Determination of conductivity parameters of dielectrics used in space applications

Bielby, R.M.; Morris, P. A.; Ryden, K.A.; Rodgers, D.; Sorensen, J.

doi:10.1109/icsd.2004.1350585

Cited by 5 publications

(3 citation statements)

References 1 publication

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“…The FR4 has a dark current resistivity of ~1×10 18 Ω-cm, between that of the other two samples; this is evident in the intermediate dark current decay constant τ DC~5 days and in the modest decay of free charge predicted in Figure 5b. Measurements with a different technique on a similar FR4 spacecraft material found a dark current resistivity of ~2.12×10 17 Ω-cm [35], a factor of ~5 less than our measured ρ DC . (ii) Fiber filled PTFE samples exhibited little polarization current and had a very high dark current resistivity of ~3×10 20 Ω-cm, with a dark current decay constant τ DC~1 yr.…”

Section: B Charge Storage Methods Test Resultscontrasting

confidence: 60%

Methods for High Resistivity Measurements Related to Spacecraft-Charging

Dennison

Brunson

Swaminathan

et al. 2006

IEEE Trans. Plasma Sci.

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A key parameter in modeling differential spacecraft charging is the resistivity of insulating materials. This parameter determines how charge will accumulate and redistribute across the spacecraft, as well as the time scale for charge transport and dissipation. ASTM constant voltage methods are shown to provide inaccurate resistivity measurements for materials with resistivities greater than ~10 17 Ω-cm or with long polarization decay times such as are found in many polymers. These data have been shown to often be inappropriate for spacecraft charging applications, and have been found to underestimate charging effects by one to four orders of magnitude for many materials. The charge storage decay method is shown to be the preferred method to determine the resistivities of such highly insulating materials. A review is presented of methods to measure the resistivity of highly insulating materials-including the electrometerresistance method, the electrometer-constant voltage method, and the charge storage method. The different methods are found to be appropriate for different resistivity ranges and for different charging circumstances. A simple, macroscopic, physics-based model of these methods allows separation of the polarization current and dark current components from long duration measurements of resistivity over day-to month-long time scales. Model parameters are directly related to the magnitude of charge transfer and storage and the rate of charge transport. The model largely explains the observed differences in resistivity found using the different methods and provides a framework for recommendations for the appropriate test method for spacecraft materials with different resistivities and applications..

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Section: B Charge Storage Methods Test Resultscontrasting

confidence: 60%

Methods for High Resistivity Measurements Related to Spacecraft-Charging

Dennison

Brunson

Swaminathan

et al. 2006

IEEE Trans. Plasma Sci.

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“…Comparison of the measured ρ DC to an ASTM standard value is not meaningful; the ASTM value listed [16] was not for the specific material tested but was rather from the FR4 standards [17], [18] that only specifies that ρ ASTM not be less than 10 9 Ω-cm. Measurements with a different technique on a similar FR4 spacecraft material found a dark current resistivity of ~2.12×10 17 Ω-cm [19], a factor of ~5 less than our measured ρ DC .…”

Section: B Fr4 Charge Decaycontrasting

confidence: 67%

Experimentally Derived Resistivity for Dielectric Samples From the CRRES Internal Discharge Monitor

Green

Frederickson

Dennison

2006

IEEE Trans. Plasma Sci.

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Resistivity values were experimentally determined using charge storage methods for six samples remaining from the construction of the Internal Discharge Monitor (IDM) flown on the Combined Release and Radiation Effects Satellite (CRRES). Three tests were performed over a period of three to five weeks each in a vacuum of ~5×10-6 torr with an average temperature of ~25 ºC to simulate a space environment. Samples tested included FR4, PTFE, and alumina with copper electrodes attached to one or more of the sample surfaces. FR4 circuit board material was found to have a dark current resistivity of ~1×10 18 Ω-cm and a moderately high polarization current. Fiber filled PTFE exhibited little polarization current and a dark current resistivity of ~3×10 20 Ω-cm. Alumina had a measured dark current resistivity of ~3•10 17 Ω-cm, with a very large and more rapid polarization. Experimentally determined resistivity values were two to three orders of magnitude more than found using standard ASTM test methods. The one minute wait time suggested for the standard ASTM tests is much shorter than the measured polarization current decay times for each sample indicating that the primary currents used to determine ASTM resistivity are caused by the polarization of molecules in the applied electric field rather than charge transport through the bulk of the dielectric. Testing over much longer periods of time in vacuum is required to allow this polarization current to decay away and to allow the observation of charged particles transport through a dielectric material. Application of a simple physicsbased model allows separation of the polarization current and dark current components from long duration measurements of resistivity over day-to month-long time scales. Model parameters are directly related to the magnitude of charge transfer and storage and the rate of charge transport.

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“…Equation (3) shows the relation between the field and potential. Equation (4) is conductivity mode [1], [6]- [10]. Equation (5) denotes that RIC rises with dose rate converted from energy deposition, which is computed directly by ATICS.…”

Section: B Electric Field Computationmentioning

confidence: 99%

A 3-dimensional model of internal charging simulation

Tang

Zhong

Zhang

et al. 2013

2013 14th European Conference on Radiation and Its Effects on Components and Systems (RADECS)

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To break through the limitation of the traditional 1-dimensional (1-D) method of internal charging computation, a 3-D calculation model of internal electric field and potential for arbitrary configuration dielectric with complex boundary conditions is developed. It includes two steps: 3-D electron transport simulation and internal electric field computation. The transport simulation, which aims for obtaining electron deposition and dose rate distribution, is implemented by a self-developed software founded on GEANT4. And the calculation of 3-D internal electric field, which takes above transport results as input, is conducted through solving a set of electrostatic equations by the software COMSOL Multiphysics. In this paper, this 3-D simulation model applied to a typical printed circuit board grounded on a rectangular circuit and cylindrical pin will be presented. For purpose of comparison, a simpler 1-D planar dielectric wholly grounded on the back surface is simulated in the same method. Finally, the electric field computed by the 3-D algorithm is much larger than the 1-D simplified method widely used at present and hence the 1-D method may neglect crucial risk. Besides, the following conclusions are drawn: grounding has significant influence on electric field distribution, and the maximum field generally occurs at grounding edges or corners. Increasing the curvature radius of the circuit corner can reduce the field and the discharge risk.Index Terms -3-D simulation, internal charging, internal electric field, GEANT4

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Determination of conductivity parameters of dielectrics used in space applications

Cited by 5 publications

References 1 publication

Methods for High Resistivity Measurements Related to Spacecraft-Charging

Methods for High Resistivity Measurements Related to Spacecraft-Charging

Experimentally Derived Resistivity for Dielectric Samples From the CRRES Internal Discharge Monitor

A 3-dimensional model of internal charging simulation

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