摘要：
We present the design and test results of a high-speed low-noise front-end readout Application Specific Integrated Circuit (ASIC) prototype, which is designed for a novel ionization chamber of the high intensity beam detection. This ASIC prototype is a single-channel ASIC and composed of a charge collection electrode, a Charge Sensitive Amplifier (CSA), a discriminator, a buffer and a two-stage source follower. Three different feedback capacitances are implemented in the CSA. The prototype has been manufactured in a standard 0.18 mu m CMOS process. The test results show that the input equivalent noise is from 22.8 e- to 30.6 e-. The input charge range is about 1.18 fC with a non-linearity of 3.13%, 3.95 fC with a non-linearity of 2.38% and 7.58 fC with a non-linearity of 3.42% for the feedback capacitance of 5 fF, 30 fF and 60 fF, respectively. The shaping time of the CSA can be less than 0.5 mu s. The power consumption of the CSA and the whole ASIC prototype is about 108 mu W and 1.179 mW under the power supply of 1.8 V, respectively.
通讯机构：
[Huang, GM ] C;Cent China Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
关键词：
scalar magnetometer;subsea power cables;attitude-independent detection;route tracking;high sea condition
摘要：
<jats:p>To overcome the shortcoming wherein the accuracy of subsea cable detection can be affected by the determination of the bias vector, scale factors, and non-orthogonality corrections of the vector magnetometer, a real-time attitude-independent route tracking method for subsea power cables is investigated theoretically and experimentally by means of scalar magnetic field checking. The measurement of the magnetic field Bc produced by the current in a cable is made immune to the influence of the platform attitude by extracting the component of Bc along the geomagnetic field using a high-bandwidth self-oscillating optically pumped magnetometer. The self-oscillating frequency is proved to be independent of the attitude of the magnetometer with the theoretical model. Experiments are carried out to test the attitude-independent performance, and the effectiveness of route tracking is verified by the results of the sea experiment. The proposed method will effectively improve the ability to locate subsea cables under high sea conditions.</jats:p>
通讯机构：
[Li, GX ; Huang, GM] C;Cent China Normal Univ, Sch Phys Sci & Technol, Wuhan 430079, Peoples R China.
关键词：
Absorption spectrum;magnetic resonance signal;multipole moment master equations;optically pumped magnetometer
摘要：
Self-oscillating magnetometers with high sensitivity are widely used in fields such as biomedicine and remote sensing. However, few studies comprehensively consider the effect of different parameters on their performance. We examined the effects of laser intensity, resonance detuning, radio frequency (RF) magnetic field, and atomic cell on the performance of portable self-oscillating magnetometers. To obtain the atomic absorption spectrum, we solved the system's master equation in the multipole moment form. In theory, we analyse the influencing factors on the atomic magnetic resonance (AMR) signal. In the experiment, we artificially varied the relevant parameters to control the trends of changes in the atomic absorption spectra and evaluated their performance. The results are beneficial for optimizing the parameters of portable self-oscillating magnetometers with a laser pump-probe structure.
通讯机构：
[Yang, P ] C;Cent China Normal Univ, Key Lab Quark & Lepton Phys, PLAC, Wuhan 430074, Peoples R China.
关键词：
DAC;R-2R;bandgap;ACBC AMP
摘要：
The Lanzhou Heavy Ion Research Facility (LIRF) is the largest heavy ion research facility in China, providing a substantial volume of experimental data for fundamental research in nuclear physics. The Topmetal-CEE is a pixel readout chip specifically designed for tracking detectors. Within the Topmetal-CEE framework, the front-end amplifier and comparator necessitate precisely adjustable bias voltages. Hence, in this paper, a 14-bit resolution DAC with an R-2R resistor network structure is designed, along with an amplifier featuring high driving capabilities as the DAC driver, thus preventing potential impedance issues when driving large pixel arrays. Test results demonstrate that the DAC module, operating under a 3.3 V supply voltage, can consistently output voltages ranging from 0 to 1.8 V. Furthermore, the differential non-linearity error is less than 1.07 LSB, and the integral non-linearity error is less than 1.57 LSB.
通讯机构：
[Sun, XM ; Xiao, L] C;Cent China Normal Univ, Dept Phys, Wuhan 430079, Hubei, Peoples R China.
关键词：
Front-end electronics for detector readout;Particle tracking detectors;VLSI circuits
摘要：
<jats:title>Abstract</jats:title>
<jats:p>We present the design of a prototype MAPS sensor MIC6_V1 based on a 55 nm Quad-well CMOS Image Sensor process for the CEPC vertex detector. A new node-based, data-driven, parallel readout architecture is implemented to achieve high spatial resolution, fast readout, and low power consumption. The size of MIC6_V1 is 2.8 mm × 2.8 mm, which contains a pixel matrix of 64 rows by 64 columns, and the pixel size is 23.6 μ m × 20 μ m. The integration time is 5 μs, and the hit arrival time measurement accuracy is 10 ns.</jats:p>
作者机构：
[Huang, Guangming; Li, Gaoxiang; Tang, Wangwang] Cent China Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.;[Yang, Guoqing] Hangzhou Dianzi Univ, Coll Elect & Informat, Hangzhou 310018, Peoples R China.
通讯机构：
[Huang, GM ] C;Cent China Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
关键词：
magnetic target localization;magnetic gradient tensor;localization dead zone;eigenvector constraints
摘要：
<jats:p>Magnetic target localization using the magnetic gradient tensor (MGT) plays a significant role in underwater localization. However, this method inherently has a localization dead zone, which presents challenges for real-world applications. This paper delves into the root cause of this dead zone, identifying the non-invertibility of the MGT when the magnetic moment vector is orthogonal to the position vector from the target to the observation point. To tackle this issue, a method based on the eigenvector constraints is proposed. By constructing an objective function with eigenvector constraints and leveraging the property that its gradient at the observation point is zero, we derive an equivalent expression for the inverse of MGT that always holds and further develop a dead-zone-free localization method. To validate the robustness and efficacy of the proposed localization method, a comparative analysis with other methods is conducted. Simulation results in a 10 m × 10 m area under Gaussian noise demonstrate the proposed method’s capability to eliminate the dead zone and achieve an average localization error of 0.032 m. Experimental results further demonstrate that the proposed method eliminates the localization dead zone and exhibits greater robustness than the dominant method in the normal region. In summation, this paper provides an effective method for eliminating localization dead zone, offering a more stable and reliable method for magnetic target localization in practice.</jats:p>
通讯机构：
[Liu, J; Zhang, DL ; Gao, CS; Wang, HL] C;[Wang, Z ] G;Guizhou Normal Univ, Sch Phys & Elect Sci, Guiyang, Peoples R China.;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, PLAC, Wuhan, Peoples R China.;Hubei Prov Engn Res Ctr Silicon Pixel Chip & Detec, Wuhan, Peoples R China.
摘要：
A beam monitor system is being developed for the cool storage ring (CSR) external-target experiment (CEE) at the Heavy Ion Research Facility in Lanzhou (HIRFL). The beam monitor is required to measure the lateral position of each beam particle with spatial resolution less than 50 mu m andwith beam rates up to 1 MHz. As the beam intensity increases, the build-up of slow-moving positive ions created from the ionization of the detector gas by the beam leads to a significant distortion of the nominal electric field in the drift region. In this work, simulation studies of the beam monitor are performed, in particular the space charge effect and the correction strategy. It shows that the space charge at the nominal drift electric field of 700 V/cm modifies the electric field in the sensitive volume by roughly 5% in both the drift and transverse directions. The distortion on the measured position is up to 0.35 mm in the 5s region of the beam profile. The expected spatial resolution of 500 MeV/u U ion is 34.5 mu m considering the pixel noise of 400 e(-) and the 100 mu m x 1 mm pixel size of the charge sensor chip in the selected gas mixture.
通讯机构：
[Chaosong Gao; Hulin Wang] P;PLAC, Key Laboratory of Quark & Lepton Physics (MOE), Central China Normal University, Wuhan, 430079, China<&wdkj&>Hubei Provincial Engineering Research Center of Silicon Pixel Chip & Detection Technology, Wuhan, 430079, China
摘要：
Within the project of building a beam monitor for the CSR external-target experiment (CEE) at HIRFL, charge sensors that are used in the gaseous ionization detector and in line with the Topmetal principle, are being developed and studied. It integrates in the same chip a topmost metal, which senses the drifting charges, and the readout circuitry. This paper presents the design and preliminary characterization of the first full-sized Topmetal-CEE chip, the Topmetal-CEEv1, which follows this design principle while tailored to the CEE physics programs. It features an enlarged 1 mm x 89 mu m topmost metal per pixel, in-pixel discrimination and sparsified readout, as well as an amplitude measurement with the Time-over-Threshold (TOT) method. The studies are carried out with the injected pulses and the alpha particles from Am-241. The major functionalities of the chip are verified. Its performance pertaining to the usage as charge sensing and readout chip in the beam monitor of CEE are also preliminarily evaluated. It will be used in the upgraded prototype of the beam monitor, superseding the common-purpose Topmetal-II- chip.
通讯机构：
[Zhao, CX ; Gao, CS; Liu, J ; Wang, HL] C;[Wang, Z ] G;Cent China Normal Univ, Key Lab Quark & Lepton Phys, PLAC, MOE, Wuhan 430079, Peoples R China.;Hubei Prov Engn Res Ctr Silicon Pixel Chip & Detec, Wuhan, Peoples R China.;Guizhou Normal Univ, Sch Phys & Elect Sci, Guiyang, Peoples R China.
摘要：
The cool storage ring (CSR) external-target experiment (CEE) will be the first large-scale nuclear physics experiment at the Heavy Ion Research Facility in Lanzhou (HIRFL). The beam monitor, designed to measure the lateral position of each beam particle, will improve the precision of primary vertex reconstruction otherwise determined by the time projection chamber (TPC) and multi-wire drift chambers (MWDCs). The beam monitor mainly contains two gaseous ionization sub-detectors, each measuring one lateral coordinate of the beam. The design requirements include the spatial resolution of <50 mu m, the two-particle separation capability of <1 mu s, the rate capability of >10(6) pps, and small material budget. It features novel front-end pixel chips for both charge sensing and readout functions. The first prototype, utilizing the common-purpose Topmetal-II-chips, has been developed and tested; the second one, deploying the custom-designed Topmetal-CEEv1 chips, is currently being assembled. In this paper we will present the detector specifications, design and test of the prototypes, in particular the charge sensing and readout chips.
摘要：
Atom-based mixers have been shown to be very useful in performing the absolute measurement of the magnitude of a radio-frequency (rf) field by using Autler-Townes (AT) splitting. However, there has been less success in measuring the phase of a rf field with the AT splitting in a magnetic-resonance system. The phase of the rf magnetic field plays a very important role in imaging applications. Here, we design an atomic mixer for measuring the phase of the rf field by detecting the transmission spectra of a laser-detected magnetic-resonance system based on the interference between Raman and cascade two-photon processes for Fg = 4 of the D1 line of cesium atoms. A scheme of measuring the rf phase can be realized with the elimination of the ac Zeeman shift of the system by adjusting the amplitude ratio of a transverse fundamental-wave field and its third-harmonic field. Theoretical and experimental results show that the scheme with cancellation of the ac Zeeman shift is superior in linear measurement of the longitudinal rf component. Our results provide schemes for a magnetic sensor based on quantum interference of nonlinear processes for the absolute measurement of the relative phase of rf fields.
作者机构：
[Chen, Zhao] Beijing National Research Center for Information Science and Technology, Tsinghua University, Beijing, China;[Xiao, Jian; Wang, Ji; Huang, Guangming] Department of Electronics and Information Engineering, College of Physical Science and Technology, Central China Normal University, Wuhan, China
摘要：
In this letter, we study the hybrid-field cascaded channel estimation in the extremely large-scale RIS (XL-RIS) assisted multi-user millimeter wave systems, where the cascaded channel is composed of far-field and near-field radiation components, and has spatial non-stationarity caused by visibility regions. We propose a U-shaped network based on the dedicated multilayer perceptron (MLP) architecture, termed as U-MLP, to realize the high-dimensional channel reconstruction with limited pilot overhead. In U-MLP, a basic feature extraction module-Permutator is designed to capture the long-range dependency of non-stationary channel, while the U-shaped backbone is constructed to exploit effective latent representation of the high-dimensional cascaded channel. Numerical results show that the proposed U-MLP outperforms existing channel estimation benchmarks with less pilot overhead.
通讯机构：
[Ai, PC; Xiao, L ] C;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, PLAC, Wuhan 430079, Peoples R China.;Hubei Prov Engn Res Ctr Silicon Pixel Chip & Detec, Wuhan 430079, Peoples R China.
关键词：
nuclear detectors;silicon photomultipliers;pulse timing;deep learning;neural networks;physical constraints;label-free loss function
摘要：
<jats:title>Abstract</jats:title>
<jats:p>Pulse timing is an important topic in nuclear instrumentation, with far-reaching applications from high energy physics to radiation imaging. While high-speed analog-to-digital converters become more and more developed and accessible, their potential uses and merits in nuclear detector signal processing are still uncertain, partially due to associated timing algorithms which are not fully understood and utilized. In this paper, we propose a novel method based on deep learning for timing analysis of modularized detectors without explicit needs of labeling event data. By taking advantage of the intrinsic time correlations, a label-free loss function with a specially designed regularizer is formed to supervise the training of neural networks (NNs) towards a meaningful and accurate mapping function. We mathematically demonstrate the existence of the optimal function desired by the method, and give a systematic algorithm for training and calibration of the model. The proposed method is validated on two experimental datasets based on silicon photomultipliers as main transducers. In the toy experiment, the NN model achieves the single-channel time resolution of 8.8 ps and exhibits robustness against concept drift in the dataset. In the electromagnetic calorimeter experiment, several NN models (fully-connected, convolutional neural network and long short-term memory) are tested to show their conformance to the underlying physical constraint and to judge their performance against traditional methods. In total, the proposed method works well in either ideal or noisy experimental condition and recovers the time information from waveform samples successfully and precisely.</jats:p>
通讯机构：
[Guangming Huang] D;Department of Physics, Central China Normal University, Wuhan 430079, China<&wdkj&>Author to whom correspondence should be addressed.
摘要：
With the demand for fast response of magnetic field measurement and the development of laser diode technology, self-oscillating laser-pumped atomic magnetometers have become a new development trend. In this work, we designed a portable self-oscillating VCSEL-pumped Cs atom magnetometer, including the probe (optical path) and circuits. The signal amplification and feedback loop of the magnetometer, VCSEL laser control unit, and atomic cell temperature control unit were realized. We tested the performance of the magnetometer in the metering station. Finally, The performance of the VCSEL-pumped magnetometer designed in this work was compared with that of a CS-3 lamp-pumped self-oscillating atomic magnetometer; their performance was found to be mostly in the same order of magnitude, while the power consumption of our magnetometer was 3 W less than that of the CS-3. This work represents an exploratory attempt to integrate and miniaturize a portable self-oscillating VCSEL-pumped Cs atomic magnetometer.
通讯机构：
[Li, GX ; Huang, GM] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
We theoretically investigate the magneto-optical rotation (MOR) effect in cesium atoms in the Voigt geometry, in which an off-resonance linearly polarized laser beam serves as both pump and probe. By calculating the detailed evolution of atomic multipole moments truncated to second-rank, alignment-to-orientation conversion (AOC) effects are observed in two hyperfine ground states. The mechanisms responsible for this effect are demonstrated. The tensor AC-Stark shift produced by the optical pumping generates a nonlinear effect, resulting in atomic alignment directly coupled to orientation, which enables spin orientation to be obtained. Simultaneously, spin-exchange collisions lead to atomic alignment and orientation transfer between two ground-state manifolds. Additionally, we present the analytical expression of atomic spin polarization described by atomic multipole moments, and the contributions of the AOC effect to the optical-rotation signals are discussed in different light power regimes. Our results can be helpful for guiding MOR experiments by refining and optimizing the parameters.
摘要：
A prototype beam monitor was designed to provide tracking information for heavy-ion projectiles for the cool storage ring (CSR) external target experiment (CEE) at the Heavy Ion Research Facility in Lanzhou (HIRFL). High granularity and direct charge sensing are the main features of this device. It measures the beam position in a two-dimensional (2D) plane transverse to the beam direction on an event-by-event basis. The current design consists of two field cages inside a single vessel that operates independently and has electrical drift fields in orthogonal directions. Preliminary tests of the prototype were performed using a
$${{}^{241}\mathrm{Am}}$$
$$\alpha$$
source. The results show that a spatial resolution of less than 40
$${\upmu \mathrm{m}}$$
and a time resolution of less than 600ns can be achieved.
