CAMAC Crate Research Articles

Development of data acquisition and control software for gamma-ray process tomography system

Data acquisition (DAQ) and control software has been developed for gamma-ray process tomography system in Malaysian Nuclear Agency. The gamma-ray computed tomography (CT) system uses Computer Automated Measurement and Control (CAMAC) standard for nuclear counting and data acquisition instead of the common Nuclear Instrumentation Module (NIM) standard. For scanning configuration, the system consists of an array of NaI(Tl) scintillation detectors that moves in a small degree of angle by using a stepper motor. The gamma-ray CT software comprises of graphical user interface (GUI) for the system automation that includes CAMAC modules setup, motor and scanning control, data acquisition from CAMAC crate controller via ethernet interface and data recording. The software is developed by using National Instruments LabView development package.

Evaluation of a Sub-Millimeter Resolution PET Detector With a 1.2 mm Pitch TSV-MPPC Array One-to-One Coupled to LFS Scintillator Crystals and Inter-Crystal Scatter Studies With Individual Signal Readout

To develop a small animal positron emission tomography (PET) scanner for whole body imaging of mice, a sub-millimeter resolution PET detector has been constructed and its performance evaluated. This PET detector is composed of a 1.2 mm pitch multi-pixel photon counter (MPPC) $ {8\times 8}$ array with through-silicon via (TSV) structure one-to-one coupled to Lutetium Fine Silicate (LFS) scintillator crystals of size 1.13 mm $ {\times \,\,1.13}$ mm $ {\times \,\,10}$ mm each. To evaluate the intrinsic spatial resolution and the energy resolution in coincidence events, the coincidence response functions (CRFs) of the detector pair, located facing each other at a distance of 80 mm, were measured by scanning a 0.25 mm diameter 22Na point source in 0.1 mm steps. The data were acquired by the computer automated measurement and control (CAMAC) system. The average full width at half maximum (FWHM) of the CRFs was 0.75 mm without point source size corrections. The average FWHM of the energy resolution was 16% at 511 keV. The coincidence timing resolution (CTR) was also evaluated by facing the detector and a fast photomultiplier tube (PMT) coupled with a BaF2 crystal. The expected average FWHM of the CTR between the detectors was 770 ps. Additionally, to improve detector efficiency while suppressing the positioning errors, we propose an interaction-order scheme based on Compton kinematics and adapt it to the same data. We also perform Monte Carlo simulations using GEANT4 10.01 to evaluate the accuracy of the proposed positioning scheme and compare it to that of a centroid calculation scheme. As a result, we demonstrate that the accuracy of the proposed positioning scheme is better than that of a centroid calculation scheme when inter-crystal scatter events occur.

GPIB based instrumentation and control system for ADITYA Thomson Scattering Diagnostic

The ADITYA Thomson Scattering Diagnostic is a single point Ruby laser based system with a spectrometer for spectral dispersion and photomultiplier tubes for the detection of scattered light. The system uses CAMAC (Computer Automated Measurement And Control) based control and data acquisition system, which synchronizes the Ruby laser, detectors and the digitizer. Previously used serial based CAMAC controller is upgraded to GPIB (General Purpose Interface Bus) based CAMAC controller for configuration and data transfer. The communication protocols for different instruments are converted to a single GPIB based for better interface. The entire control and data acquisition program is developed on LabVIEW platform for versatile operation of diagnostics with improved user friendly GUI (Graphical User Interfaces) and allows user to remotely update the laser firing time with respect to the plasma shot. The software is in handshake with the Tokamak main control program through network to minimize manual interventions for the operation of the diagnostics. The upgraded system improved the performance of the diagnostics in comparison to earlier in terms of better data transmission rate, easy to maintain and program is upgradable.

SuperKEKB 真空機器制御システムと総合試験

SuperKEKB is an upgrade project of KEKB, which is a double ring collider of electron and positron beams. The vacuum control system has also been upgraded. Key changes related to the framework of the system are that Computer Automated Measurement And Control (CAMAC) system as a data logger and VME computer as an Input Output Controller (IOC) of Experimental Physics and Industrial Control System (EPICS) have been replaced with CompactRIO (cRIO) and a Linux CPU module of Programmable Logic Controller (PLC), respectively. As an integrative and practical test, we have executed the final evacuation process, including the baking of sputter ion pumps and the activation of Non-Evaporable Getter (NEG) pumps, in a section between two gate valves in the SuperKEKB main ring. The control system supervised the discharge currents of ion pumps, readings of Cold Cathode Gauges (CCGs), heating power for the activation and so on. The new control system is in preparation for a start of the beam commissioning on fiscal 2015 in Japan.

A system of detection and data acquisition for time-of-flight neutron diffraction setups

A simple system of neutron detection and data acquisition is considered. It is composed of sector sets of 3He counters, timing amplifiers-discriminators, 8-stop time-to-digital converters (TDCs), and a gate duration generator, as well as branch and crate controllers coupled to a computer. The system is used in neutron diffraction setups on the neutron spallation source at the Institute for Nuclear Research. The output pulse from the timing amplifier-discriminator is timed with the fast electron component of an avalanche in the detector. Neutron time-of-flight spectra are formed by a TDC in its embedded memory over the recording enable time ranging from 1 to 63 ms. The TDC time range has 4096 gradations with time step of 0.125–128 μs. Fast data acquisition is ensured by the Linux kernel driver. The data acquisition software based on the Qt4 library recognizes modules in the CAMAC crate and displays spectra with their preliminary processing.

VME-based data acquisition system for multiparameter measurements

The VMEbased data acquisition system designed for physics experiments involving measure� ments of several hundreds of parameters is described. The equipment has been tested in the experiments with the 6 He, 8 He, 18 Ne, and 27 S beams at the ACCULINNA fragment separator (http://aculina.jinr.ru/) in the energy range of 20-35 MeV/nucleon. The system is composed of the RIO�3 processor module, which is used to read the VME bus, communicate with the CAMAC and FASTBUS crates, and transmit data to the per� sonal computer; the TRIVA�5 master trigger module; st andard analogtodigital, chargetodigital, and timetodigital converters from CAEN (V785, V792 , and V775 models); and related software. This data acquisition system is faster (by a factor of 10) than a CAMACbased system and is capable of operating with new types of electronic modules, e.g., with digitizers.

Picosecond Stopwatches: The Evolution of Time-to-Digital Converters

The measurement of time intervals with high resolution, precision, and stability on a large number of channels has been used in a multitude of large-scale scientific experiments in particle and nuclear physics. In the early 1950s, however, no standard instruments were available to measure time intervals with subnanosecond time resolution for such scientific experiments. The novel Vernier chronotron proposed in the 1950s by Emilio Gatti [1], based on two oscillators at slightly different frequencies, was an important step toward future detectors and instrumentation able to access high-resolution time measurements in the ps domain. During the 1960s and 1970s, further novel time-to-digital converter (TDC) architectures were developed, and several of these were used until the 1980s in standard modular instrumentation modules, including those based on the Nuclear Instrumentation Module (NIM), Computer Automated Measurement and Control (CAMAC), IEEE Fastbus, and Versa Module Eurocard (VME) standards. At the end of the 1980s, the required number of TDC channels in high energy physics (HEP) experiments increased rapidly, reaching the tens <?Pub Caret?>and hundreds of thousands of measurement channels. This gave rise to the development of various fully integrated, multichannel TDC application specified integrated circuits (ASICs) for use in HEP [2], [3].

A USB-2 based portable data acquisition system for detector development and nuclear research

A highly portable high-speed CAMAC data acquisition system has been developed using Kmax software (Sparrow, Inc.) for Macintosh laptop and tower computers. It uses a USB-2 interface to the CAMAC crate controller with custom-written software drivers. Kmax permits 2D parameter gating and specific algorithms have been developed to facilitate the rapid evaluation of various multi-element nuclear detectors for energy and time-of-flight measurements. This includes tests using neutrons from 252 Cf and a 2.5 MeV neutron generator as well as standard gamma calibration sources such as 60 Co and 137 Cs. In addition, the system has been used to measure gamma–gamma coincidences over extended time periods using radioactive sources (e.g., Ra-228, Pa-233, Np-237, and Am-243).

Global Event-identifier Module: A distributed digital approach to event-of-interest identification logic for physics experiments

The demands from current data acquisition systems are to acquire data from a large number of detectors (or signals) while providing a high throughput. This can be achieved by having some preprocessing capability in the data acquisition system so that it can identify the events of interest. Precise selection of events with minimal time for identification and preprocessing is an experimental challenge. To address this challenge, we have developed a "Global Event-identifier Module" (GEM) on the CAMAC platform, which can flexibly adapt to the experimental requirements and validate an event with minimal time. GEM is a single width CAMAC module capable of operating in a "distributed" data acquisition environment where multiple CAMAC crates (each with one GEM module) can be used to collect synchronized data from all the crates. Event-of-interest decision can be made on signals connected to different crates. Inter-GEM communication is via the ubiquitous ethernet (unshielded twisted pair, CAT5) cable. The event of interest is decided within 32 ns (excluding cable delay). Implementation is accomplished using field programmable gate array which enables greater flexibility for algorithm modifications and updates without hardware changes. GEM supports unified, distributed, and multi-strobe data acquisition, enabling higher throughput, with data collection from a large number of signals by selective reads of events of interest as determined by the experimenter while providing timestamped data of each event.

A CAMAC-USB crate controller

79-83A controller providing communication between a computer and a CAMAC crate via the USB bus is described. For this purpose, the controller includes a DLP-USB245M module, which allows a programmer to work with the controller through a virtual COM port and, at the same time, provides all the advantages of the USB standard. We consider versions of interactions of the DLP-USB module with controller registers on a programmable logic array and on the microcontroller.

Modular software for MAST multi-technology data acquisition system

The MAST (Mega-Amp Spherical Tokamak) data acquisition system is being radically upgraded. New hardware with completely different control interface and logic has been installed on all system levels from front-end devices to plant control. MAST plant control has been moved from VMS to a Windows-based OPC system. Old CAMAC and VME units are being replaced by cPCI and PXI units. A number of CAMAC crates have been upgraded with new Ethernet controllers supporting useful front-end devices. The upgrade is being performed without disturbing operations; the data acquisition units are being replaced gradually. Such an upgrade is possible due to the structure of the MAST data acquisition system which is build as a set of autonomous units, each one controlled by a computer. Modern computers are capable of controlling several units, and this has been the major opportunity and challenge because it radically changes the unit control logic. As a result practically all system components had to be redesigned. The new unit software is a step in system evolution towards greater flexibility and universality. Each unit can now manage multiple data files, possibly with different formats, and many units can be hosted on the same computer. This feature is provided by a message proxy server. Each unit is controlled independently and transparently, exactly like a stand-alone unit. A message interface has been modified for consistent handling of new functions. The unit software supports event-triggered and real-time data acquisition at the system level. New software has been developed for a number of new hardware devices, and the device modules for all usable old devices have been rewritten to operate with the new control interface. The new software allows units to be upgraded even during operations. The system structure and logic provide easy extension. The system as a whole or system design elements could also be used on other fusion facilities.

Ethernet based list processing controller for high speed data acquisition systems

CAMAC standard crates and modules continue to be used for nuclear and high energy physics experiments and test setups. They provide unbeaten performance in high precision measurements, flexibility and simplicity in the design of modules. We have designed and fabricated a new type of CAMAC crate controller with list processing capability to maximize the data throughput, event rate handling capability, while simultaneously simplifying software development efforts for data acquisition systems, also maintain complete compliance with CAMAC standards and ability to utilize all existing CAMAC compliant modules. The throughput increase is achieved by eliminating the arbitration between the CAMAC crate controller and list processing modules by integrating the list processor (auxiliary crate controller) and the crate controller. The event rate handling capability is increased by advanced list processing techniques such as Q-stop and hit-pattern based list processing. The resulting ethernet based list processing crate controller can transfer up to 1700 kbytes/s reaching up to hundreds of kilo events̸s in 16bit transfer mode from CAMAC modules measured at the analysis engine end. This makes it suitable for use in experimental systems, where a large number of signals with high event rates need to be collected with high precision.

Anode and cathode readout electronics for cylindrical multiwire proportional chambers (CMPC) of the PIBETA detector (PSI, Switzerland)

The cathode amplifier is intended to amplify the positive current pulses from the cathode strips of proportional chambers and drive the 50 Ω coaxial cable . The amplifier gain and the output voltage swing are matched for operation with the LeCroy 1882F ADC. The special feature of the anode electronics is the integration of the amplifying section, signal delay unit and digital section within one CAMAC module (ADD-32). The 1 m-wide ADD-32 module contains the electronics for 32 wires, which makes it possible to place up to 672 data channels in a CAMAC crate with a standard bus. To amplify signals, 8-channel microcircuits Ampl8.3 are used. The output logic signals are delayed by 9-channel IDT72421 FIFO microcircuits, which enables to obtain a total signal delay of up to hundreds of microseconds and longer. The digital section of the system is based on ALTERA programmable logic arrays. This system with a total of 576-channels is used in the PIBETA experiment to study rare pion decays on the PSI accelerator (Switzerland).

Anode and cathode readout electronics for cylindrical multiwire proportional chambers (CMPC) of the PIBETA detector (PSI, Switzerland)

The cathode amplifier is intended to amplify the positive current pulses from the cathode strips of proportional chambers and drive the 50 Ω coaxial cable. The amplifier gain and the output voltage swing are matched for operation with the LeCroy 1882F ADC. The special feature of the anode electronics is the integration of the amplifying section, signal delay unit and digital section within one CAMAC module (ADD-32). The 1 m-wide ADD-32 module contains the electronics for 32 wires, which makes it possible to place up to 672 data channels in a CAMAC crate with a standard bus. To amplify signals, 8-channel microcircuits Ampl8.3 are used. The output logic signals are delayed by 9-channel IDT72421 FIFO microcircuits, which enables to obtain a total signal delay of up to hundreds of microseconds and longer. The digital section of the system is based on ALTERA programmable logic arrays. This system with a total of 576-channels is used in the PIBETA experiment to study rare pion decays on the PSI accelerator (Switzerland).

A camac data acquisition system based on PC-Linux

A multi-parametric data acquisition system for Nuclear Physics experiments using camac instrumentation on a personal computer with the Linux operating system in described. The system is very reliable, inexpensive and is capable of handling event rates up to 4–6 k events/s. In the present version, the maximum number of parameters to be acquired is limited only by the number of camac modules that can be fitted in one camac crate.

32-Channel All-in-One CAMAC Module as a Basic Element of Anode Wire Read-out Systems for Proportional Chambers

A special feature of the system is the integration of the amplifying section, signal delay unit, and digital section for the data outputting to computer into a common АДД-32 module (CAMAC). The 1-M-size АДД-32 module contains the electronics for 32 wires, which makes it possible to place up to 672 data channels in the CAMAC crate with a standard bus. To amplify signals, Ampl 8.3 eight-channel microcircuits are used. The output logic signals are delayed by 9-channel IDT72421 FIFO microcircuits enabling us to obtain a total signal delay of up to hundreds of microseconds and longer. The digital section of the system is based on ALTERA programmable logic arrays. At present, this system with a total of 576-channels is used in the PIBETA experiment to study rare pion decays on the PSI accelerator (Switzerland).

Data-acquisition system for a target multifragmentation experiment with large solid angle detectors

We have developed a CAMAC data-acquisition system that is capable of handling not only high-rate interruptions, but also over one hundred inputs within a single CAMAC crate in order to perform exclusive measurements of target multifragmentation induced by 8 and 12 GeV primary proton beams on heavy nuclei. The system is run under PC-Linux and a CAMAC auxiliary crate controller. Since we have selected the UNIDAQ data-acquisition system for our DAQ software, which only uses standard UNIX technology, we expect easy migration to another platform in a future system upgrade.

Field Emission Energy Distribution and Current-Voltage Characteristics Using Single Tip Gated Diodes

ABSTRACTField emission current-voltage characteristics and simultaneous field emission electron energy distributions have been measured using single tip gate diodes. An energy distribution is generated at each step of a current-voltage characteristic using a compact low-cost simulated hemispherical energy analyzer. A PC programmed with graphics-based data acquisition software is used for data acquisition and control. The PC is connected to a CAMAC crate and a picoammeter through a GPIB interface. The picoammeter measures the current leaving the tip and the field emission electrons are energy analyzed, detected and processed in the CAMAC crate. The CAMAC crate also sends control voltages. to the gate anode and the energy analyzer. This apparatus was used to measure tip work functions and Fowler-Nordheim tip shape parameters for Mo and IrO2 field emission tips. Work function measurements from field emission tips are compared to photoelectric work function measurements from flat surfaces.

A prototype switched Ethernet data acquisition system

A prototype switched Ethernet data acquisition system has been built up and successfully operated in HL-1M tokamak experiments. The system is based on a switched high bandwidth Ethernet network with which the CAMAC crates are directly interfaced. It takes the advanced features of LAN switch and Ethernet CAMAC controller (ECC 1365 MK III, HYTEC product) to avoid the rewriting of CAMAC driver for an individual computer system and to ensure high data transmission rate between CAMAC system and host computers on the network. It is a new approach to DAS system architecture and provides a solution for a well-known bottleneck problem in traditional distributed DAS system for fusion research. An average throughput of the test system reaches over 100 Mbps. The system features also an easy and low cost migration from traditional distributed DAS system. In the paper, the hardware configuration, software structure, performance of the system and the method of migrating from current DAS system are discussed in detail.

An overall MWPC-readout system based on chamber mounted ASICs

At the Julich Cooler Synchrotron, COSY, the magnetic spectrometer ANKE (Apparatus for Studies of Nucleon and Kaon Ejectils) is installed. Reaction products emitted by an internal target in the forward direction are measured. About 11000 channels are read out. This requirement justified the design of a VLSI based readout system. For this, an analog chip (RAL 118)-a low power high speed eight channel amplifier and discriminator-is used. Digital delay, zero suppression and address encoding are performed by the digital chip RAL 111 from the Rutherford Appleton Laboratory. A scalable and flexible array of chamber mounted front end boards may be adapted to instrument detectors of any size. Readout is performed by serializing hit addresses over a high speed optical link to a CAMAC readout module which serves for additional data reduction, subevent building and a number of test functions. Furthermore, subevent data are transferred using a front panel ECLbus (FERAbus*) to a crate controller with PCI-interface. An industrial PC with diskless UNIX-compatible operating system (NetBSD) is responsible for controlling the CAMAC crate, processing the event data and connecting to a central event builder.