the underground laboratory Felsenkeller operated by VKTA. By taking into account data from UDO, Felsenkeller, and detector calibrations made at the PTB facility, it was possible to estimate the neutron fluence rate at the Felsenkeller underground laboratory.

  2. Ophthalmic applicators: an overview of calibrations following the change to SI units.

    PubMed

    Holmes, Shannon M; Micka, John A; DeWerd, Larry A

    2009-05-01

    Since the NIST dose to water standard for 90Sr/90Y ophthalmic applicators was introduced, numerous sources have undergone calibration either at NIST or at the University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL). From 1997 to 2008, 222 of these beta-emitting sources were calibrated at the UWADCL, and prior reference source strength values were available for 149 of these sources. A survey of UWADCL ophthalmic applicator calibrations is presented here, demonstrating an average discrepancy of -19% with a standard deviation of +/- 16% between prior reference values and the NIST-traceable UWADCL absorbed dose to water calibrations. Values ranged from -49% to +42%.

  3. Radiation and Health Technology Laboratory Capabilities

    SciTech Connect

    Bihl, Donald E.; Lynch, Timothy P.; Murphy, Mark K.; Myers, Lynette E.; Piper, Roman K.; Rolph, James T.

    2005-07-09

    The Radiological Standards and Calibrations Laboratory, a part of Pacific Northwest National Laboratory (PNNL)(a) performs calibrations and upholds reference standards necessary to maintain traceability to national standards. The facility supports U.S. Department of Energy (DOE) programs at the Hanford Site, programs sponsored by DOE Headquarters and other federal agencies, radiological protection programs at other DOE and commercial nuclear sites and research and characterization programs sponsored through the commercial sector. The laboratory is located in the 318 Building of the Hanford Site's 300 Area. The facility contains five major exposure rooms and several laboratories used for exposure work preparation, low-activity instrument calibrations, instrument performance evaluations, instrument maintenance, instrument design and fabrication work, thermoluminescent and radiochromic Dosimetry, and calibration of measurement and test equipment (M&TE). The major exposure facilities are a low-scatter room used for neutron and photon exposures, a source well room used for high-volume instrument calibration work, an x-ray facility used for energy response studies, a high-exposure facility used for high-rate photon calibration work, a beta standards laboratory used for beta energy response studies and beta reference calibrations and M&TE laboratories. Calibrations are routinely performed for personnel dosimeters, health physics instrumentation, photon and neutron transfer standards alpha, beta, and gamma field sources used throughout the Hanford Site, and a wide variety of M&TE. This report describes the standards and calibrations laboratory.

  4. Radiation and Health Technology Laboratory Capabilities

    SciTech Connect

    Goles, Ronald W.; Johnson, Michelle Lynn; Piper, Roman K.; Peters, Jerry D.; Murphy, Mark K.; Mercado, Mike S.; Bihl, Donald E.; Lynch, Timothy P.

    2003-07-15

    The Radiological Standards and Calibrations Laboratory, a part of Pacific Northwest National Laboratory (PNNL)(a) performs calibrations and upholds reference standards necessary to maintain traceability to national standards. The facility supports U.S. Department of Energy (DOE) programs at the Hanford Site, programs sponsored by DOE Headquarters and other federal agencies, radiological protection programs at other DOE and commercial nuclear sites and research and characterization programs sponsored through the commercial sector. The laboratory is located in the 318 Building of the Hanford Site's 300 Area. The facility contains five major exposure rooms and several laboratories used for exposure work preparation, low-activity instrument calibrations, instrument performance evaluations, instrument maintenance, instrument design and fabrication work, thermoluminescent and radiochromic Dosimetry, and calibration of measurement and test equipment (M&TE). The major exposure facilities are a low-scatter room used for neutron and photon exposures, a source well room used for high-volume instrument calibration work, an x-ray facility used for energy response studies, a high-exposure facility used for high-rate photon calibration work, a beta standards laboratory used for beta energy response studies and beta reference calibrations and M&TE laboratories. Calibrations are routinely performed for personnel dosimeters, health physics instrumentation, photon and neutron transfer standards alpha, beta, and gamma field sources used throughout the Hanford Site, and a wide variety of M&TE. This report describes the standards and calibrations laboratory.

  5. Modelling fault surface roughness and fault rocks thickness evolution with slip: calibration based on field and laboratory data

    NASA Astrophysics Data System (ADS)

    Bistacchi, A.; Tisato, N.; Spagnuolo, E.; Nielsen, S. B.; Di Toro, G.

    2012-12-01

    deformation processes (e.g. frictional melting vs. cataclasis) and experimental conditions (unconfined vs. confined). Since the model is based on geometrical and volume-conservation considerations (and not on a particular deformation mechanism), we conclude that the surface roughness and fault-rock thickness after some slip is mostly determined by the initial roughness (measured over several orders of magnitude in wavelength), rather than the particular deformation process (cataclasis, melting, etc.) activated during faulting. Conveniently, since the model can be applied (under certain conditions) to surfaces which depart from self-affine roughness, the model parameters can be calibrated with laboratory experiments. If this conclusion will be confirmed by a larger dataset, the forward model proposed here will provide realistic fault roughness and fault rock thickness predictions to be used in the mechanics of earthquakes and faulting, oil and water exploration, and underground engineering projects.

  6. Improvement in the practical implementation of neutron source strength calibration using prompt gamma rays.

    PubMed

    Khabaz, Rahim; Rene Vega-Carrillo, Hector

    2013-08-01

    In this study, the neutron emission rate from neutron sources using prompt gamma rays in hydrogen was determined, and several improvements were applied. Using Monte Carlo calculations, the best positions for the source, moderator and detector relative to each other were selected. For (241)Am-Be and (252)Cf sources, the sizes for polyethylene spheres with the highest efficiency were 12- and 10-inch, respectively. In addition, a new shielding cone was designed to account for scattered neutrons and gamma rays. The newly designed shielding cone, which is 45 cm in length, provided suitable attenuation for the source radiation.

  7. Calibration of a wide-field frequency-domain fluorescence lifetime microscopy system using light emitting diodes as light sources.

    PubMed

    Elder, A D; Frank, J H; Swartling, J; Dai, X; Kaminski, C F

    2006-11-01

    High brightness light emitting diodes are an inexpensive and versatile light source for wide-field frequency-domain fluorescence lifetime imaging microscopy. In this paper a full calibration of an LED based fluorescence lifetime imaging microscopy system is presented for the first time. A radio-frequency generator was used for simultaneous modulation of light emitting diode (LED) intensity and the gain of an intensified charge coupled device (CCD) camera. A homodyne detection scheme was employed to measure the demodulation and phase shift of the emitted fluorescence, from which phase and modulation lifetimes were determined at each image pixel. The system was characterized both in terms of its sensitivity to measure short lifetimes (500 ps to 4 ns), and its capability to distinguish image features with small lifetime differences. Calibration measurements were performed in quenched solutions containing Rhodamine 6G dye and the results compared to several independent measurements performed with other measurement methodologies, including time correlated single photon counting, time gated detection, and acousto optical modulator (AOM) based modulation of excitation sources. Results are presented from measurements and simulations. The effects of limited signal-to-noise ratios, baseline drifts and calibration errors are discussed in detail. The implications of limited modulation bandwidth of high brightness, large area LED devices ( approximately 40 MHz for devices used here) are presented. The results show that phase lifetime measurements are robust down to sub ns levels, whereas modulation lifetimes are prone to errors even at large signal-to-noise ratios. Strategies for optimizing measurement fidelity are discussed. Application of the fluorescence lifetime imaging microscopy system is illustrated with examples from studies of molecular mixing in microfluidic devices and targeted drug delivery research.

  8. Radio source calibration for the Very Small Array and other cosmic microwave background instruments at around 30 GHz

    NASA Astrophysics Data System (ADS)

    Hafez, Yaser A.; Davies, Rod D.; Davis, Richard J.; Dickinson, Clive; Battistelli, Elia S.; Blanco, Francisco; Cleary, Kieran; Franzen, Thomas; Genova-Santos, Ricardo; Grainge, Keith; Hobson, Michael P.; Jones, Michael E.; Lancaster, Katy; Lasenby, Anthony N.; Padilla-Torres, Carmen P.; Rubiño-Martin, José Alberto; Rebolo, Rafael; Saunders, Richard D. E.; Scott, Paul F.; Taylor, Angela C.; Titterington, David; Tucci, Marco; Watson, Robert A.

    2008-08-01

    Accurate calibration of data is essential for the current generation of cosmic microwave background (CMB) experiments. Using data from the Very Small Array (VSA), we describe procedures which will lead to an accuracy of 1 per cent or better for experiments such as the VSA and CBI. Particular attention is paid to the stability of the receiver systems, the quality of the site and frequent observations of reference sources. At 30 GHz the careful correction for atmospheric emission and absorption is shown to be essential for achieving 1 per cent precision. The sources for which a 1 per cent relative flux density calibration was achieved included Cas A, Cyg A, Tau A and NGC 7027 and the planets Venus, Jupiter and Saturn. A flux density, or brightness temperature in the case of the planets, was derived at 33 GHz relative to Jupiter which was adopted as the fundamental calibrator. A spectral index at ~30 GHz is given for each. Cas A, Tau A, NGC 7027 and Venus were examined for variability. Cas A was found to be decreasing at 0.394 +/- 0.019 per cent yr-1 over the period 2001 March to 2004 August. In the same period Tau A was decreasing at 0.22 +/- 0.07 per cent yr-1. A survey of the published data showed that the planetary nebula NGC 7027 decreased at 0.16 +/- 0.04 per cent yr-1 over the period 1967-2003. Venus showed an insignificant (1.5 +/- 1.3 per cent) variation with Venusian illumination. The integrated polarization of Tau A at 33 GHz was found to be 7.8 +/- 0.6 per cent at position angle =148° +/- 3°.

  9. Calibration of the KRISS reference ionization chamber for certification of ²²²Rn gaseous sources.

    PubMed

    Lee, J M; Lee, K B; Lee, S H; Oh, P J; Park, T S; Kim, B C; Lee, M S

    2013-11-01

    A primary measurement system for gaseous (222)Rn based on the defined solid angle counting method has recently been constructed at KRISS and the reference ionization chamber used to measure the activities of gamma-emitting single radionuclides was adopted as a secondary standard for gaseous (222)Rn. A 20 mL flame-sealed glass ampoule source from the primary measurement system was used to calibrate the ionization chamber for (222)Rn. The (222)Rn efficiency of the ionization chamber was compared with that calculated by using a photon energy-dependent efficiency curve and that measured by using a standard (226)Ra solution. From the comparisons we draw the conclusion that the reference ionization chamber for gamma-emitting radionuclides can be a suitable secondary measurement system for gaseous (222)Rn sources.

  10. Laboratory and field measurements to constrain atmospheric sources of acetic and formic acids

    NASA Astrophysics Data System (ADS)

    Baasandorj, M.; Hu, L.; Mitroo, D.; Martinez, R.; Walker, M.; Williams, B. J.; Millet, D. B.

    2013-12-01

    Acetic and formic acids are the most abundant organic acids in the atmosphere. They play an important role in atmospheric aqueous chemistry as they can influence the acidity of precipitation, cloud droplets, and atmospheric aerosols. Sources of these acids are highly uncertain, but include secondary production from VOC oxidation, direct emissions, and possibly organic aerosol aging. Here we present measurements of formic and acetic acid, along with a suite of other gas and particle phase species, from a field study in St. Louis during summer 2013. Calibration procedures and results are discussed, and we interpret the ambient formic and acetic acid measurements in terms of patterns of variability and implied constraints on sources. Finally, we present results from oxidative aging experiments on both ambient and test organic aerosol designed to assess the importance of this mechanism as a source of gas-phase carboxylic acids.

  11. Using cross correlations to calibrate lensing source redshift distributions: Improving cosmological constraints from upcoming weak lensing surveys

    SciTech Connect

    De Putter, Roland; Doré, Olivier; Das, Sudeep

    2014-01-10

    Cross correlations between the galaxy number density in a lensing source sample and that in an overlapping spectroscopic sample can in principle be used to calibrate the lensing source redshift distribution. In this paper, we study in detail to what extent this cross-correlation method can mitigate the loss of cosmological information in upcoming weak lensing surveys (combined with a cosmic microwave background prior) due to lack of knowledge of the source distribution. We consider a scenario where photometric redshifts are available and find that, unless the photometric redshift distribution p(z {sub ph}|z) is calibrated very accurately a priori (bias and scatter known to ∼0.002 for, e.g., EUCLID), the additional constraint on p(z {sub ph}|z) from the cross-correlation technique to a large extent restores the cosmological information originally lost due to the uncertainty in dn/dz(z). Considering only the gain in photo-z accuracy and not the additional cosmological information, enhancements of the dark energy figure of merit of up to a factor of four (40) can be achieved for a SuMIRe-like (EUCLID-like) combination of lensing and redshift surveys, where SuMIRe stands for Subaru Measurement of Images and Redshifts). However, the success of the method is strongly sensitive to our knowledge of the galaxy bias evolution in the source sample and we find that a percent level bias prior is needed to optimize the gains from the cross-correlation method (i.e., to approach the cosmology constraints attainable if the bias was known exactly).

  12. Fiber optic microphone having a pressure sensing reflective membrane and a voltage source for calibration purpose

    NASA Technical Reports Server (NTRS)

    Zuckerwar, Allan J. (Inventor); Cuomo, Frank W. (Inventor); Robbins, William E. (Inventor)

    1993-01-01

    A fiber optic microphone is provided for measuring fluctuating pressures. An optical fiber probe having at least one transmitting fiber for transmitting light to a pressure-sensing membrane and at least one receiving fiber for receiving light reflected from a stretched membrane is provided. The pressure-sensing membrane may be stretched for high frequency response. Further, a reflecting surface of the pressure-sensing membrane may have dimensions which substantially correspond to dimensions of a cross section of the optical fiber probe. Further, the fiber optic microphone can be made of materials for use in high temperature environments, for example greater than 1000 F. A fiber optic probe is also provided with a back plate for damping membrane motion. The back plate further provides a means for on-line calibration of the microphone.

  13. Practical application of electromyogram radiotelemetry: the suitability of applying laboratory-acquired calibration data to field data

    SciTech Connect

    Geist, David R. ); Brown, Richard S.; Lepla, Ken; Chandler, James P.

    2001-12-01

    One of the practical problems with quantifying the amount of energy used by fish implanted with electromyogram (EMG) radio transmitters is that the signals emitted by the transmitter provide only a relative index of activity unless they are calibrated to the swimming speed of the fish. Ideally calibration would be conducted for each fish before it is released, but this is often not possible and calibration curves derived from more than one fish are used to interpret EMG signals from individuals which have not been calibrated. We tested the validity of this approach by comparing EMG data within three groups of three wild juvenile white sturgeon Acipenser transmontanus implanted with the same EMG radio transmitter. We also tested an additional six fish which were implanted with separate EMG transmitters. Within each group, a single EMG radio transmitter usually did not produce similar results in different fish. Grouping EMG signals among fish produced less accurate results than having individual EMG-swim speed relationships for each fish. It is unknown whether these differences were a result of different swimming performances among individual fish or inconsistencies in the placement or function of the EMG transmitters. In either case, our results suggest that caution should be used when applying calibration curves from one group of fish to another group of uncalibrated fish.

  14. Comparison of laboratory calibrations of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) at the beginning and end of the first flight season

    NASA Technical Reports Server (NTRS)

    Vane, Gregg; Chrien, Thomas G.; Reimer, John H.; Green, Robert O.; Conel, James E.

    1988-01-01

    Spectral and radiometric calibrations of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) were performed in the laboratory in June and November, 1987, at the beginning and end of the first flight season. Those calibrations are described along with changes in instrument characteristics that occurred during the flight season as a result of factors such as detachment of the optical fibers to two of the four AVIRIS spectrometers, degradation in the optical alignment of the spectrometers due to thermally-induced and mechanical warpage, and breakage of a thermal blocking filter in one of the spectrometers. These factors caused loss of signal in three spectrometers, loss of spectral resolution in two spectrometers, and added uncertainty in the radiometry of AVIRIS. Results from in-flight assessment of the laboratory calibrations are presented. A discussion is presented of improvements made to the instrument since the end of the first flight season and plans for the future. Improvements include: (1) a new thermal control system for stabilizing spectrometer temperatures, (2) kinematic mounting of the spectrometers to the instrument rack, and (3) new epoxy for attaching the optical fibers inside their mounting tubes.

  15. openBIS ELN-LIMS: an open-source database for academic laboratories

    PubMed Central

    Barillari, Caterina; Ottoz, Diana S. M.; Fuentes-Serna, Juan Mariano; Ramakrishnan, Chandrasekhar; Rinn, Bernd; Rudolf, Fabian

    2016-01-01

    Summary: The open-source platform openBIS (open Biology Information System) offers an Electronic Laboratory Notebook and a Laboratory Information Management System (ELN-LIMS) solution suitable for the academic life science laboratories. openBIS ELN-LIMS allows researchers to efficiently document their work, to describe materials and methods and to collect raw and analyzed data. The system comes with a user-friendly web interface where data can be added, edited, browsed and searched. Availability and implementation: The openBIS software, a user guide and a demo instance are available at https://openbis-eln-lims.ethz.ch. The demo instance contains some data from our laboratory as an example to demonstrate the possibilities of the ELN-LIMS (Ottoz et al., 2014). For rapid local testing, a VirtualBox image of the ELN-LIMS is also available. Contact: brinn@ethz.ch or fabian.rudolf@bsse.ethz.ch PMID:26508761

  16. Evaluation of computational radiometric and spectral sensor calibration techniques

    NASA Astrophysics Data System (ADS)

    Manakov, Alkhazur

    2016-04-01

    Radiometric and spectral calibration are essential for enabling the use of digital sensors for measurement purposes. Traditional optical calibration techniques require expensive equipment such as specialized light sources, monochromators, tunable filters, calibrated photo-diodes, etc. The trade-offs between computational and physics-based characterization schemes are, however, not well understood. In this paper we perform an analysis of existing computational calibration schemes and elucidate their weak points. We highlight the limitations by comparing against ground truth measurements performed in an optical characterization laboratory (EMVA 1288 standard). Based on our analysis, we present accurate and affordable methods for the radiometric and spectral calibration of a camera.

  17. The LBA Calibrator Survey of Southern Compact Extragalactic Radio Sources - LCS1

    NASA Technical Reports Server (NTRS)

    Petrov, Leonid; Phillips, Chris; Bertarini, Alessandra; Murphy, Tara; Sadler, Elaine M.

    2011-01-01

    We present a catalogue of accurate positions and correlated flux densities for 410 flat-spectrum, compact extragalactic radio sources previously detected in the Australia Telescope 20 GHz (AT20G) survey. The catalogue spans the declination range [-90deg, -40deg] and was constructed from four 24-h very long baseline interferometry (VLBI) observing sessions with the Australian Long Baseline Array at 8.3 GHz. The VLBI detection rate in these experiments is 97 per cent, the median uncertainty of the source positions is 2.6 mas and the median correlated flux density on projected baselines longer than 1000 km is 0.14 Jy. The goals of this work are (1) to provide a pool of southern sources with positions accurate to a few milliarcsec, which can be used for phase-referencing observations, geodetic VLBI and space navigation; (2) to extend the complete flux-limited sample of compact extragalactic sources to the Southern hemisphere; and (3) to investigate the parsec-scale properties of high-frequency selected sources from the AT20G survey. As a result of this VLBI campaign, the number of compact radio sources south of declination -40deg which have measured VLBI correlated flux densities and positions known to milliarcsec accuracy has increased by a factor of 3.5.

  18. Absolute sensitivity calibration of extreme ultraviolet photoresists

    SciTech Connect

    Jones, Juanita; Naulleau, Patrick P.; Gullikson, Eric M.; Aquila, Andrew; George, Simi; Niakoula, Dimitra

    2008-05-16

    One of the major challenges facing the commercialization of extreme ultraviolet (EUV) lithography remains simultaneously achieving resist sensitivity, line-edge roughness, and resolution requirement. Sensitivity is of particular concern owing to its direct impact on source power requirements. Most current EUV exposure tools have been calibrated against a resist standard with the actual calibration of the standard resist dating back to EUV exposures at Sandia National Laboratories in the mid 1990s. Here they report on an independent sensitivity calibration of two baseline resists from the SEMATECH Berkeley MET tool performed at the Advanced Light Source Calibrations and Standards beamline. The results show the baseline resists to be approximately 1.9 times faster than previously thought based on calibration against the long standing resist standard.

  19. Absolute sensitivity calibration of extreme ultraviolet photoresists.

    PubMed

    Naulleau, Patrick P; Gullikson, Eric M; Aquila, Andrew; George, Simi; Niakoula, Dimitra

    2008-07-21

    One of the major challenges facing the commercialization of extreme ultraviolet (EUV) lithography remains simultaneously achieving resist sensitivity, line-edge roughness, and resolution requirement. Sensitivity is of particular concern owing to its direct impact on source power requirements. Most current EUV exposure tools have been calibrated against a resist standard with the actual calibration of the standard resist dating back to EUV exposures at Sandia National Laboratories in the mid 1990s. Here we report on an independent sensitivity calibration of two baseline resists from the SEMATECH Berkeley MET tool performed at the Advanced Light Source Calibrations and Standards beamline. The results show the baseline resists to be approximately 1.9 times faster than previously thought based on calibration against the long standing resist standard.

  20. Spectrally and Radiometrically Stable Wide-Band on Board Calibration Source for In-Flight Data Validation in Imaging Spectroscopy Applications

    NASA Technical Reports Server (NTRS)

    Coles, J. B.; Richardson, Brandon S.; Eastwood, Michael L.; Sarture, Charles M.; Quetin, Gregory R.; Hernandez, Marco A.; Kroll, Linley A.; Nolte, Scott H.; Porter, Michael D.; Green, Robert O.

    2011-01-01

    The quality of the quantitative spectral data collected by an imaging spectrometer instrument is critically dependent upon the accuracy of the spectral and radiometric calibration of the system. In order for the collected spectra to be scientifically useful, the calibration of the instrument must be precisely known not only prior to but during data collection. Thus, in addition to a rigorous in-lab calibration procedure, the airborne instruments designed and built by the NASA/JPL Imaging Spectroscopy Group incorporate an on board calibrator (OBC) system with the instrument to provide auxiliary in-use system calibration data. The output of the OBC source illuminates a target panel on the backside of the foreoptics shutter both before and after data collection. The OBC and in-lab calibration data sets are then used to validate and post-process the collected spectral image data. The resulting accuracy of the spectrometer output data is therefore integrally dependent upon the stability of the OBC source. In this paper we describe the design and application of the latest iteration of this novel device developed at NASA/JPL which integrates a halogen-cycle source with a precisely designed fiber coupling system and a fiber-based intensity monitoring feedback loop. The OBC source in this Airborne Testbed Spectrometer was run over a period of 15 hours while both the radiometric and spectral stabilities of the output were measured and demonstrated stability to within 1% of nominal.

  1. Film dosimetry calibration method for pulsed-dose-rate brachytherapy with an 192Ir source.

    PubMed

    Schwob, Nathan; Orion, Itzhak

    2007-05-01

    192Ir sources have been widely used in clinical brachytherapy. An important challenge is to perform dosimetric measurements close to the source despite the steep dose gradient. The common, inexpensive silver halide film is a classic two-dimensional integrator dosimeter and would be an attractive solution for these dose measurements. The main disadvantage of film dosimetry is the film response to the low-energy photon. Since the photon energy spectrum is known to vary with depth, the sensitometric curves are expected to be dependent on depth. The purpose of this study is to suggest a correction method for silver halide film dosimetry that overcomes the response changes at different depths. Sensitometric curves have been obtained at different depths with verification film near a 1 Ci 192Ir pulsed-dose-rate source. The depth dependence of the film response was observed and a correction function was established. The suitability of the method was tested through measurement of the radial dose profile and radial dose function. The results were compared to Monte Carlo-simulated values according to the TG43 formalism. Monte Carlo simulations were performed separately for the beta and gamma source emissions, using the EGS4 code system, including the low-energy photon and electron transport optimization procedures. The beta source emission simulation showed that the beta dose contribution could be neglected and therefore the film-depth dependence could not be attributed to this part of the source radioactivity. The gamma source emission simulations included photon-spectra collection at several depths. The results showed a depth-dependent softening of the photon spectrum that can explain the film-energy dependence.

  2. In situ calibration of a light source in a sensor device

    DOEpatents

    Okandan, Murat; Serkland, Darwin k.; Merchant, Bion J.

    2015-12-29

    A sensor device is described herein, wherein the sensor device includes an optical measurement system, such as an interferometer. The sensor device further includes a low-power light source that is configured to emit an optical signal having a constant wavelength, wherein accuracy of a measurement output by the sensor device is dependent upon the optical signal having the constant wavelength. At least a portion of the optical signal is directed to a vapor cell, the vapor cell including an atomic species that absorbs light having the constant wavelength. A photodetector captures light that exits the vapor cell, and generates an electrical signal that is indicative of intensity of the light that exits the vapor cell. A control circuit controls operation of the light source based upon the electrical signal, such that the light source emits the optical signal with the constant wavelength.

  3. Progress Report of CNES Activities Regarding the Absolute Calibration Method

    DTIC Science & Technology

    2010-11-01

    several receivers (Ashtech Z12-T, Septentrio PolaRx2, and Dicom GTR50) and a GNSS signal simulator (Spirent 4760) according to the temperature and...laboratories, Ashtech Z12- T, Septentrio PolaRx2, and Dicom GTR50, can be calibrated with the absolute method [6,8]. The last works concerned the...Ashtech, Septentrio, and Dicom receiver calibrations. Table 2. Uncertainty of the different receiver calibrations. Uncertainty Source

  4. Calibration of the nonlinear ring model at the Diamond Light Source

    NASA Astrophysics Data System (ADS)

    Bartolini, R.; Martin, I. P. S.; Rehm, G.; Schmidt, F.

    2011-05-01

    Nonlinear beam dynamics plays a crucial role in defining the performance of a storage ring. The beam lifetime, the injection efficiency, and the dynamic and momentum apertures available to the beam are optimized during the design phase by a proper optimization of the linear lattice and of the distribution of sextupole families. The correct implementation of the design model, especially the nonlinear part, is a nontrivial accelerator physics task. Several parameters of the nonlinear dynamics can be used to compare the real machine with the model and eventually to correct the accelerator. Most of these parameters are extracted from the analysis of turn-by-turn data after the excitation of betatron oscillations of the particles in the ring. We present the experimental results of the campaign of measurements carried out at the Diamond storage ring to characterize the nonlinear beam dynamics. A combination of frequency map analysis with the detuning with momentum measurements has allowed for a precise calibration of the nonlinear model that can accurately reproduce the nonlinear beam dynamics in Diamond.

  5. Students' Strengths and Weaknesses in Evaluating Technical Arguments as Revealed through Implementing Calibrated Peer Review™ in a Bioengineering Laboratory

    ERIC Educational Resources Information Center

    Volz, Tracy; Saterbak, Ann

    2009-01-01

    In engineering fields, students are expected to construct technical arguments that demonstrate a discipline's expected use of logic, evidence, and conventions. Many undergraduate bioengineering students struggle to enact the appropriate argument structures when they produce technical posters. To address this problem we implemented Calibrated Peer…

  6. Assessment of nonpoint-source runoff in a stream using in situ and laboratory approaches

    SciTech Connect

    Tucker, K.A.; Burton, G.A. Jr.

    1999-12-01

    Anthropogenic activities that change a watershed can cause adverse impacts to receiving water. Agricultural and urban runoff are the two leading causes of surface-water impairment in the US. When assessing pollutant sources and their effects on aquatic ecosystems, and prior to implementing source controls, it is necessary to define the systems stressors and receptors of exposure. Toxicity assays are a key component to integrative assessments that include habitat (physical), chemical, and indigenous community characterization. Traditional toxicity assay methods and the use of water-quality criteria are often inappropriate because of exposure design and effect assumptions. Hyalella azteca and Chironomus tentans were exposed in situ for varying time periods during both low- and high-flow conditions to determine the effect of urban and agricultural runoff. Short-term chronic and acute toxicity of urban and agricultural runoff was then measured in the laboratory and related to in situ test results. Nonpoint-source (NPS) runoff from urban areas was often more acutely toxic to organisms in the laboratory as compared to in situ results. Conversely, toxicity to the organisms was greater at the agricultural site during in situ exposures when compared to laboratory. In situ assays were an essential and integral component of NPS runoff assessments. They provided unique information that complemented laboratory toxicity, habitat, benthic community, and physicochemical characterizations.

  7. Final report on key comparison CCAUV.A-K5: pressure calibration of laboratory standard microphones in the frequency range 2 Hz to 10 kHz

    NASA Astrophysics Data System (ADS)

    Avison, Janine; Barham, Richard

    2014-01-01

    This document and the accompanying spreadsheets constitute the final report for key comparison CCAUV.A-K5 on the pressure calibration of laboratory standard microphones in the frequency range from 2 Hz to 10 kHz. Twelve national measurement institutes took part in the key comparison and the National Physical Laboratory piloted the project. Two laboratory standard microphones IEC type LS1P were circulated to the participants and results in the form of regular calibration certificates were collected throughout the project. One of the microphones was subsequently deemed to have compromised stability for the purpose of deriving a reference value. Consequently the key comparison reference value (KCRV) has been made based on the weighted mean results for sensitivity level and for sensitivity phase from just one of the microphones. Corresponding degrees of equivalence (DoEs) have also been calculated and are presented. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  8. Calibration of the Lawrence Livermore National Laboratory Passive-Active Neutron Drum Shuffler for Measurement of Highly Enriched Uranium in Mixed Oxide

    SciTech Connect

    Mount, M; O'Connell, W; Cochran, C; Rinard, P; Dearborn, D; Endres, E

    2002-05-23

    As a follow-on to the Lawrence Livermore National Laboratory (LLNL) effort to calibrate the LLNL passive-active neutron drum (PAN) shuffler for measurement of highly enriched uranium (HEU) oxide, a method has been developed to extend the use of the PAN shuffler to the measurement of HEU in mixed uranium-plutonium (U-Pu) oxide. This method uses the current LLNL HEU oxide calibration algorithms, appropriately corrected for the mixed U-Pu oxide assay time, and recently developed PuO{sub 2} calibration algorithms to yield the mass of {sup 235}U present via differences between the expected count rate for the PuO{sub 2} and the measured count rate of the mixed U-Pu oxide. This paper describes the LLNL effort to use PAN shuffler measurements of units of certified reference material (CRM) 149 [uranium (93% Enriched) Oxide - U{sub 3}O{sub 8} Standard for Neutron Counting Measurements] and CRM 146 [Uranium Isotopic Standard for Gamma Spectrometry Measurements] and a selected set of LLNL PuO{sub 2}-bearing containers in consort with Monte Carlo simulations of the PAN shuffler response to each to (1) establish and validate a correction to the HEU calibration algorithm for the mixed U-Pu oxide assay time, (2) develop a PuO{sub 2} calibration algorithm that includes the effect of PuO{sub 2} density (2.4 g/cm{sup 3} to 4.8 g/cm{sup 3}) and container size (8.57 cm to 9.88 cm inside diameter and 9.60 cm to 13.29 cm inside height) on the PAN shuffler response, and (3) develop and validate the method for establishing the mass of {sup 235}U present in an unknown of mixed U-Pu oxide.

  9. Calibration of Fast Fiber-Optic Beam Loss Monitors for the Advanced Photon Source Storage Ring Superconducting Undulators

    SciTech Connect

    Dooling, J.; Harkay, K.; Ivanyushenkov, Y.; Sajaev, V.; Xiao, A.; Vella, Andrea K.

    2015-01-01

    We report on the calibration and use of fast fiber-optic (FO) beam loss monitors (BLMs) in the Advanced Photon Source storage ring (SR). A superconducting undulator prototype (SCU0) has been operating in SR Sector 6 (“ID6”) since the beginning of CY2013, and another undulator SCU1 (a 1.1-m length undulator that is three times the length of SCU0) is scheduled for installation in Sector 1 (“ID1”) in 2015. The SCU0 main coil often quenches during beam dumps. MARS simulations have shown that relatively small beam loss (<1 nC) can lead to temperature excursions sufficient to cause quenchingwhen the SCU0windings are near critical current. To characterize local beam losses, high-purity fused-silica FO cables were installed in ID6 on the SCU0 chamber transitions and in ID1 where SCU1 will be installed. These BLMs aid in the search for operating modes that protect the SCU structures from beam-loss-induced quenching. In this paper, we describe the BLM calibration process that included deliberate beam dumps at locations of BLMs. We also compare beam dump events where SCU0 did and did not quench.

  10. The US radiation dosimetry standards for 60Co therapy level beams, and the transfer to the AAPM accredited dosimetry calibration laboratories.

    PubMed

    Minniti, R; Chen-Mayer, H; Seltzer, S M; Huq, M Saiful; Bryson, L; Slowey, T; Micka, J A; DeWerd, L A; Wells, N; Hanson, W F; Ibbott, G S

    2006-04-01

    This work reports the transfer of the primary standard for air kerma from the National Institute of Standards and Technology (NIST) to the secondary laboratories accredited by the American Association of Physics in Medicine (AAPM). This transfer, performed in August of 2003, was motivated by the recent revision of the NIST air-kerma standards for 60Co gamma-ray beams implemented on July 1, 2003. The revision involved a complete recharacterization of the two NIST therapy-level 60Co gamma-ray beam facilities, resulting in new values for the air-kerma rates disseminated by the NIST. Some of the experimental aspects of the determination of the new air-kerma rates are briefly summarized here; the theoretical aspects have been described in detail by Seltzer and Bergstrom ["Changes in the U.S. primary standards for the air-kerma from gamma-ray beams," J. Res. Natl. Inst. Stand. Technol. 108, 359-381 (2003)]. The standard was transferred to reference-class chambers submitted by each of the AAPM Accredited Dosimetry Calibration Laboratories (ADCLs). These secondary-standard instruments were then used to characterize the 60Co gamma-ray beams at the ADCLs. The values of the response (calibration coefficient) of the ADCL secondary-standard ionization chambers are reported and compared to values obtained prior to the change in the NIST air-kerma standards announced on July 1, 2003. The relative change is about 1.1% for all of these chambers, and this value agrees well with the expected change in chambers calibrated at the NIST or at any secondary-standard laboratory traceable to the new NIST standard.

  11. CFD modeling of a laboratory-scale underwater explosion created by a spark gap source

    NASA Astrophysics Data System (ADS)

    Esplin, J. James; Kinzel, Michael P.; Kim, Benjamin; Culver, R. Lee

    2015-11-01

    Underwater explosions contain complex physical phenomena that can be difficult to observe. As large-scale tests are expensive, most researchers investigate the physical phenomena using laboratory-scale explosions with hopes that the salient physical phenomena remain similar. Most of the laboratory-scale tests use small amounts of chemical explosive as the explosive source, which have been examined using computational fluid dynamics (CFD) modeling at both large and small-scale. Other tests use a spark gap source (sparker) as the explosive source, which act similarly to chemical explosives on a small scale. Few studies have applied CFD to spark gap sources used to model underwater explosions, and fewer still have dealt with the differences between chemical explosions and spark gap sources. This work will demonstrate CFD simulations for a spark gap source discharged near a free surface. The simulation uses a compressible medium including both a gas and liquid and aims to predict the transient bubble motion and pressure field. The simulations are validated against experimental data. Work supported by the ONR Naval Undersea Research Program.

  12. A multi-source satellite data approach for modelling Lake Turkana water level: Calibration and validation using satellite altimetry data

    USGS Publications Warehouse

    Velpuri, N.M.; Senay, G.B.; Asante, K.O.

    2012-01-01

    Lake Turkana is one of the largest desert lakes in the world and is characterized by high degrees of interand intra-annual fluctuations. The hydrology and water balance of this lake have not been well understood due to its remote location and unavailability of reliable ground truth datasets. Managing surface water resources is a great challenge in areas where in-situ data are either limited or unavailable. In this study, multi-source satellite-driven data such as satellite-based rainfall estimates, modelled runoff, evapotranspiration, and a digital elevation dataset were used to model Lake Turkana water levels from 1998 to 2009. Due to the unavailability of reliable lake level data, an approach is presented to calibrate and validate the water balance model of Lake Turkana using a composite lake level product of TOPEX/Poseidon, Jason-1, and ENVISAT satellite altimetry data. Model validation results showed that the satellitedriven water balance model can satisfactorily capture the patterns and seasonal variations of the Lake Turkana water level fluctuations with a Pearson's correlation coefficient of 0.90 and a Nash-Sutcliffe Coefficient of Efficiency (NSCE) of 0.80 during the validation period (2004-2009). Model error estimates were within 10% of the natural variability of the lake. Our analysis indicated that fluctuations in Lake Turkana water levels are mainly driven by lake inflows and over-the-lake evaporation. Over-the-lake rainfall contributes only up to 30% of lake evaporative demand. During the modelling time period, Lake Turkana showed seasonal variations of 1-2m. The lake level fluctuated in the range up to 4m between the years 1998-2009. This study demonstrated the usefulness of satellite altimetry data to calibrate and validate the satellite-driven hydrological model for Lake Turkana without using any in-situ data. Furthermore, for Lake Turkana, we identified and outlined opportunities and challenges of using a calibrated satellite-driven water balance

  13. Baobab Laboratory Information Management System: Development of an Open-Source Laboratory Information Management System for Biobanking.

    PubMed

    Bendou, Hocine; Sizani, Lunga; Reid, Tim; Swanepoel, Carmen; Ademuyiwa, Toluwaleke; Merino-Martinez, Roxana; Meuller, Heimo; Abayomi, Akin; Christoffels, Alan

    2017-04-04

    A laboratory information management system (LIMS) is central to the informatics infrastructure that underlies biobanking activities. To date, a wide range of commercial and open-source LIMSs are available and the decision to opt for one LIMS over another is often influenced by the needs of the biobank clients and researchers, as well as available financial resources. The Baobab LIMS was developed by customizing the Bika LIMS software ( www.bikalims.org ) to meet the requirements of biobanking best practices. The need to implement biobank standard operation procedures as well as stimulate the use of standards for biobank data representation motivated the implementation of Baobab LIMS, an open-source LIMS for Biobanking. Baobab LIMS comprises modules for biospecimen kit assembly, shipping of biospecimen kits, storage management, analysis requests, reporting, and invoicing. The Baobab LIMS is based on the Plone web-content management framework. All the system requirements for Plone are applicable to Baobab LIMS, including the need for a server with at least 8 GB RAM and 120 GB hard disk space. Baobab LIMS is a server-client-based system, whereby the end user is able to access the system securely through the internet on a standard web browser, thereby eliminating the need for standalone installations on all machines.

  14. A new scanning system for alpha decay events as calibration sources for range-energy relation in nuclear emulsion

    NASA Astrophysics Data System (ADS)

    Yoshida, J.; Kinbara, S.; Mishina, A.; Nakazawa, K.; Soe, M. K.; Theint, A. M. M.; Tint, K. T.

    2017-03-01

    A new scanning system named "Vertex picker" has been developed to rapid collect alpha decay events, which are calibration sources for the range-energy relation in nuclear emulsion. A computer-controlled optical microscope scans emulsion layers exhaustively, and a high-speed and high-resolution camera takes their micrographs. A dedicated image processing picks out vertex-like shapes. Practical operations of alpha decay search were demonstrated by emulsion sheets of the KEK-PS E373 experiment. Alpha decays of nearly 28 events were detected in eye-check work on a PC monitor per hour. This yield is nearly 20 times more effective than that by the conventional eye-scan method. The speed and quality is acceptable for the coming new experiment, J-PARC E07.

  15. Applications of an 88Y/Be photoneutron calibration source to dark matter and neutrino experiments.

    PubMed

    Collar, J I

    2013-05-24

    The low-energy monochromatic neutron emission from an (88)Y/Be source can be exploited to mimic the few keV(nr) nuclear recoils expected from low-mass weakly interacting massive particles and coherent scattering of neutrinos off nuclei. Using this source, a

  16. Calibration and Validation of Nonpoint Source Pollution and Erosion Comparison Tool,N- SPECT, for Tropical Conditions

    NASA Astrophysics Data System (ADS)

    Fares, A.; Cheng, C. L.; Dogan, A.

    2006-12-01

    Impaired water quality caused by agriculture, urbanization, and spread of invasive species has been identified as a major factor in the degradation of coastal ecosystems in the tropics. Watershed-scale nonpoint source pollution models facilitate in evaluating effective management practices to alleviate the negative impacts of different land-use changes. The Non-Point Source Pollution and Erosion Comparison Tool (N-SPECT) is a newly released watershed model that was not previously tested under tropical conditions. The two objectives of this study were to: i) calibrate and validate N-SPECT for the Hanalei Watershed of the Hawai`ian island of Kaua`i; ii) evaluate the performance of N-SPECT under tropical conditions using the sensitivity analysis approach. Hanalei watershed has one of the wettest points on earth, Mt. Waialeale with an average annual rainfall of 11,000 mm. This rainfall decreases to 2,000 mm at the outlet of the watershed near the coast. Number of rain days is one of the major input parameters that influences N-SPECT's simulation results. This parameter was used to account for plant canopy interception losses. The watershed was divided into sub- basins to accurately distribute the number of rain days throughout the watershed. Total runoff volume predicted by the model compared well with measured data. The model underestimated measured runoff by 1% for calibration period and 5% for validation period due to higher intensity precipitation in the validation period. Sensitivity analysis revealed that the model was most sensitive to the number of rain days, followed by canopy interception, and least sensitive to the number of sub-basins. The sediment and water quality portion of the model is currently being evaluated.

  17. Development of Fiber Fabry-Perot Interferometers as Stable Near-infrared Calibration Sources for High Resolution Spectrographs

    NASA Astrophysics Data System (ADS)

    Halverson, Samuel; Mahadevan, Suvrath; Ramsey, Lawrence; Hearty, Fred; Wilson, John; Holtzman, Jon; Redman, Stephen; Nave, Gillian; Nidever, David; Nelson, Matt; Venditti, Nick; Bizyaev, Dmitry; Fleming, Scott

    2014-05-01

    We discuss the ongoing development of single-mode fiber Fabry-Perot (FFP) Interferometers as precise astro-photonic calibration sources for high precision radial velocity (RV) spectrographs. FFPs are simple, inexpensive, monolithic units that can yield a stable and repeatable output spectrum. An FFP is a unique alternative to a traditional etalon, as the interferometric cavity is made of single-mode fiber rather than an air-gap spacer. This design allows for excellent collimation, high spectral finesse, rigid mechanical stability, insensitivity to vibrations, and no need for vacuum operation. The device we have tested is a commercially available product from Micron Optics. Our development path is targeted towards a calibration source for the Habitable-Zone Planet Finder (HPF), a near-infrared spectrograph designed to detect terrestrial-mass planets around low-mass stars, but this reference could also be used in many existing and planned fiber-fed spectrographs as we illustrate using the Apache Point Observatory Galactic Evolution Experiment (APOGEE) instrument. With precise temperature control of the fiber etalon, we achieve a thermal stability of 100 $\\mu$K and associated velocity uncertainty of 22 cm s$^{-1}$. We achieve a precision of $\\approx$2 m s$^{-1}$ in a single APOGEE fiber over 12 hours using this new photonic reference after removal of systematic correlations. This high precision (close to the expected photon-limited floor) is a testament to both the excellent intrinsic wavelength stability of the fiber interferometer and the stability of the APOGEE instrument design. Overall instrument velocity precision is 80 cm s$^{-1}$ over 12 hours when averaged over all 300 APOGEE fibers and after removal of known trends and pressure correlations, implying the fiber etalon is intrinsically stable to significantly higher precision.

  18. VNIR, MWIR, and LWIR source assemblies for optical quality testing and spectro-radiometric calibration of earth observation satellites

    NASA Astrophysics Data System (ADS)

    Compain, Eric; Maquet, Philippe; Leblay, Pierrick; Gavaud, Eric; Marque, Julien; Glastre, Wilfried; Cortese, Maxime; Sugranes, Pierre; Gaillac, Stephanie; Potheau, Hervé

    2015-09-01

    This document presents several original OGSEs, Optical Ground Support Equipment, specifically designed and realized for the optical testing and calibration of earth observation satellites operating in a large spectral band from 0.4μm to 14.7μm. This work has been mainly supported by recent development dedicated to MTG, Meteosat Third Generation, the ESA next generation of meteorological satellites. The improved measurement capabilities of this new satellite generation has generated new challenging requirements for the associated optical test equipments. These improvements, based on design and component innovation will be illustrated for the MOTA, the GICS and the DEA OGSEs. MOTA and GICS are dedicated to the AIT, Assembly Integration and Test, of FCI, the Flexible Combined Imager of the imaging satellite MTG-I. DEA OGSE is dedicated to the AIT of the DEA, Detection Electronics Assembly, which is part of IRS instrument, an IR sounder part of MTG-S satellite. From an architectural point of view, the presented original designs enable to run many optical tests with a single system thanks to a limited configuration effort. Main measurement capabilities are optical quality testing (MTF based mainly on KEF measurement), Line of Sight (LoS) stability measurement, straylight analyses, VNIR-MWIR-LWIR focal plane array co-registration, and broadband large dynamic spectro-radiometric calibration. Depending on the AIT phase of the satellite, these source assemblies are operated at atmospheric pressure or under secondary vacuum. In operation, they are associated with an opto-mechanical projection system that enables to conjugate the image of the source assembly with the focal plane of the satellite instruments. These conjugation systems are usually based on high resolution, broadband collimator, and are optionally mounted on hexapod to address the entire field of instruments.

  19. Constrained Maximum Likelihood Estimation for Model Calibration Using Summary-level Information from External Big Data Sources.

    PubMed

    Chatterjee, Nilanjan; Chen, Yi-Hau; Maas, Paige; Carroll, Raymond J

    2016-03-01

    Information from various public and private data sources of extremely large sample sizes are now increasingly available for research purposes. Statistical methods are needed for utilizing information from such big data sources while analyzing data from individual studies that may collect more detailed information required for addressing specific hypotheses of interest. In this article, we consider the problem of building regression models based on individual-level data from an "internal" study while utilizing summary-level information, such as information on parameters for reduced models, from an "external" big data source. We identify a set of very general constraints that link internal and external models. These constraints are used to develop a framework for semiparametric maximum likelihood inference that allows the distribution of covariates to be estimated using either the internal sample or an external reference sample. We develop extensions for handling complex stratified sampling designs, such as case-control sampling, for the internal study. Asymptotic theory and variance estimators are developed for each case. We use simulation studies and a real data application to assess the performance of the proposed methods in contrast to the generalized regression (GR) calibration methodology that is popular in the sample survey literature.

  20. Constrained Maximum Likelihood Estimation for Model Calibration Using Summary-level Information from External Big Data Sources

    PubMed Central

    Chatterjee, Nilanjan; Chen, Yi-Hau; Maas, Paige; Carroll, Raymond J.

    2016-01-01

    Information from various public and private data sources of extremely large sample sizes are now increasingly available for research purposes. Statistical methods are needed for utilizing information from such big data sources while analyzing data from individual studies that may collect more detailed information required for addressing specific hypotheses of interest. In this article, we consider the problem of building regression models based on individual-level data from an “internal” study while utilizing summary-level information, such as information on parameters for reduced models, from an “external” big data source. We identify a set of very general constraints that link internal and external models. These constraints are used to develop a framework for semiparametric maximum likelihood inference that allows the distribution of covariates to be estimated using either the internal sample or an external reference sample. We develop extensions for handling complex stratified sampling designs, such as case-control sampling, for the internal study. Asymptotic theory and variance estimators are developed for each case. We use simulation studies and a real data application to assess the performance of the proposed methods in contrast to the generalized regression (GR) calibration methodology that is popular in the sample survey literature. PMID:27570323

  1. Calibration Techniques

    NASA Astrophysics Data System (ADS)

    Wurz, Peter; Balogh, Andre; Coffey, Victoria; Dichter, Bronislaw K.; Kasprzak, Wayne T.; Lazarus, Alan J.; Lennartsson, Walter; McFadden, James P.

    Calibration and characterization of particle instruments with supporting flight electronics is necessary for the correct interpretation of the returned data. Generally speaking, the instrument will always return a measurement value (typically in form of a digital number), for example a count rate, for the measurement of an external quantity, which could be an ambient neutral gas density, an ion composition (species measured and amount), or electron density. The returned values are used then to derive parameters associated with the distribution such as temperature, bulk flow speed, differential energy flux and others. With the calibration of the instrument the direct relationship between the external quantity and the returned measurement value has to be established so that the data recorded during flight can be correctly interpreted. While calibration and characterization of an instrument are usually done in ground-based laboratories prior to integration of the instrument in the spacecraft, it can also be done in space.

  2. Laboratory experiments designed to provide limits on the radionuclide source term for the NNWSI Project

    SciTech Connect

    Oversby, V.M.; McCright, R.D.

    1984-11-01

    The Nevada Nuclear Waste Storage Investigations Project is investigating the suitability of the tuffaceous rocks at Yucca Mountain Nevada for potential use as a high-level nuclear waste repository. The horizon under investigation lies above the water table, and therefore offers a setting that differs substantially from other potential repository sites. The unsaturated zone environment allows a simple, but effective, waste package design. The source term for radionuclide release from the waste package will be based on laboratory experiments that determine the corrosion rates and mechanisms for the metal container and the dissolution rate of the waste form under expected long term conditions. This paper describes the present status of laboratory results and outlines the approach to be used in combining the data to develop a realistic source term for release of radionuclides from the waste package. 16 refs., 3 figs., 1 tab.

  3. High Energy Laboratory Astrophysics Experiments using electron beam ion traps and advanced light sources

    NASA Astrophysics Data System (ADS)

    Brown, Gregory V.; Beiersdorfer, Peter; Bernitt, Sven; Eberle, Sita; Hell, Natalie; Kilbourne, Caroline; Kelley, Rich; Leutenegger, Maurice; Porter, F. Scott; Rudolph, Jan; Steinbrugge, Rene; Traebert, Elmar; Crespo-Lopez-Urritia, Jose R.

    2015-08-01

    We have used the Lawrence Livermore National Laboratory's EBIT-I electron beam ion trap coupled with a NASA/GSFC microcalorimeter spectrometer instrument to systematically address problems found in the analysis of high resolution X-ray spectra from celestial sources, and to benchmark atomic physics codes employed by high resolution spectral modeling packages. Our results include laboratory measurements of transition energies, absolute and relative electron impact excitation cross sections, charge exchange cross sections, and dielectronic recombination resonance strengths. More recently, we have coupled to the Max-Plank Institute for Nuclear Physics-Heidelberg's FLASH-EBIT electron beam ion trap to third and fourth generation advanced light sources to measure photoexcitation and photoionization cross sections, as well as, natural line widths of X-ray transitions in highly charged iron ions. Selected results will be presented.

  4. Laboratory source based full-field x-ray microscopy at 9 keV

    SciTech Connect

    Fella, C.; Balles, A.; Wiest, W.; Zabler, S.; Hanke, R.

    2016-01-28

    In the past decade, hard x-ray transmission microscopy experienced tremendous developments. With the avail-ability of efficient Fresnel zone plates, even set-ups utilizing laboratory sources were developed [1]. In order to improve the performance of these x-ray microscopes, novel approaches to fabricate optical elements [2] and brighter x-ray tubes [3] are promising candidates. We are currently building a laboratory transmission x-ray microscope for 9.25 keV, using an electron impact liquid-metal-jet anode source. Up to now, the further elements of our setup are: a polycapillary condenser, a tungsten zone plate, and a scintillator which is optically coupled to a CMOS camera. However, further variations in terms of optical elements are intended. Here we present the current status of our work, as well as first experimental results.

  5. KEY COMPARISON: Final report of comparison of the calibrations of hydrometers for liquid density determination between SIM laboratories: SIM.M.D-K4

    NASA Astrophysics Data System (ADS)

    Becerra, Luis Omar

    2009-01-01

    This SIM comparison on the calibration of high accuracy hydrometers was carried out within fourteen laboratories in the density range from 600 kg/m3 to 1300 kg/m3 in order to evaluate the degree of equivalence among participant laboratories. This key comparison anticipates the planned key comparison CCM.D-K4, and is intended to be linked with CCM.D-K4 when results are available. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  6. X-ray phase imaging with a laboratory source using selective reflection from a mirror.

    PubMed

    Pelliccia, Daniele; Paganin, David M

    2013-04-22

    A novel approach for hard x-ray phase contrast imaging with a laboratory source is reported. The technique is based on total external reflection from the edge of a mirror, aligned to intercept only half of the incident beam. The mirror edge thus produces two beams. The refraction x-rays undergo when interacting with a sample placed before the mirror, causes relative intensity variations between direct and reflected beams. Quantitative phase contrast and pure absorption imaging are demonstrated using this method.

  7. Laboratory Performance of Five Selected Soil Moisture Sensors Applying Factory and Own Calibration Equations for Two Soil Media of Different Bulk Density and Salinity Levels.

    PubMed

    Matula, Svatopluk; Báťková, Kamila; Legese, Wossenu Lemma

    2016-11-15

    Non-destructive soil water content determination is a fundamental component for many agricultural and environmental applications. The accuracy and costs of the sensors define the measurement scheme and the ability to fit the natural heterogeneous conditions. The aim of this study was to evaluate five commercially available and relatively cheap sensors usually grouped with impedance and FDR sensors. ThetaProbe ML2x (impedance) and ECH₂O EC-10, ECH₂O EC-20, ECH₂O EC-5, and ECH₂O TE (all FDR) were tested on silica sand and loess of defined characteristics under controlled laboratory conditions. The calibrations were carried out in nine consecutive soil water contents from dry to saturated conditions (pure water and saline water). The gravimetric method was used as a reference method for the statistical evaluation (ANOVA with significance level 0.05). Generally, the results showed that our own calibrations led to more accurate soil moisture estimates. Variance component analysis arranged the factors contributing to the total variation as follows: calibration (contributed 42%), sensor type (contributed 29%), material (contributed 18%), and dry bulk density (contributed 11%). All the tested sensors performed very well within the whole range of water content, especially the sensors ECH₂O EC-5 and ECH₂O TE, which also performed surprisingly well in saline conditions.

  8. Laboratory Performance of Five Selected Soil Moisture Sensors Applying Factory and Own Calibration Equations for Two Soil Media of Different Bulk Density and Salinity Levels

    PubMed Central

    Matula, Svatopluk; Báťková, Kamila; Legese, Wossenu Lemma

    2016-01-01

    Non-destructive soil water content determination is a fundamental component for many agricultural and environmental applications. The accuracy and costs of the sensors define the measurement scheme and the ability to fit the natural heterogeneous conditions. The aim of this study was to evaluate five commercially available and relatively cheap sensors usually grouped with impedance and FDR sensors. ThetaProbe ML2x (impedance) and ECH2O EC-10, ECH2O EC-20, ECH2O EC-5, and ECH2O TE (all FDR) were tested on silica sand and loess of defined characteristics under controlled laboratory conditions. The calibrations were carried out in nine consecutive soil water contents from dry to saturated conditions (pure water and saline water). The gravimetric method was used as a reference method for the statistical evaluation (ANOVA with significance level 0.05). Generally, the results showed that our own calibrations led to more accurate soil moisture estimates. Variance component analysis arranged the factors contributing to the total variation as follows: calibration (contributed 42%), sensor type (contributed 29%), material (contributed 18%), and dry bulk density (contributed 11%). All the tested sensors performed very well within the whole range of water content, especially the sensors ECH2O EC-5 and ECH2O TE, which also performed surprisingly well in saline conditions. PMID:27854263

  9. Apero, AN Open Source Bundle Adjusment Software for Automatic Calibration and Orientation of Set of Images

    NASA Astrophysics Data System (ADS)

    Pierrot Deseilligny, M.; Clery, I.

    2011-09-01

    IGN has developed a set of photogrammetric tools, APERO and MICMAC, for computing 3D models from set of images. This software, developed initially for its internal needs are now delivered as open source code. This paper focuses on the presentation of APERO the orientation software. Compared to some other free software initiatives, it is probably more complex but also more complete, its targeted user is rather professionals (architects, archaeologist, geomophologist) than people. APERO uses both computer vision approach for estimation of initial solution and photogrammetry for a rigorous compensation of the total error; it has a large library of parametric model of distortion allowing a precise modelization of all the kind of pinhole camera we know, including several model of fish-eye; there is also several tools for geo-referencing the result. The results are illustrated on various application, including the data-set of 3D-Arch workshop.

  10. Semi-quantitative and simulation analyses of effects of γ rays on determination of calibration factors of PET scanners with point-like (22)Na sources.

    PubMed

    Hasegawa, Tomoyuki; Sato, Yasushi; Oda, Keiichi; Wada, Yasuhiro; Murayama, Hideo; Yamada, Takahiro

    2011-09-21

    The uncertainty of radioactivity concentrations measured with positron emission tomography (PET) scanners ultimately depends on the uncertainty of the calibration factors. A new practical calibration scheme using point-like (22)Na radioactive sources has been developed. The purpose of this study is to theoretically investigate the effects of the associated 1.275 MeV γ rays on the calibration factors. The physical processes affecting the coincidence data were categorized in order to derive approximate semi-quantitative formulae. Assuming the design parameters of some typical commercial PET scanners, the effects of the γ rays as relative deviations in the calibration factors were evaluated by semi-quantitative formulae and a Monte Carlo simulation. The relative deviations in the calibration factors were less than 4%, depending on the details of the PET scanners. The event losses due to rejecting multiple coincidence events of scattered γ rays had the strongest effect. The results from the semi-quantitative formulae and the Monte Carlo simulation were consistent and were useful in understanding the underlying mechanisms. The deviations are considered small enough to correct on the basis of precise Monte Carlo simulation. This study thus offers an important theoretical basis for the validity of the calibration method using point-like (22)Na radioactive sources.

  11. Dosimetric characteristics, air-kerma strength calibration and verification of Monte Carlo simulation for a new ytterbium-169 brachytherapy source

    SciTech Connect

    Perera, H.; Williamson, J.F.; Li, Zuofeng; Mishra, V.; Meigooni, A.S. )

    1994-03-01

    Ytterbium-169 ([sup 169]Yb) is a promising new isotope for brachytherapy with a half life of 32 days and an average photon energy of 93 KeV. It has an Ir-192-equivalent dose distribution in water but a much smaller half-value layer in lead (0.2 mm), affording improved radiation protection and customized shielding of dose-limiting anatomic structures. The goals of this study are to: (a) experimentally validate Monte Carlo photon transport dose-rate calculations for this energy range, (b) to develop a secondary air-kerma strength standard for [sup 169]Yb, and (c) to present essential treatment planning data including the transverse-axis dose-rate distribution and dose correction factors for a number of local shielding materials. Several interstitial [sup 169]Yb sources (type 6) and an experimental high dose-rate source were made available for this study. Monte Carlo photon-transport (MCPT) simulations, based upon validated geometric models of source structure, were used to calculate dose rates in water. To verify MCPT predictions, the transverse-axis dose distribution in homogeneous water medium was measured using a silicon-diode detector. For use in designing shielded applicators, heterogeneity correction factors (HCF) arising from small cylindrical heterogeneities of lead, aluminum, titanium, steel and air were measured in a water medium. Finally, to provide a sound experimental basis for comparing experimental and theoretical dose-rate distributions, the air-kerma strength of the sources was measured using a calibrated ion chamber. To eliminate the influence of measurement artifacts on the comparison of theory and measurement, simulated detector readings were compared directly to measured diode readings. The final data are presented in the format endorsed by the Interstitial Collaborative Working Group. 33 refs., 8 figs., 3 tabs.

  12. The Optics and Alignment of the Divergent Beam Laboratory X-ray Powder Diffractometer and its Calibration Using NIST Standard Reference Materials

    PubMed Central

    Cline, James P.; Mendenhall, Marcus H.; Black, David; Windover, Donald; Henins, Albert

    2015-01-01

    The laboratory X-ray powder diffractometer is one of the primary analytical tools in materials science. It is applicable to nearly any crystalline material, and with advanced data analysis methods, it can provide a wealth of information concerning sample character. Data from these machines, however, are beset by a complex aberration function that can be addressed through calibration with the use of NIST Standard Reference Materials (SRMs). Laboratory diffractometers can be set up in a range of optical geometries; considered herein are those of Bragg-Brentano divergent beam configuration using both incident and diffracted beam monochromators. We review the origin of the various aberrations affecting instruments of this geometry and the methods developed at NIST to align these machines in a first principles context. Data analysis methods are considered as being in two distinct categories: those that use empirical methods to parameterize the nature of the data for subsequent analysis, and those that use model functions to link the observation directly to a specific aspect of the experiment. We consider a multifaceted approach to instrument calibration using both the empirical and model based data analysis methods. The particular benefits of the fundamental parameters approach are reviewed. PMID:26958446

  13. The Optics and Alignment of the Divergent Beam Laboratory X-ray Powder Diffractometer and its Calibration Using NIST Standard Reference Materials.

    PubMed

    Cline, James P; Mendenhall, Marcus H; Black, David; Windover, Donald; Henins, Albert

    2015-01-01

    The laboratory X-ray powder diffractometer is one of the primary analytical tools in materials science. It is applicable to nearly any crystalline material, and with advanced data analysis methods, it can provide a wealth of information concerning sample character. Data from these machines, however, are beset by a complex aberration function that can be addressed through calibration with the use of NIST Standard Reference Materials (SRMs). Laboratory diffractometers can be set up in a range of optical geometries; considered herein are those of Bragg-Brentano divergent beam configuration using both incident and diffracted beam monochromators. We review the origin of the various aberrations affecting instruments of this geometry and the methods developed at NIST to align these machines in a first principles context. Data analysis methods are considered as being in two distinct categories: those that use empirical methods to parameterize the nature of the data for subsequent analysis, and those that use model functions to link the observation directly to a specific aspect of the experiment. We consider a multifaceted approach to instrument calibration using both the empirical and model based data analysis methods. The particular benefits of the fundamental parameters approach are reviewed.

  14. Update on Calibration of the Lawrence Livermore National Laboratory Passive-Active Neutron Drum Shuffler for Measurement of Highly Enriched Uranium Oxide

    SciTech Connect

    Mount, M; O'Connell, W; Cochran, C; Rinard, P; Dearborn, D; Endres, E

    2002-05-17

    In October of 1999, Lawrence Livermore National Laboratory (LLNL) began an effort to calibrate the LLNL passive-active neutron (PAN) drum shuffler for measurement of highly enriched uranium (HEU) oxide. A single unit of certified reference material (CRM) 149 [Uranium (93% Enriched) Oxide - U{sub 3}O{sub 8} Standard for Neutron Counting Measurements] was used to (1) develop a mass calibration curve for HEU oxide in the nominal range of 393 g to 3144 g {sup 235}U, and (2) perform a detailed axial and radial mapping of the detector response over a wide region of the PAN shuffler counting chamber. Results from these efforts were reported at the Institute of Nuclear Materials Management 41st Annual Meeting in July 2000. This paper describes subsequent efforts by LLNL to use a unit of CRM 146 [Uranium Isotopic Standard for Gamma Spectrometry Measurements] in consort with Monte Carlo simulations of the PAN shuffler response to CRM 149 and CRM 146 units and a selected set of containers with CRM 149-equivalent U{sub 3}O{sub 8} to (1) extend the low range of the reported mass calibration curve to 10 g {sup 235}U, (2) evaluate the effect of U{sub 3}O{sub 8} density (2.4 g/cm{sup 3} to 4.8 g/cm{sup 3}) and container size (5.24 cm to 12.17 cm inside diameter and 6.35 cm to 17.72 cm inside height) on the PAN shuffler response, and (3) develop mass calibration curves for U{sub 3}O{sub 8} enriched to 20.1 wt% {sup 235}U and 52.5 wt% {sup 235}U.

  15. Image Calibration

    NASA Technical Reports Server (NTRS)

    Peay, Christopher S.; Palacios, David M.

    2011-01-01

    Calibrate_Image calibrates images obtained from focal plane arrays so that the output image more accurately represents the observed scene. The function takes as input a degraded image along with a flat field image and a dark frame image produced by the focal plane array and outputs a corrected image. The three most prominent sources of image degradation are corrected for: dark current accumulation, gain non-uniformity across the focal plane array, and hot and/or dead pixels in the array. In the corrected output image the dark current is subtracted, the gain variation is equalized, and values for hot and dead pixels are estimated, using bicubic interpolation techniques.

  16. Calibration of microscopic traffic-flow models using multiple data sources.

    PubMed

    Hoogendoorn, Serge; Hoogendoorn, Raymond

    2010-10-13

    Parameter identification of microscopic driving models is a difficult task. This is caused by the fact that parameters--such as reaction time, sensitivity to stimuli, etc.--are generally not directly observable from common traffic data, but also due to the lack of reliable statistical estimation techniques. This contribution puts forward a new approach to identifying parameters of car-following models. One of the main contributions of this article is that the proposed approach allows for joint estimation of parameters using different data sources, including prior information on parameter values (or the valid range of values). This is achieved by generalizing the maximum-likelihood estimation approach proposed by the authors in previous work. The approach allows for statistical analysis of the parameter estimates, including the standard error of the parameter estimates and the correlation of the estimates. Using the likelihood-ratio test, models of different complexity (defined by the number of model parameters) can be cross-compared. A nice property of this test is that it takes into account the number of parameters of a model as well as the performance. To illustrate the workings, the approach is applied to two car-following models using vehicle trajectories of a Dutch freeway collected from a helicopter, in combination with data collected with a driving simulator.

  17. Users program for storage-ring based FEL and synchrotron sources of the Duke FEL Laboratory

    SciTech Connect

    Straub, K.D.; Barnett, G.; Burnham, B.

    1995-12-31

    The storage ring at the Duke FEL Laboratory was first operated with a stored e-beam in November, 1994. It has now achieved operation energies in excess 1 GeV with more than 100 mA current at 280 MeV. The ring has several ports for FEL and synchrotron light source research. The circulating ring current can be synchronized with the seperate Mark III FEL operating in the 2-9.5 {mu}m IR region. This allows low optical jitter (10-20 ps) between the two sources and thus pump-probe operation. The ring has been configured to drive a number of light sources including the OK-4 FEL system capable of FEL operation between 400 and 65 nm, an inverse Compton scattering source using this undulator which will yield 4-200 MeV gammas, an undulator source at approximately 40 {angstrom} (not an FEL), a mm FEL with inverse compton scattering providing 1-100 keV x-rays and two synchrotron ports from the bend magnets for which the {lambda}{sub c} = 11-12 {angstrom} for 1 GeV. The broadly tunable FEL sources and their associated inverse compton scattering are extremely bright. The initial research proposals, submitted to the Laboratory emphasizes photoelectron spectroscopy, PEEM, high resolution vacuum UV of gases, solid spectroscopy and photochemistry in the UV, X-ray microprobe studies, X-ray microscopy, X-ray holography, X-ray crystallography, Mossbauer spectroscopy, nuclear spectroscopy, neutron production, photon activation therapy and broadband synchrotron as a probe of fast reaction in the IR and near IR.

  18. New radiation protection calibration facility at CERN.

    PubMed

    Brugger, Markus; Carbonez, Pierre; Pozzi, Fabio; Silari, Marco; Vincke, Helmut

    2014-10-01

    The CERN radiation protection group has designed a new state-of-the-art calibration laboratory to replace the present facility, which is >20 y old. The new laboratory, presently under construction, will be equipped with neutron and gamma sources, as well as an X-ray generator and a beta irradiator. The present work describes the project to design the facility, including the facility placement criteria, the 'point-zero' measurements and the shielding study performed via FLUKA Monte Carlo simulations.

  19. A Simple LIBS (Laser-Induced Breakdown Spectroscopy) Laboratory Experiment to Introduce Undergraduates to Calibration Functions and Atomic Spectroscopy

    ERIC Educational Resources Information Center

    Chinni, Rosemarie C.

    2012-01-01

    This laboratory experiment introduces students to a different type of atomic spectroscopy: laser-induced breakdown spectroscopy (LIBS). LIBS uses a laser-generated spark to excite the sample; once excited, the elemental emission is spectrally resolved and detected. The students use LIBS to analyze a series of standard synthetic silicate samples…

  20. Korean VLBI Network Calibrator Survey (KVNCS). 1. Source Catalog of KVN Single-dish Flux Density Measurement in the K and Q Bands

    NASA Astrophysics Data System (ADS)

    Lee, Jeong Ae; Sohn, Bong Won; Jung, Taehyun; Byun, Do-Young; Lee, Jee Won

    2017-02-01

    We present the catalog of the KVN Calibrator Survey (KVNCS). This first part of the KVNCS is a single-dish radio survey simultaneously conducted at 22 (K band) and 43 GHz (Q band) using the Korean VLBI Network (KVN) from 2009 to 2011. A total of 2045 sources are selected from the VLBA Calibrator Survey with an extrapolated flux density limit of 100 mJy at the K band. The KVNCS contains 1533 sources in the K band with a flux density limit of 70 mJy and 553 sources in the Q band with a flux density limit of 120 mJy; it covers the whole sky down to ‑32.°5 in decl. We detected 513 sources simultaneously in the K and Q bands; ∼76% of them are flat-spectrum sources (‑0.5 ≤ α ≤ 0.5). From the flux–flux relationship, we anticipated that most of the radiation of many of the sources comes from the compact components. The sources listed in the KVNCS therefore are strong candidates for high-frequency VLBI calibrators.

  1. DOE radiological calibrations intercomparison program: Results of fiscal year 1988

    SciTech Connect

    Cummings, F.M.; McDonald, J.C.; Murphy, M.K.

    1989-08-01

    Calibration measurements for personnel dosimetry purposes must be both accurate and consistent with national standards. In order to satisfy these requirements, the following methods are usually employed. In one case, a radiation source is sent to the National Institute of Standards and Technology (NIST), formerly the National Bureau of Standards, for calibration and is returned to the laboratory to be used as a local standard. Another method involves the calibration of an instrument, such as an ionization chamber, by NIST. After calibration, this instrument is then used to measure the exposure rate delivered by radiation sources at the laboratory. Such calibrations by NIST are essential, but they do not provide a complete check on the quality of the calibrations that are carried out by the individual laboratory. Additional measurements are necessary to assure the quality of such measurements. When laboratory staff are asked to carry our measurements with calibrated instruments and report results for evaluation, they are participating in a measurement quality assurance (MQA) program. Such a program tests not only the quality of the equipment but also the ability of the staff to correctly use and interpret the results obtained with the equipment. The NIST operates an MQA program with a selected number of calibration laboratories. Pacific Northwest Laboratory (PNL) participates in this MQA program even though NIST test only x-ray and gamma-ray measurements. The US Department of Energy (DOE) intercomparison program was designed specifically to include x-ray, gamma-ray, beta, and neutron calibrations for personnel dosimetry purposes. This program serves a need that is not being met by NIST, and it provides documentation of the accuracy and uniformity of the radiological calibrations carried out in DOE facilities. 7 refs., 3 figs., 6 tabs.

  2. Broad-band calibration of marine seismic sources used by R/V Polarstern for academic research in polar regions

    NASA Astrophysics Data System (ADS)

    Breitzke, Monika; Boebel, Olaf; El Naggar, Saad; Jokat, Wilfried; Werner, Berthold

    2008-08-01

    Air guns and air-gun arrays of different volumes are used for scientific seismic surveys with R/V Polarstern in polar regions. To assess the potential risk of these research activities on marine mammal populations, knowledge of the sound pressure field of the seismic sources is essential. Therefore, a broad-band (0-80 kHz) calibration study was conducted at the Heggernes Acoustic Range, Norway. A GI (2.4 l), a G (8.5 l) and a Bolt gun (32.8 l) were deployed as single sources, 3 GI (7.4 l), 3 G (25.6 l) and 8 VLF™ Prakla-Seismos air guns (24.0 l) as arrays. Each configuration was fired along a line of 3-4 km length running between two hydrophone chains with receivers in 35, 100, 198 and 263 m depth. Peak-to-peak, zero-to-peak, rms and sound exposure levels (SEL) were analysed as functions of range. They show the typical dipole-like directivity of marine seismic sources with amplitude cancellation close to the sea surface, higher amplitudes in greater depths, and sound pressure levels which continuously decrease with range. Levels recorded during the approach are lower than during the departure indicating a shadowing effect of Polarsterns's hull. Backcalculated zero-to-peak source levels range from 224-240 dB re 1 μPa @ 1 m. Spectral source levels are highest below 100 Hz and amount to 182-194 dB re 1 μPa Hz-1. They drop off continuously with range and frequency. At 1 kHz they are ~30 dB, at 80 kHz ~60 dB lower than the peak level. Above 1 kHz amplitude spectra are dominated by Polarstern's self-noise. From the rms and sound exposure levels of the deepest hydrophone radii for different thresholds are derived. For a 180 dB rms-level threshold radii maximally vary between 200 and 600 m, for a 186 dB SEL threshold between 50 and 300 m.

  3. ESTIMATION OF NEUTRON SCATTER CORRECTION FOR CALIBRATION OF PERSONNEL DOSIMETER AND DOSERATEMETER AGAINST 241Am-Be SOURCE-MONTE CARLO SIMULATION AND MEASUREMENTS.

    PubMed

    Dawn, Sandipan; Bakshi, A K; Sathian, Deepa; Selvam, T Palani

    2016-10-07

    Neutron scatter contributions as a function of distance along the transverse axis of (241)Am-Be source were estimated by three different methods such as shadow cone, semi-empirical and Monte Carlo. The Monte Carlo-based FLUKA code was used to simulate the existing room used for the calibration of CR-39 detector as well as LB6411 doseratemeter for selected distances from (241)Am-Be source. The modified (241)Am-Be spectra at different irradiation geometries such as at different source detector distances, behind the shadow cone, at the surface of the water phantom were also evaluated using Monte Carlo calculations. Neutron scatter contributions, estimated using three different methods compare reasonably well. It is proposed to use the scattering correction factors estimated through Monte Carlo simulation and other methods for the calibration of CR-39 detector and doseratemeter at 0.75 and 1 m distance from the source.

  4. BROOKHAVEN NATIONAL LABORATORY SOURCE WATER ASSESSMENT FOR DRINKING WATER SUPPLY WELLS

    SciTech Connect

    BENNETT,D.B.; PAQUETTE,D.E.; KLAUS,K.; DORSCH,W.R.

    2000-12-18

    The BNL water supply system meets all water quality standards and has sufficient pumping and storage capacity to meet current and anticipated future operational demands. Because BNL's water supply is drawn from the shallow Upper Glacial aquifer, BNL's source water is susceptible to contamination. The quality of the water supply is being protected through (1) a comprehensive program of engineered and operational controls of existing aquifer contamination and potential sources of new contamination, (2) groundwater monitoring, and (3) potable water treatment. The BNL Source Water Assessment found that the source water for BNL's Western Well Field (comprised of Supply Wells 4, 6, and 7) has relatively few threats of contamination and identified potential sources are already being carefully managed. The source water for BNL's Eastern Well Field (comprised of Supply Wells 10, 11, and 12) has a moderate number of threats to water quality, primarily from several existing volatile organic compound and tritium plumes. The g-2 Tritium Plume and portions of the Operable Unit III VOC plume fall within the delineated source water area for the Eastern Well Field. In addition, portions of the much slower migrating strontium-90 plumes associated with the Brookhaven Graphite Research Reactor, Waste Concentration Facility and Building 650 lie within the Eastern source water area. However, the rate of travel in the aquifer for strontium-90 is about one-twentieth of that for tritium and volatile organic compounds. The Laboratory has been carefully monitoring plume migration, and has made adjustments to water supply operations. Although a number of BNL's water supply wells were impacted by VOC contamination in the late 1980s, recent routine analysis of water samples from BNL's supply wells indicate that no drinking water standards have been reached or exceeded. The high quality of the water supply strongly indicates that the operational and engineered controls implemented over the past

  5. Performance of viruses and bacteriophages for fecal source determination in a multi-laboratory, comparative study.

    PubMed

    Harwood, Valerie J; Boehm, Alexandria B; Sassoubre, Lauren M; Vijayavel, Kannappan; Stewart, Jill R; Fong, Theng-Theng; Caprais, Marie-Paule; Converse, Reagan R; Diston, David; Ebdon, James; Fuhrman, Jed A; Gourmelon, Michele; Gentry-Shields, Jennifer; Griffith, John F; Kashian, Donna R; Noble, Rachel T; Taylor, Huw; Wicki, Melanie

    2013-11-15

    An inter-laboratory study of the accuracy of microbial source tracking (MST) methods was conducted using challenge fecal and sewage samples that were spiked into artificial freshwater and provided as unknowns (blind test samples) to the laboratories. The results of the Source Identification Protocol Project (SIPP) are presented in a series of papers that cover 41 MST methods. This contribution details the results of the virus and bacteriophage methods targeting human fecal or sewage contamination. Human viruses used as source identifiers included adenoviruses (HAdV), enteroviruses (EV), norovirus Groups I and II (NoVI and NoVII), and polyomaviruses (HPyVs). Bacteriophages were also employed, including somatic coliphages and F-specific RNA bacteriophages (FRNAPH) as general indicators of fecal contamination. Bacteriophage methods targeting human fecal sources included genotyping of FRNAPH isolates and plaque formation on bacterial hosts Enterococcus faecium MB-55, Bacteroides HB-73 and Bacteroides GB-124. The use of small sample volumes (≤50 ml) resulted in relatively insensitive theoretical limits of detection (10-50 gene copies or plaques × 50 ml(-1)) which, coupled with low virus concentrations in samples, resulted in high false-negative rates, low sensitivity, and low negative predictive values. On the other hand, the specificity of the human virus methods was generally close to 100% and positive predictive values were ∼40-70% with the exception of NoVs, which were not detected. The bacteriophage methods were generally much less specific toward human sewage than virus methods, although FRNAPH II genotyping was relatively successful, with 18% sensitivity and 85% specificity. While the specificity of the human virus methods engenders great confidence in a positive result, better concentration methods and larger sample volumes must be utilized for greater accuracy of negative results, i.e. the prediction that a human contamination source is absent.

  6. Integrated Verification Experiment data collected as part of the Los Alamos National Laboratory`s Source Region Program. Appendix B: Surface ground motion

    SciTech Connect

    Weaver, T.A.; Baker, D.F.; Edwards, C.L.; Freeman, S.H.

    1993-10-01

    Surface ground motion was recorded for many of the Integrated Verification Experiments using standard 10-, 25- and 100-g accelerometers, force-balanced accelerometers and, for some events, using golf balls and 0.39-cm steel balls as surface inertial gauges (SIGs). This report contains the semi-processed acceleration, velocity, and displacement data for the accelerometers fielded and the individual observations for the SIG experiments. Most acceleration, velocity, and displacement records have had calibrations applied and have been deramped, offset corrected, and deglitched but are otherwise unfiltered or processed from their original records. Digital data for all of these records are stored at Los Alamos National Laboratory.

  7. Establishing cytogenetic biodosimetry laboratory in Saudi Arabia and producing preliminary calibration curve of dicentric chromosomes as biomarker for medical dose estimation in response to radiation emergencies.

    PubMed

    Al-Hadyan, Khaled; Elewisy, Sara; Moftah, Belal; Shoukri, Mohamed; Alzahrany, Awad; Alsbeih, Ghazi

    2014-12-01

    In cases of public or occupational radiation overexposure and eventual radiological accidents, it is important to provide dose assessment, medical triage, diagnoses and treatment to victims. Cytogenetic bio-dosimetry based on scoring of dicentric chromosomal aberrations assay (DCA) is the "gold standard" biotechnology technique for estimating medically relevant radiation doses. Under the auspices of the National Science, Technology and Innovation Plan in Saudi Arabia, we have set up a biodosimetry laboratory and produced a national standard dose-response calibration curve for DCA, pre-required to estimate the doses received. For this, the basic cytogenetic DCA technique needed to be established. Peripheral blood lymphocytes were collected from four healthy volunteers and irradiated with radiation doses between 0 and 5 Gy of 320 keV X-rays. Then, lymphocytes were PHA stimulated, Colcemid division arrested and stained cytogenetic slides were prepared. The Metafer4 system (MetaSystem) was used for automatic and manually assisted metaphase finding and scoring of dicentric chromosomes. Results were fit to the linear-quadratic dose-effect model according to the IAEA EPR-Biodosimetry-2011 report. The resulting manually assisted dose-response calibration curve (Y = 0.0017 + 0.026 × D + 0.081 × D(2)) was in the range of those described in other populations. Although the automated scoring over-and-under estimates DCA at low (<1 Gy) and high (>2 Gy) doses, respectively, it showed potential for use in triage mode to segregate between victims with potential risk to develop acute radiotoxicity syndromes. In conclusion, we have successfully established the first biodosimetry laboratory in the region and have produced a preliminary national dose-response calibration curve. The laboratory can now contribute to the national preparedness plan in response to eventual radiation emergencies in addition to providing information for decision makers and public health

  8. Design of laboratory experiments to study photoionization fronts driven by thermal sources

    SciTech Connect

    Drake, R. P.; Hazak, G.; Keiter, P. A.; Davis, J. S.; Patterson, C. R.; Frank, A.; Blackman, E. G.; Busquet, Michel

    2016-12-20

    This study analyzes the requirements of a photoionization-front experiment that could be driven in the laboratory, using thermal sources to produce the necessary flux of ionizing photons. It reports several associated conclusions. Such experiments will need to employ the largest available facilities, capable of delivering many kJ to MJ of energy to an x-ray source. They will use this source to irradiate a volume of neutral gas, likely of N, on a scale of a few mm to a few cm, increasing with source energy. For a gas pressure of several to ten atmospheres at room temperature, and a source temperature near 100 eV, one will be able to drive a photoionization front through a system of tens to hundreds of photon mean free paths. The front should make the familiar transition from the so-called R-Type to D-Type as the radiation flux diminishes with distance. The N is likely to reach the He-like state. Preheating from the energetic photons appears unlikely to become large enough to alter the essential dynamics of the front beyond some layer near the surface. For well-chosen experimental conditions, competing energy transport mechanisms are small.

  9. [Investigation of the present management status of calibration source based on the law concerning prevention of radiation hazards due to radioisotopes].

    PubMed

    Takahashi, Yasuyuki; Igarashi, Hiroshi; Hirano, Kunihiro; Kawaharada, Yasuhiro; Igarashi, Hitoshi; Murase, Ken-ya; Mochizuki, Teruhito

    2007-03-20

    An amendment concerning the enforcement of the law on the prevention of radiation hazards due to radioisotopes, etc., and the medical service law enforcement regulations were promulgated on June 1, 2005. This amendment concerned international basic safety standards and the sealing of radiation sources. Sealed radiation sources < or =3.7 MBq, which had been excluded from regulation, were newly included as an object of regulation. Investigation of the SPECT system instituted in hospitals indicated that almost all institutions adhere to the new amendment, and the calibration source, the checking source, etc., corresponding to this amendment were maintained appropriately. Any institutions planning to return sealed radioisotopes should refer to this report.

  10. Calibration of the WFC3 Emission-Line Filters and Application of the Results to the Greatest Source of Uncertainties in Determining Abundances in Gase

    NASA Astrophysics Data System (ADS)

    O'Dell, C.

    2010-09-01

    The WFC3 is arguably the most powerful camera that has been used on the HST. This capability arises in part from the uniquely complete set of narrow-band filters that were incorporated for making images of nebulae in emission-lines. Turning these oft-times beautiful images into scientifically useful information requires accurate flux calibration of the filters, which is the first subject of this proposal. The present plan is that WFC3 calibration will be done from pre-launch properties of the filters and observations of stars. The WFC3 filters transmission profiles were measured pre-launch in a different optical configuration and temperature than applies within the WFC3, thus rendering uncertain any flux calibrations tied to those pre-launch measurements. We propose to perform a ?ground-truth? calibration of the WFC3 narrow-band filters using NGC 6720 as a reference source, in much the same manner that the PI did when calibrating similar filters in the WFPC2 and the ACS.These new calibrations will then be used to address the t^2 problem in Gaseous Nebulae. This is the source of uncertainties in the relative abundances of factors 1.1 to 10 and undermines efforts to trace the abundance variations within our Galaxy and other galaxies. The t^2 problem remains unresolved after four decades and the NGC 6720 images used for the filter calibration may resolve the problem if they show that regions of small-scale temperature fluctuations arise from low-temperature shadow-zones behind knots that are known to exist within the nebula or from high-temperature shocks that have been posited. Unlike the case of the Orion Nebula, where we have addressed this problem with fewer diagnostic filters, the geometry of NGC 6720 is ideally favorable for seeing these temperature variations and identifying their cause.

  11. Water in cratonic lithosphere: Calibrating laboratory-determined models of electrical conductivity of mantle minerals using geophysical and petrological observations

    NASA Astrophysics Data System (ADS)

    Jones, Alan G.; Fullea, Javier; Evans, Rob L.; Muller, Mark R.

    2012-06-01

    Measurements of electrical conductivity of "slightly damp" mantle minerals from different laboratories are inconsistent, requiring geophysicists to make choices between them when interpreting their electrical observations. These choices lead to dramatically different conclusions about the amount of water in the mantle, resulting in conflicting conclusions regarding rheological conditions; this impacts on our understanding of mantle convection, among other processes. To attempt to reconcile these differences, we test the laboratory-derived proton conduction models by choosing the simplest petrological scenario possible - cratonic lithosphere - from two locations in southern Africa where we have the most complete knowledge. We compare and contrast the models with field observations of electrical conductivity and of the amount of water in olivine and show that none of the models for proton conduction in olivine proposed by three laboratories are consistent with the field observations. We derive statistically model parameters of the general proton conduction equation that satisfy the observations. The pre-exponent dry proton conduction term (σ0) and the activation enthalpy (ΔHwet) are derived with tight bounds, and are both within the broader 2σ errors of the different laboratory measurements. The two other terms used by the experimentalists, one to describe proton hopping (exponent ron pre-exponent water contentCw) and the other to describe H2O concentration-dependent activation enthalpy (termαCw1/3 added to the activation energy), are less well defined and further field geophysical and petrological observations are required, especially in regions of higher temperature and higher water content.

  12. Estimating usual food intake distributions by using the multiple source method in the EPIC-Potsdam Calibration Study.

    PubMed

    Haubrock, Jennifer; Nöthlings, Ute; Volatier, Jean-Luc; Dekkers, Arnold; Ocké, Marga; Harttig, Ulrich; Illner, Anne-Kathrin; Knüppel, Sven; Andersen, Lene F; Boeing, Heiner

    2011-05-01

    Estimating usual food intake distributions from short-term quantitative measurements is critical when occasionally or rarely eaten food groups are considered. To overcome this challenge by statistical modeling, the Multiple Source Method (MSM) was developed in 2006. The MSM provides usual food intake distributions from individual short-term estimates by combining the probability and the amount of consumption with incorporation of covariates into the modeling part. Habitual consumption frequency information may be used in 2 ways: first, to distinguish true nonconsumers from occasional nonconsumers in short-term measurements and second, as a covariate in the statistical model. The MSM is therefore able to calculate estimates for occasional nonconsumers. External information on the proportion of nonconsumers of a food can also be handled by the MSM. As a proof-of-concept, we applied the MSM to a data set from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Calibration Study (2004) comprising 393 participants who completed two 24-h dietary recalls and one FFQ. Usual intake distributions were estimated for 38 food groups with a proportion of nonconsumers > 70% in the 24-h dietary recalls. The intake estimates derived by the MSM corresponded with the observed values such as the group mean. This study shows that the MSM is a useful and applicable statistical technique to estimate usual food intake distributions, if at least 2 repeated measurements per participant are available, even for food groups with a sizeable percentage of nonconsumers.

  13. Mean-free-paths in concert and chamber music halls and the correct method for calibrating dodecahedral sound sources.

    PubMed

    Beranek, Leo L; Nishihara, Noriko

    2014-01-01

    The Eyring/Sabine equations assume that in a large irregular room a sound wave travels in straight lines from one surface to another, that the surfaces have an average sound absorption coefficient αav, and that the mean-free-path between reflections is 4 V/Stot where V is the volume of the room and Stot is the total area of all of its surfaces. No account is taken of diffusivity of the surfaces. The 4 V/Stot relation was originally based on experimental determinations made by Knudsen (Architectural Acoustics, 1932, pp. 132-141). This paper sets out to test the 4 V/Stot relation experimentally for a wide variety of unoccupied concert and chamber music halls with seating capacities from 200 to 5000, using the measured sound strengths Gmid and reverberation times RT60,mid. Computer simulations of the sound fields for nine of these rooms (of varying shapes) were also made to determine the mean-free-paths by that method. The study shows that 4 V/Stot is an acceptable relation for mean-free-paths in the Sabine/Eyring equations except for halls of unusual shape. Also demonstrated is the proper method for calibrating the dodecahedral sound source used for measuring the sound strength G, i.e., the reverberation chamber method.

  14. FlowCal: A User-Friendly, Open Source Software Tool for Automatically Converting Flow Cytometry Data from Arbitrary to Calibrated Units.

    PubMed

    Castillo-Hair, Sebastian M; Sexton, John T; Landry, Brian P; Olson, Evan J; Igoshin, Oleg A; Tabor, Jeffrey J

    2016-07-15

    Flow cytometry is widely used to measure gene expression and other molecular biological processes with single cell resolution via fluorescent probes. Flow cytometers output data in arbitrary units (a.u.) that vary with the probe, instrument, and settings. Arbitrary units can be converted to the calibrated unit molecules of equivalent fluorophore (MEF) using commercially available calibration particles. However, there is no convenient, nonproprietary tool available to perform this calibration. Consequently, most researchers report data in a.u., limiting interpretation. Here, we report a software tool named FlowCal to overcome current limitations. FlowCal can be run using an intuitive Microsoft Excel interface, or customizable Python scripts. The software accepts Flow Cytometry Standard (FCS) files as inputs and is compatible with different calibration particles, fluorescent probes, and cell types. Additionally, FlowCal automatically gates data, calculates common statistics, and produces publication quality plots. We validate FlowCal by calibrating a.u. measurements of E. coli expressing superfolder GFP (sfGFP) collected at 10 different detector sensitivity (gain) settings to a single MEF value. Additionally, we reduce day-to-day variability in replicate E. coli sfGFP expression measurements due to instrument drift by 33%, and calibrate S. cerevisiae Venus expression data to MEF units. Finally, we demonstrate a simple method for using FlowCal to calibrate fluorescence units across different cytometers. FlowCal should ease the quantitative analysis of flow cytometry data within and across laboratories and facilitate the adoption of standard fluorescence units in synthetic biology and beyond.

  15. MODIS airborne simulator visible and near-infrared calibration, 1991 FIRE-Cirrus field experiment. Calibration version: FIRE King 1.1

    NASA Technical Reports Server (NTRS)

    Arnold, G. Thomas; Fitzgerald, Michael; Grant, Patrick S.; King, Michael D.

    1994-01-01

    Calibration of the visible and near-infrared channels of the MODIS Airborne Simulator (MAS) is derived from observations of a calibrated light source. For the 1991 FIRE-Cirrus field experiment, the calibrated light source was the NASA Goddard 48-inch integrating hemisphere. Laboratory tests during the FIRE Cirrus field experiment were conducted to calibrate the hemisphere and from the hemisphere to the MAS. The purpose of this report is to summarize the FIRE-Cirrus hemisphere calibration, and then describe how the MAS was calibrated from observations of the hemisphere data. All MAS calibration measurements are presented, and determination of the MAS calibration coefficients (raw counts to radiance conversion) is discussed. Thermal sensitivity of the MAS visible and near-infrared calibration is also discussed. Typically, the MAS in-flight is 30 to 60 degrees C colder than the room temperature laboratory calibration. Results from in-flight temperature measurements and tests of the MAS in a cold chamber are given, and from these, equations are derived to adjust the MAS in-flight data to what the value would be at laboratory conditions. For FIRE-Cirrus data, only channels 3 through 6 were found to be temperature sensitive. The final section of this report describes comparisons to an independent MAS (room temperature) calibration by Ames personnel using their 30-inch integrating sphere.

  16. Measurement of Turbulence with Acoustic Doppler Current Profilers - Sources of Error and Laboratory Results

    USGS Publications Warehouse

    Nystrom, E.A.; Oberg, K.A.; Rehmann, C.R.; ,

    2002-01-01

    Acoustic Doppler current profilers (ADCPs) provide a promising method for measuring surface-water turbulence because they can provide data from a large spatial range in a relatively short time with relative ease. Some potential sources of errors in turbulence measurements made with ADCPs include inaccuracy of Doppler-shift measurements, poor temporal and spatial measurement resolution, and inaccuracy of multi-dimensional velocities resolved from one-dimensional velocities measured at separate locations. Results from laboratory measurements of mean velocity and turbulence statistics made with two pulse-coherent ADCPs in 0.87 meters of water are used to illustrate several of inherent sources of error in ADCP turbulence measurements. Results show that processing algorithms and beam configurations have important effects on turbulence measurements. ADCPs can provide reasonable estimates of many turbulence parameters; however, the accuracy of turbulence measurements made with commercially available ADCPs is often poor in comparison to standard measurement techniques.

  17. The Advanced Light Source at the Lawrence Berkeley Laboratory (ALS, LBL)

    SciTech Connect

    Jackson, A.

    1990-08-01

    The Advanced Light Source (ALS), a national facility currently under construction at the Lawrence Berkeley Laboratory (LBL), is a third-generation synchrotron light source designed to produce extremely bright beams of synchrotron radiation, in the energy range from a few eV to 10 keV. The design is based on a 1-1.9 GeV electron storage ring (optimized at 1.5 GeV), and utilizes special magnets, known as undulators and wigglers (collectively referred to as insertion devices), to generate the radiation. In this paper we describe the main accelerator components of the ALS, the variety of insertion devices, the radiation spectra expected from these devices, and the complement of experiments that have been approved for initial operation, starting in April 1993.

  18. Study of the influence of heat sources on the out-of-pile calibration curve of calorimetric cells used for nuclear energy deposition quantification

    SciTech Connect

    De Vita, C.; Brun, J.; Reynard-Carette, C.; Carette, M.; Amharrak, H.; Lyoussi, A.; Fourmentel, D.; Villard, J.F.

    2015-07-01

    At present the Jules Horowitz Reactor is under construction in Cadarache research center of CEA 'French Alternative Energies and Atomic Energy Commission' center located in the south-east of France. This new Material Testing Reactor (MTR) will be operational in late 2019 and will allow the generation of a new experimental potential (up to 20 irradiation devices simultaneously) and new harsh conditions such as higher neutron fluxes (5.10{sup 14} n.cm{sup -2}.s{sup -1} for E≥1 MeV), faster material ageing and higher nuclear heating (up to 20 W/g for nominal capacity of 100 MW). In nuclear research field, the control and the measurement of the nuclear heating (energy deposition rate per mass unit induced by the interactions of radiations with matter) is crucial to carry out accurate studies on ageing of materials and on the behavior of nuclear fuels under irradiation. Several experiments need to know precisely this key parameter in order to establish dedicated thermal conditions. The measurement of the nuclear heating inside MTRs is realized by three kinds of sensors: single-cell calorimeter, differential calorimeter and gamma thermometer. One scientific objective of the IN-CORE program, between CEA and Aix-Marseille University in 2009, is to improve the nuclear heating measurement. In this context a new multi-sensor device, called CARMEN, was made. This device contains in particular a differential calorimeter which was designed to measure the nuclear heating in the periphery of OSIRIS reactor (a MTR located at Saclay, France) up to 2 W/g and tested during two irradiation campaigns. Results obtained during these campaigns showed that temperatures reached inside the calorimeter are higher than ones obtained during the preliminary out-of-pile calibration experiments. For instance for 1.74 W/g, the in-pile temperature of the calorimeter rod is equal to 305 deg. C against 225 deg. C in laboratory conditions by simulating the nuclear heating by Joule Effect inside the

  19. Report on key comparison COOMET.AUV.A-K5: pressure calibration of laboratory standard microphones in the frequency range 2 Hz to 10 kHz

    NASA Astrophysics Data System (ADS)

    Dobrowolska, D.; Kosterov, A.

    2016-01-01

    This is the final report for regional key comparison COOMET.AUV.A-K5 on the pressure calibration of laboratory standard microphones in the frequency range from 2 Hz to 10 kHz. Two laboratories—Central Office of Measures (GUM)—the national metrology institute for Poland and the State Enterprise Scientific-Research Institute for Metrology of Measurement and Control Systems (DP NDI Systema)— the designated institute for acoustics in Ukraine took part in this comparison with the GUM as a pilot. One travelling type LS1P microphone was circulated to the participants and results in the form of regular calibration certificates were collected. The results of the DP NDI Systema obtained in this comparison were linked to the CCAUV.A-K5 key comparison through the joint participation of the GUM. The degrees of equivalence were computed for DP NDI Systema with respect to the CCAUV.A-K5 key comparison reference value. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  20. Multi-Objective vs. Single Objective Calibration of a Hydrologic Model using Either Different Hydrologic Signatures or Complementary Data Sources

    NASA Astrophysics Data System (ADS)

    Mai, J.; Cuntz, M.; Zink, M.; Schaefer, D.; Thober, S.; Samaniego, L. E.; Shafii, M.; Tolson, B.

    2015-12-01

    Hydrologic models are traditionally calibrated against discharge. Recent studies have shown however, that only a few global model parameters are constrained using the integral discharge measurements. It is therefore advisable to use additional information to calibrate those models. Snow pack data, for example, could improve the parametrization of snow-related processes, which might be underrepresented when using only discharge. One common approach is to combine these multiple objectives into one single objective function and allow the use of a single-objective algorithm. Another strategy is to consider the different objectives separately and apply a Pareto-optimizing algorithm. Both methods are challenging in the choice of appropriate multiple objectives with either conflicting interests or the focus on different model processes. A first aim of this study is to compare the two approaches employing the mesoscale Hydrologic Model mHM at several distinct river basins over Europe and North America. This comparison will allow the identification of the single-objective solution on the Pareto front. It is elucidated if this position is determined by the weighting and scaling of the multiple objectives when combing them to the single objective. The principal second aim is to guide the selection of proper objectives employing sensitivity analyses. These analyses are used to determine if an additional information would help to constrain additional model parameters. The additional information are either multiple data sources or multiple signatures of one measurement. It is evaluated if specific discharge signatures can inform different parts of the hydrologic model. The results show that an appropriate selection of discharge signatures increased the number of constrained parameters by more than 50% compared to using only NSE of the discharge time series. It is further assessed if the use of these signatures impose conflicting objectives on the hydrologic model. The usage of

  1. ORNL calibrations facility

    SciTech Connect

    Berger, C.D.; Gupton, E.D.; Lane, B.H.; Miller, J.H.; Nichols, S.W.

    1982-08-01

    The ORNL Calibrations Facility is operated by the Instrumentation Group of the Industrial Safety and Applied Health Physics Division. Its primary purpose is to maintain radiation calibration standards for calibration of ORNL health physics instruments and personnel dosimeters. This report includes a discussion of the radioactive sources and ancillary equipment in use and a step-by-step procedure for calibration of those survey instruments and personnel dosimeters in routine use at ORNL.

  2. Laboratory Calibration Studies in Support of ORGANICS on the International Space Station: Evolution of Organic Matter in Space

    NASA Technical Reports Server (NTRS)

    Ruiterkamp, R.; Ehrenfreund, P.; Halasinski, T.; Salama, F.; Foing, B.; Schmidt, W.

    2002-01-01

    This paper describes the scientific overview and current status of ORGANICS an exposure experiment performed on the International Space Station (ISS) to study the evolution of organic matter in space (PI: P. Ehrenfreund), with supporting laboratory experiments performed at NASA Ames. ORGANICS investigates the chemical evolution of samples submitted to long-duration exposure to space environment in near-Earth orbit. This experiment will provide information on the nature, evolution, and survival of carbon species in the interstellar medium (ISM) and in solar system targets.

  3. New laboratory EUV reflectometer for large optics using a laser plasma source

    NASA Astrophysics Data System (ADS)

    van Loyen, Ludwig; Boettger, Thomas; Braun, Stefan; Mai, Hermann; Leson, Andreas; Scholze, Frank; Tuemmler, Johannes; Ulm, Gerhard; Legall, Herbert; Nickles, Peter V.; Sandner, Wolfgang; Stiel, Holger; Rempel, Christian E.; Schulze, Mirko; Brutscher, Joerg; Macco, Fritz; Muellender, Stefan

    2003-05-01

    The quality assurance for production of optical components for EUV lithography strongly requires at-wavelength metrology. Presently, at-wavelength characterizations of mirrors and masks are done using the synchrotron radiation of electron storage rings, e.g. BESSY II. For the production process of EUV optics, however, the immediate access to metrology tools is necessary and availability of laboratory devices is mandatory. Within the last years a stand alone laboratory EUV reflectometer for large samples has been developed It consists of a laser produced plasma (LLP) radiation source, a monochromator and a large goniometer systme. The manipulation system of the reflectometer can handle samples with diameters of up to 500 mm, thicknesses of up to 200 mm and weights of up to 30 kg. The wavelength can be varied from 10 nm to 16 nm. The spot size on the sample surface is about 2mm. The angle of incidence can be varied from 3° to 60°. In this paper, we describe the laboratory reflectometer in detail and discuss the achieved performance. First measurements of 4 inch mirrors are presented and discussed in comparison to the results obtained at the PTB soft x-ray radiometry beamline at BESSY II.

  4. Design of laboratory experiments to study photoionization fronts driven by thermal sources

    DOE PAGES

    Drake, R. P.; Hazak, G.; Keiter, P. A.; ...

    2016-12-20

    This study analyzes the requirements of a photoionization-front experiment that could be driven in the laboratory, using thermal sources to produce the necessary flux of ionizing photons. It reports several associated conclusions. Such experiments will need to employ the largest available facilities, capable of delivering many kJ to MJ of energy to an x-ray source. They will use this source to irradiate a volume of neutral gas, likely of N, on a scale of a few mm to a few cm, increasing with source energy. For a gas pressure of several to ten atmospheres at room temperature, and a sourcemore » temperature near 100 eV, one will be able to drive a photoionization front through a system of tens to hundreds of photon mean free paths. The front should make the familiar transition from the so-called R-Type to D-Type as the radiation flux diminishes with distance. The N is likely to reach the He-like state. Preheating from the energetic photons appears unlikely to become large enough to alter the essential dynamics of the front beyond some layer near the surface. For well-chosen experimental conditions, competing energy transport mechanisms are small.« less

  5. Requirements for dynamical differential phase contrast x-ray imaging with a laboratory source

    NASA Astrophysics Data System (ADS)

    Macindoe, David; Kitchen, Marcus J.; Irvine, Sarah C.; Fouras, Andreas; Morgan, Kaye S.

    2016-12-01

    X-ray phase contrast enables weakly-attenuating structures to be imaged, with bright synchrotron sources adding the ability to capture time sequences and analyse sample dynamics. Here, we describe the translation of dynamical differential phase contrast imaging from the synchrotron to a compact x-ray source, in order to achieve this kind of time sequence imaging in the laboratory. We formulate broadly-applicable set-up guidelines for the single-grid, single-exposure imaging technique using a divergent source, exploring the experimental factors that restrict set-up size, imaging sensitivity and sample size. Experimental images are presented using the single-grid phase contrast technique with a steel attenuation grid and a liquid-metal-jet x-ray source, enabling exposure times as short as 0.5 s for dynamic imaging. Differential phase contrast images were retrieved from phantoms, incorporating noise filtering to improve the low-count images encountered when imaging dynamics using short exposures.

  6. 3D nanoscale imaging of biological samples with laboratory-based soft X-ray sources

    NASA Astrophysics Data System (ADS)

    Dehlinger, Aurélie; Blechschmidt, Anne; Grötzsch, Daniel; Jung, Robert; Kanngießer, Birgit; Seim, Christian; Stiel, Holger

    2015-09-01

    In microscopy, where the theoretical resolution limit depends on the wavelength of the probing light, radiation in the soft X-ray regime can be used to analyze samples that cannot be resolved with visible light microscopes. In the case of soft X-ray microscopy in the water-window, the energy range of the radiation lies between the absorption edges of carbon (at 284 eV, 4.36 nm) and oxygen (543 eV, 2.34 nm). As a result, carbon-based structures, such as biological samples, posses a strong absorption, whereas e.g. water is more transparent to this radiation. Microscopy in the water-window, therefore, allows the structural investigation of aqueous samples with resolutions of a few tens of nanometers and a penetration depth of up to 10μm. The development of highly brilliant laser-produced plasma-sources has enabled the transfer of Xray microscopy, that was formerly bound to synchrotron sources, to the laboratory, which opens the access of this method to a broader scientific community. The Laboratory Transmission X-ray Microscope at the Berlin Laboratory for innovative X-ray technologies (BLiX) runs with a laser produced nitrogen plasma that emits radiation in the soft X-ray regime. The mentioned high penetration depth can be exploited to analyze biological samples in their natural state and with several projection angles. The obtained tomogram is the key to a more precise and global analysis of samples originating from various fields of life science.

  7. DESIGN NOTE: Reduction of uncertainties in temperature calibrations by comparison

    NASA Astrophysics Data System (ADS)

    Drnovsek, Janko; Pusnik, Igor; Bojkovski, Jovan

    1998-11-01

    The objective of this design note is to discuss and define the total uncertainty in temperature calibrations by comparison, by analysing most of the likely error sources. As a result of the proposed and developed uncertainty analysis, further reductions of uncertainties could be realized if/when better equipment becomes available. The analysis is performed as a case study using state-of-the-art calibration equipment described in the design note. This equipment is located in the authors' own secondary temperature calibration laboratory. Accreditation for this laboratory has been granted through The Dutch Council of Accreditation (RVA) for calibrations in the temperature range -55 to 0957-0233/9/11/017/img1C. In temperature calibrations by comparison the four main groups of uncertainties are the reproducibility, uncertainty of a reference thermometer, uncertainty of a calibration bath or a furnace and uncertainty of a measuring device. Special care is taken, using a thorough evaluation procedure, to ensure that the uncertainty contribution of the calibration bath or furnace is as low as possible. This is necessary because the total uncertainty assigned to an instrument under calibration is larger than the largest individual uncertainty contribution. In temperature calibrations the largest uncertainty is most likely to be the uncertainty of the calibration bath or a furnace. Therefore this uncertainty typically represents the lowest limit for further reduction of the total uncertainty of the calibration process. The analysis performed allows optimal use of temperature calibration equipment for calibration of thermometers by comparison. In this way most practical calibration needs are satisfied in a more economical way than by using substantially more expensive fixed point calibrations.

  8. The EnzymeTracker: an open-source laboratory information management system for sample tracking

    PubMed Central

    2012-01-01

    Background In many laboratories, researchers store experimental data on their own workstation using spreadsheets. However, this approach poses a number of problems, ranging from sharing issues to inefficient data-mining. Standard spreadsheets are also error-prone, as data do not undergo any validation process. To overcome spreadsheets inherent limitations, a number of proprietary systems have been developed, which laboratories need to pay expensive license fees for. Those costs are usually prohibitive for most laboratories and prevent scientists from benefiting from more sophisticated data management systems. Results In this paper, we propose the EnzymeTracker, a web-based laboratory information management system for sample tracking, as an open-source and flexible alternative that aims at facilitating entry, mining and sharing of experimental biological data. The EnzymeTracker features online spreadsheets and tools for monitoring numerous experiments conducted by several collaborators to identify and characterize samples. It also provides libraries of shared data such as protocols, and administration tools for data access control using OpenID and user/team management. Our system relies on a database management system for efficient data indexing and management and a user-friendly AJAX interface that can be accessed over the Internet. The EnzymeTracker facilitates data entry by dynamically suggesting entries and providing smart data-mining tools to effectively retrieve data. Our system features a number of tools to visualize and annotate experimental data, and export highly customizable reports. It also supports QR matrix barcoding to facilitate sample tracking. Conclusions The EnzymeTracker was designed to be easy to use and offers many benefits over spreadsheets, thus presenting the characteristics required to facilitate acceptance by the scientific community. It has been successfully used for 20 months on a daily basis by over 50 scientists. The EnzymeTracker is

  9. Comparison of Spectral Radiance Calibration Techniques Used for Backscatter Ultraviolet Satellite Instruments

    NASA Technical Reports Server (NTRS)

    Kowalewski, Matthew G.; Janz, Scott

    2014-01-01

    Methods for determining the absolute radiometric calibration sensitivities of backscatter ultraviolet (BUV) satellite instruments are compared as part of an effort to minimize pre-launch calibration errors. An internally illuminated integrating sphere source has been used for the Shuttle Solar BUV (SSBUV), Total Ozone Mapping Spectrometer (TOMS), Ozone Mapping Instrument (OMI), and Global Ozone Monitoring Experiment 2 (GOME-2) using standardized procedures traceable to national standards. These sphere-based sensitivities agree to within three percent [k equals 2] relative to calibrations performed using an external diffuser illuminated by standard irradiance sources, the customary radiance calibration method for BUV instruments. The uncertainty for these calibration techniques as implemented at the NASA Goddard Space Flight Centers Radiometric Calibration and Development Laboratory is shown to be 4 percent at 250nm [k equals 2] when using a single traceable calibration standard. Significant reduction in the uncertainty of nearly 1 percent is demonstrated when multiple calibration standards are used.

  10. Calibration of a helium-cooled infrared spatial radiometer and grating spectrometer

    NASA Technical Reports Server (NTRS)

    Jacobsen, Larry; Sargent, Steve; Wyatt, Clair L.; Steed, Allan J.

    1992-01-01

    Methods used by the Space Dynamics Laboratory of Utah State University (SDL/USU) to calibrate infrared sensors are described, using the Infrared Background Signature Survey (IBSS) spatial radiometer and grating spectrometer as examples. A calibration equation and a radiometric model are given for each sensor to describe their responsivity in terms of individual radiometric parameters. The calibration equation terms include dark offset, linearity, absolute responsivity, and measurement uncertainty, and the radiometric model domains include spatial, spectral, and temporal domains. A portable calibration facility, designed and fabricated by SDL/USU, provided collimated, extended, diffuse scatter, and Jones sources in a single cryogenic dewar. This multi-function calibrator allowed calibration personnel to complete a full calibration of the IBSS infrared radiometer and spectrometer in two 15-day periods. A calibration data system was developed to control and monitor the calibration facility, and to record and analyze sensor data.

  11. Laboratory calibration and field testing of the Chemcatcher-Metal for trace levels of rare earth elements in estuarine waters.

    PubMed

    Petersen, Jördis; Pröfrock, Daniel; Paschke, Albrecht; Broekaert, Jose A C; Prange, Andreas

    2015-10-01

    Little knowledge is available about water concentrations of rare earth elements (REEs) in the marine environment. The direct measurement of REEs in coastal waters is a challenging task due to their ultra-low concentrations as well as the high salt content in the water samples. To quantify these elements at environmental concentrations (pg L(-1) to low ng L(-1)) in coastal waters, current analytical techniques are generally expensive and time consuming, and require complex chemical preconcentration procedures. Therefore, an integrative passive sampler was tested as a more economic alternative sampling approach for REE analysis. We used a Chemcatcher-Metal passive sampler consisting of a 3M Empore Chelating Disk as the receiving phase, as well as a cellulose acetate membrane as the diffusion-limiting layer. The effect of water turbulence and temperature on the uptake rates of REEs was analyzed during 14-day calibration experiments by a flow-through exposure tank system. The sampling rates were in the range of 0.42 mL h(-1) (13 °C; 0.25 m s(-1)) to 4.01 mL h(-1) (13 °C; 1 m s(-1)). Similar results were obtained for the different REEs under investigation. The water turbulence was the most important influence on uptake. The uptake rates were appropriate to ascertain time-weighted average concentrations of REEs during a field experiment in the Elbe Estuary near Cuxhaven Harbor (exposure time 4 weeks). REE concentrations were determined to be in the range 0.2 to 13.8 ng L(-1), where the highest concentrations were found for neodymium and samarium. In comparison, most of the spot samples measured along the Chemcatcher samples had REE concentrations below the limit of detection, in particular due to necessary dilution to minimize the analytical problems that arise with the high salt content in marine water samples. This study was among the first efforts to measure REE levels in the field using a passive sampling approach. Our results suggest that passive samplers could be

  12. Conceptual study of moderately coupled plasmas and experimental comparison of laboratory x-ray sources

    SciTech Connect

    Li, Chikang

    1993-12-01

    In this thesis the fundamental concepts of moderately coupled plasmas, for which 2≲lnΛb≲10, are, for the first time, presented. This investigation is motivated because neither the conventional Fokker-Planck approximation [for weakly coupled plasmas (lnΛb≲10)] nor the theory of dielectric response with correlations for strongly coupled plasmas (lnΛb≲1) has satisfactorily addressed this regime. Specifically, herein the standard Fokker-Planck operator for Coulomb collisions has been modified to include hitherto neglected terms that are directly associated with large-angle scattering. In addition a reduced electron-ion collision operator has been calculated that, for the first time, manifests 1/lnΛb corrections. Precise calculations of some relaxation rates and crude calculations of electron transport coefficients have been made. As one of major applications of the modified Fokker-Planck equation, the stopping powers and ρR have been calculated for charged fusion products (α`s, 3H, 3He) and hot electrons interacting with plasmas relevant to inertial confinement fusion. In the second major topic of this thesis, advances made in the area of laboratory x-ray sources are presented. First, and most importantly, through the use a Cockcroft-Walton linear accelerator, a charged particle induced x-ray emission (PIXE) source has been developed. Intense line x radiation (including K-, L-, M-, and N-lines) with wavelengths from 0.5 Å to 111 Å have been successfully produced. Second, a new high intensity electron-beam x-ray generator has also been developed, and it has been used with advantage in the soft x-ray region ( < 3 keV). Finally, a direct comparisons of both sources (PIXE and electron-beam x-ray sources) to a commercially available radioactive α fluorescent x-ray source has been made.

  13. Instrument calibration and measurement plan for the poorly measured/unmeasured category of highly enriched uranium at Lawrence Livermore National Laboratory

    SciTech Connect

    Glosup, J; Mount, M E

    1999-07-01

    In partial response to a Department of Energy (DOE) request to evaluate the state of measurements of special nuclear material, Lawrence Livermore National Laboratory (LLNL) evaluated and classified all highly enriched uranium (HEU) metal and oxide items in its inventory. Because of a lack of traceable HEU standards, no items were deemed to fit the category of well measured. A subsequent DOE-HQ sponsored survey by New Brunswick Laboratory resulted in their preparation of a set of certified reference material (CRM) standards for HEU oxide (U{sub 3}O{sub 8}) that are projected for delivery during September of 1999. However, CRM standards for HEU metal are neither in preparation nor are they expected to be prepared within the foreseeable future. Consequently, HEU metal working standards must be developed if the poorly measured/unmeasured portion of the LLNL inventory is to be reclassified. This paper describes the approach that LLNL will take to (1) develop a set of HEU metal working standards; (2) develop HEU metal and oxide calibration curves for the passive-active neutron (PAN) shuffler that are functions of mass, enrichment, size, and shape; and (3) reclassify the poorly measured/unmeasured inventory through direct measurement or reprocessing of previously archived data.

  14. Proximal potentially seismogenic sources for Sandia National Laboratories, Albuquerque, New Mexico

    SciTech Connect

    Gibson, J.D.

    1995-10-01

    Recent geologic and geophysical investigations within the Albuquerque Basin have shed light on the potentially seismogenic sources that might affect Sandia National Laboratories, New Mexico (SNL/NM), a multi-disciplinary research and engineering facility of the US Department of Energy (DOE). This paper presents a summary of potentially seismogenic sources for SNL/NM, emphasizing those sources within approximately 8 kilometers (km) of the site. Several significant faults of the central Rio Grande rift transect SNL/NM. Although progress has been made on understanding the geometry and interactions of these faults, little is known of the timing of most recent movement or on recurrent intervals for these faults. Therefore, whether particular faults or fault sections have been active during the Holocene or even the late Pleistocene is undocumented. Although the overall subdued surface expression of many of these faults suggests that they have low to moderate slip rates, the proximity of these faults to critical (e.g., nuclear) and non-critical (e.g., high-occupancy, multistory office/light lab) facilities at SNL/NM requires their careful examination for evaluation of potential seismic hazard.

  15. A New Electron Source for Laboratory Simulation of the Space Environment

    NASA Technical Reports Server (NTRS)

    Krause, Linda Habash; Everding, Daniel; Bonner, Mathew; Swan, Brian

    2012-01-01

    We have developed a new collimated electron source called the Photoelectron Beam Generator (PEBG) for laboratory and spaceflight applications. This technology is needed to replace traditional cathodes because of serious fundamental weaknesses with the present state of the art. Filament cathodes suffer from numerous practical problems, even if expertly designed, including the dependence of electron emission on filament temperature, short lifetimes (approx 100 hours), and relatively high power (approx 10s of W). Other types of cathodes have solved some of these problems, but they are plagued with other difficult problems, such as the Spindt cathode's extreme sensitivity to molecular oxygen. None to date have been able to meet the demand of long lifetime, robust packaging, and precision energy and flux control. This new cathode design avoids many common pitfalls of traditional cathodes. Specifically, there are no fragile parts, no sensitivity to oxygen, no intrinsic emission dependencies on device temperature, and no vacuum requirements for protecting the source from contamination or damage. Recent advances in high-brightness Light Emitting Diodes (LEDs) have provided the key enabling technology for this new electron source. The LEDs are used to photoeject electrons off a target material of a low work-function, and these photoelectrons are subsequently focused into a laminar beam using electrostatic lenses. The PEBG works by illuminating a target material and steering photoelectrons into a laminar beam using electrostatic lenses

  16. Source document for waste area groupings at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Osborne, P.L.; Kuhaida, A.J., Jr.

    1996-09-01

    This document serves as a source document for Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and other types of documents developed for and pertaining to Environmental Restoration (ER) Program activities at Oak Ridge National Laboratory (ORNL). It contains descriptions of the (1) regulatory requirements for the ORR ER Program, (2) Oak Ridge Reservation (ORR) ER Program, (3) ORNL site history and characterization, and (4) history and characterization of Waste Area Groupings (WAGS) 1-20. This document was created to save time, effort, and money for persons and organizations drafting documents for the ER Program and to improve consistency in the documents prepared for the program. By eliminating the repetitious use of selected information about the program, this document will help reduce the time and costs associated with producing program documents. By serving as a benchmark for selected information about the ER Program, this reference will help ensure that information presented in future documents is accurate and complete.

  17. Structural testing of the Los Alamos National Laboratory Heat Source/Radioisotopic Thermoelectric Generator shipping container

    SciTech Connect

    Bronowski, D.R.; Madsen, M.M.

    1991-06-01

    The Heat Source/Radioisotopic Thermoelectric Generator shipping container is a Type B packaging design currently under development by Los Alamos National Laboratory. Type B packaging for transporting radioactive material is required to maintain containment and shielding after being exposed to the normal and hypothetical accident environments defined in Title 10 Code of Federal Regulations Part 71. A combination of testing and analysis is used to verify the adequacy of this package design. This report documents the test program portion of the design verification, using several prototype packages. Four types of testing were performed: 30-foot hypothetical accident condition drop tests in three orientations, 40-inch hypothetical accident condition puncture tests in five orientations, a 21 psi external overpressure test, and a normal conditions of transport test consisting of a water spray and a 4 foot drop test. 18 refs., 104 figs., 13 tabs.

  18. Increased robustness and speed in low-dose phase-contrast tomography with laboratory sources

    NASA Astrophysics Data System (ADS)

    Zamir, Anna; Hagen, Charlotte K.; Diemoz, Paul C.; Endrizzi, Marco; Vittoria, Fabio A.; Urbani, Luca; De Coppi, Paolo; Olivo, Alessandro

    2016-10-01

    In this article we discuss three different developments in Edge Illumination (EI) X-ray phase contrast imaging (XPCi), all ultimately aimed at optimising EI computed tomography (CT) for use in different environments, and for different applications. For the purpose of reducing scan times, two approaches are presented; the "reverse projection" acquisition scheme which allows a continuous rotation of the sample, and the "single image" retrieval algorithm, which requires only one frame for retrieval of the projected phase map. These are expected to lead to a substantial reduction of EI CT scan times, a prospect which is likely to promote the translation of EI into several applications, including clinical. The last development presented is the "modified local" phase retrieval. This retrieval algorithm is specifically designed to accurately retrieve sample properties (absorption, refraction, scattering) in cases where high-resolution scans are required in non-ideal environments. Experimental results, using both synchrotron radiation and laboratory sources, are shown for the various approaches.

  19. Applied x-ray computed tomography with high resolution in paleontology using laboratory and synchrotron sources

    NASA Astrophysics Data System (ADS)

    Bidola, Pidassa; Pacheco, Mirian L. A. F.; Stockmar, Marco K.; Achterhold, Klaus; Pfeiffer, Franz; Beckmann, Felix; Tafforeau, Paul; Herzen, Julia

    2014-09-01

    X-ray computed tomography (CT) has become an established technique in the biomedical imaging or materials science research. Its ability to non-destructively provide high-resolution images of samples makes it attractive for diverse fields of research especially the paleontology. Exceptionally, the Precambrian is a geological time of rocks deposition containing several fossilized early animals, which still need to be investigated in order to predict the origin and evolution of early life. Corumbella werneri is one of those fossils skeletonized in Corumbá (Brazil). Here, we present a study on selected specimens of Corumbella werneri using absorption-based contrast imaging at diverse tomographic setups. We investigated the potential of conventional laboratory-based device and synchrotron radiation sources to visualize internal structures of the fossils. The obtained results are discussed as well as the encountered limitations of those setups.

  20. On the measurement of intensity correlations from laboratory and astronomical sources with SPADs and SNSPDs

    NASA Astrophysics Data System (ADS)

    Schroeder, Edward; Mauskopf, Philip; Pilyavsky, Genady; Sinclair, Adrian; Smith, Nathan; Bryan, Sean; Mani, Hamdi; Morozov, Dmitry; Berggren, Karl; Zhu, Di; Smirnov, Konstantin; Vakhtomin, Yuriy

    2016-08-01

    We describe the performance of detector modules containing silicon single photon avalanche photodiodes (SPADs) and superconducting nanowire single photon detectors (SNSPDs) to be used for intensity interferometry. The SPADs are mounted in fiber-coupled and free-space coupled packages. The SNSPDs are mounted in a small liquid helium cryostat coupled to single mode fiber optic cables which pass through a hermetic feed-through. The detectors are read out with microwave amplifiers and FPGA-based coincidence electronics. We present progress on measurements of intensity correlations from incoherent sources including gas-discharge lamps and stars with these detectors. From the measured laboratory performance of the correlation system, we estimate the sensitivity to intensity correlations from stars using commercial telescopes and larger existing research telescopes.

  1. Elemental contrast imaging with a polychromatic laboratory x-ray source using energy-discriminating detectors

    NASA Astrophysics Data System (ADS)

    Yokhana, Viona S. K.; Arhatari, Bendicta D.; Gureyev, Timur E.; Abbey, Brian

    2016-11-01

    Determining the specific spatial distributions of elements within compound samples is of critical importance to a range of applied research fields. The usual approaches to obtaining elemental contrast involve measurement of the characteristic peaks associated with x-ray fluorescence or measuring the x-ray transmission as a function of energy. In the laboratory these measurements are challenging due to the polychromaticity and lack of tunability of the source. Here we demonstrate how newly developed, high-resolution, energy-discriminating area detector technology can be exploited to enhance elemental contrast. The detector we employ here is the Pixirad area detector which can simultaneously have up to four separate colour channels. We also discuss the potential of this new technology in the context of tomographic imaging of soft tissue.

  2. Certification testing of the Los Alamos National Laboratory Heat Source/Radioisotopic Thermoelectric Generator shipping container

    SciTech Connect

    Bronowski, D.R.; Madsen, M.M.

    1991-09-01

    The Heat Source/Radioisotopic Thermoelectric Generator shipping counter is a Type B packaging currently under development by Los Alamos National Laboratory. Type B packaging for transporting radioactive material is required to maintain containment and shielding after being exposed to normal and hypothetical accident environments defined in Title 10 of the Code of Federal Regulations Part 71. A combination of testing and analysis is used to verify the adequacy of this packaging design. This report documents the testing portion of the design verification. Six tests were conducted on a prototype package: a water spray test, a 4-foot normal conditions drop test, a 30-foot drop test, a 40-inch puncture test, a 30-minute thermal test, and an 8-hour immersion test.

  3. Variability among sources and laboratories in analyses of wheat middlings. NCR-42 Committee on Swine Nutrition.

    PubMed

    Cromwell, G L; Cline, T R; Crenshaw, J D; Crenshaw, T D; Easter, R A; Ewan, R C; Hamilton, C R; Hill, G M; Lewis, A J; Mahan, D C; Nelssen, J L; Pettigrew, J E; Veum, T L; Yen, J T

    2000-10-01

    A cooperative research study was conducted by members of a regional committee (North Central Regional Committee on Swine Nutrition [NCR-42]) to assess the variability in nutrient composition (DM, CP, Ca, P, Se, NDF, and amino acids) of 14 sources of wheat middlings from 13 states (mostly in the Midwest). A second objective was to assess the analytical variability in nutrient assays among 20 laboratories (labs; 14 experiment station labs and six commercial labs). Wheat middlings were obtained from each participating station's feed mill. The bulk density of the middlings ranged from 289 to 365 g/L. The number of labs that analyzed samples were as follows: DM and CP, 20; Ca, 16; P, 15; Se, 7; NDF, 10; and amino acids, 9. Each lab used its own analytical procedures. The middlings averaged 89.6% DM, 16.2% CP, .12% Ca, .97% P, 36.9% NDF, .53 mg/kg Se, .66% lysine, .19% tryptophan, .54% threonine, .25% methionine, .34% cystine, .50% isoleucine, and .73% valine. As expected, there was considerable variation in nutrient composition among the 14 sources (P < .01), especially for Ca (.08 to .30%) and Se (.05 to 1.07 mg/kg). "Heavy" middlings (high bulk density, >335 g/L), having a greater proportion of flour attached to the bran, were lower in CP, lysine, P, and NDF than "light" middlings (<310 g/L), having cleaner bran, resulting in negative correlations between bulk density and CP (r = -.61), lysine (r = -.59), P (r = -.54), and NDF (r = -.81). Each 1-percentage-point increase in CP in the wheat middlings was associated with .0235 (r2 = .61) and 2.1 (r2 = .39)-percentage-point increases in lysine and NDF, respectively. Lysine content was associated with NDF, CP, and bulk density of wheat middlings (r2 = .88). There was considerable variation among laboratories (P < .01) in analysis of all nutrients. The CV among sources (100 x sigmaS/mean) was greater than among labs (100 x sigmaL/mean) for CP, Ca, P, Se, and NDF, but the CV among labs was greater than that among sources

  4. Imager for Mars Pathfinder (IMP) image calibration

    USGS Publications Warehouse

    Reid, R.J.; Smith, P.H.; Lemmon, M.; Tanner, R.; Burkland, M.; Wegryn, E.; Weinberg, J.; Marcialis, R.; Britt, D.T.; Thomas, N.; Kramm, R.; Dummel, A.; Crowe, D.; Bos, B.J.; Bell, J.F.; Rueffer, P.; Gliem, F.; Johnson, J. R.; Maki, J.N.; Herkenhoff, K. E.; Singer, Robert B.

    1999-01-01

    The Imager for Mars Pathfinder returned over 16,000 high-quality images from the surface of Mars. The camera was well-calibrated in the laboratory, with <5% radiometric uncertainty. The photometric properties of two radiometric targets were also measured with 3% uncertainty. Several data sets acquired during the cruise and on Mars confirm that the system operated nominally throughout the course of the mission. Image calibration algorithms were developed for landed operations to correct instrumental sources of noise and to calibrate images relative to observations of the radiometric targets. The uncertainties associated with these algorithms as well as current improvements to image calibration are discussed. Copyright 1999 by the American Geophysical Union.

  5. Automated calibration of a flight particle spectrometer

    NASA Technical Reports Server (NTRS)

    Torbert, Roy B.

    1986-01-01

    An automatic calibration system was designed for use in the vacuum facility at the Space Science Laboratory of the Marshall Space Flight Center. That system was developed and used in the intervening winter to calibrate the ion spectrometer that eventually flew in May 1986 aboard the NASA project, CRIT 1. During this summer, it is planned to implement the calibration of both an ion and electron spectrometer of a new design whose basic elements were conceived during the winter of 1985 to 1986. This spectrometer was completed in the summer and successfully mounted in the vacuum tank for calibration. However, the source gate valve malfunctioned, and, at the end of the summer, it still needed a replacement. During the inevitable delays in the experimental research, the numerical model of the Critical Velocity effect was completed and these results were presented.

  6. Calibration of hydrometers

    NASA Astrophysics Data System (ADS)

    Lorefice, Salvatore; Malengo, Andrea

    2006-10-01

    After a brief description of the different methods employed in periodic calibration of hydrometers used in most cases to measure the density of liquids in the range between 500 kg m-3 and 2000 kg m-3, particular emphasis is given to the multipoint procedure based on hydrostatic weighing, known as well as Cuckow's method. The features of the calibration apparatus and the procedure used at the INRiM (formerly IMGC-CNR) density laboratory have been considered to assess all relevant contributions involved in the calibration of different kinds of hydrometers. The uncertainty is strongly dependent on the kind of hydrometer; in particular, the results highlight the importance of the density of the reference buoyant liquid, the temperature of calibration and the skill of operator in the reading of the scale in the whole assessment of the uncertainty. It is also interesting to realize that for high-resolution hydrometers (division of 0.1 kg m-3), the uncertainty contribution of the density of the reference liquid is the main source of the total uncertainty, but its importance falls under about 50% for hydrometers with a division of 0.5 kg m-3 and becomes somewhat negligible for hydrometers with a division of 1 kg m-3, for which the reading uncertainty is the predominant part of the total uncertainty. At present the best INRiM result is obtained with commercially available hydrometers having a scale division of 0.1 kg m-3, for which the relative uncertainty is about 12 × 10-6.

  7. Complementary b/y fragment ion pairs from post-source decay of metastable YahO for calibration of MALDI-TOF-TOF-MS/MS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Complementary b/y fragment ion pairs from post-source decay (PSD) of metastable YahO protein ion were evaluated for use in the calibration of MALDI-TOF-TOF for tandem mass spectrometry (MS/MS). The yahO gene from pathogenic Escherichia coli O157:H7 strain EDL933 was cloned into a pBAD18 plasmid vect...

  8. Inter-laboratory calibration of natural gas round robins for δ2H and δ13C using off-line and on-line techniques

    USGS Publications Warehouse

    Dai, Jinxing; Xia, Xinyu; Li, Zhisheng; Coleman, Dennis D.; Dias, Robert F.; Gao, Ling; Li, Jian; Deev, Andrei; Li, Jin; Dessort, Daniel; Duclerc, Dominique; Li, Liwu; Liu, Jinzhong; Schloemer, Stefan; Zhang, Wenlong; Ni, Yunyan; Hu, Guoyi; Wang, Xiaobo; Tang, Yongchun

    2012-01-01

    Compound-specific carbon and hydrogen isotopic compositions of three natural gas round robins were calibrated by ten laboratories carrying out more than 800 measurements including both on-line and off-line methods. Two-point calibrations were performed with international measurement standards for hydrogen isotope ratios (VSMOW and SLAP) and carbon isotope ratios (NBS 19 and L-SVEC CO2). The consensus δ13C values and uncertainties were derived from the Maximum Likelihood Estimation (MLE) based on off-line measurements; the consensus δ2H values and uncertainties were derived from MLE of both off-line and on-line measurements, taking the bias of on-line measurements into account. The calibrated consensus values in ‰ relative to VSMOW and VPDB are: NG1 (coal-related gas): Methane: δ2HVSMOW = − 185.1‰ ± 1.2‰, δ13CVPDB = − 34.18‰ ± 0.10‰ Ethane: δ2HVSMOW = − 156.3‰ ± 1.8‰, δ13CVPDB = − 24.66‰ ± 0.11‰ Propane: δ2HVSMOW = − 143.6‰ ± 3.3‰, δ13CVPDB = − 22.21‰ ± 0.11‰ i-Butane: δ13CVPDB = − 21.62‰ ± 0.12‰ n-Butane: δ13CVPDB = − 21.74‰ ± 0.13‰ CO2: δ13CVPDB = − 5.00‰ ± 0.12‰ NG2 (biogas): Methane: δ2HVSMOW = − 237.0‰ ± 1.2‰, δ13CVPDB = − 68.89‰ ± 0.12‰ NG3 (oil-related gas): Methane: δ2HVSMOW = − 167.6‰ ± 1.0‰, δ13CVPDB = − 43.61‰ ± 0.09‰ Ethane: δ2HVSMOW = − 164.1‰ ± 2.4‰, δ13CVPDB = − 40.24‰ ± 0.10‰ Propane: δ2HVSMOW = − 138.4‰ ± 3.0‰, δ13CVPDB = − 33.79‰ ± 0.09‰ All of the assigned values are traceable to the international carbon isotope standard of VPDB and hydrogen isotope standard of VSMOW.

  9. Design of an inexpensive integrating sphere student laboratory setup for the optical characterization of light sources

    NASA Astrophysics Data System (ADS)

    Leloup, Frédéric B.; Leyre, Sven; Bauwens, Eva; Van den Abeele, Toon; Hanselaer, Peter

    2016-01-01

    In this paper, the design of an inexpensive integrating sphere setup is presented, enabling students to perform optical characterization of light sources with reasonable accuracy, in a student laboratory context. Instead of using an expensive sphere with magnesium oxide or barium sulfate coating, a cheap polystyrene sphere is employed. In combination with a low-cost USB spectroradiometer, the system enables the direct measurement of the spectral radiant power of a light source. In addition to the radiant power, the luminous flux, luminous efficacy, and distinctive colorimetric quantities (colour coordinates, colour temperature, and colour rendering index) can be determined. Besides a description of the equipment used, the experimental measurement procedure and some typical measurement results are presented. A comparison between the data and the results obtained with scientific metrology instrumentation indicates reasonable accuracy. As a result, it can be concluded that the purpose of the presented experiments, being that students become acquainted with applications of radiometry and photometry, and with data collection and data analysis as in a professional context, is fully achieved with the described test setup.

  10. Design of a laboratory for experiments with a pulsed neutron source.

    PubMed

    Memoli, G; Trusler, J P M; Ziver, A K

    2009-06-01

    We present the results of a neutron shielding design and optimisation study performed to reduce the exposure to radiological doses arising from a 14 MeV pulsed neutron generator (PNG) having a maximum emission strength of 2.0 x 10(8) neutrons s(-1). The source was intended to be used in a new irradiation facility for the realisation of an experiment on acoustical cavitation in liquids. This paper describes in detail how the facility was designed to reduce both neutron and gamma-ray dose rates to acceptable levels, taking into account the ALARP principle in following the steps of optimisation. In particular, this work compares two different methods of optimisation to assess neutron dose rates: the use of analytical methods and the use of Monte Carlo simulations (MCNPX 2.4). The activation of the surrounding materials during operation was estimated using the neutron spectra as input to the FISPACT 3.0 code. The limitations of a first-order analytical model to determine the neutron activation levels are highlighted. The impact that activation has on the choice of the materials to be used inside the laboratory and on the waiting time before anyone can safely enter the room after the neutron source is switched off is also discussed.

  11. Phase 1 environmental report for the Advanced Neutron Source at Oak Ridge National Laboratory

    SciTech Connect

    Blasing, T.J.; Brown, R.A.; Cada, G.F.; Easterly, C.; Feldman, D.L.; Hagan, C.W.; Harrington, R.M.; Johnson, R.O.; Ketelle, R.H.; Kroodsma, R.L.; McCold, L.N.; Reich, W.J.; Scofield, P.A.; Socolof, M.L.; Taleyarkhan, R.P.; Van Dyke, J.W.

    1992-02-01

    The US Department of Energy (DOE) has proposed the construction and operation of the Advanced Neutron Source (ANS), a 330-MW(f) reactor, at Oak Ridge National Laboratory (ORNL) to support neutron scattering and nuclear physics experiments. ANS would provide a steady-state source of neutrons that are thermalized to produce sources of hot, cold, and very coal neutrons. The use of these neutrons in ANS experiment facilities would be an essential component of national research efforts in basic materials science. Additionally, ANS capabilities would include production of transplutonium isotopes, irradiation of potential fusion and fission reactor materials, activation analysis, and production of medical and industrial isotopes such as {sup 252}Cf. Although ANS would not require licensing by the US Nuclear Regulatory Commission (NRC), DOE regards the design, construction, and operation of ANS as activities that would produce a licensable facility; that is, DOE is following the regulatory guidelines that NRC would apply if NRC were licensing the facility. Those guidelines include instructions for the preparation of an environmental report (ER), a compilation of available data and preliminary analyses regarding the environmental impacts of nuclear facility construction and operation. The ER, described and outlined in NRC Regulatory Guide 4.2, serves as a background document to facilitate the preparation of environmental impact statements (EISs). Using Regulatory Guide 4.2 as a model, this ANS ER provides analyses and information specific to the ANS site and area that can be adopted (and modified, if necessary) for the ANS EIS. The ER is being prepared in two phases. Phase 1 ER includes many of the data and analyses needed to prepare the EIS but does not include data or analyses of alternate sites or alternate technologies. Phase 2 ER will include the additional data and analyses stipulated by Regulatory Guide 4.2.

  12. Monitoring of event-based mobilization of hydrophobic pollutants in rivers: calibration of turbidity as a proxy for particle facilitated transport in field and laboratory.

    PubMed

    Rügner, Hermann; Schwientek, Marc; Egner, Marius; Grathwohl, Peter

    2014-08-15

    Transport of many pollutants in rivers is coupled to mobilization of suspended particles which typically occurs during floods. Since the amount of total suspended solids (TSS) in rivers can be monitored by turbidity measurements this may be used as a proxy for the total concentration of particle associated pollutants such as PAHs, PCBs, etc. and several heavy metals. Online turbidity measurements (e.g. by optical backscattering sensors) would then also allow for an assessment of particle and pollutant flux dynamics if once calibrated against TSS and total pollutant concentrations for a given catchment. In this study, distinct flood and thus turbidity events were sampled at high temporal resolution in three contrasting sub-catchments of the River Neckar in Southwest Germany (Ammer, Goldersbach, Steinlach) as well as in the River Neckar itself and investigated for the total amount of PAHs and TSS in water; turbidity (NTU) and grain size distributions of suspended solids were determined as well. Laboratory experiments were performed with natural river bed sediments from different locations (Ammer) to investigate PAH concentrations, TSS and turbidity during sedimentation of suspended particles under controlled conditions (yielding smaller and smaller suspended particles and TSS with time). Laboratory and field results agreed very well and showed that turbidity and TSS were linearly correlated over an extended turbidity range up to 2000 NTU for the field samples and up to 8000 NTU in lab experiments. This also holds for total PAH concentrations which can be reasonably well predicted based on turbidity measurements and TSS vs. PAHs relationships - even for high turbidity values observed during flood events (>2000 NTU). Total PAH concentrations on suspended solids were independent of grain size of suspended particles. This implies that for the rivers investigated the sorption capacity of particles did not change significantly during the observed events.

  13. Development of the front end test stand and vessel for extraction and source plasma analyses negative hydrogen ion sources at the Rutherford Appleton Laboratory

    SciTech Connect

    Lawrie, S. R.; Faircloth, D. C.; Letchford, A. P.; Perkins, M.; Whitehead, M. O.; Wood, T.; Gabor, C.; Back, J.

    2014-02-15

    The ISIS pulsed spallation neutron and muon facility at the Rutherford Appleton Laboratory (RAL) in the UK uses a Penning surface plasma negative hydrogen ion source. Upgrade options for the ISIS accelerator system demand a higher current, lower emittance beam with longer pulse lengths from the injector. The Front End Test Stand is being constructed at RAL to meet the upgrade requirements using a modified ISIS ion source. A new 10% duty cycle 25 kV pulsed extraction power supply has been commissioned and the first meter of 3 MeV radio frequency quadrupole has been delivered. Simultaneously, a Vessel for Extraction and Source Plasma Analyses is under construction in a new laboratory at RAL. The detailed measurements of the plasma and extracted beam characteristics will allow a radical overhaul of the transport optics, potentially yielding a simpler source configuration with greater output and lifetime.

  14. Real-time dynamic calibration of a tunable frequency laser source using a Fabry-Pérot interferometer

    SciTech Connect

    Mandula, Gábor Kis, Zsolt; Lengyel, Krisztián

    2015-12-15

    We report on a method for real-time dynamic calibration of a tunable external cavity diode laser by using a partially mode-matched plano-concave Fabry-Pérot interferometer in reflection geometry. Wide range laser frequency scanning is carried out by piezo-driven tilting of a diffractive grating playing the role of a frequency selective mirror in the laser cavity. The grating tilting system has a considerable mechanical inertness, so static laser frequency calibration leads to false results. The proposed real-time dynamic calibration based on the identification of primary- and Gouy-effect type secondary interference peaks with known frequency and temporal history can be used for a wide scanning range (from 0.2 GHz to more than 1 GHz). A concave spherical mirror with a radius of R = 100 cm and a plain 1% transmitting mirror was used as a Fabry-Pérot interferometer with various resonator lengths to investigate and demonstrate real-time calibration procedures for two kinds of laser frequency scanning functions.

  15. Comparison of spectral radiance responsivity calibration techniques used for backscatter ultraviolet satellite instruments

    NASA Astrophysics Data System (ADS)

    Kowalewski, M. G.; Janz, S. J.

    2015-02-01

    Methods of absolute radiometric calibration of backscatter ultraviolet (BUV) satellite instruments are compared as part of an effort to minimize pre-launch calibration uncertainties. An internally illuminated integrating sphere source has been used for the Shuttle Solar BUV, Total Ozone Mapping Spectrometer, Ozone Mapping Instrument, and Global Ozone Monitoring Experiment 2 using standardized procedures traceable to national standards. These sphere-based spectral responsivities agree to within the derived combined standard uncertainty of 1.87% relative to calibrations performed using an external diffuser illuminated by standard irradiance sources, the customary spectral radiance responsivity calibration method for BUV instruments. The combined standard uncertainty for these calibration techniques as implemented at the NASA Goddard Space Flight Center’s Radiometric Calibration and Development Laboratory is shown to less than 2% at 250 nm when using a single traceable calibration standard.

  16. HalX: an open-source LIMS (Laboratory Information Management System) for small- to large-scale laboratories.

    PubMed

    Prilusky, Jaime; Oueillet, Eric; Ulryck, Nathalie; Pajon, Anne; Bernauer, Julie; Krimm, Isabelle; Quevillon-Cheruel, Sophie; Leulliot, Nicolas; Graille, Marc; Liger, Dominique; Trésaugues, Lionel; Sussman, Joel L; Janin, Joël; van Tilbeurgh, Herman; Poupon, Anne

    2005-06-01

    Structural genomics aims at the establishment of a universal protein-fold dictionary through systematic structure determination either by NMR or X-ray crystallography. In order to catch up with the explosive amount of protein sequence data, the structural biology laboratories are spurred to increase the speed of the structure-determination process. To achieve this goal, high-throughput robotic approaches are increasingly used in all the steps leading from cloning to data collection and even structure interpretation is becoming more and more automatic. The progress made in these areas has begun to have a significant impact on the more 'classical' structural biology laboratories, dramatically increasing the number of individual experiments. This automation creates the need for efficient data management. Here, a new piece of software, HalX, designed as an 'electronic lab book' that aims at (i) storage and (ii) easy access and use of all experimental data is presented. This should lead to much improved management and tracking of structural genomics experimental data.

  17. Calibration method for a photoacoustic system for real time source apportionment of light absorbing carbonaceous aerosol based on size distribution measurements

    NASA Astrophysics Data System (ADS)

    Utry, Noemi; Ajtai, Tibor; Pinter, Mate; Orvos, Peter I.; Szabo, Gabor; Bozoki, Zoltan

    2016-04-01

    In this study, we introduce a calibration method with which sources of light absorbing carbonaceous particulate matter (LAC) can be apportioned in real time based on multi wavelength optical absorption measurements with a photoacoustic system. The method is primary applicable in wintry urban conditions when LAC is dominated by traffic and biomass burning. The proposed method was successfully tested in a field campaign in the city center of Szeged, Hungary during winter time where the dominance of traffic and wood burning aerosol has been experimentally demonstrated earlier. With the help of the proposed calibration method a relationship between the measured Aerosol Angström Exponent (AAE) and the number size distribution can be deduced. Once the calibration curve is determined, the relative strength of the two pollution sources can be deduced in real time as long as the light absorbing fraction of PM is exclusively related to traffic and wood burning. This assumption is indirectly confirmed in the presented measurement campaign by the fact that the measured size distribution is composed of two unimodal size distributions identified to correspond to traffic and wood burning aerosols. The proposed method offers the possibility of replacing laborious chemical analysis with simple in-situ measurement of aerosol size distribution data.

  18. Speckle-Based X-Ray Phase-Contrast and Dark-Field Imaging with a Laboratory Source

    NASA Astrophysics Data System (ADS)

    Zanette, I.; Zhou, T.; Burvall, A.; Lundström, U.; Larsson, D. H.; Zdora, M.; Thibault, P.; Pfeiffer, F.; Hertz, H. M.

    2014-06-01

    We report on the observation and application of near-field speckles with a laboratory x-ray source. The detection of speckles is possible thanks to the enhanced brilliance properties of the used liquid-metal-jet source, and opens the way to a range of new applications in laboratory-based coherent x-ray imaging. Here, we use the speckle pattern for multimodal imaging of demonstrator objects. Moreover, we introduce algorithms for phase and dark-field imaging using speckle tracking, and we show that they yield superior results with respect to existing methods.

  19. Identification by genotyping of a commercial antigen preparation as the source of a laboratory contamination with Coxiella burnetii and as an unexpected rich source of control DNA.

    PubMed

    Tilburg, Jeroen J H C; Horrevorts, Alphons M; Peeters, Marcel F; Klaassen, Corné H W; Rossen, John W A

    2011-01-01

    By performing genotyping, a laboratory contamination involving Q fever was traced back to the antigen preparation used in a commercially available complement fixation test. It was established that such antigen preparations contain relatively high loads of DNA/RNA, making them potential sources of contamination but also convenient preparations for control material.

  20. A new chapter in environmental sensing: The Open-Source Published Environmental Sensing (OPENS) laboratory

    NASA Astrophysics Data System (ADS)

    Selker, J. S.; Roques, C.; Higgins, C. W.; Good, S. P.; Hut, R.; Selker, A.

    2015-12-01

    The confluence of 3-Dimensional printing, low-cost solid-state-sensors, low-cost, low-power digital controllers (e.g., Arduinos); and open-source publishing (e.g., Github) is poised to transform environmental sensing. The Open-Source Published Environmental Sensing (OPENS) laboratory has launched and is available for all to use. OPENS combines cutting edge technologies and makes them available to the global environmental sensing community. OPENS includes a Maker lab space where people may collaborate in person or virtually via on-line forum for the publication and discussion of environmental sensing technology (Corvallis, Oregon, USA, please feel free to request a free reservation for space and equipment use). The physical lab houses a test-bed for sensors, as well as a complete classical machine shop, 3-D printers, electronics development benches, and workstations for code development. OPENS will provide a web-based formal publishing framework wherein global students and scientists can peer-review publish (with DOI) novel and evolutionary advancements in environmental sensor systems. This curated and peer-reviewed digital collection will include complete sets of "printable" parts and operating computer code for sensing systems. The physical lab will include all of the machines required to produce these sensing systems. These tools can be addressed in person or virtually, creating a truly global venue for advancement in monitoring earth's environment and agricultural systems. In this talk we will present an example of the process of design and publication the design and data from the OPENS-Permeameter. The publication includes 3-D printing code, Arduino (or other control/logging platform) operational code; sample data sets, and a full discussion of the design set in the scientific context of previous related devices. Editors for the peer-review process are currently sought - contact John.Selker@Oregonstate.edu or Clement.Roques@Oregonstate.edu.

  1. Oscillatory hydraulic testing as a strategy for NAPL source zone monitoring: Laboratory experiments.

    PubMed

    Zhou, YaoQuan; Cardiff, Michael

    2017-03-21

    Non-aqueous phase liquids (NAPLs) have a complex mode of transport in heterogeneous aquifers, which can result in pools and lenses of NAPLs (the "source zone") that are difficult to detect and can cause long-term contamination via slow dissolution into groundwater (the "dissolved plume"). Characterizing the extent and evolution of NAPL contamination within the source zone is a useful strategy for designing and adapting appropriate remedial actions at many contaminated sites. As a NAPL flows into a given aquifer volume, the effective hydraulic conductivity (K) and specific storage (Ss) of the volume changes associated with the viscosity and compressibility of the impinging fluid, meaning that NAPL movement may be detectable with hydraulic testing. Recently, the use of oscillatory pumping tests - in which sinusoidal pumping variations are implemented and oscillatory pressure changes are detected at monitoring locations - has been suggested as a low-impact hydraulic testing strategy for characterizing aquifer properties (Cardiff et al., 2013; Zhou et al., 2016). Here, we investigate this strategy in an experimental laboratory sandbox where dyed vegetable oil is injected and allowed to migrate as a NAPL. Initial qualitative analyses demonstrate that measurable changes in pressure signal amplitude and phase provide clear evidence for NAPL plume emplacement and migration. Using the approach developed in Zhou et al. (2016), we then apply tomographic analyses to estimate the location of effective K changes (representing fluid changes) and their movement throughout time. This approach provides a method for monitoring ongoing NAPL movement without net extraction or injection of fluid, making it advantageous in field remediation applications.

  2. TA489A calibrator: SANDUS

    SciTech Connect

    LeBlanc, R.

    1987-08-01

    The TA489A Calibrator, designed to operate in the MA164 Digital Data Acquisition System, is used to calibrate up to 128 analog-to-digital recording channels. The TA489A calibrates using a dc Voltage Source or any of several special calibration modes. Calibration schemes are stored in the TA489A memory and are initiated locally or remotely through a Command Link.

  3. Radiance calibration of spherical integrators

    NASA Technical Reports Server (NTRS)

    Mclean, James T.; Guenther, Bruce W.

    1989-01-01

    Techniques for improving the knowledge of the radiance of large area spherical and hemispherical integrating energy sources have been investigated. Such sources are used to calibrate numerous aircraft and spacecraft remote sensing instruments. Comparisons are made between using a standard source based calibration method and a quantum efficient detector (QED) based calibration method. The uncertainty involved in transferring the calibrated values of the point source standard lamp to the extended source is estimated to be 5 to 10 percent. The use of the QED allows an improvement in the uncertainty to 1 to 2 percent for the measurement of absolute radiance from a spherical integrator source.

  4. Effect of the solenoid in various conditions of the laser ion source at Brookhaven National Laboratory.

    PubMed

    Ikeda, S; Kumaki, M; Kanesue, T; Okamura, M

    2016-02-01

    In the laser ion source (LIS) at the Brookhaven National Laboratory (BNL), a solenoid is used to guide the laser ablation plasma and modulate the extracted beam current. Many types of ion species are guided. In some cases, the plasma plume is injected into the solenoid away from the solenoidal axis. To investigate the effects of the solenoid on the beam extracted from the plasma that has different properties, the beam current was measured in the setup of the LIS at the BNL. The beam current of Li, Al, Si, Fe, and Au increased when the magnetic field was applied. For most of the species the peak current and the total charge within a single beam pulse increased around 10 times with a magnetic field less than 100 G. In addition, for some species the rate of increase of the peak currents became smaller when the magnetic flux densities were larger than certain values depending on the species. In this case, the current waveforms were distorted. At the same magnetic field value, the field was more effective on lighter species than on heavier ones. When plasma was injected offset from the axis of the solenoid, peak current and total charge became half of those without offset. The experimental data are useful for the operation of the LIS at the BNL.

  5. Effect of the solenoid in various conditions of the laser ion source at Brookhaven National Laboratory

    NASA Astrophysics Data System (ADS)

    Ikeda, S.; Kumaki, M.; Kanesue, T.; Okamura, M.

    2016-02-01

    In the laser ion source (LIS) at the Brookhaven National Laboratory (BNL), a solenoid is used to guide the laser ablation plasma and modulate the extracted beam current. Many types of ion species are guided. In some cases, the plasma plume is injected into the solenoid away from the solenoidal axis. To investigate the effects of the solenoid on the beam extracted from the plasma that has different properties, the beam current was measured in the setup of the LIS at the BNL. The beam current of Li, Al, Si, Fe, and Au increased when the magnetic field was applied. For most of the species the peak current and the total charge within a single beam pulse increased around 10 times with a magnetic field less than 100 G. In addition, for some species the rate of increase of the peak currents became smaller when the magnetic flux densities were larger than certain values depending on the species. In this case, the current waveforms were distorted. At the same magnetic field value, the field was more effective on lighter species than on heavier ones. When plasma was injected offset from the axis of the solenoid, peak current and total charge became half of those without offset. The experimental data are useful for the operation of the LIS at the BNL.

  6. The advanced light source at Lawrence Berkeley laboratory: a new tool for research in atomic physics

    NASA Astrophysics Data System (ADS)

    Schlachter, Alfred S.; Robinson, Arthur L.

    1991-04-01

    The Advanced Light Source, a third-generation national synchrotron-radiation facility now under construction at the Lawrence Berkeley Laboratory, is scheduled to begin serving qualified users across a broad spectrum of research areas in the spring of 1993. Based on a low-emittance electron storage ring optimized to operate at 1.5 GeV, the ALS will have 10 long straight sections available for insertion devices (undulators and wigglers) and 24 high-quality bend-magnet ports. The short pulse width (30-50 ps) will be ideal for time-resolved measurements. Undulators will generate high-brightness partially coherent soft X-ray and ultraviolet (XUV) radiation from below 10 eV to above 2 keV; this radiation is plane polarized. Wigglers and bend magnets will extend the spectrum by generating high fluxes of X-rays to photon energies above 10 keV. The ALS will have an extensive research program in which XUV radiation is used to study matter in all its varied gaseous, liquid, and solid forms. The high brightness will open new areas of research in the materials sciences, such as spatially resolved spectroscopy (spectromicroscopy), and in biology, such as X-ray microscopy with element-specific sensitivity; the high flux will allow measurements in atomic physics and chemistry to be made with tenuous gas-phase targets. Technological applications could include lithography and nano-fabrication.

  7. The low-energy toroidal grating monochromator beamline at the synchrotron radiation source at Daresbury Laboratory

    SciTech Connect

    Hoyland, M.A. ); Harrington, J.Q.; Weston, M.I. )

    1992-01-01

    The bending magnet beam line 1.2 low-energy toroidal grating monochromator of the synchrotron radiation source (SRS) at Daresbury Laboratory, was designed{sup 1} to deliver moderately high fluxes ({similar to} 5 {times} 10{sup 11} photons s{sup {minus}1}), of linearly polarized, medium resolution ({similar to}0.2 eV) radiation in the energy range 5--85 eV. The colinear optical system utilizes platinum-coated silicon-carbide mirrors to focus the broad-band radiation emergent from the SRS at the entrance slits of the three grating monochromator. A single ellipsoidal mirror is then used to doubly focus the desired narrow-band radiation at the sample position. The colinear arrangement of the optical elements ensures that the radiation at the sample point is strongly horizontally plane polarized (estimated to be of order 90%). The entire system has been the subject of detailed analyses using the raytracing program SHADOW,{sup 2} and standard optical theory. These calculations have been compared with experimental determinations of photon flux outputs and resolution measurements.

  8. Effect of the solenoid in various conditions of the laser ion source at Brookhaven National Laboratory

    SciTech Connect

    Ikeda, S.; Kumaki, M.; Kanesue, T.; Okamura, M.

    2016-02-15

    In the laser ion source (LIS) at the Brookhaven National Laboratory (BNL), a solenoid is used to guide the laser ablation plasma and modulate the extracted beam current. Many types of ion species are guided. In some cases, the plasma plume is injected into the solenoid away from the solenoidal axis. To investigate the effects of the solenoid on the beam extracted from the plasma that has different properties, the beam current was measured in the setup of the LIS at the BNL. The beam current of Li, Al, Si, Fe, and Au increased when the magnetic field was applied. For most of the species the peak current and the total charge within a single beam pulse increased around 10 times with a magnetic field less than 100 G. In addition, for some species the rate of increase of the peak currents became smaller when the magnetic flux densities were larger than certain values depending on the species. In this case, the current waveforms were distorted. At the same magnetic field value, the field was more effective on lighter species than on heavier ones. When plasma was injected offset from the axis of the solenoid, peak current and total charge became half of those without offset. The experimental data are useful for the operation of the LIS at the BNL.

  9. An open-source, extensible system for laboratory timing and control

    NASA Astrophysics Data System (ADS)

    Gaskell, Peter E.; Thorn, Jeremy J.; Alba, Sequoia; Steck, Daniel A.

    2009-11-01

    We describe a simple system for timing and control, which provides control of analog, digital, and radio-frequency signals. Our system differs from most common laboratory setups in that it is open source, built from off-the-shelf components, synchronized to a common and accurate clock, and connected over an Ethernet network. A simple bus architecture facilitates creating new and specialized devices with only moderate experience in circuit design. Each device operates independently, requiring only an Ethernet network connection to the controlling computer, a clock signal, and a trigger signal. This makes the system highly robust and scalable. The devices can all be connected to a single external clock, allowing synchronous operation of a large number of devices for situations requiring precise timing of many parallel control and acquisition channels. Provided an accurate enough clock, these devices are capable of triggering events separated by one day with near-microsecond precision. We have achieved precisions of ˜0.1 ppb (parts per 109) over 16 s.

  10. New developments and applications of intense pulsed radiation sources at Sandia National Laboratories

    SciTech Connect

    Cook, D.

    1998-02-01

    In the past thirty-six months, tremendous strides have been made in x-ray production using high-current z-pinches. Today, the x-ray energy (1.9 MJ) and power (200 TW) output of the Z accelerator (formerly PBFA-II) is the largest available in the laboratory. These z-pinch x-ray sources are being developed for research into the physics of high energy density plasmas of interest in weapon behavior and in inertial confinement fusion. Beyond the Z accelerator current of 20 MA, an extrapolation to the X-1 accelerator level of 60 MA may have the potential to drive high-yield ICF reactions at affordable cost if several challenging technical problems can be overcome. New developments have also taken place at Sandia in the area of high current, mm-diameter electron beams for advanced hydrodynamic radiography. On SABRE, x-ray spot diameters were less than 2 mm with a dose of 100 R at 1 meter in a 40 ns pulse.

  11. Developing small vacuum spark as an x-ray source for calibration of an x-ray focusing crystal spectrometer.

    PubMed

    Ghomeishi, Mostafa; Karami, Mohammad; Adikan, Faisal Rafiq Mahamd

    2012-10-01

    A new technique of x-ray focusing crystal spectrometers' calibration is the desired result. For this purpose the spectrometer is designed to register radiated copper Kα and Kβ lines by using a flat α-quartz crystal. This experiment uses pre-breakdown x-ray emissions in low vacuum of about 2.5-3 mbar. At this pressure the pinch will not form so the plasma will not radiate. The anode material is copper and the capacity of the capacitor bank is 22.6 nF. This experiment designed and mounted a repetitive triggering system to save the operator time making hundreds of shots. This emission amount is good for calibration and geometrical adjustment of an optical crystal x-ray focusing spectrometer.

  12. Absolute Radiometric Calibration of EUNIS-06

    NASA Technical Reports Server (NTRS)

    Thomas, R. J.; Rabin, D. M.; Kent, B. J.; Paustian, W.

    2007-01-01

    The Extreme-Ultraviolet Normal-Incidence Spectrometer (EUNIS) is a soundingrocket payload that obtains imaged high-resolution spectra of individual solar features, providing information about the Sun's corona and upper transition region. Shortly after its successful initial flight last year, a complete end-to-end calibration was carried out to determine the instrument's absolute radiometric response over its Longwave bandpass of 300 - 370A. The measurements were done at the Rutherford-Appleton Laboratory (RAL) in England, using the same vacuum facility and EUV radiation source used in the pre-flight calibrations of both SOHO/CDS and Hinode/EIS, as well as in three post-flight calibrations of our SERTS sounding rocket payload, the precursor to EUNIS. The unique radiation source provided by the Physikalisch-Technische Bundesanstalt (PTB) had been calibrated to an absolute accuracy of 7% (l-sigma) at 12 wavelengths covering our bandpass directly against the Berlin electron storage ring BESSY, which is itself a primary radiometric source standard. Scans of the EUNIS aperture were made to determine the instrument's absolute spectral sensitivity to +- 25%, considering all sources of error, and demonstrate that EUNIS-06 was the most sensitive solar E W spectrometer yet flown. The results will be matched against prior calibrations which relied on combining measurements of individual optical components, and on comparisons with theoretically predicted 'insensitive' line ratios. Coordinated observations were made during the EUNIS-06 flight by SOHO/CDS and EIT that will allow re-calibrations of those instruments as well. In addition, future EUNIS flights will provide similar calibration updates for TRACE, Hinode/EIS, and STEREO/SECCHI/EUVI.

  13. Pore-space alteration in source rock (shales) during hydrocarbons generation: laboratory experiment

    NASA Astrophysics Data System (ADS)

    Giliazetdinova, D. R.; Korost, D. V.; Nadezhkin, D. V.

    2013-12-01

    Hydrocarbons (HC) are generated from solid organic matter (kerogen) due to thermocatalytic reactions. The rate of such reactions shows direct correlation with temperature and depends on the depth of source rock burial. Burial of sedimentary rock is also inevitably accompanied by its structural alteration owing to compaction, dehydration and re-crystallization. Processes of HC generation, primary migration and structural changes are inaccessible for direct observation in nature, but they can be studied in laboratory experiments. Experiment was carried out with a clayey-carbonate rock sample of the Domanik Horizon taken from boreholes drilled in the northeastern part of the south Tatar arch. The rock chosen fits the very essential requirements - high organic matter content and its low metamorphic grade. Our work aimed at laboratory modeling of HC generation in an undisturbed rock sample by its heating in nitrogen atmosphere based on a specified temperature regime and monitoring alterations in the pore space structure. Observations were carried out with a SkyScan-1172 X-ray microtomography scanner (resulting scan resolution of 1 μm). A cylinder, 44 mm in diameter, was prepared from the rock sample for the pyrolitic and microtomographic analyses. Scanning procedures were carried out in 5 runs. Temperature interval for each run had to match the most important stage of HC generation in the source rock, namely: (1) original structure; (2) 100-300°C - discharge of free and adsorbed HC and water; (3) 300-400°C - initial stage of HC formation owing to high-temperature pyrolysis of the solid organic matter and discharge of the chemically bound water; (4) 400-470°C - temperature interval fitting the most intense stage of HC formation; (5) 470-510°C - final stage of HC formation. Maximum sample heating in the experiment was determined as temperature of the onset of active decomposition of carbonates, i.e., in essence, irreversible metamorphism of the rock. Additional

  14. Mathematical calibration of Ge detectors, and the instruments that use them

    SciTech Connect

    Bronson, F.L.; Young, B.

    1997-11-01

    Efficiency calibrations for Ge detectors are typically done with the use of multiple energy calibrations sources which are added to a bulk matrix intended to simulate the measurement sample, and then deposited in the sample container. This is rather easy for common laboratory samples. Bu, even there, for many environmental samples, waste assay samples, and operational health physics samples, accurate calibrations are difficult. For these situations, various mathematical corrections or direct calibration techniques are used at Canberra. EML has pioneered the use of mathematical calibrations following source-based detector characterization measurements for in situ measurements of environmental fallout. Canberra has expanded this by the use of MCNP for the source measurements required in EML. For other calibration situations, MCNP was used directly, as the primary calibration method. This is demonstrated to be at least as accurate as source based measurements, and probably better. Recently, a new method [ISOCS] has been developed and is nearing completion. This promises to be an easy to use calibration software that can be used by the customer for in situ gamma spectroscopy to accurately measure many large sized samples, such as boxes, drums, pipes, or to calibrate small laboratory-type samples. 8 refs., 8 figs., 5 tabs.

  15. Recommendations following a multi-laboratory comparison of microbial source tracking methods

    EPA Science Inventory

    Microbial source tracking (MST) methods are under development to provide resource managers with tools to identify sources of fecal contamination in water. Some of the most promising methods currently under development were recently evaluated in the Source Identification Protocol ...

  16. Source Tracking of Nitrous Oxide using A Quantum Cascade Laser System in the Field and Laboratory Environments

    EPA Science Inventory

    Nitrous oxide is an important greenhouse gas and ozone depleting substance. Nitrification and denitrification are two major biological pathways that are responsible for soil emissions of N2O. However, source tracking of in-situ or laboratory N2O production is still challenging to...

  17. Development and calibration of mirrors and gratings for the soft x-ray materials science beamline at the Linac Coherent Light Source free-electron laser.

    PubMed

    Soufli, Regina; Fernández-Perea, Mónica; Baker, Sherry L; Robinson, Jeff C; Gullikson, Eric M; Heimann, Philip; Yashchuk, Valeriy V; McKinney, Wayne R; Schlotter, William F; Rowen, Michael

    2012-04-20

    This work discusses the development and calibration of the x-ray reflective and diffractive elements for the Soft X-ray Materials Science (SXR) beamline of the Linac Coherent Light Source (LCLS) free-electron laser (FEL), designed for operation in the 500 to 2000 eV region. The surface topography of three Si mirror substrates and two Si diffraction grating substrates was examined by atomic force microscopy (AFM) and optical profilometry. The figure of the mirror substrates was also verified via surface slope measurements with a long trace profiler. A boron carbide (B4C) coating especially optimized for the LCLS FEL conditions was deposited on all SXR mirrors and gratings. Coating thickness uniformity of 0.14 nm root mean square (rms) across clear apertures extending to 205 mm length was demonstrated for all elements, as required to preserve the coherent wavefront of the LCLS source. The reflective performance of the mirrors and the diffraction efficiency of the gratings were calibrated at beamline 6.3.2 at the Advanced Light Source synchrotron. To verify the integrity of the nanometer-scale grating structure, the grating topography was examined by AFM before and after coating. This is to our knowledge the first time B4C-coated diffraction gratings are demonstrated for operation in the soft x-ray region.

  18. Development and calibration of mirrors and gratings for the Soft X-ray materials science beamline at the Linac Coherent Light Source free-electron laser

    SciTech Connect

    Soufli, Regina; Fernandez-Perea, Monica; Baker, Sherry L.; Robinson, Jeff C.; Gullikson, Eric M.; Heimann, Philip; Yashchuk, Valerie V.; McKinney, Wayne R.; Schlotter, William F.; Rowen, Michael

    2012-04-18

    This article discusses the development and calibration of the x-ray reflective and diffractive elements for the Soft X-ray Materials Science (SXR) beamline of the Linac Coherent Light Source (LCLS) free-electron laser (FEL), designed for operation in the 500 – 2000 eV region. The surface topography of three Si mirror substrates and two Si diffraction grating substrates was examined by atomic force microscopy (AFM) and optical profilometry. The figure of the mirror substrates was also verified via surface slope measurements with a long trace profiler. A boron carbide (B4C) coating especially optimized for the LCLS FEL conditions was deposited on all SXR mirrors and gratings. Coating thickness uniformity of 0.14 nm root mean square (rms) across clear apertures extending to 205 mm length was demonstrated for all elements, as required to preserve the coherent wavefront of the LCLS source. The reflective performance of the mirrors and the diffraction efficiency of the gratings were calibrated at beamline 6.3.2 at the Advanced Light Source synchrotron. To verify the integrity of the nanometer-scale grating structure, the grating topography was examined by AFM before and after coating. This is to our knowledge the first time B4C-coated diffraction gratings are demonstrated for operation in the soft x-ray region.

  19. Development and calibration of mirrors and gratings for the Soft X-ray materials science beamline at the Linac Coherent Light Source free-electron laser

    DOE PAGES

    Soufli, Regina; Fernandez-Perea, Monica; Baker, Sherry L.; ...

    2012-04-18

    This article discusses the development and calibration of the x-ray reflective and diffractive elements for the Soft X-ray Materials Science (SXR) beamline of the Linac Coherent Light Source (LCLS) free-electron laser (FEL), designed for operation in the 500 – 2000 eV region. The surface topography of three Si mirror substrates and two Si diffraction grating substrates was examined by atomic force microscopy (AFM) and optical profilometry. The figure of the mirror substrates was also verified via surface slope measurements with a long trace profiler. A boron carbide (B4C) coating especially optimized for the LCLS FEL conditions was deposited on allmore » SXR mirrors and gratings. Coating thickness uniformity of 0.14 nm root mean square (rms) across clear apertures extending to 205 mm length was demonstrated for all elements, as required to preserve the coherent wavefront of the LCLS source. The reflective performance of the mirrors and the diffraction efficiency of the gratings were calibrated at beamline 6.3.2 at the Advanced Light Source synchrotron. To verify the integrity of the nanometer-scale grating structure, the grating topography was examined by AFM before and after coating. This is to our knowledge the first time B4C-coated diffraction gratings are demonstrated for operation in the soft x-ray region.« less

  20. Scaling Transition in Earthquake Sources: A Possible Link Between Seismic and Laboratory Measurements

    NASA Astrophysics Data System (ADS)

    Malagnini, Luca; Mayeda, Kevin; Nielsen, Stefan; Yoo, Seung-Hoon; Munafo', Irene; Rawles, Christopher; Boschi, Enzo

    2014-10-01

    We estimate the corner frequencies of 20 crustal seismic events from mainshock-aftershock sequences in different tectonic environments (mainshocks 5.7 < M W < 7.6) using the well-established seismic coda ratio technique ( Mayeda et al. in Geophys Res Lett 34:L11303, 2007; Mayeda and Malagnini in Geophys Res Lett, 2010), which provides optimal stability and does not require path or site corrections. For each sequence, we assumed the Brune source model and estimated all the events' corner frequencies and associated apparent stresses following the MDAC spectral formulation of Walter and Taylor (A revised magnitude and distance amplitude correction (MDAC2) procedure for regional seismic discriminants, 2001), which allows for the possibility of non-self-similar source scaling. Within each sequence, we observe a systematic deviation from the self-similar line, all data being rather compatible with , where ɛ > 0 ( Kanamori and Rivera in Bull Seismol Soc Am 94:314-319, 2004). The deviation from a strict self-similar behavior within each earthquake sequence of our collection is indicated by a systematic increase in the estimated average static stress drop and apparent stress with increasing seismic moment (moment magnitude). Our favored physical interpretation for the increased apparent stress with earthquake size is a progressive frictional weakening for increasing seismic slip, in agreement with recent results obtained in laboratory experiments performed on state-of-the-art apparatuses at slip rates of the order of 1 m/s or larger. At smaller magnitudes ( M W < 5.5), the overall data set is characterized by a variability in apparent stress of almost three orders of magnitude, mostly from the scatter observed in strike-slip sequences. Larger events ( M W > 5.5) show much less variability: about one order of magnitude. It appears that the apparent stress (and static stress drop) does not grow indefinitely at larger magnitudes: for example, in the case of the Chi

  1. Calibrating R-LINE model results with observational data to develop annual mobile source air pollutant fields at fine spatial resolution: Application in Atlanta

    NASA Astrophysics Data System (ADS)

    Zhai, Xinxin; Russell, Armistead G.; Sampath, Poornima; Mulholland, James A.; Kim, Byeong-Uk; Kim, Yunhee; D'Onofrio, David

    2016-12-01

    The Research LINE-source (R-LINE) dispersion model for near-surface releases is a dispersion model developed to estimate the impacts of line sources, such as automobiles, on primary air pollutant levels. In a multiyear application in Atlanta, R-LINE simulations overestimated concentrations and spatial gradients compared to measurements. In this study we present a computationally efficient procedure for calculating annual average spatial fields and develop an approach for calibrating R-LINE concentrations with observational data. Simulated hourly concentrations of PM2.5, CO and NOx from mobile sources at 250 m resolution in the 20-county Atlanta area based on average diurnal emission profiles and meteorological categories were used to estimate annual averages. Compared to mobile source PM2.5 impacts estimated by chemical mass balance with gas constraints (CMB-GC), a source apportionment model based on PM2.5 speciation measurements, R-LINE estimates of traffic-generated PM2.5 impacts were found to be higher by a factor of 1.8 on average across all sites. Compared to observations of daily 1 h maximum CO and NOx, R-LINE estimates were higher by factors of 1.3 and 4.2 on average, respectively. Annual averages estimated by R-LINE were calibrated by regression with observations from 2002 to 2011 at multiple sites for daily 1 h maximum CO and NOx and with measurement-based mobile source impacts estimated by CMB-GC for PM2.5. The calibration reduced normalized mean bias (NMB) from 29% to 0.3% for PM2.5, from 22% to -1% for CO, and from 303% to 49% for NOx. Cross-validation analysis (withholding sites one at a time) leads to NMB of 13%, 1%, and 69% for PM2.5, CO, and NOx, respectively. The observation-calibrated R-LINE annual average spatial fields were compared with pollutant fields from observation-blended, 12 km resolution Community Multi-scale Air Quality (CMAQ) model fields for CO and NOx, with Pearson correlation R2 values of 0.55 for CO and 0.54 for NOx found. The

  2. Internet-Based Calibration of a Multifunction Calibrator

    SciTech Connect

    BUNTING BACA,LISA A.; DUDA JR.,LEONARD E.; WALKER,RUSSELL M.; OLDHAM,NILE; PARKER,MARK

    2000-12-19

    A new way of providing calibration services is evolving which employs the Internet to expand present capabilities and make the calibration process more interactive. Sandia National Laboratories and the National Institute of Standards and Technology are collaborating to set up and demonstrate a remote calibration of multijunction calibrators using this Internet-based technique that is becoming known as e-calibration. This paper describes the measurement philosophy and the Internet resources that can provide real-time audio/video/data exchange, consultation and training, as well as web-accessible test procedures, software and calibration reports. The communication system utilizes commercial hardware and software that should be easy to integrate into most calibration laboratories.

  3. Internet-based calibration of a multifunction calibrator

    SciTech Connect

    BUNTING BACA,LISA A.; DUDA JR.,LEONARD E.; WALKER,RUSSELL M.; OLDHAM,NILE; PARKER,MARK

    2000-04-17

    A new way of providing calibration services is evolving which employs the Internet to expand present capabilities and make the calibration process more interactive. Sandia National Laboratories and the National Institute of Standards and Technology are collaborating to set up and demonstrate a remote calibration of multifunction calibrators using this Internet-based technique that is becoming known as e-calibration. This paper describes the measurement philosophy and the Internet resources that can provide real-time audio/video/data exchange, consultation and training, as well as web-accessible test procedures, software and calibration reports. The communication system utilizes commercial hardware and software that should be easy to integrate into most calibration laboratories.

  4. Water Quality & Pollutant Source Monitoring: Field and Laboratory Procedures. Training Manual.

    ERIC Educational Resources Information Center

    Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

    This training manual presents material on techniques and instrumentation used to develop data in field monitoring programs and related laboratory operations concerned with water quality and pollution monitoring. Topics include: collection and handling of samples; bacteriological, biological, and chemical field and laboratory methods; field…

  5. DOE radiological calibrations intercomparison program: Results of fiscal year 1986

    SciTech Connect

    Cummings, F.M.; Roberson, P.L.; McDonald, J.C.

    1987-05-01

    The Department of Energy Radiological Calibration Intercomparison Program was initiated in January 1986, under the research portion of the DOE Laboratory Accreditation Program. The program operates via the exchange of transfer standards, consisting of instrument sets and standard secondary beta sources. There are two instrument sets and the scheduled use has been staggered such that one set is available for use during each month. One set of secondary standard beta sources is available for use bimonthly. During the 1986 fiscal year, five laboratories used the instrument sets and three laboratories used the beta source set. Results were reported for all the measurements. The average and one standard deviation of the ratios of participant results to Pacific Northwest Laboratory calibration values were 1.12 +- 0.17 for gamma measurements. Those ratios for the gamma measurements varied from 0.98 to 3.06. The larger differences of results from measurements performed at two facilities were directly attributable to unfamiliarity with the intercomparison instruments. The average and one standard deviation of the ratios of participant results to PNL calibration values obtained using the secondary /sup 90/Sr beta source was 1.02 +- 0.05, which is well within measurement uncertainties. The one participant who performed measurements using /sup 147/Pm and /sup 204/Tl sources obtained ratios of 0.68 and 1.11, respectively. No measurements were performed using neutron or x-ray sources.

  6. Photometric calibrations for 21st century science

    SciTech Connect

    Kent, Stephen; Kaiser, Mary Elizabeth; Deustua, Susana E.; Smith, J.Allyn; Adelman, Saul; Allam, Sahar S.; Baptista, Brian; Bohlin, Ralph C.; Clem, James L.; Conley, Alex; Edelstein, Jerry; /UC, Berkeley, Space Sci. Dept. /NOAO, Tucson

    2009-02-01

    The answers to fundamental science questions in astrophysics, ranging from the history of the expansion of the universe to the sizes of nearby stars, hinge on our ability to make precise measurements of diverse astronomical objects. As our knowledge of the underlying physics of objects improves along with advances in detectors and instrumentation, the limits on our capability to extract science from measurements is set, not by our lack of understanding of the nature of these objects, but rather by the most mundane of all issues: the precision with which we can calibrate observations in physical units. In principle, photometric calibration is a solved problem - laboratory reference standards such as blackbody furnaces achieve precisions well in excess of those needed for astrophysics. In practice, however, transferring the calibration from these laboratory standards to astronomical objects of interest is far from trivial - the transfer must reach outside the atmosphere, extend over 4{pi} steradians of sky, cover a wide range of wavelengths, and span an enormous dynamic range in intensity. Virtually all spectrophotometric observations today are calibrated against one or more stellar reference sources, such as Vega, which are themselves tied back to laboratory standards in a variety of ways. This system's accuracy is not uniform. Selected regions of the electromagnetic spectrum are calibrated extremely well, but discontinuities of a few percent still exist, e.g., between the optical and infrared. Independently, model stellar atmospheres are used to calibrate the spectra of selected white dwarf stars, e.g. the HST system, but the ultimate accuracy of this system should be verified against laboratory sources. Our traditional standard star systems, while sufficient until now, need to be improved and extended in order to serve future astrophysics experiments. This white paper calls for a program to improve upon and expand the current networks of spectrophotometrically

  7. Lifetime and Failure Characteristics of Pt/Ne Hollow Cathode Lamps Used as Calibration Sources for UV Space Instruments

    NASA Astrophysics Data System (ADS)

    Nave, Gillian; Sansonetti, Craig J.; Penton, Steven V.; Cunningham, Nathaniel; Beasley, Matthew; Osterman, Steven; Kerber, Florian; (Tony Keyes, Charles D.; Rosa, Michael R.

    2012-12-01

    We report accelerated aging tests on three Pt/Ne lamps from the same manufacturing run as lamps installed on the Cosmic Origins Spectrograph (COS). One lamp was aged in air at the National Institute of Standards and Technology (NIST) at a current of 10 mA and 50% duty cycle (30 s on, 30 s off) until failure. Two other lamps were aged by the COS instrument development team in a vacuum chamber. Initial radiometrically calibrated spectra were taken of all three lamps at NIST. Calibrated spectra of the air-aged lamp were taken after 206, 500, 778, 783 and 897 hr of operation. Spectra of the vacuum-aged lamps were taken after 500 hr for both lamps, and after 1000 hr for one of the lamps. During vacuum aging, the lamp voltage, photometric stability and temperature were monitored. All three lamps lasted for over 900 hr (100,000 cycles) when run at 10 mA, sufficient for 10–12 years of operation on COS. The total output dropped by less than 15% over 500 hr, with short-term repeatability within a few percent. We recommend that future space operation of these lamps include the lamp voltage in the telemetry as a diagnostic for the lamp aging.

  8. Sandia WIPP calibration traceability

    SciTech Connect

    Schuhen, M.D.; Dean, T.A.

    1996-05-01

    This report summarizes the work performed to establish calibration traceability for the instrumentation used by Sandia National Laboratories at the Waste Isolation Pilot Plant (WIPP) during testing from 1980-1985. Identifying the calibration traceability is an important part of establishing a pedigree for the data and is part of the qualification of existing data. In general, the requirement states that the calibration of Measuring and Test equipment must have a valid relationship to nationally recognized standards or the basis for the calibration must be documented. Sandia recognized that just establishing calibration traceability would not necessarily mean that all QA requirements were met during the certification of test instrumentation. To address this concern, the assessment was expanded to include various activities.

  9. DIRBE External Calibrator (DEC)

    NASA Technical Reports Server (NTRS)

    Wyatt, Clair L.; Thurgood, V. Alan; Allred, Glenn D.

    1987-01-01

    Under NASA Contract No. NAS5-28185, the Center for Space Engineering at Utah State University has produced a calibration instrument for the Diffuse Infrared Background Experiment (DIRBE). DIRBE is one of the instruments aboard the Cosmic Background Experiment Observatory (COBE). The calibration instrument is referred to as the DEC (Dirbe External Calibrator). DEC produces a steerable, infrared beam of controlled spectral content and intensity and with selectable point source or diffuse source characteristics, that can be directed into the DIRBE to map fields and determine response characteristics. This report discusses the design of the DEC instrument, its operation and characteristics, and provides an analysis of the systems capabilities and performance.

  10. 10 CFR 32.102 - Schedule C-prototype tests for calibration or reference sources containing americium-241 or...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... sources containing americium-241 or radium-226. 32.102 Section 32.102 Energy NUCLEAR REGULATORY COMMISSION... americium-241 or radium-226. An applicant for a license under § 32.57 shall, for any type of source which is designed to contain more than 0.185 kilobecquerel (0.005 microcurie) of americium-241 or...

  11. 10 CFR 32.102 - Schedule C-prototype tests for calibration or reference sources containing americium-241 or...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... sources containing americium-241 or radium-226. 32.102 Section 32.102 Energy NUCLEAR REGULATORY COMMISSION... americium-241 or radium-226. An applicant for a license under § 32.57 shall, for any type of source which is designed to contain more than 0.185 kilobecquerel (0.005 microcurie) of americium-241 or...

  12. 10 CFR 32.102 - Schedule C-prototype tests for calibration or reference sources containing americium-241 or...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... sources containing americium-241 or radium-226. 32.102 Section 32.102 Energy NUCLEAR REGULATORY COMMISSION... americium-241 or radium-226. An applicant for a license under § 32.57 shall, for any type of source which is designed to contain more than 0.185 kilobecquerel (0.005 microcurie) of americium-241 or...

  13. 10 CFR 70.39 - Specific licenses for the manufacture or initial transfer of calibration or reference sources.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... radioactive material from the source shall be determined by measuring the radioactivity on the filter paper or by direct measurement of the radioactivity on the source following the dry wipe. (iii) Wet wipe test... be determined by measuring the radioactivity on the filter paper after it has dried or by...

  14. 10 CFR 70.39 - Specific licenses for the manufacture or initial transfer of calibration or reference sources.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... radioactive material from the source shall be determined by measuring the radioactivity on the filter paper or by direct measurement of the radioactivity on the source following the dry wipe. (iii) Wet wipe test... be determined by measuring the radioactivity on the filter paper after it has dried or by...

  15. 10 CFR 70.39 - Specific licenses for the manufacture or initial transfer of calibration or reference sources.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... radioactive material from the source shall be determined by measuring the radioactivity on the filter paper or by direct measurement of the radioactivity on the source following the dry wipe. (iii) Wet wipe test... be determined by measuring the radioactivity on the filter paper after it has dried or by...

  16. 10 CFR 70.39 - Specific licenses for the manufacture or initial transfer of calibration or reference sources.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... radioactive material from the source shall be determined by measuring the radioactivity on the filter paper or by direct measurement of the radioactivity on the source following the dry wipe. (iii) Wet wipe test... be determined by measuring the radioactivity on the filter paper after it has dried or by...

  17. 10 CFR 70.39 - Specific licenses for the manufacture or initial transfer of calibration or reference sources.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... radioactive material from the source shall be determined by measuring the radioactivity on the filter paper or by direct measurement of the radioactivity on the source following the dry wipe. (iii) Wet wipe test... be determined by measuring the radioactivity on the filter paper after it has dried or by...

  18. Lidar Calibration Centre

    NASA Astrophysics Data System (ADS)

    Pappalardo, Gelsomina; Freudenthaler, Volker; Nicolae, Doina; Mona, Lucia; Belegante, Livio; D'Amico, Giuseppe

    2016-06-01

    This paper presents the newly established Lidar Calibration Centre, a distributed infrastructure in Europe, whose goal is to offer services for complete characterization and calibration of lidars and ceilometers. Mobile reference lidars, laboratories for testing and characterization of optics and electronics, facilities for inspection and debugging of instruments, as well as for training in good practices are open to users from the scientific community, operational services and private sector. The Lidar Calibration Centre offers support for trans-national access through the EC HORIZON2020 project ACTRIS-2.

  19. Sources of Variability in Chlorophyll Analysis by Fluorometry and High-Performance Liquid Chromatography in a SIMBIOS Inter-Calibration Exercise

    NASA Technical Reports Server (NTRS)

    VanHeukelem, Laurie; Thomas, Crystal S.; Gilbert, Patricia M.; Fargion, Giulietta S. (Editor); McClain, Charles R. (Editor)

    2002-01-01

    The purpose of this technical report is to provide current documentation of the Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project activities, NASA Research Announcement (NRA) research status, satellite data processing, data product validation, and field calibration. This documentation is necessary to ensure that critical information is related to the scientific community and NASA management. This critical information includes the technical difficulties and challenges of validating and combining ocean color data from an array of independent satellite systems to form consistent and accurate global bio-optical time series products. This technical report is not meant as a substitute for scientific literature. Instead, it will provide a ready and responsive vehicle for the multitude of technical reports issued by an operational project. This particular document focus on the variability in chlorophyll pigment measurements resulting from differences in methodologies and laboratories conducting the pigment analysis.

  20. Comparison of a Joule effect calibration system using Kanthal wire and a laser diode as heat sources

    NASA Astrophysics Data System (ADS)

    Maldonado, Blas A.; Bárcena-Soto, Maximiliano; Casillas, Norberto; Flores, Jorge L.

    2009-09-01

    Here it is presented a comparison of two calibration techniques applied to a thermistor element used in a surface microcalorimeter which operates under Isoperibol conditions. Usually surface microcalorimeters employ a thermistor as a temperature sensing element, whose heat capacity requires to be evaluated before they can be used. One alternative method to estimate its heat capacity is by supplying a known amount of energy and detecting its temperature changes. Thus, surface heating can be achieved by different techniques; one of them is by supplying energy to the thermistor by passing current through a Ni-Cr coil wined around the glass bulb thermistor. A rather different and more convenient technique consists of directly illuminating a small well-defined thermistor area with an infrared 1550 nm wavelength laser beam, while detecting the thermistor temperature changes. Both procedures are thoroughly compared and the heat capacities obtained by both methods are presented.

  1. First beam measurements on the vessel for extraction and source plasma analyses (VESPA) at the Rutherford Appleton Laboratory (RAL)

    NASA Astrophysics Data System (ADS)

    Lawrie, Scott R.; Faircloth, Daniel C.; Letchford, Alan P.; Perkins, Mike; Whitehead, Mark O.; Wood, Trevor

    2015-04-01

    In order to facilitate the testing of advanced H- ion sources for the ISIS and Front End Test Stand (FETS) facilities at the Rutherford Appleton Laboratory (RAL), a Vessel for Extraction and Source Plasma Analyses (VESPA) has been constructed. This will perform the first detailed plasma measurements on the ISIS Penning-type H- ion source using emission spectroscopic techniques. In addition, the 30-year-old extraction optics are re-designed from the ground up in order to fully transport the beam. Using multiple beam and plasma diagnostics devices, the ultimate aim is improve H- production efficiency and subsequent transport for either long-term ISIS user operations or high power FETS requirements. The VESPA will also accommodate and test a new scaled-up Penning H- source design. This paper details the VESPA design, construction and commissioning, as well as initial beam and spectroscopy results.

  2. First beam measurements on the vessel for extraction and source plasma analyses (VESPA) at the Rutherford Appleton Laboratory (RAL)

    SciTech Connect

    Lawrie, Scott R.; Faircloth, Daniel C.; Letchford, Alan P.; Perkins, Mike; Whitehead, Mark O.; Wood, Trevor

    2015-04-08

    In order to facilitate the testing of advanced H{sup −} ion sources for the ISIS and Front End Test Stand (FETS) facilities at the Rutherford Appleton Laboratory (RAL), a Vessel for Extraction and Source Plasma Analyses (VESPA) has been constructed. This will perform the first detailed plasma measurements on the ISIS Penning-type H{sup −} ion source using emission spectroscopic techniques. In addition, the 30-year-old extraction optics are re-designed from the ground up in order to fully transport the beam. Using multiple beam and plasma diagnostics devices, the ultimate aim is improve H{sup −} production efficiency and subsequent transport for either long-term ISIS user operations or high power FETS requirements. The VESPA will also accommodate and test a new scaled-up Penning H{sup −} source design. This paper details the VESPA design, construction and commissioning, as well as initial beam and spectroscopy results.

  3. Universal main magnetic focus ion source: A new tool for laboratory research of astrophysics and Tokamak microplasma

    NASA Astrophysics Data System (ADS)

    Ovsyannikov, V. P.; Nefiodov, A. V.; Levin, A. A.

    2017-01-01

    A novel room-temperature ion source for the production of atomic ions in electron beam within wide ranges of electron energy and current density is developed. The device can operate both as conventional Electron Beam Ion Source/Trap (EBIS/T) and novel Main Magnetic Focus Ion Source. The ion source is suitable for generation of the low-, medium- and high-density microplasma in steady state, which can be employed for investigation of a wide range of physical problems in ordinary university laboratory, in particular, for microplasma simulations relevant to astrophysics and ITER reactor. For the electron beam characterized by the incident energy Ee = 10 keV, the current density je ∼ 20 kA/cm2 and the number density ne ∼ 2 × 1013 cm‑3 were achieved experimentally. For Ee ∼ 60 keV, the value of electron number density ne ∼ 1014 cm‑3 is feasible. The efficiency of the novel ion source for laboratory astrophysics significantly exceeds that of other existing warm and superconducting EBITs.

  4. The calibration of read-out-streak photometry in the XMM-Newton Optical Monitor and the construction of a bright-source catalogue

    NASA Astrophysics Data System (ADS)

    Page, M. J.; Chan, N.; Breeveld, A. A.; Talavera, A.; Yershov, V.; Kennedy, T.; Kuin, N. P. M.; Hancock, B.; Smith, P. J.; Carter, M.

    2017-04-01

    The dynamic range of the XMM-Newton Optical Monitor (XMM-OM) is limited at the bright end by coincidence loss, the superposition of multiple photons in the individual frames recorded from its micro-channel-plate (MCP) intensified charge-coupled device (CCD) detector. One way to overcome this limitation is to use photons that arrive during the frame transfer of the CCD, forming vertical read-out streaks for bright sources. We calibrate these read-out streaks for photometry of bright sources observed with XMM-OM. The bright-source limit for read-out-streak photometry is set by the recharge time of the MCPs. For XMM-OM, we find that the MCP recharge time is 5.5 × 10-4 s. We determine that the effective bright limits for read-out-streak photometry with XMM-OM are approximately 1.5 mag brighter than the bright-source limits for normal aperture photometry in full-frame images. This translates into bright-source limits in Vega magnitudes of UVW2=7.1, UVM2=8.0, UVW1=9.4, U=10.5, B=11.5, V=10.2, and White=12.5 for data taken early in the mission. The limits brighten by up to 0.2 mag, depending on filter, over the course of the mission as the detector ages. The method is demonstrated by deriving UVW1 photometry for the symbiotic nova RR Telescopii, and the new photometry is used to constrain the e-folding time of its decaying ultraviolet (UV) emission. Using the read-out-streak method, we obtain photometry for 50 per cent of the missing UV source measurements in version 2.1 of the XMM-Newton Serendipitous UV Source Survey catalogue.

  5. Investigation of ISIS and Brookhaven National Laboratory ion source electrodes after extended operation.

    PubMed

    Lettry, J; Alessi, J; Faircloth, D; Gerardin, A; Kalvas, T; Pereira, H; Sgobba, S

    2012-02-01

    Linac4 accelerator of Centre Européen de Recherches Nucléaires is under construction and a RF-driven H(-) ion source is being developed. The beam current requirement for Linac4 is very challenging: 80 mA must be provided. Cesiated plasma discharge ion sources such as Penning or magnetron sources are also potential candidates. Accelerator ion sources must achieve typical reliability figures of 95% and above. Investigating and understanding the underlying mechanisms involved with source failure or ageing is critical when selecting the ion source technology. Plasma discharge driven surface ion sources rely on molybdenum cathodes. Deformation of the cathode surfaces is visible after extended operation periods. A metallurgical investigation of an ISIS ion source is presented. The origin of the deformation is twofold: Molybdenum sputtering by cesium ions digs few tenths of mm cavities while a growth of molybdenum is observed in the immediate vicinity. The molybdenum growth under hydrogen atmosphere is hard and loosely bound to the bulk. It is, therefore, likely to peel off and be transported within the plasma volume. The observation of the cathode, anode, and extraction electrodes of the magnetron source operated at BNL for two years are presented. A beam simulation of H(-), electrons, and Cs(-) ions was performed with the IBSimu code package to qualitatively explain the observations. This paper describes the operation conditions of the ion sources and discusses the metallurgical analysis and beam simulation results.

  6. Investigation of ISIS and Brookhaven National Laboratory ion source electrodes after extended operation

    SciTech Connect

    Lettry, J.; Gerardin, A.; Pereira, H.; Sgobba, S.; Alessi, J.; Faircloth, D.; Kalvas, T.

    2012-02-15

    Linac4 accelerator of Centre Europeen de Recherches Nucleaires is under construction and a RF-driven H{sup -} ion source is being developed. The beam current requirement for Linac4 is very challenging: 80 mA must be provided. Cesiated plasma discharge ion sources such as Penning or magnetron sources are also potential candidates. Accelerator ion sources must achieve typical reliability figures of 95% and above. Investigating and understanding the underlying mechanisms involved with source failure or ageing is critical when selecting the ion source technology. Plasma discharge driven surface ion sources rely on molybdenum cathodes. Deformation of the cathode surfaces is visible after extended operation periods. A metallurgical investigation of an ISIS ion source is presented. The origin of the deformation is twofold: Molybdenum sputtering by cesium ions digs few tenths of mm cavities while a growth of molybdenum is observed in the immediate vicinity. The molybdenum growth under hydrogen atmosphere is hard and loosely bound to the bulk. It is, therefore, likely to peel off and be transported within the plasma volume. The observation of the cathode, anode, and extraction electrodes of the magnetron source operated at BNL for two years are presented. A beam simulation of H{sup -}, electrons, and Cs{sup -} ions was performed with the IBSimu code package to qualitatively explain the observations. This paper describes the operation conditions of the ion sources and discusses the metallurgical analysis and beam simulation results.

  7. Investigation of ISIS and Brookhaven National Laboratory ion source electrodes after extended operation

    SciTech Connect

    Lettry J.; Alessi J.; Faircloth, D.; Gerardin, A.; Kalvas, T.; Pereira, H.; Sgobba, S.

    2012-02-23

    Linac4 accelerator of Centre Europeen de Recherches Nucleaires is under construction and a RF-driven H{sup -} ion source is being developed. The beam current requirement for Linac4 is very challenging: 80 mA must be provided. Cesiated plasma discharge ion sources such as Penning or magnetron sources are also potential candidates. Accelerator ion sources must achieve typical reliability figures of 95% and above. Investigating and understanding the underlying mechanisms involved with source failure or ageing is critical when selecting the ion source technology. Plasma discharge driven surface ion sources rely on molybdenum cathodes. Deformation of the cathode surfaces is visible after extended operation periods. A metallurgical investigation of an ISIS ion source is presented. The origin of the deformation is twofold: Molybdenum sputtering by cesium ions digs few tenths of mm cavities while a growth of molybdenum is observed in the immediate vicinity. The molybdenum growth under hydrogen atmosphere is hard and loosely bound to the bulk. It is, therefore, likely to peel off and be transported within the plasma volume. The observation of the cathode, anode, and extraction electrodes of the magnetron source operated at BNL for two years are presented. A beam simulation of H{sup -}, electrons, and Cs{sup -} ions was performed with the IBSimu code package to qualitatively explain the observations. This paper describes the operation conditions of the ion sources and discusses the metallurgical analysis and beam simulation results.

  8. Investigation of ISIS and Brookhaven National Laboratory ion source electrodes after extended operationa)

    NASA Astrophysics Data System (ADS)

    Lettry, J.; Alessi, J.; Faircloth, D.; Gerardin, A.; Kalvas, T.; Pereira, H.; Sgobba, S.

    2012-02-01

    Linac4 accelerator of Centre Européen de Recherches Nucléaires is under construction and a RF-driven H- ion source is being developed. The beam current requirement for Linac4 is very challenging: 80 mA must be provided. Cesiated plasma discharge ion sources such as Penning or magnetron sources are also potential candidates. Accelerator ion sources must achieve typical reliability figures of 95% and above. Investigating and understanding the underlying mechanisms involved with source failure or ageing is critical when selecting the ion source technology. Plasma discharge driven surface ion sources rely on molybdenum cathodes. Deformation of the cathode surfaces is visible after extended operation periods. A metallurgical investigation of an ISIS ion source is presented. The origin of the deformation is twofold: Molybdenum sputtering by cesium ions digs few tenths of mm cavities while a growth of molybdenum is observed in the immediate vicinity. The molybdenum growth under hydrogen atmosphere is hard and loosely bound to the bulk. It is, therefore, likely to peel off and be transported within the plasma volume. The observation of the cathode, anode, and extraction electrodes of the magnetron source operated at BNL for two years are presented. A beam simulation of H-, electrons, and Cs- ions was performed with the IBSimu code package to qualitatively explain the observations. This paper describes the operation conditions of the ion sources and discusses the metallurgical analysis and beam simulation results.

  9. Final Laboratory Treatabilty Report for: Emulsified Zero Valent Iron Treatment of Chlorinated Solvent DNAPL Source Areas. Revision 1.0

    DTIC Science & Technology

    2006-01-23

    is no soil in the test reactors. A possible source of the pH decrease could be from the partial dissolution and degradation of the vegetable oil...result of the use of deionized water to construct the test reactors rather than natural groundwater. Micronutrients and additional microorganisms...biodegradation were not observed to a significant degree in the laboratory tests conducted to date, likely because site groundwater and soil were not

  10. Final Laboratory Treatability Report for: Emulsified Zero Valent Iron Treatment of Chlorinated Solvent DNAPL Source Areas (Rev 1)

    DTIC Science & Technology

    2006-01-23

    the microorganisms in KB-1TM. There is no buffering capacity in the treatments as there is no soil in the test reactors. A possible source of the pH...reactors rather than natural groundwater. Micronutrients and additional microorganisms that may assist in breaking down the vegetable oil into...laboratory tests conducted to date, likely because site groundwater and soil were not used in the test reactors. GeoSyntec Consultants TR0173

  11. Primary calibration in acoustics metrology

    NASA Astrophysics Data System (ADS)

    Bacelar Milhomem, T. A.; Defilippo Soares, Z. M.

    2015-01-01

    SI unit in acoustics is realized by the reciprocity calibrations of laboratory standard microphones in pressure field, free field and diffuse field. Calibrations in pressure field and in free field are already consolidated and the Inmetro already done them. Calibration in diffuse field is not yet consolidated, however, some national metrology institutes, including Inmetro, are conducting researches on this subject. This paper presents the reciprocity calibration, the results of Inmetro in recent key comparisons and the research that is being developed for the implementation of reciprocity calibration in diffuse field.

  12. Two-dimensional X-ray focusing by off-axis grazing incidence phase Fresnel zone plate on the laboratory X-ray source

    NASA Astrophysics Data System (ADS)

    Grigoriev, Maxim; Fakhrtdinov, Rashid; Irzhak, Dmitry; Firsov, Alexander; Firsov, Anatoly; Svintsov, Alexander; Erko, Alexey; Roshchupkin, Dmitry

    2017-02-01

    The results of studying a two-dimensional X-ray focusing by an off-axis grazing incidence phase Fresnel zone plate on the laboratory X-ray source are presented. This optics enables obtaining a focal spot of 2 μm on the laboratory X-ray source with a focusing efficiency of 30% at a high signal/noise ratio.

  13. Gross-beta activity in ground water: natural sources and artifacts of sampling and laboratory analysis

    USGS Publications Warehouse

    Welch, Alan H.

    1995-01-01

    Gross-beta activity has been used as an indicator of beta-emitting isotopes in water since at least the early 1950s. Originally designed for detection of radioactive releases from nuclear facilities and weapons tests, analysis of gross-beta activity is widely used in studies of naturally occurring radioactivity in ground water. Analyses of about 800 samples from 5 ground-water regions of the United States provide a basis for evaluating the utility of this measurement. The data suggest that measured gross-beta activities are due to (1) long-lived radionuclides in ground water, and (2) ingrowth of beta-emitting radionuclides during holding times between collection of samples and laboratory measurements.Although40K and228Ra appear to be the primary sources of beta activity in ground water, the sum of40K plus228Ra appears to be less than the measured gross-beta activity in most ground-water samples. The difference between the contribution from these radionuclides and gross-beta activity is most pronounced in ground water with gross-beta activities > 10 pCi/L, where these 2 radionuclides account for less than one-half the measured ross-beta activity. One exception is groundwater from the Coastal Plain of New Jersey, where40K plus228Ra generally contribute most of the gross-beta activity. In contrast,40K and228Ra generally contribute most of beta activity in ground water with gross-beta activities < 1 pCi/L.The gross-beta technique does not measure all beta activity in ground water. Although3H contributes beta activity to some ground water, it is driven from the sample before counting and therefore is not detected by gross-beta measurements. Beta-emitting radionuclides with half-lives shorter than a few days can decay to low values between sampling and counting. Although little is known about concentrations of most short-lived beta-emitting radionuclides in environmental ground water (water unaffected by direct releases from nuclear facilities and weapons tests), their

  14. Ultra-Stable Beacon Source for Laboratory Testing of Optical Tracking

    NASA Technical Reports Server (NTRS)

    Aso, Yoichi; Marka, Szabolcs; Kovalik, Joseph

    2008-01-01

    The ultra-stable beacon source (USBS) provides a laser-beam output with a very low angular jitter and can be used as an absolute angular reference to simulate a beacon in the laboratory. The laser is mounted on the top of a very short (approximately equal to 1 m) inverted pendulum (IP) with its optical axis parallel to the carbon fiber pendulum leg. The 85-cm, carbon fiber rods making up the leg are very lightweight and rigid, and are supported by a flex-joint at the bottom (see figure). The gimbal-mounted laser is a weight-adjustable load of about 1.5 kg with its center of rotation co-located with the center of percussion of the inverted pendulum. This reduces the coupling of transverse motion at the base of the pendulum to angular motion of the laser at the top. The inverted pendulum is mounted on a gimbal with its center of rotation coinciding with the pivot position of the inverted pendulum flexure joint. This reduces coupling of ground tilt at the inverted pendulum base to motion of the laser mounted at the top. The mass of the top gimbal is adjusted to give the pendulum a very low resonant frequency (approximately equal to 10 mHz) that filters transverse seismic disturbances from the ground where the base is attached. The motion of the IP is monitored by an optical-lever sensor. The laser light is reflected by the mirror on the IP, and then is detected by a quadrant photo-detector (QPD). The position of the beam spot on the QPD corresponds to the tilt of the IP. Damping of this motion is provided by two coil and magnet pairs. The bottom gimbal mount consists of two plates. The IP is mounted on the second plate. The first plate is supported by two posts through needles and can be rotated about the axis connecting the tips of the needles. The second plate hangs from the first plate and can be rotated about the axis perpendicular to the first plate. As a result, the second plate acts as a two-axis rotation stage. Its center of rotation is located at the

  15. Optical detector calibrator system

    NASA Technical Reports Server (NTRS)

    Strobel, James P. (Inventor); Moerk, John S. (Inventor); Youngquist, Robert C. (Inventor)

    1996-01-01

    An optical detector calibrator system simulates a source of optical radiation to which a detector to be calibrated is responsive. A light source selected to emit radiation in a range of wavelengths corresponding to the spectral signature of the source is disposed within a housing containing a microprocessor for controlling the light source and other system elements. An adjustable iris and a multiple aperture filter wheel are provided for controlling the intensity of radiation emitted from the housing by the light source to adjust the simulated distance between the light source and the detector to be calibrated. The geared iris has an aperture whose size is adjustable by means of a first stepper motor controlled by the microprocessor. The multiple aperture filter wheel contains neutral density filters of different attenuation levels which are selectively positioned in the path of the emitted radiation by a second stepper motor that is also controlled by the microprocessor. An operator can select a number of detector tests including range, maximum and minimum sensitivity, and basic functionality. During the range test, the geared iris and filter wheel are repeatedly adjusted by the microprocessor as necessary to simulate an incrementally increasing simulated source distance. A light source calibration subsystem is incorporated in the system which insures that the intensity of the light source is maintained at a constant level over time.

  16. Spectral responsivity calibration of the reference radiation thermometer at KRISS by using a super-continuum laser-based high-accuracy monochromatic source

    NASA Astrophysics Data System (ADS)

    Yoo, Yong Shim; Kim, Gun Jung; Park, Seongchong; Lee, Dong-Hoon; Kim, Bong-Hak

    2016-12-01

    We report on the calibration of the relative spectral responsivity of the reference radiation thermometer, model LP4, which is used for the experimental realisation of the international temperature scale of 1990 above 960 °C at the Korea Research Institute of Standards and Science. The relative spectral responsivity of LP4 is measured by using a monochromatic source consisting of a super-continuum laser and a double-grating monochromator. By monitoring the wavelength of the output beam directly with a calibrated wavelength-meter, we achieved a high-accuracy measurement of spectral responsivity with a maximum wavelength error of less than 3 pm, a narrow spectral bandwidth of less than 0.4 nm, and a high dynamic range over 8 decades. We evaluated the contributions of various uncertainty components of the spectral responsivity measurement to the uncertainty of the temperature scale based on a practical estimation approach, which numerically calculates the maximal effects of the variations of each component. As a result, we evaluate the uncertainty contribution from the spectral responsivity measurement to the temperature scale to be less than 64 mK (k  =  1) in a range from 660 °C to 2749 °C for the LP4 with a filter at 650 nm.

  17. Application of a superoxide (O(2)(-)) thermal source (SOTS-1) for the determination and calibration of O(2)(-) fluxes in seawater.

    PubMed

    Heller, M I; Croot, P L

    2010-05-14

    Superoxide (O(2)(-)) is an important short lived transient reactive oxygen species (ROS) in seawater. The main source of O(2)(-) in the ocean is believed to be through photochemical reactions though biological processes may also be important. Sink terms for O(2)(-) include redox reactions with bioactive trace metals, including Cu and Fe, and to a lesser extent dissolved organic matter (DOM). Information on the source fluxes, sinks and concentration of superoxide in the open ocean are crucial to improving our understanding of the biogeochemical cycling of redox active species. As O(2)(-) is a highly reactive transient species present at low concentrations it is not a trivial task to make accurate and precise measurements in seawater. In this study we developed the appropriate numerical analysis tools and investigated a number of superoxide sources and methods for the purposes of calibrating O(2)(-) concentrations and/or fluxes specifically in seawater. We found the superoxide thermal source bis(4-carboxybenzyl)hyponitrite (SOTS)-1 easy to employ as a reliable source of O(2)(-) which could be successfully applied in seawater. The thermal decomposition of SOTS-1 in seawater was evaluated over a range of seawater temperatures using both a flux based detection scheme developed using two spectrophotometric methods: (i) 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) and (ii) ferricytochrome c (FC), or a concentration based detection scheme using a chemiluminescence flow injection method based on the Cypridina luciferin analog 2-methyl-6-(p-methoxyphenyl)3-7-dihydroimidazol[1,2-alpha]pyrazin-3-one (MCLA) as reagent. Our results suggest SOTS-1 is the best available O(2)(-) source for determining concentrations and fluxes, all detection systems tested have their pros and cons and the choice of which to use depends more on the duration and type of experiment that is required.

  18. The Inquiry Laboratory as a Source for Development of Metacognitive Skills

    ERIC Educational Resources Information Center

    Kipnis, Mira; Hofstein, Avi

    2008-01-01

    The study described in this article is based on a long-term comprehensive series of investigations that were conducted in the context of teaching high school chemistry in the laboratory using inquiry-type experiments. The students that study chemistry according to this program are involved in an inquiry process that included all the inquiry skills…

  19. Sources of Differences in On-Orbit Total Solar Irradiance Measurements and Description of Proposed Laboratory Intercomparison

    NASA Technical Reports Server (NTRS)

    Butler, J.J.; Johnson, B. C.; Rice, J. P.; Shirley, E. L.; Barnes, R.A.

    2008-01-01

    There is a 5 W/sq m (about 0.35 %) difference between current on-orbit Total Solar Irradiance (TSI) measurements. On 18-20 July 2005, a workshop was held at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland that focused on understanding possible reasons for this difference, through an examination of the instrument designs, calibration approaches, and appropriate measurement equations. The instruments studied in that workshop included the Active Cavity Radiometer Irradiance Monitor III (ACRIM III) on the Active Cavity Radiometer Irradiance Monitor SATellite (ACRIMSAT), the Total Irradiance Monitor (TIM) on the Solar Radiation and Climate Experiment (SORCE), the Variability of solar IRradiance and Gravity Oscillations (VIRGO) on the Solar and Heliospheric Observatory (SOHO), and the Earth Radiation Budget Experiment (ERBE) on the Earth Radiation Budget Satellite (ERBS). Presentations for each instrument included descriptions of its design, its measurement equation and uncertainty budget, and the methods used to assess on-orbit degradation. The workshop also included a session on satellite- and ground-based instrument comparisons and a session on laboratory-based comparisons and the application of new laboratory comparison techniques. The workshop has led to investigations of the effects of diffraction and of aperture area measurements on the differences between instruments. In addition, a laboratory-based instrument comparison is proposed that uses optical power measurements (with lasers that underEll the apertures of the TSI instruments), irradiance measurements (with lasers that overfill the apertures of the TSI instrument), and a cryogenic electrical substitution radiometer as a standard for comparing the instruments. A summary of the workshop and an overview of the proposed research efforts are presented here.

  20. Sources of Differences in On-Orbital Total Solar Irradiance Measurements and Description of a Proposed Laboratory Intercomparison.

    PubMed

    Butler, J J; Johnson, B C; Rice, J P; Shirley, E L; Barnes, R A

    2008-01-01

    There is a 5 W/m(2) (about 0.35 %) difference between current on-orbit Total Solar Irradiance (TSI) measurements. On 18-20 July 2005, a workshop was held at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland that focused on understanding possible reasons for this difference, through an examination of the instrument designs, calibration approaches, and appropriate measurement equations. The instruments studied in that workshop included the Active Cavity Radiometer Irradiance Monitor III (ACRIM III) on the Active Cavity Radiometer Irradiance Monitor SATellite (ACRIMSAT), the Total Irradiance Monitor (TIM) on the Solar Radiation and Climate Experiment (SORCE), the Variability of solar IRradiance and Gravity Oscillations (VIRGO) on the Solar and Heliospheric Observatory (SOHO), and the Earth Radiation Budget Experiment (ERBE) on the Earth Radiation Budget Satellite (ERBS). Presentations for each instrument included descriptions of its design, its measurement equation and uncertainty budget, and the methods used to assess on-orbit degradation. The workshop also included a session on satellite- and ground-based instrument comparisons and a session on laboratory-based comparisons and the application of new laboratory comparison techniques. The workshop has led to investigations of the effects of diffraction and of aperture area measurements on the differences between instruments. In addition, a laboratory-based instrument comparison is proposed that uses optical power measurements (with lasers that underfill the apertures of the TSI instruments), irradiance measurements (with lasers that overfill the apertures of the TSI instrument), and a cryogenic electrical substitution radiometer as a standard for comparing the instruments. A summary of the workshop and an overview of the proposed research efforts are presented here.

  1. Integration of Atmospheric, Laboratory, and Satellite Data to Estimate Biospheric Sources of Oxygenated Organic Compounds

    NASA Technical Reports Server (NTRS)

    Myneni, Ranga B.

    2001-01-01

    For this study, we intend to use a long time series of coarse resolution (8 km and quarter degree) vegetation leaf area index (LAI) and fraction of absorbed PAR (FAPAR) derived from AVHRR data for the time period July 1981 through Dec 2001. The Global Inventory Monitoring and Modeling Studies (GIMMS) data set of AVHRR channel reflectances currently was developed by Dr. Tucker at NASA Goddard. The spatial resolution of the data is 8 km, and a 15-day maximum Normalized Difference Vegetation Index (NDVI) composite time series for the period July 1981 through December 1999 has been produced. The data processing included improved navigation, calibration for intra- and inter-sensor variations, partial atmospheric correction for gaseous absorption and scattering. Stratospheric aerosol effects associated with volcanic eruptions were corrected using a combination of the methods for the data from the period April 1982 - December 1984 (El Chichon) and June 1991 - December 1993 (Mt. Pinatubo).

  2. Calibration and operational data for a compact photodiode detector useful for monitoring the location of moving sources of positron emitting radioisotopes

    NASA Astrophysics Data System (ADS)

    Marsland, M. G.; Dehnel, M. P.; Johansson, S.; Rajander, J.; Solin, O.; Theroux, J.; Stewart, T. M.; Christensen, T.; Hollinger, C.

    2013-04-01

    D-Pace has developed a compact cost-effective gamma detector system based on technology licensed from TRIUMF [1]. These photodiode detectors are convenient for detecting the presence of positron emitting radioisotopes, particularly for the case of transport of radioisotopes from a PET cyclotron to hotlab, or from one location to another in an automated radiochemistry processing unit. This paper describes recent calibration experiments undertaken at the Turku PET Centre for stationary and moving sources of F18 and C11 in standard setups. The practical diagnostic utility of using several of these devices to track the transport of radioisotopes from the cyclotron to hotlab is illustrated. For example, such a detector system provides: a semi-quantitative indication of total activity, speed of transport, location of any activity lost en route and effectiveness of follow-up system flushes, a means of identifying bolus break-up, feedback useful for deciding when to change out tubing.

  3. Calibration and operational data for a compact photodiode detector useful for monitoring the location of moving sources of positron emitting radioisotopes

    SciTech Connect

    Marsland, M. G.; Dehnel, M. P.; Theroux, J.; Christensen, T.; Hollinger, C.; Johansson, S.; Rajander, J.; Solin, O.; Stewart, T. M.

    2013-04-19

    D-Pace has developed a compact cost-effective gamma detector system based on technology licensed from TRIUMF. These photodiode detectors are convenient for detecting the presence of positron emitting radioisotopes, particularly for the case of transport of radioisotopes from a PET cyclotron to hotlab, or from one location to another in an automated radiochemistry processing unit. This paper describes recent calibration experiments undertaken at the Turku PET Centre for stationary and moving sources of F18 and C11 in standard setups. The practical diagnostic utility of using several of these devices to track the transport of radioisotopes from the cyclotron to hotlab is illustrated. For example, such a detector system provides: a semi-quantitative indication of total activity, speed of transport, location of any activity lost en route and effectiveness of follow-up system flushes, a means of identifying bolus break-up, feedback useful for deciding when to change out tubing.

  4. Long Duration Multi-hohlraum X-ray Sources for Eagle Nebula Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Kane, Jave; Heeter, Robert; Martinez, David; Casner, Alexis; Villette, Bruno; Mancini, Roberto; Pound, Marc

    2013-10-01

    A novel foam-filled multi-hohlraum long-duration x-ray source has been demonstrated at the Omega EP laser and used to obtain L-band spectra of photoionized Ti. A larger scale version of the source will be used in the Science on NIF Eagle Nebula experiments studying dynamic evolution of distinctive pillar and cometary structures in star-forming clouds, where the long duration and directionality of photoionizing radiation from nearby stars generates new classes of flows and instabilities. At NIF, a target representing an astrophysical molecular cloud will be placed several mm from an x-ray source lasting 40-100 ns. At EP, three hohlraums were illuminated in sequence with 3.3 kJ pulses lasting 6 ns, or 4.3 kJ pulses lasting 10 ns, generating 18 or 30 ns of x-ray output at 90-100 eV color temperature. Performance of the source was validated using the μ DMX and VSG spectrometers, ASBO VISAR, and x-ray pinhole imagery. The HYDRA code suggests the EP-scale source can also be shot at NIF with at least 10 kJ per hohlraum. The multi-hohlraum source concept has potential further application to hard x-ray sources, soft x-ray backlighters, and nonlinear ablative hydrodynamics. Prepared by LLNL under Contract DE-AC52-07NA27344. J. Kane supported by DOE OFES grant HEDLP LAB 11-583.

  5. Potential for a near-term very-low-energy antiproton source at Brookhaven Bational Laboratory. Special report

    SciTech Connect

    Nordley, G.D.

    1989-04-01

    The resolution of key issues in the use of antimatter for applications ranging from aerospace-materials analysis in the near term and propulsion energy storage in the far term requires experiments with low-energy, relatively slow-moving, or thermal, antiprotons. There is no United States source of antiprotons at that energy; therefore, a task was initiated with Brookhaven National Laboratory to determine what would be required in time, equipment, and money to create a source producing antiprotons at a rate (approx 10{sup 14}/yr) sufficient to support applications experiments. The estimate eventually derived from this first-order analysis was approximately $8.6M for an initial source of 20 KeV antiprotons plus another roughly estimated $5M for cooling to increase the production rate to 10{sup 14} - 10{sup 15} antiprotons per year.

  6. Investigating Sources of Toxicity in Stormwater: Algae Mortality in Runoff Upstream of the Lawrence Livermore National Laboratory

    SciTech Connect

    Campbell, C G; Folks, K; Mathews, S; Martinelli, R

    2003-10-06

    A source evaluation case study is presented for observations of algae toxicity in an intermittent stream passing through the Lawrence Livermore National Laboratory near Livermore, California. A five-step procedure is discussed to determine the cause of water toxicity problems and to determine appropriate environmental management practices. Using this approach, an upstream electrical transfer station was identified as the probable source of herbicides causing the toxicity. In addition, an analytical solution for solute transport in overland flow was used to estimate the application level of 40 Kg/ha. Finally, this source investigation demonstrates that pesticides can impact stream water quality regardless of application within levels suggested on manufacturer labels. Environmental managers need to ensure that pesticides that could harm aquatic organisms (including algae) not be used within close proximity to streams or storm drainages and that application timing should be considered for environmental protection.

  7. CALIBRATION OF PHOTOELASTIC MODULATORS IN THE VACUUM UV.

    SciTech Connect

    OAKBERG, T.C.; TRUNK, J.; SUTHERLAND, J.C.

    2000-02-15

    Measurements of circular dichroism (CD) in the UV and vacuum UV have used photoelastic modulators (PEMs) for high sensitivity (to about 10{sup -6}). While a simple technique for wavelength calibration of the PEMs has been used with good results, several features of these calibration curves have not been understood. The authors have calibrated a calcium fluoride PEM and a lithium fluoride PEM using the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory as a light source. These experiments showed calibration graphs that are linear bit do not pass through the graph origin. A second ''multiple pass'' experiment with laser light of a single wavelength, performed on the calcium fluoride PEM, demonstrates the linearity of the PEM electronics. This implies that the calibration behavior results from intrinsic physical properties of the PEM optical element material. An algorithm for generating calibration curves for calcium fluoride and lithium fluoride PEMs has been developed. The calibration curves for circular dichroism measurement for the two PEMs investigated in this study are given as examples.

  8. Uniform calibration of night vision goggles and test sets

    NASA Astrophysics Data System (ADS)

    Eppeldauer, George P.

    2007-10-01

    There are orders of magnitude differences between the ~0.1 % (k=2) uncertainty of NIST reference detector calibrations and the uncertainty of night vision (NV) goggle measurements. NIST developed a night vision radiometer calibration facility including NV radiometer transfer standards. The transfer standards, that propagate the radiance responsivity scale to the military primary standards laboratories, are calibrated against a NIST reference radiometer. The reference radiometer has been calibrated on the NIST Spectral Comparator Facility (SCF) for spectral power and irradiance responsivities. Spectral considerations are discussed to lower the uncertainties of the radiance responsivity scale transfer to the test sets and then to the goggles. Since direct determination of the final uncertainties in goggle calibrations and measurements is difficult, models have been made to estimate the most important uncertainty components based on individual spectral measurements of the applied source distributions and radiometer spectral responsivities. It is also shown, that because of source spectral mismatch problems, the goggle measurement uncertainty at applications can be much higher than at calibration. A suggestion is being made to mimic the no-moon (stars only) night sky radiation distribution using several LEDs in the test-sets to decrease the large spectral mismatch errors. A broad-band correction factor has been developed to further decrease calibration uncertainty when the goggles to be used have different spectral responsivities than the standard. Geometrical considerations to optimize the radiance measurement angle and the out-of-target blocking are also discussed to decrease the uncertainty in the radiance responsivity transfer.

  9. Tracing water sources of terrestrial animal populations with stable isotopes: laboratory tests with crickets and spiders.

    PubMed

    McCluney, Kevin E; Sabo, John L

    2010-12-31

    Fluxes of carbon, nitrogen, and water between ecosystem components and organisms have great impacts across levels of biological organization. Although much progress has been made in tracing carbon and nitrogen, difficulty remains in tracing water sources from the ecosystem to animals and among animals (the "water web"). Naturally occurring, non-radioactive isotopes of hydrogen and oxygen in water provide a potential method for tracing water sources. However, using this approach for terrestrial animals is complicated by a change in water isotopes within the body due to differences in activity of heavy and light isotopes during cuticular and transpiratory water losses. Here we present a technique to use stable water isotopes to estimate the mean mix of water sources in a population by sampling a group of sympatric animals over time. Strong correlations between H and O isotopes in the body water of animals collected over time provide linear patterns of enrichment that can be used to predict a mean mix of water sources useful in standard mixing models to determine relative source contribution. Multiple temperature and humidity treatment levels do not greatly alter these relationships, thus having little effect on our ability to estimate this population-level mix of water sources. We show evidence for the validity of using multiple samples of animal body water, collected across time, to estimate the isotopic mix of water sources in a population and more accurately trace water sources. The ability to use isotopes to document patterns of animal water use should be a great asset to biologists globally, especially those studying drylands, droughts, streamside areas, irrigated landscapes, and the effects of climate change.

  10. Tracing Water Sources of Terrestrial Animal Populations with Stable Isotopes: Laboratory Tests with Crickets and Spiders

    PubMed Central

    McCluney, Kevin E.; Sabo, John L.

    2010-01-01

    Fluxes of carbon, nitrogen, and water between ecosystem components and organisms have great impacts across levels of biological organization. Although much progress has been made in tracing carbon and nitrogen, difficulty remains in tracing water sources from the ecosystem to animals and among animals (the “water web”). Naturally occurring, non-radioactive isotopes of hydrogen and oxygen in water provide a potential method for tracing water sources. However, using this approach for terrestrial animals is complicated by a change in water isotopes within the body due to differences in activity of heavy and light isotopes during cuticular and transpiratory water losses. Here we present a technique to use stable water isotopes to estimate the mean mix of water sources in a population by sampling a group of sympatric animals over time. Strong correlations between H and O isotopes in the body water of animals collected over time provide linear patterns of enrichment that can be used to predict a mean mix of water sources useful in standard mixing models to determine relative source contribution. Multiple temperature and humidity treatment levels do not greatly alter these relationships, thus having little effect on our ability to estimate this population-level mix of water sources. We show evidence for the validity of using multiple samples of animal body water, collected across time, to estimate the isotopic mix of water sources in a population and more accurately trace water sources. The ability to use isotopes to document patterns of animal water use should be a great asset to biologists globally, especially those studying drylands, droughts, streamside areas, irrigated landscapes, and the effects of climate change. PMID:21209877

  11. VLBI measurements of radio source positions at the Jet Propulsion Laboratory

    NASA Technical Reports Server (NTRS)

    Purcell, G. H., Jr.; Fanselow, J. L.; Thomas, J. B.; Cohen, E. J.; Rogstad, D. H.; Sovers, O. J.; Skjerve, L. J.; Spitzmesser, D. J.

    1980-01-01

    The results of approximately 1300 observations of 67 radio sources are presented. Most of the measurements were made at the stations of the Deep Space Network in California, Spain, and Australia at wavelengths of 13.1 and 3.6 cm, between 1971 and 1978. The formal errors in the derived source positions are generally in the neighborhood of 0.01 seconds of arc and the positions agree fairly well with those previously published.

  12. Absolute Calibration Accuracy for Hyperspectral Imagers in the Solar Reflective

    NASA Technical Reports Server (NTRS)

    Thome, Kurtis

    2009-01-01

    The characterization and calibration of hyperspectral imagers is a challenging one that is expected to become even more challenging as needs increase for highly-accurate radiometric data from such systems. The preflight calibration of the Advanced Responsive Tactically Effective Military Imaging Spectrometer (ARTEMIS) is used as an example of the difficulties to calibrate hyperspectrally. Results from a preflight solar radiation-based calibration are presented with a discussion of the uncertainties in such a method including the NISI-traceable and SItraceable aspects. Expansion on the concept of solar-based calibration is given with descriptions of methods that view the solar disk directly, illuminate a solar diffuser that is part of the sensor's inflight calibration, and illuminate an external diffuser that is imaged by the sensor. The results of error analysis show that it is feasible to achieve preflight calibration using the sun as a source at the same level of uncertainty as those of lamp-based approaches. The error analysis is evaluated and verified through the solar-radiation-based calibration of several of laboratory grade radiometers. Application of these approaches to NASA's upcoming CLARREO mission are discussed including proposed methods for significantly reducing the uncertainties to allow CLARREO data to be used for climate data records.

  13. Open-source Software for Demand Forecasting of Clinical Laboratory Test Volumes Using Time-series Analysis

    PubMed Central

    Mohammed, Emad A.; Naugler, Christopher

    2017-01-01

    Background: Demand forecasting is the area of predictive analytics devoted to predicting future volumes of services or consumables. Fair understanding and estimation of how demand will vary facilitates the optimal utilization of resources. In a medical laboratory, accurate forecasting of future demand, that is, test volumes, can increase efficiency and facilitate long-term laboratory planning. Importantly, in an era of utilization management initiatives, accurately predicted volumes compared to the realized test volumes can form a precise way to evaluate utilization management initiatives. Laboratory test volumes are often highly amenable to forecasting by time-series models; however, the statistical software needed to do this is generally either expensive or highly technical. Method: In this paper, we describe an open-source web-based software tool for time-series forecasting and explain how to use it as a demand forecasting tool in clinical laboratories to estimate test volumes. Results: This tool has three different models, that is, Holt-Winters multiplicative, Holt-Winters additive, and simple linear regression. Moreover, these models are ranked and the best one is highlighted. Conclusion: This tool will allow anyone with historic test volume data to model future demand.

  14. Application of open-source photogrammetric software MicMac for monitoring surface deformation in laboratory models

    NASA Astrophysics Data System (ADS)

    Galland, Olivier; Bertelsen, Hâvard S.; Guldstrand, Frank; Girod, Luc; Johannessen, Rikke F.; Bjugger, Fanny; Burchardt, Steffi; Mair, Karen

    2016-04-01

    Quantifying deformation is essential in modern laboratory models of geological systems. This paper presents a new laboratory monitoring method through the implementation of the open-source software MicMac, which efficiently implements photogrammetry in Structure-from-Motion algorithms. Critical evaluation is provided using results from two example laboratory geodesy scenarios: magma emplacement and strike-slip faulting. MicMac automatically processes images from synchronized cameras to compute time series of digital elevation models (DEMs) and orthorectified images of model surfaces. MicMac also implements digital image correlation to produce high-resolution displacements maps. The resolution of DEMs and displacement maps corresponds to the pixel size of the processed images. Using 24 MP cameras, the precision of DEMs and displacements is ~0.05 mm on a 40 × 40 cm surface. Processing displacement maps with Matlab® scripts allows automatic fracture mapping on the monitored surfaces. MicMac also offers the possibility to integrate 3-D models of excavated structures with the corresponding surface deformation data. The high resolution and high precision of MicMac results and the ability to generate virtual 3-D models of complex structures make it a very promising tool for quantitative monitoring in laboratory models of geological systems.

  15. The front end test stand high performance H- ion source at Rutherford Appleton Laboratory.

    PubMed

    Faircloth, D C; Lawrie, S; Letchford, A P; Gabor, C; Wise, P; Whitehead, M; Wood, T; Westall, M; Findlay, D; Perkins, M; Savage, P J; Lee, D A; Pozimski, J K

    2010-02-01

    The aim of the front end test stand (FETS) project is to demonstrate that chopped low energy beams of high quality can be produced. FETS consists of a 60 mA Penning Surface Plasma Ion Source, a three solenoid low energy beam transport, a 3 MeV radio frequency quadrupole, a chopper, and a comprehensive suite of diagnostics. This paper details the design and initial performance of the ion source and the laser profile measurement system. Beam current, profile, and emittance measurements are shown for different operating conditions.

  16. The front end test stand high performance H{sup -} ion source at Rutherford Appleton Laboratory

    SciTech Connect

    Faircloth, D. C.; Lawrie, S.; Letchford, A. P.; Gabor, C.; Wise, P.; Whitehead, M.; Wood, T.; Westall, M.; Findlay, D.; Perkins, M.; Savage, P. J.; Lee, D. A.; Pozimski, J. K.

    2010-02-15

    The aim of the front end test stand (FETS) project is to demonstrate that chopped low energy beams of high quality can be produced. FETS consists of a 60 mA Penning Surface Plasma Ion Source, a three solenoid low energy beam transport, a 3 MeV radio frequency quadrupole, a chopper, and a comprehensive suite of diagnostics. This paper details the design and initial performance of the ion source and the laser profile measurement system. Beam current, profile, and emittance measurements are shown for different operating conditions.

  17. Laboratory investigation of flux reduction from dense non-aqueous phase liquid (DNAPL) partial source zone remediation by enhanced dissolution

    NASA Astrophysics Data System (ADS)

    Kaye, Andrew J.; Cho, Jaehyun; Basu, Nandita B.; Chen, Xiaosong; Annable, Michael D.; Jawitz, James W.

    2008-11-01

    This study investigated the benefits of partial removal of dense nonaqueous phase liquid (DNAPL) source zones using enhanced dissolution in eight laboratory scale experiments. The benefits were assessed by characterizing the relationship between reductions in DNAPL mass and the corresponding reduction in contaminant mass flux. Four flushing agents were evaluated in eight controlled laboratory experiments to examine the effects of displacement fluid property contrasts and associated override and underride on contaminant flux reduction ( Rj) vs. mass reduction ( Rm) relationships ( Rj( Rm)): 1) 50% ethanol/50% water (less dense than water), 2) 40% ethyl-lactate/60% water (more dense than water), 3) 18% ethanol/26% ethyl-lactate/56% water (neutrally buoyant), and 4) 2% Tween-80 surfactant (also neutrally buoyant). For each DNAPL architecture evaluated, replicate experiments were conducted where source zone dissolution was conducted with a single flushing event to remove most of the DNAPL from the system, and with multiple shorter-duration floods to determine the path of the Rj( Rm) relationship. All of the single-flushing experiments exhibited similar Rj( Rm) relationships indicating that override and underride effects associated with cosolvents did not significantly affect the remediation performance of the agents. The Rj( Rm) relationship of the multiple injection experiments for the cosolvents with a density contrast with water tended to be less desirable in the sense that there was less Rj for a given Rm. UTCHEM simulations supported the observations from the laboratory experiments and demonstrated the capability of this model to predict Rj( Rm) relationships for non-uniformly distributed NAPL sources.

  18. Laboratory study of the PCB transport from primary sources to building materials

    EPA Science Inventory

    The sorption of airborne polychlorinated biphenyls (PCBs) by twenty building materials and their subsequent re-emission (desorption) from concrete were investigated using two 53-L environmental chambers connected in series with a field-collected caulk in the source chamber servin...

  19. Laboratory Evaluation of Selected Ways for Determining Black Carbon Source Emissions

    EPA Science Inventory

    A number of studies have been conducted which compare various methods for the determination of black carbon in the atmosphere. Relatively little attention has been paid, however, to similar measurements of black carbon from different types of emission sources. Of particular int...

  20. Calibration of high-heat-flux sensors in a solar furnace

    NASA Astrophysics Data System (ADS)

    Ballestrín, J.; Rodríguez-Alonso, M.; Rodríguez, J.; Cañadas, I.; Barbero, F. J.; Langley, L. W.; Barnes, A.

    2006-12-01

    The most common sensors used for the measurement of high solar irradiance are the Gardon gauges, which are usually calibrated using a black body at a certain temperature as the radiant source. This calibration procedure is assumed to produce a systematic error when solar irradiance measurements are taken using these sensors. This paper demonstrates a calorimetric method for calibrating these high-heat-flux gauges in a solar furnace. This procedure has enabled these sensors to be calibrated under concentrated solar radiation at higher irradiances under non-laboratory conditions in the CIEMAT solar furnace at the Plataforma Solar de Almería. Working at higher irradiances has allowed the uncertainty in the calibration constant of these sensors to be reduced. This work experimentally confirms the predicted systematic errors committed when measuring high solar irradiances using Gardon sensors calibrated with a black body.

  1. Comparisons of uniform and discrete source distributions for use in bioassay laboratory performance testing

    SciTech Connect

    Scherpelz, R.I.; MacLellan, J.A.

    1987-09-01

    The Pacific Northwest Laboratory (PNL) is sending a torso phantom with radioactive material uniformly distributed in the lungs to in vivo bioassay laboratories for analysis. Although the radionuclides ultimately chosen for the studies had relatively long half-lives, future accreditation testing will require repeated tests with short half-life test nuclides. Computer modeling was used to simulate the major components of the phantom. Radiation transport calculations were then performed using the computer models to calculate dose rates either 15 cm from the chest or at its surface. For /sup 144/Ce and /sup 60/Co, three configurations were used for the lung comparison tests. Calculations show that, for most detector positions, a single plug containing /sup 40/K located in the back of the heart provides a good approximation to a uniform distribution of /sup 40/K. The approximation would lead, however, to a positive bias for the detector reading if the detector were located at the chest surface near the center. Loading the /sup 40/K in a uniform layer inside the chest wall is not a good approximation of the uniform distribution in the lungs, because most of the radionuclides would be situated close to the detector location and the only shielding would be the thickness of the chest wall. The calculated dose rates for /sup 60/Co and /sup 144/Ce were similar at all calculated reference points. 3 refs., 5 figs., 10 tabs.

  2. Routine habitat change: a source of unrecognized transient alteration of intestinal microbiota in laboratory mice.

    PubMed

    Ma, Betty W; Bokulich, Nicholas A; Castillo, Patricia A; Kananurak, Anchasa; Underwood, Mark A; Mills, David A; Bevins, Charles L

    2012-01-01

    The mammalian intestine harbors a vast, complex and dynamic microbial population, which has profound effects on host nutrition, intestinal function and immune response, as well as influence on physiology outside of the alimentary tract. Imbalance in the composition of the dense colonizing bacterial population can increase susceptibility to various acute and chronic diseases. Valuable insights on the association of the microbiota with disease critically depend on investigation of mouse models. Like in humans, the microbial community in the mouse intestine is relatively stable and resilient, yet can be influenced by environmental factors. An often-overlooked variable in research is basic animal husbandry, which can potentially alter mouse physiology and experimental outcomes. This study examined the effects of common husbandry practices, including food and bedding alterations, as well as facility and cage changes, on the gut microbiota over a short time course of five days using three culture-independent techniques, quantitative PCR, terminal restriction fragment length polymorphism (TRFLP) and next generation sequencing (NGS). This study detected a substantial transient alteration in microbiota after the common practice of a short cross-campus facility transfer, but found no comparable alterations in microbiota within 5 days of switches in common laboratory food or bedding, or following an isolated cage change in mice acclimated to their housing facility. Our results highlight the importance of an acclimation period following even simple transfer of mice between campus facilities, and highlights that occult changes in microbiota should be considered when imposing husbandry variables on laboratory animals.

  3. Multi-modal hard x-ray imaging with a laboratory source using selective reflection from a mirror.

    PubMed

    Pelliccia, Daniele; Paganin, David M

    2014-04-01

    Multi-modal hard x-ray imaging sensitive to absorption, refraction, phase and scattering contrast is demonstrated using a simple setup implemented with a laboratory source. The method is based on selective reflection at the edge of a mirror, aligned to partially reflect a pencil x-ray beam after its interaction with a sample. Quantitative scattering contrast from a test sample is experimentally demonstrated using this method. Multi-modal imaging of a house fly (Musca domestica) is shown as proof of principle of the technique for biological samples.

  4. PROSPECT: Optical Calibration System

    NASA Astrophysics Data System (ADS)

    Trinh, Ken; Prospect Collaboration

    2016-09-01

    The Precision Reactor Oscillation and SPECTrum Experiment (PROSPECT), is a short baseline, reactor neutrino experiment which focuses on measurements of the flux and energy spectrum of antineutrinos emitted from the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Using these measurements, PROSPECT will probe for eV-scale sterile neutrinos while making a high precision measurement of the U-235 antineutrino spectrum. PROSPECT contains two phases; the first phase consists of a mobile detector near the reactor core while the second phase adds a larger fixed detector further from the core. The PROSPECT Phase 1 detector consists of a 2ton optically segmented liquid scintillator with each segment read-out by two photomultiplier tubes (PMTs). The PMTs are calibrated with a photon source generated by a nanosecond pulsed laser. In this project, we developed a plan to determine the effectiveness of a 450nm fiber-pigtailed diode laser as it coupled with several modules including an optical fiber splitter, an optical diffuser, and an attenuator. The project tested for the system ability to deliver light uniformly to each of the cells in the detector. We will present the design and result of this project as well as discuss how it will be implemented in PROSPECT.

  5. Comparison of laboratory calibrations of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) at the beginning and end of the first flight season

    NASA Technical Reports Server (NTRS)

    Vane, Gregg; Chrien, Thomas G.; Reimer, John H.; Green, Robert O.; Conel, James E.

    1988-01-01

    Spectral and radiometric calibrations of AVIRIS are described together with changes in instrument characteristics that occurred during the flight season. These changes include detachment of the optical fibers to two of the four AVIRIS spectrometers, degradation in the optical alignment of the spectrometers due to thermally induced and mechanical warpage, and breakage of a thermal blocking filter in one of the spectrometers. Means of improving the instrument are discussed.

  6. Selection of the appropriate radionuclide source for the efficiency calibration in methods of determining gross alpha activity in water.

    PubMed

    Corbacho, J A; Zapata-García, D; Montaña, M; Fons, J; Camacho, A; Guillén, J; Serrano, I; Baeza, A; Llauradó, M; Vallés, I

    2016-01-01

    Measuring the gross alpha activity in water samples is a rapid, straightforward way of determining whether the water might contain a radionuclide concentration whose consumption would imply a total indicative dose (TID) greater than some reference limit - currently set at 0.1 mSv/y in Europe. There are several methods used for such measurements. Two of them are desiccation with the salts being deposited on a planchet, and coprecipitation. The main advantage of these two methods is their ease of implementation and low cost of preparing the source to measure. However, there is considerable variability in the selection of the most suitable radioactive reference standard against which to calculate the water's gross alpha activity. The goal of this paper is to propose the most appropriate reference radionuclides to use as standards in determining gross alpha activities with these two methods, taking into account the natural radioactive characteristics of a wide range of waters collected at different points in Spain. Thus, the results will be consistent with each other and representative of the sum of alpha activities of all the alpha-emitters contained in a sample.

  7. Psychophysical contrast calibration

    PubMed Central

    To, Long; Woods, Russell L; Goldstein, Robert B; Peli, Eli

    2013-01-01

    Electronic displays and computer systems offer numerous advantages for clinical vision testing. Laboratory and clinical measurements of various functions and in particular of (letter) contrast sensitivity require accurately calibrated display contrast. In the laboratory this is achieved using expensive light meters. We developed and evaluated a novel method that uses only psychophysical responses of a person with normal vision to calibrate the luminance contrast of displays for experimental and clinical applications. Our method combines psychophysical techniques (1) for detection (and thus elimination or reduction) of display saturating nonlinearities; (2) for luminance (gamma function) estimation and linearization without use of a photometer; and (3) to measure without a photometer the luminance ratios of the display’s three color channels that are used in a bit-stealing procedure to expand the luminance resolution of the display. Using a photometer we verified that the calibration achieved with this procedure is accurate for both LCD and CRT displays enabling testing of letter contrast sensitivity to 0.5%. Our visual calibration procedure enables clinical, internet and home implementation and calibration verification of electronic contrast testing. PMID:23643843

  8. Calibration approach and plan for the sea and land surface temperature radiometer

    NASA Astrophysics Data System (ADS)

    Smith, David L.; Nightingale, Tim J.; Mortimer, Hugh; Middleton, Kevin; Edeson, Ruben; Cox, Caroline V.; Mutlow, Chris T.; Maddison, Brian J.; Coppo, Peter

    2014-01-01

    The sea and land surface temperature radiometer (SLSTR) to be flown on the European Space Agency's (ESA) Sentinel-3 mission is a multichannel scanning radiometer that will continue the 21 year dataset of the along-track scanning radiometer (ATSR) series. As its name implies, measurements from SLSTR will be used to retrieve global sea surface temperatures to an uncertainty of <0.3 K traced to international standards. To achieve, these low uncertainties require an end-to-end instrument calibration strategy that includes prelaunch calibration at subsystem and instrument level, on-board calibration systems, and sustained postlaunch activities. The authors describe the preparations for the prelaunch calibration activities, including the spectral response, the instrument level alignment tests, and the solar and infrared radiometric calibrations. A purpose built calibration rig has been designed and built at the Rutherford Appleton Laboratory space department (RAL Space) that will accommodate the SLSTR instrument, the infrared calibration sources, and the alignment equipment. The calibration rig has been commissioned and results of these tests will be presented. Finally, the authors will present the planning for the on-orbit monitoring and calibration activities to ensure that the calibration is maintained. These activities include vicarious calibration techniques that have been developed through previous missions and the deployment of ship-borne radiometers.

  9. Optical design of soft x-ray focusing system with ellipsoidal mirror for laboratory-based sources

    NASA Astrophysics Data System (ADS)

    Motoyama, Hiroto; Saito, Takahiro; Mimura, Hidekazu

    2013-09-01

    The ellipsoidal mirror is one of the most effective achromatic focusing optic with large aperture and nanofocusing ability. Because of the large aperture of mm-order size, this optic is suitable for a laboratory-based light source that has a large divergence angle. Recently, soft X-rays produced by high-order harmonics have become available. Such a beam has high spatial coherency but relatively large divergence angle. This light in combination with an ellipsoidal mirror will generate a highly intense focusing nanobeam that will contribute to various experiments and analyses such as those of photoelectron spectroscopy and nonlinear optical phenomena. In this paper, we present the optical design for a lab-based soft X-ray beamline and the results of optical simulation considering the parameters of the source. Finally, we introduce a two-stage focusing system with an axisymmetric mirror as a promising soft X-ray focusing system.

  10. Initial control of the H sup minus ion source at the Superconducting Super Collider Laboratory

    SciTech Connect

    Martinsen, G.; Acharya, S.; Allen, M.; Faught, E.; Low, K.; Sage, J.

    1991-05-01

    The ion source produces a 30 mA beam of 35 keV H{sup {minus}} ions for SSC accelerators. The beam is chopped at 10 Hz into pulses of 7 to 100 {mu}sec. The ion source presents an opportunity to implement and exercise software tools and techniques which will be useful in future SSC control system. TACL, a software package from the Continuous Electron Beam Accelerator Facility, forms the core of the system. TACL controls several analog channels and monitors interlocks. Emittance measurement control is now under design. In addition to TACL, components of ISTK are also used to interactively acquire and display ion beam information. The integrated system, including VXI and CAMAC acquisition modules attached to a network of heterogeneous computers, is described. 5 refs., 2 figs.

  11. The bedding of laboratory animals as a source of airborne contaminants.

    PubMed

    Kaliste, E; Linnainmaa, M; Meklin, T; Torvinen, E; Nevalainen, A

    2004-01-01

    In work environments with laboratory animals, the bedding of animals binds the excreta as well as other compounds originating from the animals and their environment. These may be generated into the ambient air when the personnel handle bedding in different procedures. This study compares the dustiness of different types of six clean and four soiled beddings from rat or mouse cages. The dust generation of clean bedding varied from <1 to 25 mg/m(3). When used in the cages of rats or mice for 4 days, the dust concentration of the beddings decreased, increased or stayed the same, depending on the type of bedding and animal species. A decrease in dustiness was, however, more common. The levels in the soiled beddings varied from <1 to 8.6 mg/m(3). In the case of the aspen chip bedding, the contents of bedding used in mouse, rat or rabbit cages were analysed for mesophilic bacteria and fungi, mycobacteria and endotoxins. All of these contaminants were variably found in the bedding samples, the maximal concentrations for bacteria were >6 500 000 colony-forming units (cfu)/g, for fungi 212 000 cfu/g, and for endotoxins 6500 ng/g (81 000 EU/g). The results showed that the bedding of laboratory animals may contain biologically effective compounds, and that these may be distributed into the ambient air depending on the characteristics of the bedding material. The dustiness of different bedding types is an important factor affecting the amount and quality of the occupational exposure of the personnel to airborne contaminants.

  12. A comparison of genotoxicity of automotive exhaust particles from laboratory and environmental sources.

    PubMed

    Brooks, A L; Li, A P; Dutcher, J S; Clark, C R; Rothenberg, S J; Kiyoura, R; Bechtold, W E; McClellan, R O

    1984-01-01

    This research (1) ranked the genotoxicity of methylene chloride extracts of laboratory and environmentally collected particles and (2) evaluated the role of collection location and sample composition on genotoxic potency. Samples of exhaust from a spark-ignition automobile, light-duty diesel automobile, and a heavy-duty diesel engine operated in a laboratory on a dynamometer were studied, as well as samples taken in a highway tunnel and outside the same tunnel. The tunnel samples were collected 30 m inside or 56 m outside the exit portal at times when between 70%-95% of the traffic consisted of diesel trucks. In the Ames Salmonella mutagenicity assay, each extract produced a dose-dependent increase in mutagenicity in strain TA-98 without addition of liver S-9 fraction. Extracts from two tunnel samples collected 1 yr apart, and extracts of particles collected outside the tunnel had similar mutagenic activity. The order of mutagenic activity per microgram of extract in TA-98 without S-9 from the lowest to the highest was environmental sample less than or equal to tunnel less than heavy-duty diesel less than light-duty diesel less than spark ignition. Addition of S-9 or testing in Salmonella strains resistant to the mutagenicity of nitroaromatic compounds (TA-98 NR and TA-98 1,8-DNP6) decreased the mutagenic response. With cell killing, sister chromatid exchanges, and mutations as endpoints in Chinese hamster ovary cells (CHO), the order of potency was tunnel less than light-duty less than spark-ignition samples. All three extracts induced a similar amount of mitotic delay per microgram with or without S-9. Enhanced chromosome aberration frequency was detected only in cells exposed to extracts from spark-ignition exhaust. The data indicated that genotoxic activity was detected in each particle extract, that the potency ranking was similar using different genetic endpoints, and that the magnitude of the genotoxic potency was similar.

  13. A variable acceleration calibration system

    NASA Astrophysics Data System (ADS)

    Johnson, Thomas H.

    2011-12-01

    A variable acceleration calibration system that applies loads using gravitational and centripetal acceleration serves as an alternative, efficient and cost effective method for calibrating internal wind tunnel force balances. Two proof-of-concept variable acceleration calibration systems are designed, fabricated and tested. The NASA UT-36 force balance served as the test balance for the calibration experiments. The variable acceleration calibration systems are shown to be capable of performing three component calibration experiments with an approximate applied load error on the order of 1% of the full scale calibration loads. Sources of error are indentified using experimental design methods and a propagation of uncertainty analysis. Three types of uncertainty are indentified for the systems and are attributed to prediction error, calibration error and pure error. Angular velocity uncertainty is shown to be the largest indentified source of prediction error. The calibration uncertainties using a production variable acceleration based system are shown to be potentially equivalent to current methods. The production quality system can be realized using lighter materials and a more precise instrumentation. Further research is needed to account for balance deflection, forcing effects due to vibration, and large tare loads. A gyroscope measurement technique is shown to be capable of resolving the balance deflection angle calculation. Long term research objectives include a demonstration of a six degree of freedom calibration, and a large capacity balance calibration.

  14. Fitness components of Drosophila melanogaster developed on a standard laboratory diet or a typical natural food source.

    PubMed

    Kristensen, Torsten Nygaard; Henningsen, Astrid Kallestrup; Aastrup, Christian; Bech-Hansen, Mads; Bjerre, Lise B Hoberg; Carlsen, Benjamin; Hagstrup, Marie; Jensen, Sofie Graarup; Karlsen, Pernille; Kristensen, Line; Lundsgaard, Cecillie; Møller, Tine; Nielsen, Lise D; Starcke, Camilla; Sørensen, Christine Riisager; Schou, Mads Fristrup

    2016-10-01

    Drosophila melanogaster is often used as a model organism in evolutionary biology and ecophysiology to study evolutionary processes and their physiological mechanisms. Diets used to feed Drosophila cultures differ between laboratories and are often nutritious and distinct from food sources in the natural habitat. Here we rear D. melanogaster on a standard diet used in our laboratory and a field diet composed of decomposing apples collected in the field. Flies developed on these two diet compositions are tested for heat, cold, desiccation, and starvation resistance as well as developmental time, dry body mass and fat percentage. The nutritional compositions of the standard and field diets were analyzed, and discussed in relation to the phenotypic observations. Results showed marked differences in phenotype of flies from the two types of diets. Flies reared on the field diet are more starvation resistant and they are smaller, leaner, and have lower heat resistance compared to flies reared on the standard diet. Sex specific effects of diet type are observed for several of the investigated traits and the strong sexual dimorphism usually observed in desiccation resistance in D. melanogaster disappeared when rearing the flies on the field diet. Based on our results we conclude that care should be taken in extrapolating results from one type of diet to another and especially from laboratory to field diets.

  15. The Planck List of High-z source candidates: A laboratory for high-z star-forming galaxies

    NASA Astrophysics Data System (ADS)

    Montier, L.

    The Planck satellite (Planck 2015 results. I) has provided the first FIR/submm all-sky survey with a sensitivity allowing us to identify the rarest, most luminous hig-z dusty star-forming sources on the sky. The Planck list of high-z source candidates (PHZ, PIP XXXIX subm) has been built and charcaterized over 25% of the sky by selecting the 2151 brightest red submm sources at a 5' resolution (Montier et al. 2010). Follow-up observations with Herschel/SPIRE over 228 Planck candidates have already shown that 93% of these candidates are actually overdensities of red sources (PIP XXVII 2015), while 12 Planck high-z candidates are identified as strongly lensed star-forming galaxies at redshift between 2.2 and 3.6 (Canameras et al. 2015). The first confirmed Planck proto-cluster candidate has been revealed to be a double structure at z = 1.7 and zz = 2.03 (Flores-Cacho et al. 2015). The PHZ opens a new window on these extreme star-forming systems at high-z, providing a powerful laboratory to study the mechanisms of galaxy evolution and enrichment in the frame of the large scale structure growth.

  16. Potential for a Near Term Very Low Energy Antiproton Source at Brookhaven National Laboratory.

    DTIC Science & Technology

    1989-04-01

    Source; Beam 0 07 Deceleration; Antiproton Production Rates - I)= 20 08 19. ABSTRACT (Continue on reverse if necessary and identify by block number) 7...CLASSIFICATION rIUNCLASSIFIED/UNLIMITED 0 SAME AS RPT. 03 DTIC USERS Unclassified 22a. NAME OF RESPONSIBLE INDIVIDUAL 22b. TELEPHONE (Include Area Code) 22c...1979) 13F/i1.5 x1 0 PROTONS (Collected at 3.5 GeV/c) WITHOUR COOLING 108 07 1 6 I 102 0 T (MeV) 4 BNL- 39142 AGSIAD/ 87-1 AGS SUPERCONDUCTING

  17. Target designs for the Brookhaven National Laboratory 5-MW pulsed spallation neutron source

    SciTech Connect

    Ludewig, H.; Todosow, M.; Powell, J.R.

    1996-03-01

    A feasibility study of a compact high power density target for a spallation neutron source was under-taken. The target arrangement consists primarily of heavy metal, with appropriate cooling passages. A high intensity proton beam of intermediate energy is directed at the target, where it interacts with the heavy metal nuclei. The subsequent spallation reactions produce several neutrons per proton resulting in an intense neutron source. The proton beam is assumed to havean energy of 5 MW, and to be cyclic with a repetition rate of 10Hz and 50Hz. The study was divided into two broad sections. First, an analysis of preliminary target designs was undertaken to ensure the overall feasibility of the concepts involved in the design and eventual construction of such a high power density target. Second, two proposed target designs, based on the first set of analyses, are investigated in more detail. Special care is taken to ensure that the neutron fluxes in the moderator are at the desired level no material compatibility problems exist,and the target is able to operate in a reliable and safe manner. Several target materials, coolant types, and target arrangements are investigated in the first section. The second section concentrates on a single target material and geometric arrangement. However, several structural material choices continue to be investigated with the aim of minimizing the effects of structural heating, and associated thermally induced stresses. In the final section the conclusions of this preliminary study are summarized.

  18. Absorption and Phase Contrast X-Ray Imaging in Paleontology Using Laboratory and Synchrotron Sources.

    PubMed

    Bidola, Pidassa; Stockmar, Marco; Achterhold, Klaus; Pfeiffer, Franz; Pacheco, Mírian L A F; Soriano, Carmen; Beckmann, Felix; Herzen, Julia

    2015-10-01

    X-ray micro-computed tomography (μCT) is commonly used for imaging of samples in biomedical or materials science research. Owing to the ability to visualize a sample in a nondestructive way, X-ray μCT is perfectly suited to inspect fossilized specimens, which are mostly unique or rare. In certain regions of the world where important sedimentation events occurred in the Precambrian geological time, several fossilized animals are studied to understand questions related to their origin, environment, and life evolution. This article demonstrates the advantages of applying absorption and phase-contrast CT on the enigmatic fossil Corumbella werneri, one of the oldest known animals capable of building hard parts, originally discovered in Corumbá (Brazil). Different tomographic setups were tested to visualize the fossilized inner structures: a commercial laboratory-based μCT device, two synchrotron-based imaging setups using conventional absorption and propagation-based phase contrast, and a commercial X-ray microscope with a lens-coupled detector system, dedicated for radiography and tomography. Based on our results we discuss the strengths and weaknesses of the different imaging setups for paleontological studies.

  19. Absorption and Phase Contrast X-Ray Imaging in Paleontology Using Laboratory and Synchrotron Sources

    SciTech Connect

    Bidola, Pidassa; Stockmar, Marco; Achterhold, Klaus; Pfeiffer, Franz; Pacheco, Mirian L.A.F.; Soriano, Carmen; Beckmann, Felix; Herzen, Julia

    2015-10-01

    X-ray micro-computed tomography (CT) is commonly used for imaging of samples in biomedical or materials science research. Owing to the ability to visualize a sample in a nondestructive way, X-ray CT is perfectly suited to inspect fossilized specimens, which are mostly unique or rare. In certain regions of the world where important sedimentation events occurred in the Precambrian geological time, several fossilized animals are studied to understand questions related to their origin, environment, and life evolution. This article demonstrates the advantages of applying absorption and phase-contrast CT on the enigmatic fossil Corumbella werneri, one of the oldest known animals capable of building hard parts, originally discovered in Corumba (Brazil). Different tomographic setups were tested to visualize the fossilized inner structures: a commercial laboratory-based CT device, two synchrotron-based imaging setups using conventional absorption and propagation-based phase contrast, and a commercial X-ray microscope with a lens-coupled detector system, dedicated for radiography and tomography. Based on our results we discuss the strengths and weaknesses of the different imaging setups for paleontological studies.

  20. Mars Science Laboratory with Power Source and Extended Arm, Artist's Concept

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Mars Science Laboratory, a mobile robot for investigating Mars' past or present ability to sustain microbial life, is in development for a launch opportunity in 2009. This picture is an artist's concept portraying what the advanced rover would look like in Martian terrain, from a side aft angle.

    The arm extending from the front of the rover is designed both to position some of the rover's instruments onto selected rocks or soil targets and also to collect samples for analysis by other instruments. Near the base of the arm is a sample preparation and handling system designed to grind samples, such as rock cores or small pebbles, and distribute the material to analytical instruments.

    The mast, rising to about 2.1 meters (6.9 feet) above ground level, supports two remote-sensing instruments: the Mast Camera for stereo color viewing of surrounding terrain and material collected by the arm, and the ChemCam for analyzing the types of atoms in material that laser pulses have vaporized from rocks or soil targets up to about 9 meters (30 feet) away.