scholarly journals 73.1: Large-Area Plasma-Panel Radiation Detectors for Nuclear Medicine Imaging to Homeland Security and the Super Large Hadron Collider

2010 ◽  
Vol 41 (1) ◽  
pp. 1080 ◽  
Author(s):  
Peter S. Friedman ◽  
Robert Ball ◽  
J. Wehrley Chapman ◽  
Daniel S. Levin ◽  
Curtis Weaverdyck ◽  
...  

In this chapter, the exciting developments in micropattern detectors in recent years are described. This includes GEM and MICROMEGAS detectors combined with micropixel readout, some peculiar designs of GEM and GEM-like detectors sensitive to UV and visible light, large area (>1m2) GEM and MICROMEGAS prototypes developed for the upgrades of the experiments at the large hadron collider, etc. A special focus is put on a new generation of spark-proof micropattern detectors, using resistive electrodes instead of traditional metallic ones. These detectors operate as ordinary micropattern detectors. However, in the case of occasional sparks, their current is limited by the resistivity of the electrodes so that the energy of the discharge is reduced by several orders of magnitude. Various designs of such detectors have been developed and successfully tested, including resistive GEM, resistive MICROMEGAS, resistive MSGC, etc. Among this family of detectors, a special place belongs to resistive parallel-plate micropattern detectors allowing one to achieve at the same time excellent spatial (38 µm) and time (77 ps) resolutions. Finally, the potential of multilayer detector technology for further optimization of the detector operation is discussed.


1997 ◽  
Vol 487 ◽  
Author(s):  
J. M. Woolfenden ◽  
H. B. Barber ◽  
H. H. Barrett ◽  
E. L. Dereniak ◽  
J. D. Eskin ◽  
...  

AbstractWe are developing modular arrays of CdZnTe radiation detectors for high-resolution nuclear medicine imaging. Each detector is delineated into a 64×64 array of pixels; the pixel pitch is 380 jim. Each pixel is connected to a corresponding pad on a multiplexer readout circuit. The imaging system is controlled by a personal computer. We obtained images of standard nuclear medicine phantoms in which the spatial resolution of approximately 1.5 mm was limited by the collimator that was used. Significant improvements in spatial resolution should be possible with different collimator designs. These results are promising for high-resolution nuclear medicine imaging.


1997 ◽  
Vol 484 ◽  
Author(s):  
J. M. Woolfenden ◽  
H. B. Barber ◽  
H. H. Barrett ◽  
E. L. Dereniak ◽  
J. D. Eskin ◽  
...  

AbstractWe are developing modular arrays of CdZnTe radiation detectors for high-resolution nuclear medicine imaging. Each detector is delineated into a 64×64 array of pixels; the pixel pitch is 380 ptm. Each pixel is connected to a corresponding pad on a multiplexer readout circuit. The imaging system is controlled by a personal computer. We obtained images of standard nuclear medicine phantoms in which the spatial resolution of approximately 1.5 mm was limited by the collimator that was used. Significant improvements in spatial resolution should be possible with different collimator designs. These results are promising for high-resolution nuclear medicine imaging.


2013 ◽  
Vol 28 (13) ◽  
pp. 1340020 ◽  
Author(s):  
JOERG WOTSCHACK

The upgrade of the ATLAS detector at the Large Hadron Collider (LHC) at CERN calls for a new generation of muon detectors capable of operating in a flux of collision and background particles approximately ten times larger compared to today's conditions. We report here on the Muon ATLAS MicroMegas Activity (MAMMA) R&D project aimed at the construction of large-area spark-resistant muon chambers using the micromegas technology.


2004 ◽  
Vol 51 (4) ◽  
pp. 1631-1635 ◽  
Author(s):  
W. Metzger ◽  
J. Engdahl ◽  
W. Rossner ◽  
O. Boslau ◽  
J. Kemmer

2001 ◽  
Vol 40 (03) ◽  
pp. 59-70 ◽  
Author(s):  
W. Becker ◽  
J. Meiler

SummaryFever of unknown origin (FUO) in immunocompetent and non neutropenic patients is defined as recurrent fever of 38,3° C or greater, lasting 2-3 weeks or longer, and undiagnosed after 1 week of appropriate evaluation. The underlying diseases of FUO are numerous and infection accounts for only 20-40% of them. The majority of FUO-patients have autoimmunity and collagen vascular disease and neoplasm, which are responsible for about 50-60% of all cases. In this respect FOU in its classical definition is clearly separated from postoperative and neutropenic fever where inflammation and infection are more common. Although methods that use in-vitro or in-vivo labeled white blood cells (WBCs) have a high diagnostic accuracy in the detection and exclusion of granulocytic pathology, they are only of limited value in FUO-patients in establishing the final diagnosis due to the low prevalence of purulent processes in this collective. WBCs are more suited in evaluation of the focus in occult sepsis. Ga-67 citrate is the only commercially available gamma emitter which images acute, chronic, granulomatous and autoimmune inflammation and also various malignant diseases. Therefore Ga-67 citrate is currently considered to be the tracer of choice in the diagnostic work-up of FUO. The number of Ga-67-scans contributing to the final diagnosis was found to be higher outside Germany than it has been reported for labeled WBCs. F-l 8-2’-deoxy-2-fluoro-D-glucose (FDG) has been used extensively for tumor imaging with PET. Inflammatory processes accumulate the tracer by similar mechanisms. First results of FDG imaging demonstrated, that FDG may be superior to other nuclear medicine imaging modalities which may be explained by the preferable tracer kinetics of the small F-l 8-FDG molecule and by a better spatial resolution of coincidence imaging in comparison to a conventional gamma camera.


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