arXiv subjects

A. Mahrous

Publications and source records attributed to A. Mahrous.

4 recordsLinked to original sources

arXiv2023

Solar radio bursts observations by Egypt- Alexandria CALLISTO spectrometer: First results

The newly installed CALLISTO spectrometer, hosted by the Department of Space Environment, Institute of Basic and Applied Sciences- EJUST, commenced operation on August 14, 2021. The system contains a cross dipole long-wavelength array antenna with high sensitivity to monitor solar radio transients. Its antenna was strategically positioned and appeared to be in the center of the CALLISTO network of spectrometers. Moreover, in the northern section of Africa, the Egypt-Alexandria CALLISTO and ALGERIA-CRAAG stations are the only ones operating. There are no stations in the West African region, while stations in the eastern part of Africa are not working. Thus, Egypt- Alexandria station serves as a reference for other stations within the e-CALLISTO network. Despite the low solar activity, the instrument detected several solar radio bursts not limited to type II, type III, and type V. A vigorous case study was conducted on two selected radio burst events to validate the authenticity of the recorded events. Other solar radio stations at different geographical locations recorded all the radio bursts detected by the spectrometer. The case study included brief analyses that indicated a type II radio burst observed on October 09, 2021, between 06:30 and 07:00 UT, was associated with an M1.6 solar flare located at N18E08 within NOAA-AR 12882 and a CME with a shock front speed of ~978 km/s. However, the type III radio burst is neither CME nor solar flare associated. These analyses examine the instrument's capacity to provide real-time solar radio transient data 24 hours a day to mitigate the challenges of data gaps faced in the African continent. Hence, the instrument has become an integral part of space weather monitoring and forecasting over the region and other parts of the globe.

astro-ph.SR↗

arXiv2023

Assessing the spectral characteristics of band splitting type II radio bursts observed by CALLISTO spectrometers

Metric type II radio bursts are usually early indicators of CME-driven shocks and other space weather phenomena in the solar corona. This paper presents a detailed investigation of the spectral properties of band-splitting type II radio bursts and their association with sunspot number. Using type II radio bursts in a frequency range 20 to 200MHz observed by CALLISTO from 2010 to 2017, it was discovered that the analyzed type II shock height, magnetic field strength, CME shock speed, and Alfven speed synchronize with the trajectory of the solar cycle 24. Also, the study revealed that the onset of the declining phase of solar cycle 24 has the highest electron density. The analysis ascertained that the frequency of type II bursts depicts a bimodal distribution during the study period, with peaks in 2012 and 2015. Further, a good correlation(with correlation factor R=0.87) was obtained between the estimated CME shock speeds from the dynamic spectra, and the associated CME speeds from SOHO-LASCO. Moreover, the study confirmed a significant correlation(R=0.8) between the absolute drift rates and the plasma frequency. Additionally, the study explored that 60% of the type II radio bursts considered in this study emanated from the western longitudes. Hence, these findings emphasize that the temporal dynamics of the physical conditions of band-splitting type II radio are essential parameters in space weather monitoring and forecasting.

astro-ph.SR↗

arXiv2022

Simulation Studies of a Novel Muography Detector for the Great Pyramids

Muography is an imaging technique that can be used to examine the interior structure of large-size objects. The technique is based on measurements of the absorption of cosmic-ray muons passing through the object under study. Muographic imaging was already successfully applied to the discovery of a new void inside the Great Pyramid of Khufu at Giza, Egypt. With the aim of studying the Pyramid of Khafre, the second largest pyramid at Giza, a new muography detector is currently being constructed. In this paper we report on the development of a corresponding new simulation framework of the Great Pyramids and the detector setup. This simulation will serve as a basis to develop the data and image reconstruction algorithms to be used during our future muography campaign in the Pyramid of Khafre, and will allow us to study the relevant experimental conditions at the site.

physics.ins-det↗

arXiv2018

High Rate RPC detector for LHC

The High Luminosity LHC (HL-LHC) phase is designed to increase by an order of magnitude the amount of data to be collected by the LHC experiments. The foreseen gradual increase of the instantaneous luminosity of up to more than twice its nominal value of $10\times10^{34}\ {\rm cm}^{-1}{\rm s}^{-2}$ during Phase I and Phase II of the LHC running, presents special challenges for the experiments. The region with high pseudo rapidity ($η$) region of the forward muon spectrometer ($2.4 > |η| > 1.9$) is not equipped with RPC stations. The increase of the expected particles rate up to 2 kHz cm$^{-1}$ ( including a safety factor 3 ) motivates the installation of RPC chambers to guarantee redundancy with the CSC chambers already present. The current CMS RPC technology cannot sustain the expected background level. A new generation of Glass-RPC (GRPC) using low-resistivity glass was proposed to equip the two most far away of the four high $η$ muon stations of CMS. In their single-gap version they can stand rates of few kHz cm$^{-1}$. Their time precision of about 1 ns can allow to reduce the noise contribution leading to an improvement of the trigger rate. The proposed design for large size chambers is examined and some preliminary results obtained during beam tests at Gamma Irradiation Facility (GIF++) and Super Proton Synchrotron (SPS) at CERN are shown. They were performed to validate the capability of such detectors to support high irradiation environment with limited consequence on their efficiency.

physics.ins-det↗