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Spektra: Jurnal Fisika dan Aplikasinya

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Published by Universitas Negeri Jakarta

ISSN : 25413384 EISSN : 25413392 DOI : -

Core Subject : Science, Engineering,

Aerospace Engineering Electrical & Electronics Engineering Energy Materials Science & Nanotechnology Physics

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Articles 260 Documents

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Back Matter SPEKTRA Volume 9 Issue 2, August 2024 Spektra, Editor
Spektra: Jurnal Fisika dan Aplikasinya Vol 9 No 2 (2024): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 9 Issue 2, August 2024
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.092111

Laser-Assisted Scattering with Screened Diatomic Potential Sapkota, Asmit; Dhobi, Saddam Husain; Khatiwada, Subash
Spektra: Jurnal Fisika dan Aplikasinya Vol. 9 No. 3 (2024): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 9 Issue 3, December 2024
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.093.01

This study explores the differential cross section (DCS) for laser-assisted scattering of diatomic molecules, considering various polarization conditions (linear, circular, elliptical) and potential parameters. The primary objective is to understand how polarization, screening effects, and potential parameters influence the scattering behavior. Utilizing a model that incorporates the Morse potential with screening effects, the analysis treats the laser field classically as a time-dependent, spatially homogeneous electric field, while the electron dynamics are described quantum mechanically using the Schrödinger equation. The Volkov wavefunction is derived, and the first-Born S-matrix element is computed to evaluate the scattering process. The results show that the DCS decreases with increasing screening parameters, with linear polarization yielding higher values than circular or elliptical polarization. Specifically, at an initial momentum of 8 MeV and a final momentum of 9 MeV, the DCS for elliptical polarization is notably higher. The DCS also varies with potential strength and well width, showing a peak at 0.14 Å for potential well width. The findings suggest that linear polarization is most effective for scattering studies under varying potential strengths. It is recommended to focus on linear polarization for enhanced scattering efficiency and to carefully adjust screening parameters and potential well widths for optimal results.

Geochemical and Magnetic Suseptibility Analysis for Critical Minerals Detection in Igneous Rocks and Beach Sand Hariyanto, Yensi; Zulaikah, Siti; Hapsoro, Cahyo Aji; Maulida, Shofi; Zakly, Hanif 'Izzudin; Muztaza, Nordiana Mohd; Suadi, Daeng Achmad; Pratama, Aditya; Hamdi, Hamdi
Spektra: Jurnal Fisika dan Aplikasinya Vol. 9 No. 3 (2024): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 9 Issue 3, December 2024
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.093.04

Critical minerals are an important natural resource that will continue to be necessary for modern industries. This study aims to determine the distribution of critical minerals based on geochemical data and magnetic susceptibility. Samples were taken from Lenggoksono beach, Southern Malang. The determination of chemical elements was conducted using X-ray fluorescence (XRF). Rare Earth Elements (REE) were identified using Inductively Coupled Plasma–Optical Emission Spectrometry (ICP-OES). Magnetic susceptibility measurements were carried out using a Barrington Magnetic Susceptibility Meter (MS2B). The results showed that the dominant elements were Silica Oxide, SiO2 (70 Wt%), Iron Oxide, Fe2O3 (14.05 Wt%), and Calcium Oxide CaO (5.57 Wt%), which were categorized as critical minerals. The average REE elements detected were Cerium, Ce (6.75 mg/kg), Gadolinium, Gd (5.98 mg/kg), Neodymium, Nd (13.56 mg/kg), Praseodymium, Pr (6.62 mg/kg), Terbium, Tb (5.57 mg/kg), and Yttrium, Y (10.98 mg/kg). The magnetic susceptibility ranges from 13.27 to 4143.47 × 10-8m3/kg. Pearson’s Correlation analysis revealed a significant correlation between low-frequency magnetic susceptibility (ꭓlf) and high-frequency magnetic susceptibility (ꭓhf) with a significance level of 0.01. ꭓlf and ꭓhf also showed a significant correlation with Gd, with a correlation value of R² = 0.84 and a significance level of 0.05. These results indicate that the presence of one critical mineral can serve as a clue to the presence of other critical minerals, and magnetic susceptibility can be used as a proxy indicator for critical minerals in natural materials.

Front Matter SPEKTRA Volume 9 Issue 2, August 2024 Spektra, Editor
Spektra: Jurnal Fisika dan Aplikasinya Vol. 9 No. 2 (2024): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 9 Issue 2, August 2024
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.09200

Back Matter SPEKTRA Volume 9 Issue 2, August 2024 Spektra, Editor
Spektra: Jurnal Fisika dan Aplikasinya Vol. 9 No. 2 (2024): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 9 Issue 2, August 2024
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.092111

Application of Variational Quantum Eigensolver for Ground State Energies Calculation in Hydrogen and Helium Atomic Sequences Hakim, Difa Farhani; Prayitno, Teguh Budi; Sarwono, Yanoar Pribadi
Spektra: Jurnal Fisika dan Aplikasinya Vol. 9 No. 3 (2024): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 9 Issue 3, December 2024
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.093.03

Exponential scaling presents a significant challenge in electronic structure calculations performed on classical computers. This paper explores how quantum computer algorithms can accurately represent quantum systems. Variational Quantum Eigensolver (VQE) algorithm is used to compute the ground state energy of hydrogen and helium sequences by implementing variational principle and quantum gates as trial wavefunction. This technique combines classical optimization with quantum computing calculations to simulate quantum systems on noisy and resource-limited computers. The resulting calculated energy is highly consistent to the corresponding exact values and Hartree-Fock calculations with a trend of when the number of atoms increases the calculated energy becomes more negative, leading to a decrease in the percentage error. Moreover, the convergence of the ground state energy of hydrogen and helium atoms was effectively optimized. The desired energy was reached, proven by adjusting the expectation value, and gradually achieving unity in state overlap. These findings demonstrate the VQE method's accuracy in calculating simple quantum systems and its scalability for larger atomic and molecular system, such as those in quantum chemistry and material science. However, challenges in quantum computer simulations, such as limited in qubit numbers and the presence of noise, require further advancements. Therefore, implementing a larger basis sets, advanced qubit mapping, specific chemistry ansatz, and flexible optimization techniques is one way to improve overall calculation.

Phase Dynamics in 3D Superconductors: Analysis Using the Sine-Gordon Khadka, Kiran; Dhobi, Saddam Husain; Yadav, Kishori
Spektra: Jurnal Fisika dan Aplikasinya Vol. 9 No. 3 (2024): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 9 Issue 3, December 2024
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.093.02

This study investigates the phase dynamics of superconducting states in 3D superconductors using the sine-Gordon equation, with a focus on the interplay between the London penetration depth (LPD) and coherence length ( ). The research employs a combination of analytical modeling and simulation techniques to explore how variations in LPD influence phase behavior across different coherence lengths in the developed model. At a critical coherence length of = 2 Å, the LPD decreases from 150 nm to 120 nm as the nanoparticle spacing increases from 5 nm to 10 nm, attributed to reduced interactions between superconducting states. Conversely, at = 1 Å, quantum confinement effects lead to non-linear LPD behavior, with an initial decrease from 180 nm to 160 nm followed by an increase to 200 nm as nanoparticle spacing changes. In 3D superconductors, phase evolution is characterized by distinct waveforms—square, rectangular, and mixed—corresponding to LPD values between 100 nm and 200 nm, with phase shifts ranging from 1° to 20°. Smaller phase shifts (1°) produce higher-frequency oscillations with amplitudes up to 0.2, while larger shifts (20°) generate broader, less intense waveforms. These findings underscore the critical role of LPD in determining superconducting properties, offering valuable insights for the design and optimization of superconducting devices to enhance performance and efficiency.

The Effects of Stellar Wind, Rotation Velocity, and Overshoot Parameters on The Evolution of Massive Stars using MESA: Case Study of MPG 324, MPG 355, MPG 682 Adira, Alin Hafizhah; Aprilia
Spektra: Jurnal Fisika dan Aplikasinya Vol. 9 No. 3 (2024): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 9 Issue 3, December 2024
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.092.06

Massive stars (over 8 solar masses) undergo intricate cosmic journeys. Their evolution, shaped by parameters like stellar wind, rotation velocity, and overshoot, generally includes the pre-main sequence, main sequence, and post-main sequence phases. In the post-main sequence, they become supergiant stars, then Wolf-Rayet stars, experience a supernova, and end as neutron stars or black holes. This study models the evolutionary path of massive stars using MESA software, considering stellar wind, rotation velocity, and overshoot. Three stars from the Small Magellanic Cloud galaxy—MPG 324, MPG 355, and MPG 682—are used to represent the mass range described in the Conti Scenario. The model is compared to Conti Scenario and observational data, showing good agreement with luminosity, effective temperature, and evolutionary phase, though not yet at final stages. This provides valuable insights into stellar evolution.

Seismometer Health Diagnosis Based on Cross Spectral Density Coherence Method in Indonesia Seismic Networks Jannah, Miftahul; Annisa, Risa; Saputro, Adhi Harmoko; Lestari, Titik
Spektra: Jurnal Fisika dan Aplikasinya Vol. 9 No. 3 (2024): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 9 Issue 3, December 2024
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.093.05

Evaluation of seismometer health is crucial in accurately detecting earthquake and tsunami events. Currently, seismometer health evaluation is based solely on data quality unrelated to seismometer sensor performance. While seismometers are essential for tracking seismic activity, environmental factors, aging components, and external interference can cause seismometers to function worse over time. This study presents a seismometer health diagnosis technique based on seismic signal analysis, including signal truncation, signal resampling, filtering, and deconvolution of instrument response. Then the proposed method of cross-spectral density coherence to extract seismometer sensor health indicators performed on two adjacent broadband seismic stations by analyzing the frequency domain with a maximum inter-station distance of 100 km. The data used are seismic signals recorded on three-component seismometers (North-South, East-West, Z-Vertical). The coherence value of cross-spectral density is used as an indicator to diagnose seismometer health. The proposed method was evaluated on a seismic network in Indonesia consisting of 88 stations and a teleseismic earthquake event in Honshu, Japan. The coherence values of almost all tested stations are above 0.8, which means good performance. The proposed method is suitable for analyzing the health of seismometers, especially in Indonesia.

Front Matter SPEKTRA Volume 9 Issue 3, December 2024 Spektra, Editor
Spektra: Jurnal Fisika dan Aplikasinya Vol. 9 No. 3 (2024): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 9 Issue 3, December 2024
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.09300

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