Search results for "Proton"
showing 10 items of 5886 documents
Proton Direct Ionization Upsets at Tens of MeV
2023
Experimental monoenergetic proton single-event upset (SEU) cross sections of a 65-nm low core-voltage static random access memory (SRAM) were found to be exceptionally high not only at low energies ($ 3 MeV and extending up to tens of MeV. The SEU cross Section from 20-MeV protons exceeds the 200-MeV proton SEU cross Section by almost a factor of 3. Similarly, monoenergetic neutron cross sections at 14 MeV are about a factor of 3 lower than the 20-MeV proton cross section. Because of Monte Carlo (MC) simulations, it was determined that this strong enhancement is due to the proton direct ionization process as opposed to the elastic and inelastic scattering processes that dominate the SEU res…
Proton irradiation-induced reliability degradation of SiC power MOSFET
2023
The effect of 53 MeV proton irradiation on the reliability of silicon carbide power MOSFETs was investigated. Post-irradiation gate voltage stress was applied and early failures in time-dependent dielectric breakdown (TDDB) test were observed for irradiated devices. The applied drain voltage during irradiation affects the degradation probability observed by TDDB tests. Proton-induced single event burnouts (SEB) were observed for devices which were biased close to their maximum rated voltage. The secondary particle production as a result of primary proton interaction with the device material was simulated with the Geant4-based toolkit. peerReviewed
Proton Direct Ionization in Sub-Micron Technologies: Numerical Method for RPP Parameter Extraction
2022
This work introduces a numerical method to iteratively extract parameters of a rectangular parallelepiped (RPP) sensitive volume (SV) from experimental proton direct ionization SEU data. The method combines two separate numerical models. The first model estimates the average LET values for energetic ions, including protons and also heavy ions, in elemental solid targets. The second model describes the statistical variance in the energy deposition events of projectile-induced primary ionization within a RPP shaped target volume. To benchmark the method, simulated cross-section values based on RPP parameters derived with this method are compared with literature data from four SRAM devices. Th…
Measurement of proton and nitrogen polarization in ammonia and a test of equal spin temperature
1998
The 1996 data taking of the SMC experiment used polarized protons to measure the spin-dependent structure function g(1) of the proton. Three liters of solid granular ammonia were irradiated at the Bonn electron linac in order to create the paramagnetic radicals which are needed for polarizing the protons. Proton polarizations of +/- (90 +/- 2.5)% were routinely reached. An analysis based on a theoretical line shape for spin-1. systems with large quadrupolar broadening was developed which allowed the nitrogen polarization in the ammonia to be determined with a 10% relative error. The measured quadrupolar coupling constant of N-14 agrees well with earlier extrapolated values. The polarization…
Advanced model for the prediction of the neutron-rich fission product yields
2013
The consistent models for the description of the independent fission product formation cross sections in the spontaneous fission and in the neutron and proton induced fission at the energies up to 100 MeV is developed. This model is a combination of new version of the two-component exciton model and a time-dependent statistical model for fusion-fission process with inclusion of dynamical effects for accurate calculations of nucleon composition and excitation energy of the fissioning nucleus at the scission point. For each member of the compound nucleus ensemble at the scission point, the primary fission fragment characteristics: kinetic and excitation energies and their yields are calculate…
Assignment of1H and13C NMR data for (−)-methyl thyrsiflorin A and some scopadulan precursors
2001
The 1H and 13C NMR spectral analysis of synthetic (−)-methylthyrsiflorin A and 10 scopadulan precursors is reported. Resonance assignments were based on one- and two-dimensional NMR techniques, which included 1H, 13C, DEPT and HMQC and also 1D NOE difference spectroscopy. Copyright © 2001 John Wiley & Sons, Ltd.
New states as observed by the Crystal Barrel experiment
1993
Abstract The Crystal Barrel Detector has been in operation since October 1989. Results on the analysis of the annihilation of protonium at rest into three pseudoscalars is presented. The π 0 π 0 π 0 final state confirms the existence of ƒ 2 (1520)→π 0 π 0 . In the ηη system of the π 0 ηη final state an isoscalar J PC = 0 ++ resonance with a mass of 1560 MeV/c 2 and a width of 245 MeV/c 2 is observed. The identification with ƒ 0 (1590) is doubtful since the ηη' decay is not observed with the corresponding strength. Our analysis yields an upper limit for the relative branching ratio BR(ƒ 0 (1560)→ηη') BR(ƒ 0 (1560)→ηη) .
Antiproton-Proton Cross Sections at Small Momenta
1990
Since the startup of LEAR in 1983 we have undertaken a series of measurements of antiproton-proton cross sections for annihilation (pp → mesons)1, charge-exchange reaction (pp → nn)2, and elastic scattering (pp → pp)3,4. We have focussed our efforts of the measurements on the beam momentum range between 160 and 600 MeV/c. Our detector is optimized to handle the antiproton beam at very small momenta5. The liquid hydrogen target is placed in the vacuum tank, and the vacuum is directly connected to the beam line. The incident beam is defined by thin scintillators also placed in the vacuum. With the apparatus of these unique designs we have explored the beam momentum region below 300 MeV/c with…
CERN’s Linac4 cesiated surface H− source
2017
Linac4 cesiated surface H− sources are routinely operated for the commissioning of the CERN’s Linac4 and on an ion source test stand. Stable current of 40-50 mA are achieved but the transmission through the LEBT of 80% was below expectations and triggered additional beam simulation and characterization. The H− beam profile is not Gaussian and emittance measurements are larger than simulation. The status of ongoing development work is described; 36 mA H− and 20 mA D− beams were produced with a 5.5 mm aperture cesiated surface ion source. The emittances measured at the test stand are presented. During a preliminary test, the Linac4 proton source delivered a total beam intensity of 70 mA (p, H…
Inclusive Pion Double Charge Exchange on Light Nuclei above 0.5 GeV
1995
Inclusive double charge exchange (DCX) reaction A(π −, π +) X on 6Li and 16O was for the first time measured at incident kinetic energy T 0 = 1.1 GeV ( ≈ 5°) for outgoing particle momentum region where additional pion production is kinematically forbidden. The experiment was performed at secondary π − beam of the ITEP proton synchrotron using the 3m magnet spectrometer. The measured double differential cross section at 1.1 GeV together with our previous results at 0.6 and 0.75 GeV [1] and with the lower energy data [2] and [3] shows rather slow decrease with energy. This result is in contradiction with the fast fall of small angle DCX cross section calculated [4] in the standard mechanism o…