This paper develops the program MCHII, numerically simulating the physical process of Compton electron currents scattered by the interaction of γ rays with ambient air molecules radiating the early time electromagnetic pulse (E1) during the high altitude nuclear explosion. The paper discusses the waveform characteristics of the electromagnetic pulse E1 as it propagates toward the ground from beneath the explosion point during the high altitude nuclear explosion, and provides a detailed study with regard to the influence of explosion height, energy, and γ spectrum. Numerical simulations are used to present the waveform characteristics of the electromagnetic pulse after going through the ionized layer above the explosion point after the high altitude nuclear explosion, and the paper presents the distribution of high altitude electromagnetic pulse waveform amplitudes at satellite orbits.

Numerical Simulation of the HEMP Environment

High-altitude nuclear electromagnetic pulse(HEMP) has a significant effect on electronic devices by cables. This paper makes an analysis of field-wire coupling. With the software of Computer Simulation Technology(CST) constructing the model, coupling current has been acquired. The effect of length, height and impedance on coupling current has been gained. To our surprise, the rise time of HEMP is faster than the time of coupling current. This provides HEMP hardening with the crucial basis.

https://www.ursi.org/Proceedings/ProcGA14/papers/ursi_paper1874.pdf

Coupling effect of transmission lines by HEMP based on CST

Ultra-high-frequency (UHF) sensor is the vital component of a partial discharge detection system and its coupling performance is affected by structural parameters. On the basis of the cavity model theory, this paper studied the influence of the disc electrode diameter, the thickness, the dielectric constant of the dielectric substrate, and the position of the coaxial connection on the performance of the disc-type UHF sensor with the application of the XFdtd software. The simplified finite-difference time-domain simulation model for the gigahertz transverse electromagnetic (GTEM) cell has been established, and the influence of the coaxial feed position on the performance of the disc-type UHF sensor is studied via the frequency domain effective heights in the simulation. The result shows that as the disc electrode diameter, the thickness, and the dielectric constant of the dielectric substrate increase, the working frequency band shifts toward the reducing direction. The position of the coaxial connection has an obvious effect on the resonant mode of sensor, too.

Study on the Disc Sensor Based on the Cavity Mold Theory

The theory of shielding is introduced, and the simulation model is built. The software based on the CST is applied to simulate and analyze the pulse waveform. The shielding effectiveness of different pulse width is computed. Comparing the pulse shielding effectiveness with continuous wave shielding effectiveness, there is consistent result approximately. And the shielding effectiveness based on the frequency function is more accurate and comprehensive than the pulse peak shielding effectiveness.

Simulation analysis for the materials shielding effectiveness of EMP

To analyze the variation of magnetic field waveforms above rails of the railgun during the launching period, the magnetic fields are measured by loop probes. According to the armature's different moving statements and measurement positions, magnetic waveforms are distinguished with each other. The experiment results show that magnetic field waveforms above the rails change at different positions, and the output voltages of probes become larger with the higher velocities. The truncated waveforms expand the spectrum of signals around the rails. The waveforms at different positions are compared with each other, which can inflect the magnetic field distribution along the rails during the launching period. The results are useful in analyzing the interference of the transient environment for the rail launcher and the electromagnetic interference design of railgun systems.

Measure Variation of Magnetic Field Waveforms Above Rails of a Railgun During Launching Period

In order to measure the waveform and amplitude of EMP accurately, the sensors need to be calibrated under the standard fields in the TEM or GTEM cell A set of calibration system is discussed in this paper A highly accurate method of calibrating such sensors is applicable to techniques in both the frequency domain and in the time domain The complete frequency-domain transfer function or the time-domain impulse response function of sensor system can be obtained, thus allowing deconvolution processes to be used to remove perturbations from the measurement waveform by the instrumentation and TEM cell

Methodology of time-domain & frequency-domain calibration and equivalence for EMP sensor

Multi-scale organs image segmentation method improved by squeeze-and-attention based on partially supervised learning

Windows method is a measurement of slot coupling effect in nature when it is used to measure material's shielding effectiveness.The error of measurement will become serious when it is used to measure material's shielding effectiveness in low frequency band.It is difficult to measure material's shielding effectiveness of electromagnetic pulse with Windows method.Device under test method(DUT method) was presented in this paper to overcome the limitations of Windows method in material's shielding effectiveness test.The method can be used to measure any material's shielding effectiveness effectively through the design and the test of the DUT.The method was used to measure shielding effectiveness of special cement.Compared with theoretical analysis,the measurement results prove the DUT method to be very efficient in material's shielding effectiveness test.

Method of Measurement on Material's Shielding Effectiveness Test in Time Domain

In this paper, the finite difference method is used to develop the Fortran software MCHII. The physical process in which the electromagnetic signal is generated by the interaction of nuclear-explosion-induced Compton currents with the geomagnetic field is numerically simulated. The electromagnetic pulse waveforms below the burst point are investigated. The effects of the height of burst, yield and the time-dependence of γ-rays are calculated by using the MCHII code. The results agree well with those obtained by using the code CHAP.

http://iopscience.iop.org/article/10.1088/1009-1963/12/12/007/pdf

Numerical simulation of the early-time high altitude electromagnetic pulse

The coupling effects of FREMP to the cavity wi th a slot are studied by using the finite difference time domain (FD TD) meth od in this paper. The computational data are compared with that of NEMP.The resu lts indicate that it is easier for FREMP than NEMP to couple into the cavity thr ough slots,and FREMP can lead to a resonance in the cavity with a slot.

Numerical Analysis on Slot Coupling Effects of FREMP

Popular Tasks used by Researchers

How can I help with your research?

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

We encountered an error while loading the panel. Please try refreshing the page.

Something went wrong

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

Anyone with the link can view this chat. You can switch it back to private anytime.

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Liu Shunkun

Author Tools

Chat about Author