TY  - JOUR
A1  - Mellinger, Axel
A1  - Singh, Rajeev
A1  - Gerhard, Reimund
T1  - Fast thermal-pulse measurements of space-charge distributions in electret polymers
N2  - Space-charge depth profiles in various electret polymers have been measured in both the time and the frequency domain using thermal pulses and waves, respectively. A comparison of the two techniques on corona-charged polytetrafluoroethylene showed that the thermal-pulse method yielded similar results as the thermal-wave technique, but approximately 20-50 times faster. The article discusses sensitivity limitations as well as possible applications, including the real-time monitoring of space-charge decay under UV irradiation. (C) 2005 American Institute of Physics
Y1  - 2005
SN  - 0034-6748
ER  - 
TY  - JOUR
A1  - Mellinger, Axel
A1  - Singh, Rajeev
A1  - Wegener, Michael
A1  - Wirges, Werner
A1  - Gerhard, Reimund
A1  - Lang, Sidney B.
T1  - Three-dimensional mapping of polarization profiles with thermal pulses
N2  - High-resolution, large-area three-dimensional mapping of polarization profiles in electret polymers was carried out by means of a fast thermal pulse technique with a focused laser beam. A lateral resolution of 38 mu m and a near- surface depth resolution of less than 0.5 mu m was achieved. At larger depths, fast thermal diffusion in the metal electrode rather than the laser spot size becomes the limiting factor for the lateral resolution. (c) 2005 American Institute of Physics
Y1  - 2005
SN  - 0003-6951
ER  - 
TY  - JOUR
A1  - Mellinger, Axel
A1  - Flores Suárez, Rosaura
A1  - Singh, Rajeev
A1  - Wegener, Michael
A1  - Wirges, Werner
A1  - Lang, Sidney B.
A1  - Gerhard, Reimund
T1  - High-resolution space-charge and polarization tomography with thermal pulses
N2  - Die Arbeit wurde am 13.03.2006 mit dem "BEST PAPER AWARD" des deutschen IEEE Instrumentation and Measurement (I&M) Chapter ausgezeichnet.
Y1  - 2006
SN  - 3-8007-2939-3
ER  - 
TY  - JOUR
A1  - Flores Suárez, Rosaura
A1  - Mellinger, Axel
A1  - Wegener, Michael
A1  - Wirges, Werner
A1  - Gerhard, Reimund
A1  - Singh, Rajeev
T1  - Thermal-pulse tomography of polarization distributions in a cylindrical geometry
JF  - IEEE transactions on dielectrics and electrical insulation
N2  - Fast, three-dimensional polarization mapping in piezoelectric sensor cables was performed by means of the novel thermal-pulse tomography (TPT) technique with a lateral resolution of 200 mum. The active piezoelectric cable material (a copolymer of polyvinylidene fluoride with trifluoroethylene) was electrically poled with a point-to-cable corona discharge. A focused laser was employed to heat the opaque outer electrode, and the short-circuit current generated by the thermal pulse was used to obtain 3D polarization maps via the scale transformation method. The article describes the TPT technique as a fast non-destructive option for studying cylindrical geometries.
Y1  - 2006
U6  - https://doi.org/10.1109/TDEI.2006.258210
SN  - 1070-9878
VL  - 13
IS  - 5
SP  - 1030
EP  - 1035
PB  - IEEE
CY  - Piscataway
ER  - 
TY  - JOUR
A1  - Mellinger, Axel
A1  - Flores Suárez, Rosaura
A1  - Singh, Rajeev
A1  - Wegener, Michael
A1  - Wirges, Werner
A1  - Gerhard, Reimund
T1  - Zerstörungsfreie Tomographie von Raumladungs- und Polarisationsverteilungen mittles Wärmepulsen
N2  - Non-destructive, three-dimensional imaging of space-charge and polarization distributions in electret materials has been implemented by means of laser-induced thermal pulses. In pyroelectric films of poled poly(vinylidene fluoride), images of up to 45 x 45 pixels with a depth resolution of less than 0.5 mu m and a lateral resolution of 40 mu m were recorded, the latter being limited by fast thermal diffusion in the absorbing metallic front electrode. Initial applications include the analysis of polarization distributions in corona-poled piezoelectric sensor cables and the detection of patterned space-charge distributions in polytetrafluoroethylene films.
Y1  - 2007
UR  - http://www.oldenbourg-link.com/loi/teme
U6  - https://doi.org/10.1524/teme.2007.74.9.437
SN  - 0171-8096
ER  - 
TY  - JOUR
A1  - Singh, Rajeev
A1  - Mellinger, Axel
T1  - Measurement of through-thickness thermal diffusivity of thermoplastics using thermal wave method
JF  - Indian journal of physics
N2  - Thermo-physical properties, such as thermal conductivity, thermal diffusivity and specific heat are important quantities that are needed to interpret and characterize thermoplastic materials. Such characterization is necessary for many applications, ranging from aerospace engineering to food packaging, electrical and electronic industry and medical science. In this work, the thermal diffusivity of commercially available polymeric films is measured in the thickness direction at room temperature using thermal wave method. The results obtained with this method are in good agreement with theoretical and experimental values.
KW  - Thermoplastics
KW  - Thermal diffusivity
KW  - Thermal wave method
KW  - Polymer
Y1  - 2015
U6  - https://doi.org/10.1007/s12648-014-0579-2
SN  - 0973-1458
SN  - 0974-9845
VL  - 89
IS  - 4
SP  - 361
EP  - 368
PB  - Indian Association for the Cultivation of Science
CY  - Kolkata
ER  -