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Articles 1 - 4 of 4
Full-Text Articles in Biomedical Engineering and Bioengineering
Cherenkov Excited Short-Wavelength Infrared Fluorescence Imaging In Vivo With External Beam Radiation, Xu Cao, Shudong Jiang, Mengyu Jeremy Jia, Jason R. Gunn, Tianshun Miao, Scott C. Davis, Petr Bruza, Brian W. Pogue
Cherenkov Excited Short-Wavelength Infrared Fluorescence Imaging In Vivo With External Beam Radiation, Xu Cao, Shudong Jiang, Mengyu Jeremy Jia, Jason R. Gunn, Tianshun Miao, Scott C. Davis, Petr Bruza, Brian W. Pogue
Dartmouth Scholarship
Cherenkov emission induced by external beam radiation therapy from a clinical linear accelerator (LINAC) can be used to excite phosphors deep in biological tissues. As with all luminescence imaging, there is a desire to minimize the spectral overlap between the excitation light and emission wavelengths, here between the Cherenkov and the phosphor. Cherenkov excited short-wavelength infrared (SWIR, 1000 to 1700 nm) fluorescence imaging has been demonstrated for the first time, using long Stokes-shift fluorophore PdSe quantum dots (QD) with nanosecond lifetime and an optimized SWIR detection. The 1 / λ2 intensity spectrum characteristic of Cherenkov emission leads to low overlap …
Spectroscopic Separation Of Čerenkov Radiation In High-Resolution Radiation Fiber Dosimeters, Arash Darafsheh, Rongxiao Zhang, Stephen Chad Kanick, Brian W. Pogue, Jarod C. Finlay
Spectroscopic Separation Of Čerenkov Radiation In High-Resolution Radiation Fiber Dosimeters, Arash Darafsheh, Rongxiao Zhang, Stephen Chad Kanick, Brian W. Pogue, Jarod C. Finlay
Dartmouth Scholarship
We have investigated Čerenkov radiation generated in phosphor-based optical fiber dosimeters irradiated with clinical electron beams. We fabricated two high-spatial resolution fiber-optic probes, with 200 and 400 μm core diameters, composed of terbium-based phosphor tips. A generalizable spectroscopic method was used to separate Čerenkov radiation from the transmitted signal by the fiber based on the assumption that the recorded signal is a linear superposition of two basis spectra: characteristic luminescence of the phosphor medium and Čerenkov radiation. We performed Monte Carlo simulations of the Čerenkov radiation generated in the fiber and found a strong dependence of the recorded Čerenkov …
Electron Beam Effects In The Analysis Of Compound Semiconductors And Devices, Nancy Burnham, Ll Kazmerski, Ab Swartzlander, Aj Nelson, Se Asher
Electron Beam Effects In The Analysis Of Compound Semiconductors And Devices, Nancy Burnham, Ll Kazmerski, Ab Swartzlander, Aj Nelson, Se Asher
Nancy A. Burnham
The effects of electron beams on the analysis of CuInSe2surfaces are examined in this paper. Potential changes in the surface chemistry—including oxidation and desorption—under a range of incident probe conditions, are investigated for possible artifactual information generation. Emphasis is placed on the relationships between beam conditions and oxygen chemisorption and physisorption, since oxygen treatments of devices utilizing this semiconductor are critical to performance. Single crystals and polycrystalline thin films are analyzed and compared to establish the beam‐induced phenomena.
Scanning Auger Microprobe Studies Of Ball Cratered Cds/Cuinse2 Solar Cells, Nancy Burnham, Ll Levenson, Rj Matson, R Noufi, Ll Kazmerski
Scanning Auger Microprobe Studies Of Ball Cratered Cds/Cuinse2 Solar Cells, Nancy Burnham, Ll Levenson, Rj Matson, R Noufi, Ll Kazmerski
Nancy A. Burnham
CdS/CuInSe2solar cell films are typically several micrometers thick. Composition profiles of these films are usually carried out on fracture cross sections by scanning Auger microscopy or by recording Auger spectra during ion milling. For fracture cross sections, the depth resolution depends on the electron beam diameter and the roughness of the fracture surface. Ion milling is time consuming, and artifacts are caused by ion beam faceting. Ball cratering requires only a fraction of an hour and provides significant magnification of the film cross section. There is sufficient contrast, both in optical and electron microscopy, to distinguish between CdS and CuInSe2 …