Session EH: Instrumentation III

E906/SeaQuest Trigger System and J/Psi Production with 120 GeV Proton Beam

E906/SeaQuest is a fixed-target dimuon experiment currently taking data using Fermilab's 120 GeV proton beam and hydrogen, deuterium, carbon, iron, and tungsten targets. The primary goal of SeaQuest is the measurement of nucleon antiquark stucture via the Drell-Yan process. A new trigger system has been developed, utilizing VME modules (v1495s) featuring 20,060 logic element FPGAs. Signals from fast scintillator detector arrays are digitized with 1 ns resolution by internal TDC blocks. The digitized signals are inputs to a muon-path lookup table implemented in the FPGA. The lookup table has been optimized for the high rates of candidate dimuon events experienced by SeaQuest. The track correlator, implemented in the final level of the v1495 system, has proven useful for separating broad categories of event types. The performance of the trigger system, based on data from the 2014 run, will be discussed. Preliminary results on forward $J/\Psi$ production in proton-nucleus interactions will be presented.   

The Data Acquisition System for the BGOegg experiment

The BGOegg experiment has started in December 2013 at SPring-8/LEPS2 facility. The aim of the experiment is to study hadron properties via photo-production using high-intensity and linear-polarized photon beam generated by backward Compton scattering with 8-GeV electrons in SPring-8 and photons from external lasers. The event rate of this experiment is expected to be about 1 kHz. In order to take data with the efficiency over 90\% for 1 kHz trigger rate, we have constructed the data acquisition system mainly consisting of FERA-UIO and VME-TDC subsystems. The BGOegg detector system consists of a beam tagging counter, the BGOegg electromagnetic calorimeter, a cylindrical drift chamber, inner plastic scintillators, a forward drift chamber, and forward TOF-RPCs. The tagging counter and the BGOegg participate in the trigger. The number of readout channels is over 2500 in total. For the readout of these detectors with short dead time, we use 16 collector VME CPUs distributed over TCP/IP networks. We will present details and the performance of the BGOegg data acquisition system.   

Development of FPGA-based NIM logic circuits

We have developed the Generic Trigger Operator (GTO) module for nuclear physics experiments. This is a NIM module aimed at providing intelligent and remote trigger operations. Logic circuits are implemented in field programmable gate array (FPGA) of GTO. NIM logic module like circuits such as fan-in/fan-out, gate, delay, latch, coincidence and scaler have been successfully implemented. One of the advantages of GTO is these logic circuits can be combined into one NIM module as you want. The performance of the time jitter in usual NIM logic modules is very good because of its function is implemented in Emitter-coupled Logic IC. However, the time jitter of GTO depends on the complexity of FPGA circuit implementation. In this contribution, we show functionalities of GTO and its timing performance in comparison with usual NIM logic modules.   

Recent status and physics overview at SPring-8 LEPS2 BGOegg

The SPring-8 LEPS2/BGOegg was newly constructed for the purpose to increase the beam intensity from the SPring-8/LEPS experiments and to achieve the large acceptance coverage with BGOegg and peripheral detectors. The new EM calorimeter BGOegg covers the large acceptance and indicate the high energy and position resolution. In January 2013, the first beam produced by Laser-Electron-Photon (LEP) has been delivered to the SPring-8/LEPS2 beamline. BGOegg and peripheral detectors successfully collected data for the few months. We'll present recent status of LEPS2/BGOegg experiment and discuss physics programs, which are aiming to perform at LEPS2/BGOegg, such as the searches for $\eta^\prime$ mesic-nuclei and excited baryon resonances.   

Improving the quantum efficiency of the CLAS12 LTCC PMTs with a p-Terphenyl wavelength shifter

An improved version of the CLAS Cherenkov detector will be used as the Low-Threshold Cherenkov Counter (LTCC) for the CLAS12 spectrometer at JLAB. The original detector used 216 UV-glass PMTs, which have a poor quantum-efficiency (QE) below 300nm due to the UV-glass transparency. The application of a p-Terphenyl wavelength shifter to the face of these PMTs dramatically improves the QE for short wavelengths, rivaling that of a much more expensive quartz PMT. This translates into an improved detector performance for the LTCC, especially in the higher-energetic regimes in the CLAS12 spectrometer. We will discuss the coating process as well as the performance testing taking place at Temple University. Furthermore, we will present the results of a study of the wavelength dependence of the gain in QE performed at JLAB.   

The GlueX Start Counter

The GlueX experiment will study meson photoproduction with unprecedented precision. This experiment will use the coherent bremsstrahlung technique to produce a 9 GeV linearly polarized photon beam incident on a liquid $\mathrm{H_{2}}$ target. A Start Counter detector has been fabricated to identify the accelerator electron beam buckets, approximately 2 ns apart, and to provide accurate timing information which is used in the level--1 trigger of the experiment. This detector is designed to operate at photon intensities of up to $\mathrm{10^{8}\gamma/s}$ in the coherent peak and provide a timing resolution $\mathrm{<\ 350\ ps}$ so as to provide successful identification of the electron beam buckets to within 99\% accuracy. Furthermore, the Start Counter detector will provide excellent solid angle coverage, $\sim 90 \%\ \mathrm{of}\ 4 \pi\ \mathrm{hermeticity}$, and a high degree of segmentation for background rejection. It consists of a cylindrical array of 30 scintillators with pointed ends that bend towards the beam at the downstream end. Silicon PhotoMultiplier (SiPM) detectors have been selected as the readout system. The physical properties of the scintillators, have been studied extensively at FIU. The results of these studies are discussed.   

Performance of the HBD for the J-PARC E16 experiment

A Hadron Blind Detector (HBD) is a mirror-less and window-less \v{C}erenkov detector for an electron identification. It consists of a radiator operated with pure CF$_4$, a UV-photon sensitive GEM detector which is directly coupled to the radiator, and a pad readout. The GEM detector consists of a triple-GEM stack on top of which CsI is evaporated. The number of photoelectrons that the HBD can detect per incident electron is the most important value, since it discriminates electrons from other charged particles by using pad charge information. We have developed two types of large GEM foils (30~$\times$~30~cm$^2$) which have different hole pitches to optimize a hole/pitch ratio. We performed a beam test with 1.0 GeV/$c$ positrons at Research Center for Electron Photon Science, Tohoku University. We observed $\sim$7.6 photoelectrons with 55 (hole diameter in copper ($\mu$m))/140 (hole pitch ($\mu$m)) GEM foils and $\sim$10.7 photoelectrons with 55/110-GEM foils. The results are consistent with the expected result calculated based on the performance of each detector element. Additionally, our GEM foils provide a trigger. Developments of a readout circuit for a trigger is in progress.   

Study of detection efficiency for the PHENIX muon identifier under the high rate circumstance

The PHENIX forward/backward muon arms provide capability to observe important probes to address the spin structures of hadrons. One of highlight is recent sea quark measurement via W boson production using polarized proton-proton collision at RHIC. The muon identifier (MUID) detector plays a key role to identify muons and composed by the sandwitch of multiple layers of iarocci tube planes and steel absorbers. Each tube is supplied HV through the current limiting resistor to prevent overloads. Over the course of time, RHIC has been improving luminosity plus its designed highest energy, i.e. $\sqrt{s} = 510$ GeV becomes operational. In Run13, MUID was operated under the highest rate circumstances as ever and observed significant inefficiency as low as 50\% which was evaluated by regular data driven manner. Since this is a large efficiency correction, the rate dependent efficiency was estimated based on the efficiency response with respect to an effective operation voltage at the tube taking into account the voltage sag at the protection resistor. Consistency of two methods will be discussed.   

Development of a highly segmented scintillator hodoscope to construct intelligent trigger system for J-PARC E07

The purposes of J-PARC E07 are a systematic study of double Lambda hypernuclei with 10 times higher yields than the previous experiment (KEK-E373) and the first measurement of $\Xi^{-}$ atomic X-rays. In the experiment, we produce $\Xi^{-}$ via the quasi-free (K$^{-}$,K$^{+})$ reaction off a diamond target and expect to observe 10$^{4}$ stopped $\Xi^{-}$ ($\Xi ^{-}$ atoms) in the emulsion counters. The (K$^{-}$,K$^{+})$ reaction is measured by using the KURAMA spectrometer and the acceptance of the KURAMA spectrometer is enlarged from the KEK-E373 experiment. So, a sophisticated online trigger system is inevitable to operate the new KURAMA spectrometer. We employ an intelligent three-dimensional matrix trigger system with a fine-beam-hodoscope (FBH), a highly segmented charge-hodoscope (CH) and a time-of-flight wall (TOF). The FBH is placed in the beamline, whereas CH is located at the upstream of the KURAMA magnet and TOF is located at the most downstream. The highly segmented CH consists of 64 segments, and each segment is made of a plastic scintillator 2 mm thickness, 11.5 mm width and 450 mm length. Scintillation light signals are read out with a wave-length-shifting fiber. Multi-pixel photon counters and front-end read-out EASIROC boards are used. The performance of CH is evaluated by using positron beams and cosmic rays. I will present the results of the performance studies of CH.   

The Kalman Filter for J-PARC E15

The E15 experiment at the J-PARC K1.8br beam line is dedicated to search of the K$^-pp$ deeply bound state via the $^3$He$(K^{-},n)K^-pp$ reaction at the kaon beam momentum of 1 GeV/c. For detecting the expected decay, $K^{-}pp\rightarrow \Lambda p \rightarrow \pi^{-}pp$, a spectrometer system composed of a beam spectrometer, a large acceptance cylindrical detector system (CDS) surrounding the target, and a forward neutron detection system, has been constructed and successfully operated during first physics run in May 2013. This presentation will report the performance of a newly developed Kalman filter tracking algorithm for the E15 data analysis. Kalman filter as a particle tracking method has been widely adopted in high energy experiments due to its advantages such as automatic compensation of energy loss, fast compute and so on. Our result will be the first trial to use Kalman filter for the data analysis in a meson beam based hadron physics experiment at J-PARC. In this presentation, the performance of Kalman filter tracking method will be evaluated by comparison with the traditional minimum $\chi^2$ method in both resolution and computing time respect.   

SciTil Detector for the PANDA experiment at FAIR

The PANDA experiment at the Facility for Antiproton and Ion Research (FAIR) is a fixed-target experiment installed in a antiproton storage ring (HESR) in the energy range of 1 GeV to 15 GeV. FAIR is being build on the area of the GSI Helmholtzzentrum f\"ur Schwerionenforschung in Darmstadt, Germany. The universal PANDA detector together with the HESR enables to study fundamental questions of hadron and nuclear physics, e.g. gluonic excitations, the physics of strange and charm quarks and nucleon structure. The SciTil detector is a barrel time-of-flight detector and is a relatively new subcomponent to the system. The demand arose in order to provide a securer event tagging at the event rates of 20-100 MHz instantaneous event rate, to improve a particle identification capability of relatively low momentum particles, and to allow a faster track finding with pattern recognition. The beam test of the SciTil prototype detector in January 2014 showed a promising result. We report the status and outlook of the project.   

Detector simulations for EIC at JLab

An Electron-Ion Collider (EIC) is considered to be the next machine to study the internal structure of hadrons and nuclei on the basis of the fundamental theory of strong interactions, Quantum Chromodynamics (QCD). Jefferson Lab (JLab) has conducted both EIC accelerator and detector designs. The detector simulation ``EIC\_GEMC'' is based on the simulation framework of GEant4 Monte-Carlo (GEMC). It works like a C++ wrapper around GEANT4. Anything specific to a particular detector like geometry, material, field, sensitivity is put into external input. And it has the ability to customize hit processing routine and output according to various detectors. Overall, these features enable simulating individual sub-detectors and the whole detector in the same framework and make it effortless to switch between them. The main features of simulation ``EIC\_GEMC'' and some simulation results will be the main focus of the talk.