A Hadron Blind Detector (HBD) has been developed, constructed and successfully operated within the PHENIX detector at RHIC. The HBD is a Cherenkov detector operated with pure
CF
4
. It has a 50
cm ...long radiator directly coupled in a windowless configuration to a readout element consisting of a triple GEM stack, with a CsI photocathode evaporated on the top surface of the top GEM and pad readout at the bottom of the stack. This paper gives a comprehensive account of the construction, operation and in-beam performance of the detector.
Our understanding of the modelling of Standard Model processes plays an important role for Higgs physics and searches beyond the Standard Model. Measurements such as vector boson plus jet production ...are essential for the understanding of backgrounds, modelling of double parton interactions, heavy flavour production from gluon splitting and modelling of the underlying event. Precision QCD measurements can also be used to constrain parton density functions, which are important for the understanding of the Higgs boson production cross section and the Standard Model backgrounds at the LHC kinematic limits. A review of recent ATLAS measurements is presented.
The PHENIX Hadron Blind Detector (HBD) is a high-performance Cherenkov counter used to detect electrons in relativistic heavy ion collisions at RHIC. A High Voltage Control and Monitoring System ...(HVC) was developed to provide optimal control over the detector for maximal performance and protection against damage from possible discharges. The HVC comprises several novel hardware components including a voltage divider board and trip detection/protection boards for each power supply module, while actual control of the HV is maintained by a software suite which incorporates Modern Optimal Control Theory and Artificial Intelligence concepts. The software suite is made up of several concurrently operating subsystems, which periodically processes measurements fed back from the HV mainframe, the HBD gas pressure (P) and temperature (T) sensors, analyzes the GEM module behavior in reference to its performance over time, determines a custom response and modifies the HV when necessary. Since the HBD gain is very sensitive to P/T fluctuations, the HVC automatically modifies the GEM/Mesh voltage accordingly in order to keep the gain variations within a nominal operating range of +/- 10%. Both hardware and software components of the HVC will be described, along with the successful performance results throughout the commissioning p+p Run-9 and the HBD's final and most important Au+Au Run-10.
The PHENIX Hadron Blind Detector (HBD) was successfully operated during the 2009 high energy polarized proton run at RHIC. This was the first data taking run after the detector was rebuilt following ...its first commissioning run in 2007. The detector was operated for several months under actual beam conditions and showed greatly improved performance over the commissioning run. Results are given on the operation of the detector, determination and calibration of the gain using scintillation light produced by charged particles in CF 4 , stability of the CsI photocathodes, the ability to identify single and double electrons using the signal from Cherenkov light, and the level of sensitivity of the detector to charged hadrons. A description is also given on the methods used to reconstruct the detector that led to its improved performance.
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