12 Matching Results

Search Results

Advanced search parameters have been applied.
in creator/contributor: "Cahoon, J."  
Results: 1 - 12
open access

Imaging properties of a positron tomograph with 280 BGO crystals

Description: The basic imaging properties of the Donner 280-BGO-Crystal positron tomograph were measured and compared with the same system when it was equipped with 280 NaI(T1) crystals. The NaI(T1) crystals were 8 mm x 30 mm x 50 mm deep, sealed in 10 mm wide stainless steel cans. The BGO crystals are 9.5 mm x 32 mm x 32 mm deep and as they are not hygroscopic do not require sealed cans. With a shielding gap of 3 cm (section thickness 1.7 cm FWHM) the sensitivity of the BGO system is 55,000 events per sec … more
Date: November 1, 1980
Creator: Derenzo, S.E.; Budinger, T.F.; Huesman, R.H.; Cahoon, J.L. & Vuletich, T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

High resolution computed tomography of positron emitters. [Phantom testing of circular ring of NaI(Tl) crystal detectors]

Description: High resolution computed transaxial radionuclide tomography has been performed on phantoms containing positron-emitting isotopes. The imaging system consisted of two opposing groups of eight NaI(Tl) crystals 8 mm x 30 mm x 50 mm deep and the phantoms were rotated to measure coincident events along 8960 projection integrals as they would be measured by a 280-crystal ring system now under construction. The spatial resolution in the reconstructed images is 7.5 mm FWHM at the center of the ring and… more
Date: October 1, 1976
Creator: Derenzo, S. E.; Budinger, T. F.; Cahoon, J. L.; Huesman, R. H. & Jackson, H. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Dynamic positron emission tomography in man using small bismuth germanate crystals

Description: Primary considerations for the design of positron emission tomographs for medical studies in humans are the need for high imaging sensitivity, whole organ coverage, good spatial resolution, high maximum data rates, adequate spatial sampling with minimum mechanical motion, shielding against out of plane activity, pulse height discrimination against scattered photons, and timing discrimination against accidental coincidences. We discuss the choice of detectors, sampling motion, shielding, and ele… more
Date: April 1, 1982
Creator: Derenzo, S.E.; Budinger, T.F.; Huesman, R.H. & Cahoon, J.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Design and construction of the Donner 280-crystal positron ring for dynamic transverse section emission imaging

Description: The design and construction of a medical imaging system for the rapid, accurate, three-dimensional imaging of positron-labeled compounds in the human body are described. Our medical research goals include quantifying blood flow and metabolism in human heart muscle and brain. The system consists of a large gantry containing lead shielding and a ring of 280 NaI(Tl) detectors that completely encircles the patient; 280 photomultiplier tubes, preamplifiers and timing discriminators; circuits that de… more
Date: September 1, 1977
Creator: Derenzo, S.E.; Banchero, P.G.; Cahoon, J.L.; Huesman, R.H.; Vuletich, T. & Budinger, T.F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Initial results from the Donner 600 crystal positron tomograph

Description: We describe a positron tomograph using a single ring of 600 close-packed 3 mm wide bismuth germanate (BGO) crystals coupled to 14 mm phototubes. The phototube preamplifier circuit derives a timing pulse from the first photoelectron, and sends it to address and coincidence circuits only if the integrated pulse height is within a pre-set window. The timing delays and pulse height windows for all 600 detectors and the coincidence timing windows are computer adjustable. An orbiting positron source … more
Date: October 1, 1986
Creator: Derenzo, S.E.; Huesman, R.H.; Cahoon, J.L.; Geyer, A.; Uber, D.; Vuletich, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Initial Characterization of a Position-Sensitive Photodiode/BGO Detector for PET (Positron Emission Tomography)

Description: We present initial results of a position-sensitive photodiode/BGO detector for high resolution, multi-layer positron emission tomography (PET). Position sensitivity is achieved by dividing the 3 mm /times/ 20 mm rectangular photosensitive area along the diagonal to form two triangular segments. Each segment was individually connected to a low-noise amplifier. The photodiodes and crystals were cooled to /minus/100/degree/C to reduce dark current and increase the BGO signal. With an amplifier pea… more
Date: November 1, 1988
Creator: Derenzo, S. E.; Moses, W. W.; Jackson, H. G.; Turko, B. T.; Cahoon, J. L.; Geyer, A. B. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Electronics for the Donner 600-Crystal Positron Tomograph

Description: The data acquisition system, designed for the Donner 600-Crystal Positron Tomograph, is described. Coincidence timing resolution of less than five nanoseconds full width at half maximum and data rates in excess of one million events per second are achieved by using high-speed emitter coupled logic circuits, first-in first-out memory to derandomize data flow, and parallel architecture to increase throughput. These data rates allow the acquisition of adequate transmission data in a reasonable amo… more
Date: October 1, 1985
Creator: Cahoon, J. L.; Huesman, R. H.; Derenzo, S. E.; Geyer, A. B.; Uber, D. C.; Turko, B. T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A Positron Tomograph with 600 BGO (Bismuth Germanate) Crystals and 2. 6 MM Resolution

Description: We describe the imaging performance of the Donner 600-Crystal Positron Tomograph, a single 600 cm diam ring of 3 mm wide bismuth germanate (BGO) crystals coupled individually to 14 mm phototubes. With a pulse height threshold of 200 keV and a slice thickness of 5 mm, the sensitivity is 7024 eventssec per ..mu..Ciml in a 20 cm cyliner of water. The measured rates for 18 ..mu..Ciml are 95,000 truessec plus 20,000 randomsec. A 0.3 mm diam /sup 22/Na line source near the center of the tomograph has… more
Date: October 1, 1987
Creator: Derenzo, S. E.; Huesman, R. H.; Cahoon, J. L.; Geyer, A. B.; Moses, W. W.; Uber, D. C. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Precision measurement of the weak mixing angle in Moller scattering

Description: We report on a precision measurement of the parity-violating asymmetry in fixed target electron-electron (Moeller) scattering: A{sub PV} = (-131 {+-} 14 (stat.) {+-} 10 (syst.)) x 10{sup -9}, leading to the determination of the weak mixing angle sin{sup 2} {theta}{sub W}{sup eff} = 0.2397 {+-} 0.0010 (stat.) {+-} 0.0008 (syst.), evaluated at Q{sup 2} = 0.026 GeV{sup 2}. Combining this result with the measurements of sin{sup 2} {theta}{sub W}{sup eff} at the Z{sup 0} pole, the running of the wea… more
Date: May 4, 2005
Creator: Anthony, P. L.; Arnold, R. G.; Arroyo, C.; Bega, K.; Biesiada, J.; Bosted, P. E. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen