A5003873006- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Gyrotron and Vacuum Electronics Research
- Radiation Therapy and Dosimetry
- Advanced Radiotherapy Techniques
- Hepatitis B Virus Studies
- Liver Disease Diagnosis and Treatment
- Radiation Shielding Materials Analysis
- Medical Imaging Techniques and Applications
- Innovative Teaching Methods
- Graphite, nuclear technology, radiation studies
- Advanced X-ray Imaging Techniques
- Hepatitis C virus research
- Orthodontics and Dentofacial Orthopedics
- Radiation Detection and Scintillator Technologies
- Liver Disease and Transplantation
- Oral microbiology and periodontitis research
- Superconducting Materials and Applications
- Soft tissue tumors and treatment
- Adrenal and Paraganglionic Tumors
- Superconducting and THz Device Technology
- Experimental Learning in Engineering
- Advanced Drug Delivery Systems
- Teaching and Learning Programming
SLAC National Accelerator Laboratory
2012-2025
COMSATS University Islamabad
2024
Stanford University
2012-2023
Menlo School
2012-2023
Georgia Institute of Technology
2023
Institute of Medical Sciences
2016
Habib University
2015
Linac Coherent Light Source
2012
Brookhaven National Laboratory
2012
Static magnetic undulators used by x-ray light sources are fundamentally too limited to achieve shorter undulator periods and dynamic control. To overcome these limitations, we report experimental demonstration of a novel short-period microwave undulator, essentially Thomson scattering device, that has yielded tunable spontaneous emission seeded coherent radiation. Its equivalent period (λu) is 13.9 mm while it achieved an field 0.65 T. For future-generation sources, this device promises...
The application of radio frequency (RF) vacuum electronics for the betterment human condition began soon after invention first tubes in 1920s and has not stopped since. Today, microwave devices are powering important applications health treatment, material biological science, wireless communication-terrestrial space, Earth environment remote sensing, promise safe, reliable, inexhaustible energy. This article highlights some exciting frontiers electronics.
Abstract C 3 is an opportunity to realize e + - collider for the study of Higgs boson at √ s = 250 GeV, with a well defined upgrade path 550 GeV while staying on same short facility footprint [2,3]. based fundamentally new approach normal conducting linear accelerators that achieves both high gradient and efficiency relatively low cost. Given advanced state designs, key system requires technical maturation main linac. This paper presents staged towards demonstrate technology Direct (source...
In this work, we investigated the delivery of a clinically acceptable pediatric whole brain radiotherapy plan at FLASH dose rates using two lateral opposing 40-MeV electron beams produced by practically realizable linear accelerator system. The EGSnrc Monte Carlo software modules, BEAMnrc and DOSXYZnrc, were used to generate plans for patient beams. Electron beam phase space files simulated model diverging with diameter 10 cm 50 SAD (defined midline). collimated 10-cm-thick block composed 5...
Abstract Chronic periodontitis poses long‐term challenges in dentistry, requiring the development of innovative dental composites with biocompatibility, bone regeneration, and antibacterial properties. This study focuses on synthesis novel injectable thermoresponsive hydrogels composed chitosan, sodium bicarbonate, bioactive glass (20 40% w/w), acetanilide drug (0.3 0.6% w/w). These exhibit a sol–gel transition at 37°C, addressing periodontal reduced gelation time. The smooth flow...
We describe a comprehensive project, funded under the DARPA AXiS program, to develop an all-optical table-top X-ray FEL based on dielectric acceleration and electromagnetic undulators, yielding compact source of coherent X-rays for medical related applications. The compactness this demands that high field (>GV/m) undulation-inducing fields be employed, thus giving rise project's acronym: GV/m AcceLerator And Integrated Experiment (GALAXIE). There are numerous physics technical hurdles...
Single electron dynamics for a circular polarized standing wave (CPSW) undulator synthesized from corrugated cavity operating with very low-loss HE11 mode are analyzed. The mechanism of the transverse drift CPSW and its elimination researched, tapered-field ends found effectively to suppress kick. A prototype characters short undulating-period 1.4 cm, high field K ∼ 1, large aperture 5 variable polarization is designed modeled, whose 3-dimensional electromagnetic fields used research suppression
Permanent magnet insertion devices (IDs), which are the main radiation generating in synchrotron light sources and free-electron lasers, use a time-invariant but space-periodic magnetic field to wiggle relativistic electrons for short-wavelength generation. Recently, high power microwave based undulator has also been successfully demonstrated at SLAC promises advantage of dynamic tunability spectrum polarization. Such IDs employ transverse elecromagnetic fields periodic both space time...
A preclinical MV-energy photon FLASH radiotherapy system is being designed at Stanford and SLAC National Accelerator Laboratory. Because of the higher energy dose rate compared to conventional kV-energy laboratory-scale irradiators, adequate shielding in a stand-alone cabinet form factor more challenging achieve. We present Monte Carlo simulation multilayered for compact self-shielding without need radiation therapy vault.A approach using multiple alternating layers high-Z low-Z materials...
In radiation therapy, x-ray dose must be precisely sculpted to the tumor, while simultaneously avoiding surrounding organs at risk. This requires modulation of intensity in space and/or time. Typically, this is achieved using a multi leaf collimator (MLC)-a complex mechatronic device comprising over one hundred individually powered tungsten 'leaves' that move or out field as required. Here, an all-electronic collimation concept with no moving parts presented, termed "SPHINX": Scanning...
We present beam dynamics studies of a proposed circularly polarized RF undulator cavity to be operated at 50 MW yield the strength parameter K = 0.7. A symplectic integration scheme is used for numerical studies. The expressions field integrals are also developed. Simulation results electron trajectories, showing off-axis drift and bunch defocusing, 60 120 MeV energies presented.
A preclinical radiotherapy system producing FLASH dose rates with 12 MV bremsstrahlung x rays is being developed at Stanford University and SLAC National Accelerator Laboratory. Because of the high expected workload 6,800 Gy w -1 isocenter, an efficient shielding methodology needed to protect operators public while operated in a radiation therapy vault designed for 6 rays. In this study, analysis performed assess local treatment head using Monte Carlo code FLUKA empirical given Council on...
As part of the curriculum development for Digital Logic and Design (DLD) course at Habib University, we developed a hands-on learning module. The technical goal was to create analogue signals with Field Programmable Gate Array (FPGA) logic. practical realization this took form Analogue Converter (DAC) board connected an FPGA prototyping system. chosen such that it captivates challenges second semester science engineering students. educational framework which helps students explore boundaries...
Objectives: The aim behind this study was to scientifically assess the poorprognostic factors and in-hospital mortality rate in patients infected with HCV HBV infectionwith liver cirrhosis. Study Design: Comparative hospital based study. Setting: Gastroenterologyand hepatology dedicated center, Asian Institute of Medical Sciences (AIMS), Hyderabad.Period: Thirty one months from 1st October 2012 31st May 2015. Patients Methods: 419participants between ages 20 80 years including both male...
Objectives: The aim behind this study was to scientifically assess the poorprognostic factors and in-hospital mortality rate in patients infected with HCV HBV infectionwith liver cirrhosis. Study Design: Comparative hospital based study. Setting: Gastroenterologyand hepatology dedicated center, Asian Institute of Medical Sciences (AIMS), Hyderabad.Period: Thirty one months from 1st October 2012 31st May 2015. Patients Methods: 419participants between ages 20 80 years including both male...
The electromagnetic wakefields excited by the bunches of charged particles in particle accelerators may cause instability longitudinal and transverse motion these leading to beam loss. These multibunch effects need be analyzed carefully an accelerator design ensure stability beams. This paper presents analytical method describing instabilities for ultrarelativistic electron whose energy changes linearly through accelerating section interest. Fast algorithmic implementations this are...