54 research outputs found

    An Analysis of Differential Delayed Mortality Experienced by Stream-type Chinook Salmon of the Snake River

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    In the Anadromous Fish Appendix of the US Army Corp of Engineers (USACE) Environmental Impact Statement on the Lower Snake River Hydrosystem Alternatives for recovery of Snake River salmon and steelhead (hereafter referred to as A-Fish ), the National Marine Fisheries Service (NMFS) suggested that transportation effectiveness of spring/summer chinook may have improved markedly in recent years. The NMFS conclusion was based on estimates of \u27D\u27-values (the differential delayed survival rate between transported fish and fish that migrated in-river) for 1994-1995 (NMFS, 1999). NMFS suggested, if \u27D\u27 is high (estimated in A-Fish at 0.8) and extra mortality of in-river and transported smolts is unrelated to the hydropower system, transportation options may meet recovery standards as well or better than natural river options. NMFS also suggested that further studies could reduce the uncertainty about true values of \u27D\u27 and provide greater confidence to make a decision on the alternative management action needed to recover listed Snake River salmon and steelhead. In this analysis, we demonstrate that the evidence is compatible with a wide range of ‘D’ values, but only a small portion of this distribution is as high as the A-Fish estimate. We also present evidence that the extra mortality of in-river fish is related to the hydrosystem. We analyzed a suite of plausible assumptions used in the calculation of \u27D\u27. Based on our analysis of the 1994-1996 PIT-tag data, there is a wide range of possible \u27D\u27-values. The NMFS\u27 estimate falls at the upper end of this distribution (90th – 95th percentiles). Alternative \u27D\u27-values, based on what we believe to be more reasonable assumptions, were closer to 0.48. Because \u27D\u27 is a modeled value (and not a measurement, as implied in the A-Fish), it is very sensitive to the suite of assumptions made and how the data are grouped. \u27D\u27 estimates were most sensitive to: (1) whether or not fish that were transported from downstream collection/transport sites (Lower Monumental (LMO) and McNary (MCN) dams) were included in the group of fish used to estimate transport smolt to adult return rates (SAR); and (2) how reach survival rate estimates were extrapolated down to Bonneville Dam (BON). In 1994 the ‘D’-value estimated using four collection projects was much lower than two collection projects. However, in 1995 and 1996 the difference in ‘D’ using two and four collection projects was not as dramatic as in 1994. Therefore, the estimated high ‘D’-values are mainly driven by this single assumption for one year. Based on past and proposed future transportation operations, it is unclear why fish transported at the lower two projects were excluded from the NMFS analysis. Transported fish are subjected to stress, injury, and crowding at the collection projects. In addition, the physiological state of fish may be poorly synchronized with the time of saltwater entry for transported fish. These factors could explain the higher delayed mortality experienced by transported fish as suggested by a consistently estimated ‘D’ value that is less than 1. We disagree with the NMFS assertion that “ongoing direct experiments that contrast the return rates of tagged fish that pass through the hydrosystem versus the return rates of transported fish can resolve this question in a clear and unambiguous manner”. While a few components of the \u27D\u27-value estimate are measurable, the sensitivity analysis highlights differences in assumptionsand uncertainties that are not likely resolvable in the near term. In addition, low numbers of returning adults and small numbers of smolts for wild spring/summer chinook salmon may hamper reducing the uncertainty in estimates for reach survival rates and SARs for a non-detected group. Therefore, data are unlikely to perfect our understanding of \u27D\u27 or eliminate the uncertainty in the most influential assumptions. The hypothesis of extra or delayed mortality due to hydrosystem passage has an empirical basis, as well as biological rationale. Based on recent PIT tag data we also found evidence that delayed mortality of both in-river and transported smolts was related to hydropower. More specifically, the evidence suggests that, at least for collected and bypassed smolts, there is a difference between the patterns of direct passage survival rates and SARs. Smolts first detected and transported from the downstream projects (LMO and MCN) had lower SARs than smolts collected and transported from higher up in the system. Similarly (as reported in the A-Fish), SARs of in-river smolts decreased as the number of times the fish were collected and bypassed increased. These pieces of information provide evidence that the Snake River spring summer chinook extra mortality is related to the juvenile migration hydrosystem experience. Based on results from life-cycle modeling (Marmorek and Peters 1998b), transport based management options lead to a high likelihood of recovery only when ‘D’ is high and the source of extra mortality is not related to the experience during hydrosystem passage. However, when extra mortality is hydrosystem related (which our analysis supports), the natural river options are still the most likely management action to recover these stocks, even if ‘D’ is high (which our analysis does not support). Simply studying ‘D’, if that were possible, without determining the source of extra mortality, yields little additional insight into effects of the different management actions on Snake River spring/summer chinook recovery. Given the dangerously low level ofthese populations, we do not believe it is prudent to make management decision on the configuration and operation of the Snake and Columbia hydrosystem for the next 5-20 years (i.e. delaying a decision preserves status quo configuration), based solely on one optimistic assumption about the effectiveness of past and current hydrosystem operations

    Alignment of the CMS silicon tracker during commissioning with cosmic rays

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    This is the Pre-print version of the Article. The official published version of the Paper can be accessed from the link below - Copyright @ 2010 IOPThe CMS silicon tracker, consisting of 1440 silicon pixel and 15 148 silicon strip detector modules, has been aligned using more than three million cosmic ray charged particles, with additional information from optical surveys. The positions of the modules were determined with respect to cosmic ray trajectories to an average precision of 3–4 microns RMS in the barrel and 3–14 microns RMS in the endcap in the most sensitive coordinate. The results have been validated by several studies, including laser beam cross-checks, track fit self-consistency, track residuals in overlapping module regions, and track parameter resolution, and are compared with predictions obtained from simulation. Correlated systematic effects have been investigated. The track parameter resolutions obtained with this alignment are close to the design performance.This work is supported by FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)

    Commissioning and performance of the CMS pixel tracker with cosmic ray muons

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    This is the Pre-print version of the Article. The official published verion of the Paper can be accessed from the link below - Copyright @ 2010 IOPThe pixel detector of the Compact Muon Solenoid experiment consists of three barrel layers and two disks for each endcap. The detector was installed in summer 2008, commissioned with charge injections, and operated in the 3.8 T magnetic field during cosmic ray data taking. This paper reports on the first running experience and presents results on the pixel tracker performance, which are found to be in line with the design specifications of this detector. The transverse impact parameter resolution measured in a sample of high momentum muons is 18 microns.This work is supported by FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)

    Performance of the CMS drift-tube chamber local trigger with cosmic rays

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    The performance of the Local Trigger based on the drift-tube system of the CMS experiment has been studied using muons from cosmic ray events collected during the commissioning of the detector in 2008. The properties of the system are extensively tested and compared with the simulation. The effect of the random arrival time of the cosmic rays on the trigger performance is reported, and the results are compared with the design expectations for proton-proton collisions and with previous measurements obtained with muon beams

    Performance of the CMS Level-1 trigger during commissioning with cosmic ray muons and LHC beams

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    This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2010 IOPThe CMS Level-1 trigger was used to select cosmic ray muons and LHC beam events during data-taking runs in 2008, and to estimate the level of detector noise. This paper describes the trigger components used, the algorithms that were executed, and the trigger synchronisation. Using data from extended cosmic ray runs, the muon, electron/photon, and jet triggers have been validated, and their performance evaluated. Efficiencies were found to be high, resolutions were found to be good, and rates as expected.This work is supported by FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)

    Performance of the CMS hadron calorimeter with cosmic ray muons and LHC beam data

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    This is the Pre-print version of the Article. The official published version of the Paper can be accessed from the link below - Copyright @ 2010 IOPThe CMS Hadron Calorimeter in the barrel, endcap and forward regions is fully commissioned. Cosmic ray data were taken with and without magnetic field at the surface hall and after installation in the experimental hall, hundred meters underground. Various measurements were also performed during the few days of beam in the LHC in September 2008. Calibration parameters were extracted, and the energy response of the HCAL determined from test beam data has been checked.This work is supported by FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)

    Performance of the CMS Level-1 trigger during commissioning with cosmic ray muons and LHC beams

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    This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2010 IOPThe CMS Level-1 trigger was used to select cosmic ray muons and LHC beam events during data-taking runs in 2008, and to estimate the level of detector noise. This paper describes the trigger components used, the algorithms that were executed, and the trigger synchronisation. Using data from extended cosmic ray runs, the muon, electron/photon, and jet triggers have been validated, and their performance evaluated. Efficiencies were found to be high, resolutions were found to be good, and rates as expected.This work is supported by FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)

    Performance study of the CMS barrel resistive plate chambers with cosmic rays

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    This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2010 IOPIn October and November 2008, the CMS collaboration conducted a programme of cosmic ray data taking, which has recorded about 270 million events. The Resistive Plate Chamber system, which is part of the CMS muon detection system, was successfully operated in the full barrel. More than 98% of the channels were operational during the exercise with typical detection efficiency of 90%. In this paper, the performance of the detector during these dedicated runs is reported.This work is supported by FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)
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