Papers by Septimiu Balascuta
A dipole permanent magnet for Laser Wakefield Plasma Acceleration experiments
AIP Advances
Charge carrier density, mobility, and Seebeck coefficient of melt-grown bulk ZnGa 2 O 4 single cr... more Charge carrier density, mobility, and Seebeck coefficient of melt-grown bulk ZnGa 2 O 4 single crystals AIP Advances 10, 055005 (2020);
At the E6 experimental area at ELI-NP, two 10 PW Laser (pump and probe) pulses, with their direct... more At the E6 experimental area at ELI-NP, two 10 PW Laser (pump and probe) pulses, with their directions making an 135 o angle, will be used for the study of the radiation reaction, non-linear Thomson scattering, electron beam cooling and other QED phenomena in the relativistic regime. The pump 10 PW Laser beam focused in a gasjet will generate a plasma wakefield that accelerate electrons by self-injection. The probe 10PW Laser pulse has to be synchronized and focused on the electron bunch. In order to maximize the flux of gamma rays produced in this collision, for a given Laser field intensity, the transversal area of the electron beam at the collision point has to be smaller than the focus of the probe pulse. This work presents the calculation of electron beam emittance and angular divergence, versus the distance traveled by electron bunch in vacuum. A configuration of dipole permanent magnets is proposed for the study of energy distribution of electrons and positrons.
Gamma-ray asymmetry measurements in the capture of polarized cold neutrons on ^27Al
Parity Violation in the Hadronic Weak Interaction
This thesis deals with the first measurements done with a cold neutron beam at the Spallation Neu... more This thesis deals with the first measurements done with a cold neutron beam at the Spallation Neutron Source at Oak Ridge National Laboratory. The experimental technique consisted of capturing polarized cold neutrons by nuclei to measure parity-violating observables from the emission of gamma rays following neutron capture. The measurements presented here for the nuclei Chlorine (Cl) and Aluminum (Al) are part of a program with the ultimate goal of measuring the asymmetry in the angular distribution of gamma rays emitted from the radiative capture of neutrons on protons (~n+p→ d+γ ) with a precision better than 1 · 10−8, in order to extract the weak hadronic coupling constant due to pion exchange interaction with isospin change equal with one (hπ ). Based on theoretical calculations the asymmetry in the ~n + p → d + γ reaction has an estimated size of 5 · 10−8. This implies that the Al parity violation asymmetry and its uncertainty have to be known with a precision smaller than 4 · ...
Measurement of parity violation in the capture of polarized neutrons on 27Al
Polarized Cold Neutron Capture in $^{27}$Al
Bulletin of the American Physical Society, Apr 14, 2013
A Pulsed Electromagnet for Laser Wakefield Electron Acceleration Experiments
Journal of Electromagnetic Analysis and Applications, 2016
Construction and commissioning of the magnetic field system for the NPDGamma experiment at the SNS and results of the spin transport calculations
The NPDGamma experiment measures the parity-violating (PV) angular asymmetry of the gamma rays em... more The NPDGamma experiment measures the parity-violating (PV) angular asymmetry of the gamma rays emitted in the capture of the polarized cold neutrons on protons. The neutrons from the Spallation Neutron Source (SNS) are polarized by a super mirror polarizer with a 350 G internal field. The polarizer fringe field is decreased using an additional magnet. After the polarizer the neutrons
Multi-Ton Argon and Xenon
Calibration of CsI Detectors for the NPDG Experiment
Bulletin of the American …, 2010
The NPDGamma experiment at Oak Ridge National Lab will measure the asymmetry in gamma production ... more The NPDGamma experiment at Oak Ridge National Lab will measure the asymmetry in gamma production in the reaction: neutron+ proton-$> $ deuteron+ gamma. The parity violating component of this reaction is measured from the correlation of neutron spin and $ ...
A Novel Detector for High Flux Thermal Neutrons
Bulletin of the American …, 2011
... Elise Martin Septimiu Balascuta David Bowman Chris Crawford Charles Fieseler Nadia Fomin Kyle... more ... Elise Martin Septimiu Balascuta David Bowman Chris Crawford Charles Fieseler Nadia Fomin Kyle Grammer Geoffrey Greene Seppo Penttila. ... The projected sensitivity is $\delta A_\gamma=10^{-8}$. To verify we can achieve the required counting statistics we must know ...
Biochemistry, 2005
AppA is a blue-light and redox-responding regulator of photosynthesis gene expression in Rhodobac... more AppA is a blue-light and redox-responding regulator of photosynthesis gene expression in Rhodobacter sphaeroides. Detailed time-resolved fluorescence spectroscopy and subpicosecond transient absorption spectroscopy study of the BLUF domain is presented for wild-type AppA (AppAwt) and a photoinactive Y21F mutant of AppA. The main findings discussed here are that (1) time-resolved laser excitation studies on dark-adapted protein show that AppAwt and Y21F mutant protein exhibits a fluorescence decay with a lifetime of 0.6 ns. Dark-adapted AppAwt but not Y21F also exhibits slower fluorescence decay with a lifetime of 1.7 ns. Analysis of AppAwt that was light-excited to a stable lightadapted form prior to data collection shows monoexponential fluorescence decay with a lifetime of 1.0 ns. This component disappeared after 1 min of data collection after which the original "dark-adapted" values were recovered, demonstrating the presence of a ∼1 min lifetime intermediate during the return of AppA from light-to dark-adapted form.
Uploads
Papers by Septimiu Balascuta