Nemp
Author: J | 2025-04-25
NEMP: Northeast Metropolitan Park: NEMP: N cleo de Estudos sobre M dia e Pol tica: NEMP: Northeast Monitoring Program: NEMP: Neurology Matching Program: NEMP: National Eutrophication Monitoring Programme: NEMP: National Eutrophication Management Program: NEMP: Newcastle Environmental Management Plan (Australia) NEMP: National Examination
Nemp/readme.md at master DanielGausi/Nemp - GitHub
Distances. The study provides a theoretical foundation for further research on nuclear explosion detection and offers scientific support for formulating relevant protective measures. 2. Mechanism of GenerationA NEMP is a strong electromagnetic wave generated instantaneously during a nuclear explosion. The large amount of gamma rays released by the explosion interacts with the surrounding atmosphere, primarily involving the electron–positron pair production, photoelectric effect, and Compton scattering. The average energy of the photons (1.5 MeV) and the atomic numbers of the atmospheric constituents (such as nitrogen and oxygen) determine that the Compton effect is the primary mechanism exciting the NEMP, as illustrated in Figure 1. This paper mainly considers the physical process whereby radiation interacts with surrounding air molecules to produce Compton currents, thereby exciting electromagnetic pulses [20].When a nuclear weapon detonates in a low-altitude environment, the photons radiated downward are absorbed by the upper layers of the ground’s geological medium. In contrast, radiation emitted outward and upward ionizes the air, causing charge separation and resulting in the generation of a significant number of Compton electrons. These electrons move outward, creating a Compton current, which manifests as a net vertical flow of electrons directed upward. Consequently, the source region is excited and radiates electromagnetic energy outward. The electromagnetic pulse generated by low-altitude nuclear explosion is shown in Figure 2. 3. Introduction to Numerical Simulation MethodsA NEMP primarily originates from the Compton currents generated by the interaction of prompt gamma rays produced by explosions with air (or ground media). The ionization of air
NEMP - What does NEMP Stand For? - Acronyms and Slang
Study on electromagnetic pulse of air nuclear explosion. In Proceedings of the 2005 China Association for Science and Technology Annual Conference, Urumqi, China, 20–22 August 2005. [Google Scholar] Figure 1. Comparison of the relative occurrence rates of three processes as a function of photon energy and atomic number the medium. Figure 1. Comparison of the relative occurrence rates of three processes as a function of photon energy and atomic number the medium. Figure 2. Schematic diagram of low–altitude NEMP generation. Figure 2. Schematic diagram of low–altitude NEMP generation. Figure 3. The geometric schematic diagram of the spherical coordinate system ( r , θ , ϕ ) and the rotating ellipsoid–hyperbolic orthogonal coordinate system ( ξ , ζ , ϕ ) at the field point P. Click here to enlarge figure --> Figure 3. The geometric schematic diagram of the spherical coordinate system ( r , θ , ϕ ) and the rotating ellipsoid–hyperbolic orthogonal coordinate system ( ξ , ζ , ϕ ) at the field point P. Figure 4. Comparison of results between the study and existing literature. Figure 4. Comparison of results between the study and existing literature. Figure 5. Distribution map of source area under specific conditions. Figure 5. Distribution map of source area under specific conditions. Figure 6. Schematic diagram of nuclear explosion points and observation points from different angles at the same distance. Figure 6. Schematic diagram of nuclear explosion points and observation points from different angles at the same distance. Figure 7. Comparison ofDanielGausi/Nemp: Nemp - Noch ein mp3-Player - GitHub
. NEMP: Northeast Metropolitan Park: NEMP: N cleo de Estudos sobre M dia e Pol tica: NEMP: Northeast Monitoring Program: NEMP: Neurology Matching Program: NEMP: National Eutrophication Monitoring Programme: NEMP: National Eutrophication Management Program: NEMP: Newcastle Environmental Management Plan (Australia) NEMP: National Examination NEMP Range: l/m Heavy duty magnetically coupled leak free centrifugal pumps manufactured in chemical resistant thermoplastic and entirely non-metallic. Informational PDFs - NEMP 25/5 - NEMP 20/30 - NEMP 40/6 - NEMP 50/7 - NEMP 60/6Nemp - Browse Files at SourceForge.net
Results AnalysisThe gamma waveform used in the low-altitude NEMP was a double-pulse waveform, where the two pulses represented the primary and secondary nuclear reactions of the nuclear device, respectively. The time interval between these two pulses corresponded to the action time interval between the primary and secondary stages of a thermonuclear bomb. The two pulses reached their peak values at 0.1 μ s and 1.6 μ s , with a peak ratio of 33.5:1. 4.1. Algorithm VerificationTo verify the correctness of the algorithm presented in this paper, we set the input parameters, such as ground parameters, explosion height, and explosive yield, to be consistent with those in the literature [21]. We selected an explosive yield of 100 kilotons and an explosion height of 10 km, and simulated E θ time-domain waveforms at the monitoring point r = 11.3 km, θ = 49.9 ° . The results were then compared with those from the literature.As shown in Figure 4, the scatter points and the line represent the computed results of this study and those from the literature, respectively. It can be observed that the results of both are in good agreement.Using single-thread calculation, the time step consisted of 7200 steps, and a single calculation took 208 min. However, when OpenMP parallel computing was employed with 6 threads, only requiring 45 min, the acceleration ratio reached 4.62 times, significantly improving computational efficiency. 4.2. Coverage Area of the Source RegionA low-altitude NEMP source region formed by gamma radiation is a function of theDownload Nemp 4.6.2 (latest)
1. IntroductionNuclear explosions produce not only shockwaves, thermal radiation, and radioactive contaminations but also a significant destructive effect known as the nuclear electromagnetic pulse (NEMP) [1,2]. A NEMP is a strong electromagnetic wave released at the moment of a nuclear explosion, posing a severe threat to various electronic devices and systems [3,4,5,6]. To fully understand the information contained within NEMPs, it is essential to have a clear understanding of the source region. Compared to high-altitude nuclear explosions, due to the relatively high air density in a low-altitude environment, the average free path of gamma rays is shorter, so low-altitude nuclear detonations have a smaller source region; however, the energy is concentrated in a smaller area, resulting in greater destructive power in nearby regions. Therefore, in-depth research on the electromagnetic field distribution characteristics of NEMPs from low-altitude nuclear explosions is crucial in enhancing nuclear explosion detection technology and improving systems’ resistance to nuclear radiation.Gilinsky Victor et al. [7] proposed a dipole model for low-altitude NEMPs. Longley H Jerry et al. [8] employed a two-dimensional time-domain finite-difference method based on a spherical–cylindrical coordinate system to calculate the source region fields of near-surface nuclear explosions. The Northwest Nuclear Technology Research Institute was the first to develop a two-dimensional differential calculation program for simulating low-altitude NEMPs [9]. Wang Taichun et al. [10] derived approximate analytical formulas for the current and electric field generated by instantaneous gamma photons in the source region under the conditions of a low-altitude nuclear explosion. Liang Rui et al. [11]Nemp download for Windows - OnWorks
The appearance of an alleged Chinese spy balloon, shot down by the American military in February, has provoked anxiety around national security and the technology China possesses to interfere in the U.S.Last week, in the first meeting since its discovery, a senior Chinese official offered "no apology" to U.S. Secretary of State Anthony Blinken, who had called the incident "unacceptable". Blinken noted that the U.S. wasn't the only nation to have intercepted Chinese spy balloons, but anxious claims that it could deliver a devastating EMP—electromagnetic pulse—payload have taken root online.Claims have appeared on social media that the Chinese spy balloon, shot down over the U.S., has the capability to carry an EMP device. Pictured here, the Chinese surveillance balloon that was shot down by...Handout/Getty The ClaimA tweet posted by Cernovich, on February 4, 2023, viewed more than three million times, included a clip of conspiracy theorist Alex Jones on Infowars discussing the possibility of China using balloons to deliver EMP devices across the U.S.During the clip, Jones said the spy balloon seen over the U.S., "could very easily be an EMP weapon package or a test package to test an EMP attack.""And you can bet your bottom dollar that China has got thousands of them lined up ready to launch and send over the North Pole right into the United States," Jones said."They can detonate them over any targets they want and with a couple dozen of these, you would guarantee knock out everything above ground in the U.S."A similar claim was repeated on February 16, 2023, by right-wing activist Laura Loomer who, responding to a tweet by President Joe Biden about U.S. EV charging networks, wrote: "This won't matter when the Chinese Communist Party sets off an EMP in the US now that they know there are no consequences for sending spy balloons to do dry run EMPs in America."When the electrical grid is attacked and we have no power, what good will electrical vehicles be?"The FactsAccording to a 2018 report by the U.S. Department of Homeland Security (DHS), the term EMP refers to an "electromagnetic pulse caused by a nuclear device or nonnuclear device.""A nuclear electromagnetic pulse (NEMP) is a burst of electromagnetic (gamma) radiation created by a nuclear explosion that produces rapidly changing electric and magnetic fields," it added.The report states that electronics that are exposed to EMP, particularly semiconductor components, "may not function normally until cycled in power—or can be damaged through a surge in voltage or current."The altitude of detonation is crucial as the effect is small for bursts below about 20km. However, a high-altitude EMP could generate a pulse "in the tens of kilovolts per meter with a radius of effects from hundreds toDownload Nemp 5.1.0 - SnapFiles
Explosion center is characterized by low impedance, with magnetic induction intensity B ϕ being significantly stronger than E θ ; conversely, the source region above the explosion center exhibits characteristics of a high impedance field, with magnetic induction intensity B ϕ being much weaker than E θ . Overall, the strong electromagnetic field in the source region poses a considerable threat to electronic systems operating within that area. 4.3.2. Comparison of Time-Domain Waveforms of TE WaveThe TE wave field components were B r , B θ , E φ . Since the B r field does not radiate outward, this paper focused on E φ and B θ , and the time-domain waveform comparisons at four observation points are shown in Figure 8.From Figure 8, it can be observed that: (1)The pulse width of TE wave is narrower compared to TM wave. This is attributed to the fact that J ϕ ′ serves as the primary current source for exciting TE wave (as derived from Equations (4) and (7), which indicate that TM wave are excited by J ϕ ′ ). Since gamma rays propagate forward at the speed of light c, the resulting Compton electrons also travel slightly below the speed of light. From the monitoring point’s perspective, the contributions of the current sources along the line connecting the explosion center to the monitoring point to the NEMP are nearly simultaneous, leading to a narrower pulse width for TE wave.(2)In the TE wave, E ϕ and B θ opposite. NEMP: Northeast Metropolitan Park: NEMP: N cleo de Estudos sobre M dia e Pol tica: NEMP: Northeast Monitoring Program: NEMP: Neurology Matching Program: NEMP: National Eutrophication Monitoring Programme: NEMP: National Eutrophication Management Program: NEMP: Newcastle Environmental Management Plan (Australia) NEMP: National Examination
RS105 HEMP and NEMP Testing
Of Coupling Currents in HEMP Field Tests. IEEE Trans. Electromagn. Compat. 2021, 63, 125–133. [Google Scholar] [CrossRef]Lee, R.; Shetye, K.S.; Birchfield, A.B.; Overbye, T.J. Using Detailed Ground Modeling to Evaluate Electric Grid Impacts of Late-Time High-Altitude Electromagnetic Pulses (E3 HEMP). IEEE Trans. Power Syst. 2019, 34, 1549–1557. [Google Scholar] [CrossRef]Xie, H.Y.; Du, T.J.; Zhang, M.Y.; Li, Y.; Qiao, H.L.; Yang, J.; Shi, Y.W.; Wang, J.G. Theoretical and Experimental Study of Effective Coupling Length for Transmission Lines Illuminated by HEMP. IEEE Trans. Electromagn. Compat. 2015, 57, 1529–1538. [Google Scholar] [CrossRef]Gilinsky, V. Kompaneets Model for Radio Emission from a Nuclear Explosion. Phys. Rev. 1965, 137, A50–A55. [Google Scholar] [CrossRef]Longley, H.J.; Longmire, C.L. Development of the GLANC EMP Code; Los Alamos National Lab.: Santa Barbara, CA, USA, 1969. [Google Scholar]Qiao, D.J. Introduction to Nuclear Explosion Physics, 1st ed.; Atomic Energy Publishing House: Beijing, China, 1988; p. 336. [Google Scholar]Wang, T.C.; Wang, Y.Z. Approximate estimation of electromagnetic pulse produced in atomosphere under condition of nuclear airburst. Chin. J. Comput. Phys. 1987, 8, 189–196. [Google Scholar]Liang, R.; Zhang, E.S.; Zheng, Y. Numerical calculation of NEMP from near-surface. Nucl. Electron. Detect. Technol. 2003, 23, 62–65. [Google Scholar]Cui, Z.T.; Nie, X.; Sun, B.Y. Detection System Design of Far Region E-Field from Low-altitude Nuclear Explosion Nuclear Explosions. Nucl. Electron. Detect. Technol. 2013, 33, 198–201. [Google Scholar]Chen, J.N.; Zhang, M.Y.; Liu, L.; Xie, H.Y.; Qiao, H.L. Self-Consistent numerical simulation method of near ground source region electromagnetic pulse combined with MCNP. Mod. Appl. Phys. 2022, 13, 118–126. [Google Scholar]Li, Z.M.;The NEMP family supports metazoan
. NEMP: Northeast Metropolitan Park: NEMP: N cleo de Estudos sobre M dia e Pol tica: NEMP: Northeast Monitoring Program: NEMP: Neurology Matching Program: NEMP: National Eutrophication Monitoring Programme: NEMP: National Eutrophication Management Program: NEMP: Newcastle Environmental Management Plan (Australia) NEMP: National Examination NEMP Range: l/m Heavy duty magnetically coupled leak free centrifugal pumps manufactured in chemical resistant thermoplastic and entirely non-metallic. Informational PDFs - NEMP 25/5 - NEMP 20/30 - NEMP 40/6 - NEMP 50/7 - NEMP 60/6PFAS NEMP 3.0 - dcceew.gov.au
Comments
Distances. The study provides a theoretical foundation for further research on nuclear explosion detection and offers scientific support for formulating relevant protective measures. 2. Mechanism of GenerationA NEMP is a strong electromagnetic wave generated instantaneously during a nuclear explosion. The large amount of gamma rays released by the explosion interacts with the surrounding atmosphere, primarily involving the electron–positron pair production, photoelectric effect, and Compton scattering. The average energy of the photons (1.5 MeV) and the atomic numbers of the atmospheric constituents (such as nitrogen and oxygen) determine that the Compton effect is the primary mechanism exciting the NEMP, as illustrated in Figure 1. This paper mainly considers the physical process whereby radiation interacts with surrounding air molecules to produce Compton currents, thereby exciting electromagnetic pulses [20].When a nuclear weapon detonates in a low-altitude environment, the photons radiated downward are absorbed by the upper layers of the ground’s geological medium. In contrast, radiation emitted outward and upward ionizes the air, causing charge separation and resulting in the generation of a significant number of Compton electrons. These electrons move outward, creating a Compton current, which manifests as a net vertical flow of electrons directed upward. Consequently, the source region is excited and radiates electromagnetic energy outward. The electromagnetic pulse generated by low-altitude nuclear explosion is shown in Figure 2. 3. Introduction to Numerical Simulation MethodsA NEMP primarily originates from the Compton currents generated by the interaction of prompt gamma rays produced by explosions with air (or ground media). The ionization of air
2025-04-05Study on electromagnetic pulse of air nuclear explosion. In Proceedings of the 2005 China Association for Science and Technology Annual Conference, Urumqi, China, 20–22 August 2005. [Google Scholar] Figure 1. Comparison of the relative occurrence rates of three processes as a function of photon energy and atomic number the medium. Figure 1. Comparison of the relative occurrence rates of three processes as a function of photon energy and atomic number the medium. Figure 2. Schematic diagram of low–altitude NEMP generation. Figure 2. Schematic diagram of low–altitude NEMP generation. Figure 3. The geometric schematic diagram of the spherical coordinate system ( r , θ , ϕ ) and the rotating ellipsoid–hyperbolic orthogonal coordinate system ( ξ , ζ , ϕ ) at the field point P. Click here to enlarge figure --> Figure 3. The geometric schematic diagram of the spherical coordinate system ( r , θ , ϕ ) and the rotating ellipsoid–hyperbolic orthogonal coordinate system ( ξ , ζ , ϕ ) at the field point P. Figure 4. Comparison of results between the study and existing literature. Figure 4. Comparison of results between the study and existing literature. Figure 5. Distribution map of source area under specific conditions. Figure 5. Distribution map of source area under specific conditions. Figure 6. Schematic diagram of nuclear explosion points and observation points from different angles at the same distance. Figure 6. Schematic diagram of nuclear explosion points and observation points from different angles at the same distance. Figure 7. Comparison of
2025-03-27Results AnalysisThe gamma waveform used in the low-altitude NEMP was a double-pulse waveform, where the two pulses represented the primary and secondary nuclear reactions of the nuclear device, respectively. The time interval between these two pulses corresponded to the action time interval between the primary and secondary stages of a thermonuclear bomb. The two pulses reached their peak values at 0.1 μ s and 1.6 μ s , with a peak ratio of 33.5:1. 4.1. Algorithm VerificationTo verify the correctness of the algorithm presented in this paper, we set the input parameters, such as ground parameters, explosion height, and explosive yield, to be consistent with those in the literature [21]. We selected an explosive yield of 100 kilotons and an explosion height of 10 km, and simulated E θ time-domain waveforms at the monitoring point r = 11.3 km, θ = 49.9 ° . The results were then compared with those from the literature.As shown in Figure 4, the scatter points and the line represent the computed results of this study and those from the literature, respectively. It can be observed that the results of both are in good agreement.Using single-thread calculation, the time step consisted of 7200 steps, and a single calculation took 208 min. However, when OpenMP parallel computing was employed with 6 threads, only requiring 45 min, the acceleration ratio reached 4.62 times, significantly improving computational efficiency. 4.2. Coverage Area of the Source RegionA low-altitude NEMP source region formed by gamma radiation is a function of the
2025-04-111. IntroductionNuclear explosions produce not only shockwaves, thermal radiation, and radioactive contaminations but also a significant destructive effect known as the nuclear electromagnetic pulse (NEMP) [1,2]. A NEMP is a strong electromagnetic wave released at the moment of a nuclear explosion, posing a severe threat to various electronic devices and systems [3,4,5,6]. To fully understand the information contained within NEMPs, it is essential to have a clear understanding of the source region. Compared to high-altitude nuclear explosions, due to the relatively high air density in a low-altitude environment, the average free path of gamma rays is shorter, so low-altitude nuclear detonations have a smaller source region; however, the energy is concentrated in a smaller area, resulting in greater destructive power in nearby regions. Therefore, in-depth research on the electromagnetic field distribution characteristics of NEMPs from low-altitude nuclear explosions is crucial in enhancing nuclear explosion detection technology and improving systems’ resistance to nuclear radiation.Gilinsky Victor et al. [7] proposed a dipole model for low-altitude NEMPs. Longley H Jerry et al. [8] employed a two-dimensional time-domain finite-difference method based on a spherical–cylindrical coordinate system to calculate the source region fields of near-surface nuclear explosions. The Northwest Nuclear Technology Research Institute was the first to develop a two-dimensional differential calculation program for simulating low-altitude NEMPs [9]. Wang Taichun et al. [10] derived approximate analytical formulas for the current and electric field generated by instantaneous gamma photons in the source region under the conditions of a low-altitude nuclear explosion. Liang Rui et al. [11]
2025-04-08Explosion center is characterized by low impedance, with magnetic induction intensity B ϕ being significantly stronger than E θ ; conversely, the source region above the explosion center exhibits characteristics of a high impedance field, with magnetic induction intensity B ϕ being much weaker than E θ . Overall, the strong electromagnetic field in the source region poses a considerable threat to electronic systems operating within that area. 4.3.2. Comparison of Time-Domain Waveforms of TE WaveThe TE wave field components were B r , B θ , E φ . Since the B r field does not radiate outward, this paper focused on E φ and B θ , and the time-domain waveform comparisons at four observation points are shown in Figure 8.From Figure 8, it can be observed that: (1)The pulse width of TE wave is narrower compared to TM wave. This is attributed to the fact that J ϕ ′ serves as the primary current source for exciting TE wave (as derived from Equations (4) and (7), which indicate that TM wave are excited by J ϕ ′ ). Since gamma rays propagate forward at the speed of light c, the resulting Compton electrons also travel slightly below the speed of light. From the monitoring point’s perspective, the contributions of the current sources along the line connecting the explosion center to the monitoring point to the NEMP are nearly simultaneous, leading to a narrower pulse width for TE wave.(2)In the TE wave, E ϕ and B θ opposite
2025-04-18