| 1. |
- Tenishev, Vladimir, et al.
(författare)
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On-line diagnostic tool for measurement of the time delay between two ultrashort light pulses
- 2004
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Ingår i: Measurement Science & Technology. - : IOP Publishing. - 0957-0233 .- 1361-6501. ; 15:9, s. 1762-1767
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Tidskriftsartikel (refereegranskat)abstract
- Ultrafast accelerator-based sources combined with synchronized femtosecond lasers are currently being developed. The method described here is intended as a jitter monitor at such facilities. We report on the possibility of extracting a time-offset signal between two different synchronized ultrashort light pulses. The method is based on sum-frequency generation in a nonlinear crystal. Aiming at extracting the time-difference from visible pulsed radiation from an x-ray undulator and femtosecond laser pulses we are investigating the possibility of obtaining timing information when one of the two pulses is very weak (10(6) photons/pulse). This will enable on-line monitoring of the relative timing of an accelerator-based free-electron laser and a synchronized visible laser. The spatial position of the sum-frequency mixed region is registered using a position sensitive detector (PSD). We show that for an 80 fs light source the described electronic equipment is capable of delivering a signal proportional to the temporal shift of different ultrashort light pulses with an accuracy of approximately 30 fs in a time interval of several ps.
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| 2. |
- Adler, Jan-Olof, et al.
(författare)
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The upgraded photon tagging facility at the MAX IV Laboratory
- 2013
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 715, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- A description is given of the upgraded photon tagging facility at the MAX IV Laboratory. Two magnetic spectrometers are used to momentum analyze post-bremsstrahlung electrons. The tagged photon range extends from 10 to 180 MeV with an energy resolution of about 300 keV. The system has been operated at rates up to 4 x 10(6) photons s(-1) MeV (-1). Different diagnostic tools are described as well as the experimental program.
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| 3. |
- Altstadt, S.G., et al.
(författare)
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B-13,B-14(n,gamma) via Coulomb Dissociation for Nucleosynthesis towards the r-Process
- 2014
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Ingår i: Nuclear Data Sheets. - : Elsevier BV. - 1095-9904 .- 0090-3752. ; 120, s. 197-200
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Konferensbidrag (refereegranskat)abstract
- Radioactive beams of 14,15B produced by fragmentation of a primary 40Ar beam were directed onto a Pb target to investigate the neutron breakup within the Coulomb field. The experiment was performed at the LAND/R3B setup. Preliminary results for the Coulomb dissociation cross sections as well as for the astrophysically interesting inverse reactions, 13,14B(n,γ), are presented.
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| 4. |
- Avdeichikov, Vladimir, et al.
(författare)
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Analysis of charged particle emission sources and coalescence in E/A=61 (MeVAr)-Ar-36+Al-27, Sn-112 and Sn-124 collisions
- 2004
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Ingår i: Nuclear Physics, Section A. - : Elsevier BV. - 0375-9474. ; 736:1-2, s. 22-38
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Tidskriftsartikel (refereegranskat)abstract
- Single-particle kinetic energy spectra and two-particle small angle correlations of protons (p), deuterons (d) and tritons (t) have been measured simultaneously in 61 A MeV Ar-36 + Al-27, Sn-112 and Sn-124 collisions. Characteristics of the emission sources have been derived from a "source identification plot" (beta(source)-E-CM plot), constructed from the single-particle invariant spectra, and compared to the complementary results from two-particle correlation functions. Furthermore, the source identification plot has been used to determine the conditions when the coalescence mechanism can be applied for composite particles. In our data, this is the case only for the Ar + Al reaction, where p, d and t are found to originate from a common source of emission (from the overlap region between target and projectile). In this case, the coalescence model parameter, (p) over tilde (0)-the radius of the complex particle emission source in momentum space, has been analyzed.
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| 5. |
- Avdeichikov, Vladimir, et al.
(författare)
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Systematics in the light response of BGO, CsI(T1) and GSO(Ce) scintillators to charged particles
- 2002
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 484:1-3, s. 251-258
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Tidskriftsartikel (refereegranskat)abstract
- The light response of a BGO crystal has been measured for particles Z = 1-8, A = 1-16 in the energy range similar to2-60 A MeV. The reaction products are identified by a DeltaE(Si) - E(Sci/PD) telescope, The position of the jump in the value of the signal from the PD at the punch-through points is used to calibrate both the DeltaE(Si) and E(Sci/PD) scales in MeV. The dependence of the light output on the energy E, ion atomic number Z and mass A is parameterized by the power law relation, L(Z, A, E) = a(1)((Z, A))E(a2(Z, A)). The parameters a(1) and a(2) have a smooth dependence on Z for all three crystals. The mass dependence of a(1), a(2) is deduced as a simple analytical expression, The systematics of these parameters is presented for BGO, CsI(Tl) and GSO(Ce) scintillators as a function of Z, A. Calculations of the response function, based on the Murray-Mayer model provide an excellent description of the shape of L(Z, A, E) versus E dependence, but show some deviations in the individual ion normalization constant for the BGO and GSO(Ce) scintillators. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 6. |
- Boillos, J. M., et al.
(författare)
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Isotopic cross sections of fragmentation residues produced by light projectiles on carbon near
- 2022
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Ingår i: Physical Review C. - 2469-9993 .- 2469-9985. ; 105:1
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Tidskriftsartikel (refereegranskat)abstract
- We measured 135 cross sections of residual nuclei produced in fragmentation reactions of C12, N14, and O13−16,20,22 projectiles impinging on a carbon target at kinetic energies of near 400A MeV, most of them for the first time, with the RB3/LAND setup at the GSI facility in Darmstadt (Germany). The use of this state-of-the-art experimental setup in combination with the inverse kinematics technique gave the full identification in atomic and mass numbers of fragmentation residues with a high precision. The cross sections of these residues were determined with uncertainties below 20% for most of the cases. These data are compared to other previous measurements with stable isotopes and are also used to benchmark different model calculations.
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| 7. |
- Caesar, C., et al.
(författare)
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Beyond the neutron drip line: The unbound oxygen isotopes O-25 and O-26
- 2013
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993 .- 0556-2813. ; 88:3
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Tidskriftsartikel (refereegranskat)abstract
- The very neutron-rich oxygen isotopes O-25 and O-26 are investigated experimentally and theoretically. The unbound states are populated in an experiment performed at the R3B-LAND setup at GSI via proton-knockout reactions from F-26 and F-27 at relativistic energies around 442 and 414 MeV/nucleon, respectively. From the kinematically complete measurement of the decay into O-24 plus one or two neutrons, the O-25 ground-state energy and width are determined, and upper limits for the O-26 ground-state energy and lifetime are extracted. In addition, the results provide indications for an excited state in O-26 at around 4 MeV. The experimental findings are compared to theoretical shell-model calculations based on chiral two- and three-nucleon (3N) forces, including for the first time residual 3N forces, which are shown to be amplified as valence neutrons are added.
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| 8. |
- Carlén, Lars, et al.
(författare)
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Dynamical. and statistical fragment emission properties in 200 A MeV Ne-20+Ar-40 collisions
- 2006
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Ingår i: Nuclear Physics, Section A. - : Elsevier BV. - 0375-9474. ; 764, s. 15-23
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Tidskriftsartikel (refereegranskat)abstract
- Dynamical and statistical fragment emission processes in 200 A MeV Ne-20 + Ar-40 collisions are well probed by measurements of charge (Z), mass (A) and momentum vector ((p) over right arrow) of all fragments in large parts of the available momentum space. We present such data obtained at the cluster-jet target of the CELSIUS storage ring, for the first time with an internal, ultra-high vacuum (UHV) compatible detector system (CHICSi). Energy and angular dependence in Z and A distributions are not reproduced by a single-step model, e.g., those based on molecular dynamics (MD), but require a complete three-step model. We use here the intranuclear cascade+ statistical multifragmentation + secondary evaporation model (CFEM). The angular dependence of isobaric ratios, like He-6/Li-6 at low emission velocities and temperatures extracted from isotopic (double) ratios, do exhibit differences, even from this model. These differences, which call for adjustment of model parameters, are discussed. (c) 2005 Elsevier B.V. All rights reserved.
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| 9. |
- DiJulio, Douglas, et al.
(författare)
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Proton in-beam tests of the Lund (RB)-B-3 calorimeter prototype
- 2009
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 612:1, s. 127-132
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Tidskriftsartikel (refereegranskat)abstract
- A small-scale prototype of the CALIFA calorimeter, which is a subsystem of the R 3 B detector, has been constructed and tested using the 179 MeV proton beam at The Svedberg Laboratory, Uppsala, Sweden. The prototype consists of 15 Csl(Tl) elements with a size of 10 x 30 x 130 mm(3), assembled in a 3 x 5 array. Each crystal was individually tested using gamma-ray sources and the light output uniformity along the longitudinal axes was adjusted to better than 0.6%. An energy resolution of similar to 0.5% has been achieved with a technique consisting of non-uniform polishing/lapping of the crystal side facets. The performance of the prototype is evaluated using experimental data and GEANT4 simulations. Results from the experiment, including multiplicity and sum spectra, show good agreement with simulations. The quality requirements for Csl(Tl) elements for construction of a high precision calorimeter/spectrometer are summarized. (C) 2009 Elsevier B.V. All rights reserved.
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| 10. |
- Ghetti, Roberta, et al.
(författare)
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Calibration of a neutron time-of-flight multidetector system for an intensity interferometry experiment
- 2004
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 516:2-3, s. 492-501
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Tidskriftsartikel (refereegranskat)abstract
- We present the details of an experiment on light particle interferometry. In particular, we focus on a time-of-flight technique which uses a cyclotron RF signal as a start and a liquid scintillator time signal as a stop, to measure neutron energy in the range of En approximate to 1.8-150 MeV. This dynamic range (up to 300 ns) is much larger than the beam bunch separation (54 ns) of the AGOR cyclotron (KVI). However, the problem of a short burst period is overcome by using the time information obtained from a fast projectile fragment phoswich detector. The complete analysis procedure to extract the final neutron kinetic energy spectra, is discussed. (C) 2003 Elsevier B.V. All rights reserved.
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