The front-end electronics design of dose monitors for beam delivery system of Shanghai Advanced Proton Therapy Facility

A front-end electronics of dose monitor has been developed for measuring irradiation dose to the patient in Shanghai Advanced Proton Therapy Facility.The parallel plate ionization chamber is used for the dose monitoring.Unlike the traditional method of recycling capacitor integration and voltage-to-frequency conversion,this dose monitor electronics uses the trans-impedance amplifier and analog-to-digital conversion method.It performs satisfactorily,with the integral nonlinearity of less than ±0.04 nA in the range of-400 to 50 nA and the resolution of about±0.6 nA.

Front-end Control Mechanism of Electronic Records

In the digital era,how to ensure the authenticity and integrity of elec-tronic records has become an open challenging issue.Front-end control is an important concept as well as a basic principle in electronic record management.Under the instruction of front-end control,many original management links in the record-management stage are required to move forward,and the managers enter the formation stage of the electronic records to ensure the originality.How-ever,the front-end control technique primarily focuses on transaction manage-ment,and it lacks the strategy of providing the control of electronic records.In this paper,a novel electronic record front-end control mechanism is proposed by adopting proxy re-encryption and requiring archivists to participate in the man-agement of electronic records before the record is created to solve the problem.Specifically,when an electronic record is generated,the proposed mechanism interacts with the producer of the electronic record to generate a corresponding encryption key.Moreover,electronic records are encrypted by the key to protect their confidentiality,which can prevent the leakage of electronic record informa-tion.In addition,when transferring the electronic record,archivists use proxy re-encryption technology to convert electronic records,allowing management by an archivist,ensuring their originality and authenticity.

Classical Dynamics of Muonic-Electronic Helium and Heliumlike Ions: The Allowance for the Eccentricity of the Muon and Nucleus Orbits

In the previous paper by one of us (hereafter paper I), the author considered Rydberg states of the muonic-electronic helium atom or helium-like ion and used the fact that the muon motion occurs much more rapidly than the electron motion. Assuming that the muon and nucleus orbits are circular, he applied the analytical method based on separating rapid and slow subsystems. He showed that the electron moves in an effective potential that is mathematically equivalent to the potential of a satellite orbiting an oblate planet like the Earth. He also showed that the “unperturbed” elliptical orbit of the electron engages in two precessions simultaneously: the precession of the electron orbit in the plane of the orbit and the precession of the orbital plane of the electron around the axis perpendicular to the plane of the muon and nuclear orbits. The problem remained whether or not the allowance for the ellipticity of the orbit could significantly change the results. In the present paper, we address this problem: we study how the allowance for a relatively low eccentricity ε of the muon and nucleus orbits affects the motion of the electron. We derive an additional, ε-dependent term in the effective potential for the motion of the electron. We show analytically that in the particular case of the planar geometry (where the electron orbit is in the plane of the muon and nucleus orbits), it leads to an additional contribution to the frequency of the precession of the electron orbit. We demonstrate that this additional, ε-depen- dent contribution to the precession frequency of the electron orbit can reach the same order of magnitude as the primary, ε-independent contribution to the precession frequency. Therefore, the results of our paper seem to be important not only qualitatively, but also quantitatively.

BESⅢ Muon电子学VME控制扇出插件的优化设计

主要阐述BESⅢ Muon电子学VME控制扇出插件的优化设计,主要内容包括对VME控制扇出插件控制芯片FPGA的固件进行优化,并且设计了相关实验来对优化方案进行测试。

BESⅢ Muon前端电子学数据链过流保护系统设计

论文介绍了BESⅢ Muon前端电子学数据链过流保护系统的设计,其主要功能是监控数据链供电,防止数据链受大电流损伤。文章主要阐述了过流保护系统的软硬件设计,同时给出了过流保护系统原型机各项基本指标的测试结果。

An Electron Model Consistent with Electron-Positron Pair Production from High Energy Photons

This is a rotating charge loop model of an electron which explains the electron’s de Broglie base frequency to an accuracy of over 6 decimal places. The model also predicts the magnetic moment of the electron to over 6 decimal places and helps explain the transition from a purely electromagnetic photon to a fermion state of matter. The model also explains how charge and spin are conserved in the transition. Finally, this concept might be extended to explain the muon and tau higher energy states of the electron as well.

Low-temperature metal–oxide thin-film transistor technologies for implementing flexible electronic circuits and systems

Here we review two 300℃metal–oxide(MO)thin-film transistor(TFT)technologies for the implementation of flexible electronic circuits and systems.Fluorination-enhanced TFTs for suppressing the variation and shift of turn-on voltage(VON),and dual-gate TFTs for acquiring sensor signals and modulating VON have been deployed to improve the robustness and performance of the systems in which they are deployed.Digital circuit building blocks based on fluorinated TFTs have been designed,fabricated,and characterized,which demonstrate the utility of the proposed low-temperature TFT technologies for implementing flexible electronic systems.The construction and characterization of an analog front-end system for the acquisition of bio-potential signals and an active-matrix sensor array for the acquisition of tactile images have been reported recently.

An Electron Model Based on the Fine Structure Constant

In previous publications, the author has proposed a model of the electron’s internal structure, wherein a positively-charged negative mass outer shell and a negatively-charged positive mass central core are proposed to resolve the electron’s charge and mass inconsistencies. That model is modified in this document by assuming the electron’s radius is exactly equal to the classical electron radius. The attributes of the internal components of the electron’s structure have been recalculated accordingly. The shape of the electron is also predicted, and found to be slightly aspherical on the order of an oblate ellipsoid. This shape is attributed to centrifugal force and compliant outer shell material. It is interesting to note that all of the electron’s attributes, both external and internal, with the exception of mass and angular moment, are functions of the fine structure constant a, and can be calculated from just three additional constants: electron mass, Planck’s constant, and speed of light. In particular, the ratios of the outer shell charge and mass to the electron charge and mass, respectively, are 3/2a. The ratios of the central core charge and mass to the electron charge and mass, respectively, are 1-(3/2a). Attributes of the electron are compared with those of the muon. Charge and spin angular momentum are the same, while mass, magnetic moment, and radius appear to be related by the fine structure constant. The mass of the electron outer shell is nearly equal to the mass of the muon. The muon internal structure can be modeled exactly the same as for the electron, with exactly the same attribute relationships.

Design of a Novel Front-End Readout ASIC for PET Imaging System

The architecture of a multi-channel front-end system is important for realizing a high-resolution PET system. We propose a novel front-end readout electronic system with TDC to deal with time information for PET system which can easily design the timing control. Each channel consists of a charge preamplifier, slow/fast shaper, discriminator and an analog memory. There are an ADC and a TDC to process the energy information and time information for each channel at the same time. In this paper, the whole system signals flow is all simulated by MATLAB. The simulation results show that the proposed system can process slender current from the detector and achieve the energy and time information. The proposed architecture can be applied to high-resolution PET imaging systems with multi-channel ASICs.

Low-power SiPM readout BETA ASIC for space applications

The BETA application-specific integrated circuit(ASIC)is a fully programmable chip designed to amplify,shape and digitize the signal of up to 64 Silicon photomultiplier(SiPM)channels,with a power consumption of approximately~1 mW/channel.Owing to its dual-path gain,the BETA chip is capable of resolving single photoelectrons(phes)with a signal-to-noise ratio(SNR)>5 while simultaneously achieving a dynamic range of~4000 phes.Thus,BETA can provide a cost-effective solution for the readout of SiPMs in space missions and other applications with a maximum rate below 10 kHz.In this study,we describe the key characteristics of the BETA ASIC and present an evaluation of the performance of its 16-channel version,which is implemented using 130 nm technology.The ASIC also contains two discriminators that can provide trigger signals with a time jitter down to 400 ps FWHM for 10 phes.The linearity error of the charge gain measurement was less than 2%for a dynamic range as large as 15 bits.

Onboard calibration circuit for the DAMPE BGO calorimeter front-end electronics

DAMPE （DArk Matter Particle Explorer） is a scientific satellite which is mainly aimed at indirectly searching for clark matter in st）ace. One critical sub-detector of the DAMPE payload is the BGO （bismuth germanium oxide） calorimeter, which contains 1848 PMT （photomultiplier tube） dynodes and 16 FEE （Front-End Electronics） boards. VA160 and VATA160, two 32-channel low power ASICs （Application Specific Integrated Circuits）, are adopted as the key components on the FEEs to perform charge measurement for the PMT signals. In order to inonitor the parameter drift which may be caused by temperature variation, aging, or other environmental factors, an onboard calibration circuit is designed for the VA160 and VATA160 ASICs. It is mainly composed of a 12-bit DAC （Digital to Analog Converter）, an operatioual amplifier and an analog switch. Test results showed that a dynamic range of 0- 30 pC with a precision of 5 fC （Root Meam Square, RMS） was achieved, which covers the VA160＇s input range. It can be used to compensate for the teinperature drift and test the trigger function of the FEEs. The calibration circuit has been implemented for the front-end electronics of the BGO Calorimeter and verified by all the environmental tests for both Qualification Model and Flight Model of DAMPE. The DAMPE satellite was launched at the end of 2015 and the calibration circuit will operate periodically in space.

Estimates of the Charges and Size of the Three Types of Neutrinos

It is the current belief of the Physics Community that neutrinos are bereft of Charge because of Conservation of Charge in decay processes such as Beta Decay and are point particles with no physical size or shape. It is the purpose of this paper to calculate the charges and the size of the electron neutrino, the muon neutrino, and the tau neutrino based on data available of their rest masses using the charges and rest masses of the electron, muon, and tau leptons from the Standard Model of Particle Physics Table. We base our calculations on the premise that Energy can create both Mass and Charge. Charge by itself is not conserved in any process that produces neutrinos. Only Total Energy is conserved.

Development of front-end readout electronics for silicon strip detectors

Front-end readout electronics have been developed for silicon strip detectors at our institute. In this system an Application Specific Integrated Circuit （ASIC） ATHED is used to realize multi-channel energy and time measurements. The slow control of ASIC chips is achieved by parallel port and the timing control signals of ASIC chips are implemented with the CPLD. The data acquisition is carried out with a PXI-DAQ card. The software has a user-friendly GUI developed with LabWindows/CVI in the Windows XP operating system. The test results show that the energy resolution is about 1.14% for alpha at 5.48 MeV and the maximum channel crosstalk of the system is 4.60%. The performance of the system is very reliable and is suitable for nuclear physics experiments.

Design of front-end electronics based on a programmable transimpedance amplifier for an HIAF beam intensity detector

Background The beam intensity of the High Intensity Heavy-ion Accelerator Facility(HIAF)is converted into current sig-nals by beam intensity detectors and then processed by front-end electronics.The performance of the front-end electronics affects the measurement accuracy of the accelerator.Purpose To design front-end electronics to readout the current signals from a beam intensity detector.Methods A programmable transimpedance amplifier(TIA)converts current signals into voltage signals and amplify the signals.An analog-to-digital converter(ADC)converts analog signals into digital signals under the control of ZYNQ7015.Results and conclusion An integrated front-end electronics system was designed and verified.The electronics could collect and process current signals from 40 pA to 4 mA.The system had a higher dynamic range than traditional beam intensity measuring electronics.

Design of a high-dynamic-range prototype readout system for VLAST calorimeter

In the future, the Very Large Area gamma-ray Space Telescope is expected to observe high-energy electrons and gamma rays in the MeV to TeV range with unprecedented acceptance. As part of the detector suite, a high-energy imaging calorimeter(HEIC) is currently being developed as a homogeneous calorimeter that utilizes long bismuth germanate(BGO) scintillation crystals as both absorbers and detectors. To accurately measure the energy deposition in the BGO bar of HEIC, a highdynamic-range readout method using a silicon photomultiplier(SiPM) and multiphotodiode(PD) with different active areas has been proposed. A prototype readout system that adopts multichannel charge measurement ASICs was also developed to read out the combined system of SiPMs and PDs. Preliminary tests confirmed the feasibility of the readout scheme, which is expected to have a dynamic range close to 10~6.

FPGA implementation of neural network accelerator for pulse information extraction in high energy physics

Extracting the amplitude and time information from the shaped pulse is an important step in nuclear physics experiments.For this purpose,a neural network can be an alternative in off-line data processing.For processing the data in real time and reducing the off-line data storage required in a trigger event,we designed a customized neural network accelerator on a field programmable gate array platform to implement specific layers in a convolutional neural network.The latter is then used in the front-end electronics of the detector.With fully reconfigurable hardware,a tested neural network structure was used for accurate timing of shaped pulses common in front-end electronics.This design can handle up to four channels of pulse signals at once.The peak performance of each channel is 1.665 Giga operations per second at a working frequency of 25 MHz.

A 5.12-GHz LC-based phase-locked loop for silicon pixel readouts of high-energy physics

There is an urgent need for high-quality and high-frequency clock generators for high-energy physics experiments.The transmission data rate exceeds 10 Gbps for a single channel in future readout electronics of silicon pixel detectors.Others,such as time measurement detectors,require a high time resolution based on the time-to-digital readout architecture.A phase-locked loop(PLL)is an essential and broadly used circuit in these applications.This study presents an application-specific integrated circuit of a low-jitter,low-power LC-tank that is PLL fabricated using 55-nm CMOS technology.It includes a 3rd-order frequency synthesis loop with a programmable bandwidth,a divide-by-2 pre-scaler,standard low-voltage differential signaling interfaces,and a current mode logic(CML)driver for clock transmissions.All the d-flip-flop dividers and phase-frequency detectors are protected from single-event upsets using the triple modular redundancy technique.The proposed VCO uses low-pass filters to suppress the noise from bias circuits.The tested LC-PLL covers a frequency locking range between 4.74 GHz and 5.92 GHz with two sub-bands.The jitter measurements of the frequency-halved clock(2.56 GHz)are less than 460 fs and 0.8 ps for the random and deterministic jitters,respectively,and a total of 7.5 ps peak-to-peak with a bit error rate of 10^(-12).The random and total jitter values for frequencies of 426 MHz and 20 MHz are less than 1.8 ps and 65 ps,respectively.The LC-PLL consumed 27 mW for the core and 73.8 mW in total.The measured results nearly coincided with the simulations and validated the analyses and tests.

Design of fast adaptive readout system for wire scanners

A new wide-range fast readout system capable of adaptive identification is designed for wire scanners,which are used to measure beam profiles and emittance.This system is capable of handling varying current signals with Gaussian distributions and current pulses up to 1000 counts/s, as well as an input current range of 1 n A–1 m A. When tested, the resolution was found to exceed 3.68% for full scale, the nonlinearity was found to be less than 0.11%, and the measurement sensibility was found to be less than 5 p A. We believe that the system will play a crucial role in improving the measurement accuracy of beam diagnosis and the efficiency of accelerator operation,as well as decreasing the time required for beam tuning.This system was applied to the beam diagnosis of an injector II prototype for an accelerator-driven subcritical system and produced excellent measurement results. A description of the adaptive fast readout system for wire scanners is presented in this paper.

A SKIROC2-based prototype electronics system for silicon PIN array

Background Silicon PIN(Si-PIN)diode has been widely used in high-energy physics experiments.The next-generation experiments ask for a large amount of the Si-PIN diode arrays,leading to a requirement for the electronics system with features of higher integration and lower power consumption than the traditional ones.Purpose The aim was to design and implement a prototype of multi-channel electronic system,which is based on the SKIROC2 ASIC.The system is also considered as the pre-research of the silicon–tungsten(Si-W)ECAL for CEPC.Methods The prototype is divided into two parts,so that it has the potentiality for the expansion of more readout channels.The front-end board(FEB),which carries a Si-PIN diode array and an ASIC of SKIROC2 on it,provides high voltage to the Si-PIN diodes and processes the signals as well.The FEB is configured by a data interface board(DIF)and sends data to the DIF,which then transfers data to PC via USB interface after packing process.Results The prototype electronics system has been implemented.The equivalent noise level of all the 64 channels is below 0.4 fC.The dynamic range is up to+3000 fC with an integral nonlinearity(INL)of 0.2%,and the gain non-uniformity is better than 5%.The energy resolution with 59 keV X-rays from 241Am is about 13.3%(in RMS),while the signal-to-noise ratio(SNR)reaches about 10.9 for minimum ionizing particles(MIPs).Conclusion In this paper,a SKIROC2-based prototype electronics system for Si-PIN array,as well as the performance test,has been presented.The system has features of high integration,low noise,and high dynamic range.The SKIROC2,as well as the design concept of the electronics system,can be applied to the preliminary prototype Si-W ECAL of CEPC.

On the Nature of πand μMesons

Earlier it was shown [1], that neutrino is a specific magnetic γ-quantum, which as any γ-quantum carries away the reaction energy. This allows taking a fresh look at the chain of reactions pion±→muon± →e±, which is accompanied by the emission of three neutrinos, but in which no other particles are generated. Since the role of neutrinos is a throwing away the energy of the initial particles, it is easy to conclude that both pion and muon are excited states of electron. The introduction of an additional assumption about the possible mechanism of the excited state of an elementary particle allows us to estimate the mass of these excited states. The obtained estimates are in good agreement with the experimentally measured values of the pion and muon masses.