The particle tracking silicon microscope PTSM Sadrozinski, H.F.-W.; Bashkirov, V.; Bruzzi, M. ...
IEEE transactions on nuclear science,
2004-Oct., 2004-10-00, 20041001, Letnik:
51, Številka:
5
Journal Article
Recenzirano
Odprti dostop
A novel position- and energy-sensitive particle detector for radiobiological application is described. The aim is to support research in radiation response of biological systems, for example in the ...induction of mutations in C. elegans, where precise knowledge of location and intensity of the radiation is crucial to understand radiation sensitivity of individual cells. The "Particle Tracking Silicon Microscope" (PTSM) consists of a silicon strip detector in direct contact with radiobiological samples (e.g., C. elegans), such that the location and intensity of particle radiation can be controlled at the 10 /spl mu/m scale. The readout is performed with low-noise readout electronics, which allows the determination of the particle's position from the hit strip address and its energy from the specific energy loss. In our implementation, the energy loss is measured through the time-over-threshold (TOT). The noise rate at acceptable thresholds is so low that the single particles can be detected with 100% efficiency. The performance of the front-end ASIC is described, and the results of initial environmental tests are reported. These include placing biological samples and saline solutions in direct contact with the silicon detectors.
The BB detector: Upgrades, operation and performance Martinelli, M.; Zhu, Y.S.; Gill, M.S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2013, Letnik:
729, Številka:
C
Journal Article
We present the first direct measurement of A(s), the parity-violating coupling of the Z0 boson to the strange quark, using approximately 550 000 e(+)e(-)-->Z0-->hadrons events recorded by the SLC ...Large Detector with a polarized e(-) beam. We tagged Z0-->s events by the absence of B or D hadrons and the presence in each hemisphere of a high momentum K+/- or K(0)(s). Fitting the polar angle distributions of the strangeness-signed thrust axis gave A(s) = 0.895+/-0.066(stat)+/-0.062(syst). The analyzing power and uu+d background were constrained using the data, greatly reducing any model dependence.
BaBar silicon vertex tracker: Status and prospects Re, V.; Bondioli, M.; Bruinsma, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2006, Letnik:
569, Številka:
1
Journal Article
Costea, M. (Department of Biology, Wilfrid Laurier University, ON, Canada, N2L 3C5; mcostea@wlu.ca), G. L. Nesom (Botanical Research Institute of Texas, 509 Pecan Street, Fort Worth, TX 76102-4060, ...U.S.A.; gnesom@brit.org) & F. J. Tardif (Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada; ftardif@uoguelph.ca). Taxonomic status of Cuscuta nevadensis and C. veatchii (Convolvulaceae) in North America. Brittonia 57: 264–272. 2005.—The taxonomy of Cuscuta nevadensis and C. veatchii is investigated. Cuscuta nevadensis is more closely related to C. veatchii and C. denticulata than to C. salina, and the former two taxa are accepted as species. A summary of relevant taxonomic and biological information is provided, including synonymy, distribution and ecology, keys, and a comparison of the morphology of flowers and seeds are examined. The morphological basis of vivipary in C. nevadensis is discussed. The status of Cuscuta vivipara, an invalid name in recent use, is clarified.
B a B ar silicon vertex tracker: Status and prospects Re, V.; Bondioli, M.; Bruinsma, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2006, Letnik:
569, Številka:
1
Journal Article
Recenzirano
The
B
a
B
ar Silicon Vertex Tracker (SVT) has been efficiently operated for six years since the start of data taking in 1999. Due to higher than expected background levels some unforeseen effects ...have appeared. We discuss: a shift in the pedestal for the channels of the AToM readout chips that are most exposed to radiation; an anomalous increase in the bias leakage current for the modules in the outer layers. Estimates of future radiation doses and occupancies are shown together with the extrapolated detector performance and lifetime, in light of the new observations.
Myxamoebae of the cellular slime mold Dicytostelium discoideum aggregate in response to a chemotactic substance identified as adenosine 3′:5′-cyclic monophosphate. Upon aggregation cell division is ...suppressed, the cells become adhesive, and differentiation is initiated. Freeze-fracture studies of myxamoebae were conducted to determine the effect of cyclic AMP and calcium on plasma membrane ultrastructure. The inner surfaces of the plasma membranes exhibited particulate structures whose sizes (43-187 angstrom) and frequency distribution were determined. Cyclic AMP and calcium induced within 2 hr the formation of particles having average diameters 1.7-times and 1.5-times greater, respectively, than those of the vegetative myxamoebae controls. These data suggest that cyclic AMP mobilizes the intracellular calcium which may be effective in changing plasma membrane structure.
The design and construction of the BaBar electromagnetic calorimeter are reviewed. Recent results on the expected sensitivity of the CsI(TI) to radiation damage are discussed. The performance of the ...calorimeter in the first PEP-II run is presented. Particular emphasis is placed on operational experience and the measured degradation due to radiation damage. Correlation of radiation damage with the dose recorded in a novel large-scale array of radiation sensitive FETs are presented. The consequences for the long-term performance of a CsI(TI) calorimeter operating in a high background environment are discussed.
PDF
