ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Shake-off effects on the production and decay of hollow ions (1992)
    Springer
    The European physical journal 25 (1992), S. 31-39 
    Details
    ISSN: 1434-6079
    Keywords: 32.80.H ; 82.80.P ; 32.30.R
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract An improved form of the radiative-Auger-cascade model is presented in which the shake-off contribution is incorporated into the model in a mathematically consistent way, avoiding the problem of double counting. The higher charge state distribution found in the photoionization experiment of the 1s electron in Ne is shown to be predominantly due to the shake-off effect during the formation of the 1s hole, and not during the cascade decays as previously assumed. This shake-off contribution is estimated in the sudden approximation, in terms of overlaps between the neutral and singly ionized ions. An excellent agreement with experiment is obtained in the case of Ne+ with 1s hole. The details of the X-ray and Auger spectra are also predicted by the new model both for the Ne and Mg ions. The shake-off effect on the resonant processes in general is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01437517
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Final charge state distribution in the production and decay of hollow Ar (1992)
    Springer
    The European physical journal 25 (1992), S. 41-46 
    Details
    ISSN: 1434-6079
    Keywords: 32.80.H ; 82.80.P ; 32.30.R
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The improved model of radiative-Auger-cascade with shake-off effect is applied to calculate the final charge state distribution and the X-ray and Auger electron spectra emitted during the cascade decay of Ar, with the initial 1s hole created by the synchrotron irradiation. The discrepancy in the predicted charge distribution without the shake-off effect is removed. It was found that the discrepancy was caused mainly by the neglect of the shake-off effect during the productin stage of the 1s hole, and not by the shake-off effect during the decay of the 1s hole. The X-ray and Auger spectra predicted by the improved model are compared with that without the shake-off. The charge distributions resulting from a 2s or 2p initial hole are also presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01437518
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    facet.materialart.
    Unknown
    Design of a Uranium Dioxide Spheroidization System (2013)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: The plasma spheroidization system (PSS) is the first process in the development of tungsten-uranium dioxide (W-UO2) fuel cermets. The PSS process improves particle spherocity and surface morphology for coating by chemical vapor deposition (CVD) process. Angular fully dense particles melt in an argon-hydrogen plasma jet at between 32-36 kW, and become spherical due to surface tension. Surrogate CeO2 powder was used in place of UO2 for system and process parameter development. Particles range in size from 100 - 50 microns in diameter. Student s t-test and hypothesis testing of two proportions statistical methods were applied to characterize and compare the spherocity of pre and post process powders. Particle spherocity was determined by irregularity parameter. Processed powders show great than 800% increase in the number of spherical particles over the stock powder with the mean spherocity only mildly improved. It is recommended that powders be processed two-three times in order to reach the desired spherocity, and that process parameters be optimized for a more narrow particles size range. Keywords: spherocity, spheroidization, plasma, uranium-dioxide, cermet, nuclear, propulsion
    Keywords: Spacecraft Propulsion and Power
    Type: M13-2411 , Nuclear and Emerging Technologies for Space (NETS) 2013; Feb 25, 2013 - Feb 28, 2013; Albuquerque; New Mexico
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Nuclear Cryogenic Propulsion Stage Fuel Design and Fabrication (2012)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Nuclear Cryogenic Propulsion Stage (NCPS) is a game changing technology for space exploration. Goal of assessing the affordability and viability of an NCPS includes these overall tasks: (1) Pre-conceptual design of the NCPS and architecture integration (2) NCPS Fuel Design and Testing (3) Nuclear Thermal Rocket Element Environmental Simulator (NTREES) (4) Affordable NCPS Development and Qualification Strategy (5) Second Generation NCPS Concepts. There is a critical need for fuels development. Fuel task objectives are to demonstrate capabilities and critical technologies using full scale element fabrication and testing.
    Keywords: Spacecraft Propulsion and Power
    Type: M12-1639 , Nuclear and Emerging Technologies for Space (NETS); Mar 21, 2012 - Mar 23, 2012; Houston, TX; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Fabrication and Testing of CERMET Fuel Materials for Nuclear Thermal Propulsion (2012)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: A first generation Nuclear Cryogenic Propulsion Stage (NCPS) based on Nuclear Thermal Propulsion (NTP) is currently being developed for Advanced Space Exploration Systems. The overall goal of the project is to address critical NTP technology challenges and programmatic issues to establish confidence in the affordability and viability of NTP systems. The current technology roadmap for NTP identifies the development of a robust fuel form as a critical near term need. The lack of a qualified nuclear fuel is a significant technical risk that will require a considerable fraction of program resources to mitigate. Due to these risks and the cost for qualification, the development and selection of a primary fuel must begin prior to Authority to Proceed (ATP) for a specific mission. The fuel development is a progressive approach to incrementally reduce risk, converge the fuel materials, and mature the design and fabrication process of the fuel element. A key objective of the current project is to advance the maturity of CERMET fuels. The work includes fuel processing development and characterization, fuel specimen hot hydrogen screening, and prototypic fuel element testing. Early fuel materials development is critical to help validate requirements and fuel performance. The purpose of this paper is to provide an overview and status of the work at Marshall Space Flight Center (MSFC).
    Keywords: Spacecraft Propulsion and Power
    Type: M12-2019 , AIAA Joint Propulsion Conference 2012; Jul 30, 2012 - Aug 01, 2012; Atlanta, GA; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    The Manufacture of W-UO2 Fuel Elements for NTP Using the Hot Isostatic Pressing Consolidation Process (2012)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: NTP is attractive for space exploration because: (1) Higher Isp than traditional chemical rockets (2)Shorter trip times (3) Reduced propellant mass (4) Increased payload. Lack of qualified fuel material is a key risk (cost, schedule, and performance). Development of stable fuel form is a critical path, long lead activity. Goals of this project are: Mature CERMET and Graphite based fuel materials and Develop and demonstrate critical technologies and capabilities.
    Keywords: Spacecraft Propulsion and Power
    Type: M12-1641 , Nuclear and Emerging Technologies for Space (NETS); Mar 21, 2012 - Mar 23, 2012; The Woodlands, TX; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Nuclear Cryogenic Propulsion Stage Fuel Design and Fabrication (2012)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Nuclear Cryogenic Propulsion Stage (NCPS) is a game changing technology for space exploration. Goal of assessing the affordability and viability of an NCPS includes thses overall tasks: (1) Pre-conceptual design of the NCPS and architecture integration (2) NCPS Fuel Design and Testing (3) Nuclear Thermal Rocket Element Environmental Simulator (NTREES) (4) Affordable NCPS Development and Qualification Strategy (5) Second Generation NCPS Concepts. There is a critical need for fuels development. Fuel task objectives are to demonstrate capabilities and critical technologies using full scale element fabrication and testing.
    Keywords: Spacecraft Propulsion and Power
    Type: M12-1639 , Nuclear and Emerging Technologies for Space (NETS); Mar 21, 2012 - Mar 23, 2012; Houston, TX; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    Radiation Specifications for Fission Power Conversion Component Materials (2011)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: NASA has been supporting design studies and technology development that could provide power to an outpost on the moon, Mars, or an asteroid. One power-generation system that is independent of sunlight or power-storage limitations is a fission-based power plant. There is a wealth of terrestrial system heritage that can be transferred to the design and fabrication of a fission power system for space missions, but there are certain design aspects that require qualification. The radiation tolerance of the power conversion system requires scrutiny because the compact nature of a space power plant restricts the dose reduction methodologies compared to those used in terrestrial systems. An integrated research program has been conducted to establish the radiation tolerance of power conversion system-component materials. The radiation limit specifications proposed for a Fission Power System power convertor is 10 Mrad ionizing dose and 5 x 10(exp 14) neutron per square centimeter fluence for a convertor operating at 150 C. Specific component materials and their radiation tolerances are discussed. This assessment is for the power convertor hardware; electronic components are not covered here.
    Keywords: Spacecraft Propulsion and Power
    Type: NASA/TM-2011-216996 , NETS -2011-3505 , E-17657 , Nuclear and Emerging Technologies for Space (NETS 2011); Feb 07, 2011 - Feb 10, 2011; Albuquerque, NM; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...