S. S. Upadhya

Delay and Offset Calibration Schemes for the INO ICAL Electronics

Magnetised iron calorimeter (ICAL) is a detector to study the atmospheric neutrinos, proposed by the India-based Neutrino Observatory (INO) to be built using Resistive Plate Chambers (RPCs) which are interleaved between the iron plates. The neutrino interaction within the detector leaves tracks in the RPCs. A Global trigger, based on hit pattern, initiate RPCs to record hit information and their Time Of Flight (TOF). RPCs are spread geographically throughout the ICAL detector which measures about \(48\,{\text {m}} \times 16\,{\text {m}} \times 14.5\,{\text {m}}\), therefore the global signal paths and hence trigger delays to the RPCs will be unequal. Since each RPC records TOF on a trigger arrival, a calibration scheme is needed to measure and monitor the path delays of global trigger to each RPC or offsets of RPC timers. The local time measurements in the participating RPCs can then be translated to global values by applying the measured delays or offsets.

Ethernet Scheme for Command and Data Acquisition for the INO ICAL Detector

Over 28,800 Resistive Plate Chambers (RPCs) are going to be deployed in the INO ICAL detector. To control and acquire data from these detectors, a digital front-end (DFE) module will be mounted on each of the RPCs. The DFE modules are provided with an Ethernet interface and hence each of them will function as a network node with an unique IP address. ICAL will use Local Area Network (LAN) topology with a basic TCP/IP communication protocol. Thousands of DFE modules will be grouped together and controlled by a common back-end Command Server, which will use a customized UDP protocol.Each RPC is readout on 128 channels which are connected to corresponding DFE module. This paper describes an efficient solution for transfer of raw data from RPCs in the front end to a permanent storage at the BackEnd in a packaged format, and to communicate with RPCs from the control room.

Calibration and Auxiliary Unit for INO’s ICAL Data Acquisition System

Magnetised iron calorimeter is a detector to study atmospheric neutrinos, proposed by the India based Neutrino Observatory. It will be built using 30 k Resistive Plate Chambers interleaved between iron plates. The neutrino interaction within the detector creates Muon tracks. The position information and TOF w.r.t trigger arrival of an interaction in RPC is recorded locally in each of participating DAQ nodes. CAU is a common interface between all ICAL subsystems for control, calibration and time synchronization. CAU caters global service signals over various electrical path length as per geographical position of RPC. The Global trigger delay offset at each RPC is computed by measuring the round path delay using calibration signals to translate local TOF w.r.t a global reference.

Soft-Core Processor Based Data Acquisition Module for ICAL RPCs with Network Interface

The India-based Neutrino Observatory (INO) collaboration is planning to set up a magnetised Iron-CALorimeter (ICAL) detector to study atmospheric neutrino oscillations. ICAL detector will deploy 28,800 single gap Resistive Plate Chambers (RPCs) of about \(2\,{\text {m}} \times 2\,{\text {m}}\) in area as its active detector elements. Particles produced in the neutrino interactions within the detector volume pass through alternating layers of iron plates and the RPCs, thus leaving tracks in the latter. Signals from each RPC are acquired using 128 pickup strips—64 each on X- and Y-orthogonal planes. These signals are amplified and converted to logic signals by the analog front-end modules, which are mounted on the RPC unit. Major functions of the digital front-end module, which is also mounted at one corner of the RPC unit are to collect and process the event data on trigger, package it and transmit it to the back-end via the built in TCP/IP based network interface.

Data acquisition and monitoring system for the UHE gamma ray experiment at Kolar Gold Fields

Abstract A computerised on-line data acquisition system has been implemented to acquire data and monitor all the detectors in an extensive air shower experiment at Kolar Gold Fields, India, designed to search for point sources of Ultra High Energy gamma rays. It is based on the LSI-11 microcomputer, which has a powerful instruction set and a daisy chained vectored interrupt facility. Two personal computers are linked with LSI-11 through a 16-bit communication bus, to transfer data for a quick analysis. While the system performs this function in the background, it can be interrupted, at different priority levels, by several foreground functions, such as event data acquisition, detector monitoring, etc. The hardware and software features of the data acquisition system are described in detail.