Multiwire Drift Chambers Research Articles

Studies on the temperature dependent drift velocity for the HELIX Drift Chamber Tracker

HELIX (High Energy Light Isotope eXperiment) is a ballon experiment designed to measure abundance of cosmic ray isotopes from hydrogen to neon, with a particular interest in abundances of beryllium isotopes. HELIX aim to provide essential data to study the cosmic ray propagation in our galaxy. The Drift Chamber Tracker (DCT) in HELIX is a multi-wire gas drift chamber designed to measure the position of incident cosmic rays. It is located inside a magnet, bending the trajectory of incoming particles through 72-layers of tracking, enabling the measurement of the momentum of incoming particles.Before the data can be used for scientific analysis, the background must be taken out, and the instrument must be well calibrated. In order to exclude electronic noise from the DCT data it was necessary to determine the maximum drift velocity of each wire over a short period of time. To do this I developed an algorithm to be able to identify the maximum drift velocity for each wire over each dataset. This revealed a position dependence of the data within the detector. In order to attempt to characterize this dependence, so it can be accounted for in the calibration stage, I preformed a study on the temperature dependence of the drift velocities analyzing at data from different time periods over the course of the flight. To characterize this dependence I built a predicted heat map of the gas within the detector over the course of the flight. This involved calibrating the thermistors based on data collected when the experiment was on the ground. This helped confirm that the predicted temperature was reasonable and that the variation was temperature dependent. This algorithms and this study can now be applied to the full data set to develop a calibration method.

Performance of gas electron tracking detectors for beta decay studies

At the low-energy frontier, among the experiments testing the Standard Model and searching for new physics, are precision spectrum shape and correlation coefficient measurements in nuclear and neutron beta decay. For identification and 3D-tracking of low-energy electrons, a special type of gas-based detector was designed that minimizes scattering and energy loss. First, the newly developed gas tracker was successfully used to study tiny effects in the beta spectrum shape for allowed Gamow-Teller transitions. The miniBETA spectrometer consists of a hexagonally structured multi-wire drift chamber (MWDC) filled with a mixture of helium and isobutane gas and a plastic scintillator serving as a trigger source and energy detector. The drift time information is used to establish the electron tracks in the plane perpendicular to the wires, while the charge division technique provides spatial information along the wires. Second, inspired by the performance of this spectrometer we are building a Mott polarimeter to be used in the BRAND experiment to study the neutron decay correlation coefficients.

Readout Firmware of the Readout System for the MWDC at the ETF in HIRFL-CSR

Three multiwire drift chamber (MWDC) detectors and readout electrical equipment had been installed in 2018 as part of the cooler storage ring external target facility (ETF) project to gather track data in the ETF. In addition to its high efficiency and adaptability, the electronic device requires high precision in terms of position and energy resolution, as well as good flexibility and efficiency of the electronics. In this paper, we propose an electronic readout technique for MWDC detectors and show the implementation of a 32-channel signal processing in a single Xilinx Kintex-7 Field-Programmable Gate Array. Furthermore, we also present a thorough description of the readout firmware, with a focus on the deserialization mechanism and data processing algorithms. Additionally, we conducted a series of initial tests is conducted. The results show that the proposed technique can meet the application requirement.

Development of a readout electronic prototype system for the MWDC at the ETF in HIRFL-CSR

This paper proposes and implements a readout electronic prototype system for a Multi-Wire Drift Chamber (MWDC) detector. This system includes Front-End Electronics (FEE), Sub_Data Acquisition (Sub_DAQ), and Common Data Acquisition Unit (CDAU). Based on a self-developed Application-Specific Integrated Circuit (ASIC) chip, the FEE amplifies and reshapes the detector signals before transmitting them via a high-density micro-coaxial cable to the Sub_DAQ. The Sub_DAQ, based on a Field-Programmable Gate Array (FPGA), was designed to process MWDC signals. The Sub_DAQ can perform an analogue-to-digital conversion, online data processing, and package transmission before transmitting the data to the CDAU via a high-speed optical fibre link. The CDAU gathered data, online processed the data, and then transmitted the data to the computer via the PCIe 3.0 interface. This paper will discuss the design process, the implementation, and the initial test results of the readout electronic prototype system.

Gas electron tracking detector for beta decay experiments

For identification and 3D-tracking of low-energy electrons a new type of gas-based detector was designed that minimizes scattering and energy loss. The current version of the detector is a combination of a plastic scintillator, serving as a trigger source and energy detector, and a hexagonally structured multi-wire drift chamber (MWDC), filled with a mixture of helium and isobutane gas. The drift time information is used to track particles in the plane perpendicular to the wires, while a charge division technique provides spatial information along the wires. The gas tracker was successfully used in the miniBETA project as a beta spectrometer for a measurement of the weak magnetism form factor in nuclear beta decay. The precision of the three-dimensional electron tracking, in combination with low-mass, low-Z materials and identification of backscattering from scintillator, facilitated a reduction of the main systematics effects. The results originate from performance studies with cosmic muons and low-energy electrons (<2 MeV) conducted for several pressures (300–700 mbar) and isobutane content in the gas mixture (10–50%). At certain conditions, a spatial resolution better than 0.5 mm was obtained in the plane perpendicular to the wires, while resolutions of about 6 mm were achieved along wires. Thanks to precise tracking information, it is possible to eliminate electrons and other particles not originating from the desired decay with high efficiency. Additionally, using the coincidence between MWDC and scintillator, background from gamma emission typically accompanying radioactive decays, was highly suppressed. An overview of different event topologies is presented together with the tracker’s ability to correctly recognize them. The analysis is supported by Monte Carlo simulations using Geant4 and Garfield++ packages. Finally, the preliminary results from the 114In spectrum study are presented.

Isoscalar monopole and dipole transitions in Mg24 , Mg26 , and Si28

Nuclei in the $sd$-shell demonstrate a remarkable interplay of cluster and mean-field phenomena. The $N=Z$ nuclei, such as $^{24}$Mg and $^{28}$Si, have been the focus of the theoretical study of both these phenomena in the past. The cluster and vortical mean-field phenomena can be probed by excitation of isoscalar monopole and dipole states in scattering of isoscalar particles such as deuterons or $\alpha$ particles. Inelastically scattered $\alpha$ particles were momentum-analysed in the K600 magnetic spectrometer at iThemba LABS, Cape Town, South Africa. The scattered particles were detected in two multi-wire drift chambers and two plastic scintillators placed at the focal plane of the K600. In the theoretical discussion, the QRPA and AMD+GCM were used. The QRPA calculations lead us to conclude that: i) the mean-field vorticity appears mainly in dipole states with $K=1$, ii) the dipole (monopole) states should have strong deformation-induced octupole (quadrupole) admixtures, and iii) that near the $\alpha$-particle threshold, there should exist a collective state (with $K=0$ for prolate nuclei and $K=1$ for oblate nuclei) with an impressive octupole strength. The results of the AMD+GCM calculations suggest that some observed states may have a mixed (mean-field + cluster) character or correspond to particular cluster configurations. A tentative correspondence between observed states and theoretical states from QRPA and AMD+GCM was established. The QRPA and AMD+GCM analysis shows that low-energy isoscalar dipole states combine cluster and mean-field properties. The QRPA calculations show that the low-energy vorticity is well localized in $^{24}$Mg, fragmented in $^{26}$Mg, and absent in $^{28}$Si.

The FPGA time-to-digital converter for the large-scale detector TREK based on multi-wire drift chambers

The new large-scale coordinate-tracking detector TREK is under construction in MEPhI. It is based on 264 multi-wire drift chambers (4000× 508× 112 mm3 size) developed in IHEP for experiments on the neutrino channel of the U-70 accelerator, and will have 250 m2 of continuous effective area. The main goal of the project is the solution of so-called “muon puzzle”: the unpredicted by any theory excess of high multiplicity muon bundles generated by ultra-high energy primary cosmic rays. Besides of a set of field-forming wires, each multi-wire drift chamber has 4 signal ones. The current from these wires is processed by the shaper-amplifier AMP-4, mounted on the front of the chamber. It generates LVDS pulses that should be processed by multi-channel TDC that faces two main requirements: large matching window (more than 6000 ns) with last significant digit (LSD) less than 10 ns and capability to hold more than 50 hits per channel in a single event. These conditions were fulfilled by the new time-to-digital converter developed on the basis of Cyclone V FPGA in MEPhI. This paper presents the design of the TDC, its main features and the first benchmarks of its performance.

Simulation and prototype testing of multi-wire drift chamber arrays for the CEE

The building of a large-scale external-target experiment, abbreviated as CEE, in the cooling storage ring at the Heavy Ion Research Facility in Lanzhou has been planned. The CEE is a multi-purpose spectrometer that will be used for various studies on heavy-ion collisions. A multi-wire drift chamber (MWDC) array is the forward tracking detector of the CEE. In this work, GEANT4 simulations were performed for the MWDC forward tracking array with a focus on the track reconstruction algorithm. Combined with the time of flight information, particle identification is achieved. The residue is about $$30\,\upmu \hbox {m}$$, while the tracking efficiency is higher than 90% with the current redundancy. In addition, a prototype of the forward tracking system using three MWDCs was assembled and tested using a high-energy proton beam. The firing efficiency of the detector and the reconstruction accuracy of the prototype were derived. The track residue for the protons at about 400 MeV/c is better than $$300\,\upmu \hbox {m}$$, meeting the requirements of the CEE. Suggestions for improving the performance of the forward tracking system are given.

Investigation of muon bundles generated by UHECR by means of the new coordinate-tracking detector

The new coordinate-tracking detector based on drift chambers (CTUDC) is created in MEPhI. The detector represents two planes with total area of 30 m2 placed on the opposite sides of Cherenkov water detector of 2000 m3 volume. Each plane consists of 8 large multiwire drift chambers (4000x508x112 mm3). The key advantages of these chambers are a large effective area (1.85 m2) and a good coordinate and angular resolution with a small number of measuring channels. From the beginning of 2017, CTUDC operates as a part of the experimental complex NEVOD. The detector is designed for measuring of high density muon bundles (up to 10 particles per m2) at zenith angles in the range from 30° to 90°. The results of the CTUDC operation during the last year are given, the first distributions of the events in zenith angle, muon bundle multiplicity and density obtained from the detector data are discussed.

A novel electrical method to measure wire tensions for time projection chambers

We present a novel electrical technique to measure the tension of wires in multi-wire drift chambers. We create alternating electric fields by biasing adjacent wires on both sides of a test wire with a superposition of positive and negative DC voltages on an AC signal (VAC±VDC). The resulting oscillations of the wire will display a resonance at its natural frequency, and the corresponding change of the capacitance will lead to a measurable current. This scheme is scalable to multiple wires and therefore enables us to precisely measure the tension of a large number of wires in a short time. This technique can also be applied at cryogenic temperatures making it an attractive solution for future large time-projection chambers such as the DUNE detector. We present the concept, an example implementation and its performance in a real-world scenario and discuss the limitations of the sensitivity of the system in terms of voltage and wire length.

The application of multi-wire drift chambers in cosmic ray research

Multiwire drift chambers designed for the neutrino experiment at the IHEP U-70 accelerator have found a new application in the MEPhI experiment focused on the detection of ultrahigh-energy cosmic rays. Their high durability and fine spatial and angular characteristics make these chambers perfectly suitable for such studies. The drift chambers were tested at MEPhI and used in constructing the CTUDC coordinatetracking setup, which operated together with the NEVOD water Cherenkov detector and the DECOR detector. The results of the studies of the parameters of drift chambers in the cosmic-ray flux at test benches and in the CTUDC setup are presented.

Comparison between large area PMTs and SiPM arrays deployed in a Liquid Argon Time Projection Chamber at CERN

Liquid argon Time Projection Chambers (LAr-TPCs) are among the most promising detectors for the study of neutrino oscillations. They are composed by a multi-wire drift chamber to collect the charge and a photodetection system to detect the scintillation light, both produced by ionizing charged particles that cross the argon volume. Scintillation light plays a fundamental role for the event reconstruction because it permits to calculate the absolute time t0 of the event and it is also used for triggering purposes. We present a comparison between the performances of large area Photo-Multiplier Tubes (PMTs) and Silicon Photo-Multiplier (SiPM) arrays deployed in a small LAr-TPC exposed to cosmic rays at CERN, both in terms of light collected and timing performances.

The detector on the basis of drift chambers for inclined muon bundle investigations

The results of experiments of the last decades have shown that with the increase of energy of primary cosmic rays a clear excess of muon groups in comparison with the existing models of extensive air shower development (even assuming pure iron composition of PCR) appears. The problem is called 'muon puzzle' and it can be explained either by cosmo- or nuclear-physical reasons. One of the experiments in which the excess of muon groups was registered is a NEVOD-DECOR. The new large-scale coordinate-tracking detector of 254 m2 area based on drift chambers will increase the coverage of the side aperture of the Cherenkov water detector (CWD) NEVOD and significantly improve the resolution of close tracks. Multi-wire drift chambers TREK developed in IHEP for experiments at the neutrino channel of U-70 accelerator have large effective area (1.85 m2), a good coordinate and angular resolution with a small number of measuring channels. The first part of the detector named Coordinate-Tracking Unit based on the Drift Chambers (CTUDC) representing two coordinate planes of 8 drift chambers in each has been developed and mounted on the opposite sides of the CWD. It has the same principle of joint operation with NEVOD-DECOR triggering system so the main features of the TREK detector will be examined. Results of an examination of drift chambers at muon hodoscope URAGAN, a calibration of the CTUDC with DECOR and the first results of its joint operation with NEVOD triggering system are presented.

Registration of muon bundles by a coordinate tracking unit based on drift chambers

A coordinate tracking unit based on drift chambers (CTUDC) for registering single muons and muon bundles at large zenith angles is created at the MEPhI. The unit consists of multi-wire drift chambers (DCs) with large drift gaps. These DCs were used earlier for the neutrino channel on the U-70 accelerator. The CTUDC consists of two coordinate planes with 8 drift chambers in each, assembled on the opposite sides of the NEVOD Cherenkov water detector (CWD). The effective area of the unit is 29.6 m2. The CWD trigger system and DECOR coordinate-tracking detector provide timestamps for the drift chambers. The first results from the registration of single muons and muon bundles by the unit in combination with other detectors of the NEVOD experimental complex are presented.

α clustering in Si28 probed through the identification of high-lying 0+ states

Background: Aspects of the nuclear structure of light $\ensuremath{\alpha}$-conjugate nuclei have long been associated with nuclear clustering based on $\ensuremath{\alpha}$ particles and heavier $\ensuremath{\alpha}$-conjugate systems such as $^{12}\mathrm{C}$ and $^{16}\mathrm{O}$. Such structures are associated with strong deformation corresponding to superdeformed or even hyperdeformed bands. Superdeformed bands have been identified in $^{40}\mathrm{Ca}$ and neighboring nuclei and find good description within shell model, mean-field, and $\ensuremath{\alpha}$-cluster models. The utility of the $\ensuremath{\alpha}$-cluster description may be probed further by extending such studies to more challenging cases comprising lighter $\ensuremath{\alpha}$-conjugate nuclei such as $^{24}\mathrm{Mg}, ^{28}\mathrm{Si}$, and $^{32}\mathrm{S}$.Purpose: The purpose of this study is to look for the number and energy of isoscalar ${0}^{+}$ states in $^{28}\mathrm{Si}$. These states are the potential bandheads for superdeformed bands in $^{28}\mathrm{Si}$ corresponding to the exotic structures of $^{28}\mathrm{Si}$. Of particular interest is locating the ${0}^{+}$ bandhead of the previously identified superdeformed band in $^{28}\mathrm{Si}$.Methods: $\ensuremath{\alpha}$-particle inelastic scattering from a $^{\mathrm{nat}}\mathrm{Si}$ target at very forward angles including ${0}^{\ensuremath{\circ}}$ has been performed at the iThemba Laboratory for Accelerator-Based Sciences in South Africa. Scattered particles corresponding to the excitation energy region of 6 to 14 MeV were momentum-analysed in the K600 magnetic spectrometer and detected at the focal plane using two multiwire drift chambers and two plastic scintillators.Results: Several ${0}^{+}$ states have been identified above 9 MeV in $^{28}\mathrm{Si}$. A newly identified 9.71 MeV ${0}^{+}$ state is a strong candidate for the bandhead of the previously discussed superdeformed band. The multichannel dynamical symmetry of the semimicroscopic algebraic model predicts the spectrum of the excited ${0}^{+}$ states. The theoretical prediction is in good agreement with the experimental finding, supporting the assignment of the 9.71-MeV state as the bandhead of a superdeformed band.Conclusion: Excited isoscalar ${0}^{+}$ states in $^{28}\mathrm{Si}$ have been identified. The number of states observed in the present experiment shows good agreement with the prediction of the multichannel dynamical symmetry.

New installation for inclined EAS investigations

The large-scale coordinate-tracking detector TREK for registration of inclined EAS is being developed in MEPhI. The detector is based on multiwire drift chambers from the neutrino experiment at the IHEP U-70 accelerator. Their key advantages are a large effective area (1.85 m 2 ), a good coordinate and angular resolution with a small number of measuring channels. The detector will be operated as part of the experimental complex NEVOD, in particular, jointly with a Cherenkov water detector (CWD) with a volume of 2000 cubic meters and the coordinate detector DECOR. The first part of the detector named Coordinate-Tracking Unit based on the Drift Chambers (CTUDC), representing two coordinate planes of 8 drift chambers in each, has been developed and mounted on opposite sides of the CWD. It has the same principle of joint operation with the NEVOD-DECOR triggering system and the same drift chambers alignment, so the main features of the TREK detector will be examined. Results of the CTUDC development and a joint operation with NEVOD-DECOR complex are presented.

Calibration of cathode strip gains in multiwire drift chambers of the GlueX experiment

A technique for calibrating cathode strip gains in multiwire drift chambers of the GlueX experiment is described. The accuracy of the technique is estimated based on Monte Carlo generated data with known gain coefficients in the strip signal channels. One of the four detector sections has been calibrated using cosmic rays. Results of drift chamber calibration on the accelerator beam upon inclusion in the GlueX experimental setup are presented.

The registration system of the coordinate-tracking setup on the drift chambers

The large-scale coordinate-tracking detector for registration of near-horizontal muon flux generated by ultra-high energy cosmic rays is being developed in MEPhI. Detector is based on the multiwire drift chambers from the neutrino experiment at the IHEP U-70 accelerator. Their key advantages are a large effective area (1.85 m2), good coordinate and angular resolution with a small number of measuring channels. Detector will be operated as a part of the experimental complex NEVOD, in particular, its registration system allows joint operation with Cherenkov water detector (CWD) and coordinate detector DECOR. Coordinate tracking unit on the drift chambers (CTUDC) is mounted on the opposite sides of CWD. It consists of two coordinate planes containing 8 drift chambers and represents a prototype of a full-size setup. Registration system of the CTUDC is based on the E-MISS electronics developed in IHEP, its principle of operation is presented.

Front-end electronics and data acquisition system for a multi-wire 3D gas tracker

This paper presents the design and implementation of the front-end electronics and the data acquisition (DAQ) system for readout of multi-wire drift chambers (MWDC). Apart of the conventional drift time measurement the system delivers the hit position along the wire utilizing the charge division technique. The system consists of preamplifiers, and analog and digital boards sending data to a back-end computer via an Ethernet interface. The data logging software formats the received data and enables an easy access to the data analysis software. The use of specially designed preamplifiers and peak detectors allows the charge-division readout of the low resistance signal wire. The implication of the charge-division circuitry onto the drift time measurement was studied and the overall performance of the electronic system was evaluated in dedicated off-line tests.

Prototype studies on the forward MWDC tracking array of the external target experiment at HIRFL-CSR

A prototype of the forward tracking array consisting of three multiwire drift chambers (MWDC) for the external target experiment (CEE) at the Heavy Ion Research Facility at the Lanzhou -Cooling Storage Ring (HIRFL-CSR) has been assembled and tested using cosmic rays. The signals from the anode wires are amplified and fed to a Flash-ADC to deliver the drift time and charge integration. The performances of the array prototype are investigated under various high voltages. For the tracking performances, after the space-time relation (STR) calibration and the detector displacement correction, the standard deviation of 223 μm of the residue is obtained. The performances of the forward MWDCs tracking array meets the requirements of CEE in design.