The MEDLEY setup based at The Svedberg Laboratory (TSL), Uppsala, Sweden has previously been used to measure double-differential cross-sections for elastic nd scattering, as well as light ion production reactions for various nuclei in the interaction with neutrons around 95 MeV. When moved to the new beam line, the first experimental campaign was on light-ion production from Ca at 94 MeV in February 2005.
These data sets have been analyzed for proton production in forward and backward angles. The Delta E - Delta E - E technique have been used to identify protons, and a cutoff as low as 2.5 MeV is achieved. Suppression of events induced by neutrons in the low-energy tail of the neutron field is achieved by time-of-flight techniques. The data are normalized relative to elastic np scattering measured in the 20-degree telescope. Results from an accepted neutron spectrum are presented and some methods to correct for events from low energy neutrons are presented and evaluated. The data are compared with calculations using the nuclear code TALYS. It was found that TALYS systematically overestimates the compound part, and underestimates the pre-equilibrium part of the cross-section.
To get the energy spectrum distribution and cross-sections of emitted light charged particles and explore the nuclear reaction, a experiment of 80.5 MeV/u 12C beam bombarding on C, W, Cu, Au, Pb targets has been carried out at Institute of Modern Physics, Chinese Academy of Science. 30, 60 and 120 degree relative to the incident beam have been detected using three sets of telescope detectors. The results indicate that there is a tendency that heavier targets have larger double differential cross-sections and the emitted fragments are more likely to go forward. Besides, the decrease of cross-se…
Nuclear particle production from peripheral to central events is presented. N/Z gradient between projectile and target is studied using the fact that two reactions have the same projectile+target N/Z and so the same neutron to proton ratio for the combined system. Inclusive data study in the forward part of the center of mass indicates that N/Z equilibration between the projectile-like and the target-like is achieved for central collisions. Particles are also produced from mid-rapidity region. 3He mean pre-equilibrium character is evidenced and 6He production at mid-rapidity implies a neutron …
Two-particle correlation functions, involving protons, deuterons, tritons, and alpha-particles, have been measured at very forward angles (0.7 deg < theta_lab < 7 deg), in order to study projectile-like fragment (PLF) emission in E/A = 44 and 77 MeV 40Ar + 27Al collisions. Peaks, originating from resonance decays, are larger at E/A = 44 than at 77 MeV. This reflects the larger relative importance of independently emitted light particles, as compared to two-particle decay from unstable fragments, at the higher beam energy. The time sequence of the light charged particles, emitted from the PLF, …
An analysis of the energy spectra of protons emitted in reactions of 47 MeV/u projectiles with Sn and Au targets provides evidence for high momentum tails in the intrinsic momenta spectra of the projectiles. These high momentum spectra decrease with wavenumber $k$ at a rate proportional to $1/k^4$. We suggest that additional experiments could provide a more refined value for the value of the power law exponent.
Velocity and energy spectra of the light charged particles (protons and $α$-particles) emitted in the $^{28}$Si(E$_{lab}$ = 112 MeV) + $^{28}$Si reaction have been measured at the Strasbourg VIVITRON Tandem facility. The ICARE charged particle multidetector array was used to obtain exclusive spectra of the light particles in the angular range 15 - 150 degree and to determine the angular correlations of these particles with respect to the emission angles of the evaporation residues. The experimental data are analysed in the framework of the statistical model. The exclusive energy spectra of $α$…
Experimental kinetic energy distributions and small-angle two-particle correlation functions involving deuterons and tritons are compared for 36Ar+ 112,124Sn collisions at E/A = 61 MeV (i.e. for systems similar in size, but with different isospin content). A larger triton yield is observed from the more neutron-rich system, as predicted by IBUU simulations, while the emission times of the light clusters are found to be the same for the two Sn-target systems. For both systems, the time sequence tau_{d} < tau_{p} < tau_{t}, is deduced for charged particles emitted from the intermediate velocity …
Differential cross sections of neutral pions emitted in 181Ta + 197Au collisions at a beam energy of 39.5A MeV have been measured with the photon spectrometer TAPS. The kinetic energy and transverse momentum spectra of neutral pions cannot be properly described in the framework of the thermal model, nor when the reabsorption of pions is accounted for in a phenomenological model. However, high energy and high momentum tails of the pion spectra can be well fitted through thermal distributions with unexpectedly soft temperature parameters below 10 MeV.
Spectral yield of p+Be neutrons emitted by thick (stopping) beryllium target bombarded by 16 MeV protons was estimated via extrapolation of literature data. The spectrum was validated via multi-foil activation method and irradiation of 2N2222 transistors. The hardness parameter (NIEL scaling factor) for displacement damage in bulk silicon was calculated and measured and kappa = 1.26 +- 0.1 was obtained.
The properties of the two-body channels in the $^{35}$Cl + $^{24}$Mg reaction at a bombarding energy of 275 MeV have been investigated by using fragment-fragment coincident techniques. The exclusive data show that the majority of events arises from a binary-decay process. The rather large number of secondary light charged-particles emitted from the two excited exit fragments are cnsistent with the expectations of the Extended Hauser-Feshbach Method. No evidence for the occurence of ternary break-up events is observed.
Experimental data concerning binary events in peripheral collisions for the systems 93Nb+93Nb and 93Nb+116Sn at 38 MeV/nucleon, collected with the Fiasco setup, are compared with calculations performed with the dynamic code AMD, coupled with the statistical code Gemini used as an afterburner. The comparison focuses on the properties of the quasiprojectile (QP) and on the total multiplicities of the emitted light charged particles. A good reproduction of the average mass ratio, charge Z and c.m. angle of the QP is obtained in the examined impact parameter range (b~7-12 fm). Concerning the light…
The inclusive energy distributions of the complex fragments (3 $\leq$ Z $\leq$ 7) emitted from the bombardment of ^{12}C by ^{20}Ne beams with incident energies between 145 and 200 MeV have been measured in the angular range 10$^{o} \leq θ_{lab} \leq$ 50^{o}. Damped fragment yields in all the cases have been found to be the characteristic of emission from fully energy equilibrated composites. The binary fragment yields are compared with the standard statistical model predictions. Enhanced yields of entrance channel fragments (5 $\leq$ Z $\leq$ 7) indicate the survival of orbiting-like process …
Prompt fission neutron spectra from $^{239}$Pu($n,f$) were measured for incident neutron energies from $0.7$ to $700\,$MeV at the Weapons Neutron Research facility (WNR) of the Los Alamos Neutron Science Center. A newly designed high-efficiency fission chamber was coupled to the highly segmented Chi-Nu array to detect neutrons emitted in fission events. The double time-of-flight technique was used to deduce the incident-neutron energies from the spallation target and the outgoing-neutron energies from the fission chamber. Prompt fission neutron spectra (PFNS) were measured with respect to $^{2…
Simultaneous measurement of both neutrons and charged particles emitted in the reaction $^{64}$Zn + $^{64}$Zn at 45 MeV/nucleon allows comparison of the neutron to proton ratio at midrapidity with that at projectile rapidity. The evolution of N/Z in both rapidity regimes with increasing centrality is examined. For the completely re-constructed midrapidity material one finds that the neutron-to-proton ratio is above that of the overall $^{64}$Zn + $^{64}$Zn system. In contrast, the re-constructed ratio for the quasiprojectile is below that of the overall system. This difference provides the mos…
The near-forward cross section for the pp -> pn pi^+ reaction has been measured at 492 MeV by using the large acceptance ANKE magnetic spectrometer placed at an internal target position of the storage ring COSY-Juelich. Protons and pions emitted near zero degrees were detected in coincidence, and those with theta_pi <= 2 degrees and theta_p <= 2.5degrees were subjected to detailed analysis. Under these conditions, the excitation energy in the np system was below 3 MeV over the measured momentum range. This is the region of the np final-state-interaction peak, which was measured with a resoluti…
In this paper an attempt was to measure, the excitation functions of $^{169}$Tm($^{12}$C, 4n)$^{177}$Re, $^{169}$Tm($^{12}$C, 5n)$^{176}$Re, $^{169}$Tm($^{12}$C, $α$n)$^{176}$Ta, $^{169}$Tm($^{12}$C, $α$2n)$^{175}$Ta , $^{169}$Tm($^{12}$C, $α$3n)$^{174}$Ta , $^{169}$Tm($^{12}$C, $α$4n)$^{173}$Ta, and $^{169}$Tm($^{12}$C, 2$α$2n)$^{171}$Lu reaction channels populated in the interaction of $^{12}$C projectile with $^{169}$Tm target were considered in order to investigate the mechanisms of complete and incomplete fusion reactions. The theoretically predicted excitation functions using PACE4 code …
Correlated $Λd$ pairs emitted after the absorption of negative kaons at rest $K^{-}_{stop}A\to Λd A'$ in light nuclei $^6Li$ and $^{12}C$ are studied. $Λ$-hyperons and deuterons are found to be preferentially emitted in opposite directions. The $Λd$ invariant mass spectrum of $^6Li$ shows a bump whose mass is 3251$\pm$6 MeV/c$^2$. The bump mass (binding energy), width and yield are reported. The appearance of a bump is discussed in the realm of the [$\bar{K}3N$] clustering process in nuclei. The experiment was performed with the FINUDA spectrometer at DA$Φ$NE (LNF).
The cross sections for (γ,xn) reactions at 30 MeV and 40 MeV bremsstrahlung end-point energies on natural rhenium (natRe) targets have been measured by the activation and the off-line γ-ray spectrometric techniques using a High Purity Germanium detector (HPGe). The measured natRe(γ,xn) reaction cross sections were compared to the theoretically calculated cross sections using TALYS 1.9 and EMPIRE 3.2 computer codes. The measurements allowed the determination of the Isomeric Cross section Ratios (ICR) for the 184m,g Re and 182m,gRe isomeric pairs. In addition, we have determined a semi-empirical…
The inclusive energy distributions of fragments with Z $\geq$ 3 emitted from the bombardment of $^{12}$C by $^{20}$Ne beams with incident energies between 145 and 200 MeV have been measured in the angular range $θ_{lab} \sim$ 10$^\circ$ - 50$^\circ$. Damped fragment yields in all cases have been found to be characteristic of emission from fully energy equilibrated composites; for B, C fragments, average Q-values, $<Q>$, were independent of the centre of mass emission angle ($θ_{c.m}$), and the angular distributions followed $\sim$1/sin$θ_{c.m}$ like variation, signifying long life times of the…
Correlations between pairs of projectile-like fragments, emitted by the system ${^{16}O}+{^{197}Au}$ at the laboratory bombarding energy of 515 MeV, have been studied under two stipulated conditions: (1) at least one member of the pair is emitted at an angle less than the grazing angle for the system, (2) both the members of the pair are emitted at angles larger than the grazing angle. A surprisingly large difference, by more than an order of magnitude, is found between the correlations for the two cases. This observation could be explained on the basis of a simple semi-classical break up mode…
We analyzed the $^{93}Nb$ on $^{nat}Mg$ reaction at 30 MeV/nucleon in the aim of disentangling binary sequential decay and multifragmentation decay close to the energy threshold, i.e. $\simeq 3$ MeV/nucleon. Using the backtracing technique applied to the statistical models GEMINI and SMM we reconstruct simulated charge, mass and excitation energy distributions and compare them to the experimental ones. We show that data are better described by SMM than by GEMINI in agreement with the fact that multifragmentation is responsible for fragment production at excitation energies around 3 MeV/nucleon…
We differentiate the event-by-event n-$γ$ multiplicity data from \ce{^{252}Cf}(sf) with respect to the energies of the emitted particles as well as their relative angles of emission. We determine that neutron emission enhances $γ$-ray emission around $0.7$ and $1.2$ MeV, but the only directional alignment was observed for $E_γ\leq 0.7$ MeV and tended to be parallel and antiparallel to neutrons emitted in the same event. The emission of $γ$ rays at other energies was determined to be nearly isotropic. The presence of the emission and alignment enhancements is explained by positive correlations …
An experiment was performed at the scientific neutron source FRM II in Garching to determine the cumulative antineutrino spectrum of the fission products of $^{238}$U. This was achieved by irradiating target foils of natural uranium with a thermal and a fast neutron beam and recording the emitted $β$-spectra with a gamma-suppressing electron-telescope. The obtained $β$-spectrum of the fission products of $^{235}$U was normalized to the data of the magnetic spectrometer BILL of $^{235}$U. This method strongly reduces systematic errors in the $^{238}$U measurement. The $β$-spectrum of $^{238}$U …
The double differential cross sections for $^{nat}$In($^{28}$Si, $π^{\pm}$) reactions are measured at 400, 600, and 800 MeV/nucleon. Both $π^+$ and $π^-$ are found to be emitted isotropically from a single moving source. The $π^- / π^+$ yield ratio is determined as a function of the charged pion energy between 25 and 100 MeV. The experimental results significantly differ from the prediction of the standard transport model calculation using the code PHITS. This discrepancy suggests that more theoretical works are required to deduce firm information on the nuclear symmetry energy from the $π^- /…
This paper reports a new route for production of 190-193Au radionuclides from natW target. For the first time the production cross section of 11B induced reactions on tungsten for production of 190-193Au were measured up to 63 MeV boron energy. High cross section was observed for 190,192Au at the highest energy where as 191,193Au showed moderate cross section values. The experimentally obtained cross sections were compared with the predictions of the PACE4 and EMPIRE3.2.2 code.
The inclusive energy distributions of complex fragments (3 $\leq$Z $\leq$ 9) emitted in the reactions $^{20}$Ne (145, 158, 200, 218 MeV) + $^{27}$Al have been measured in the angular range 10$^{o}$ - 50$^{o}$. The fusion-fission and the deep-inelastic components of the fragment yield have been extracted using multiple Gaussian functions from the experimental fragment energy spectra. The elemental yields of the fusion-fission component have been found to be fairly well exlained in the framework of standard statistical model. It is found that there is strong competition between the fusion-fissio…
Cross-sections for the proton-induced reactions on natural neodymium in energy regions 5-10 MeV and 30-35 MeV were measured using the cyclotron U-120M at the Nuclear Physics Institute at Rez near Prague. This measurement completes the investigation previously done in the 10-30 MeV energy range. Results revealed practical production thresholds and secondary maxima and minima in the excitation functions. It allowed for more appropriate calculation of thick target yields and production rates of many longer-lived radionuclides potentially disturbing the search for neutrinoless double beta decay. M…
Activation cross-sections for deuteron induced reactions on Sm are presented for the first time for $^{nat}$Sm(d,xn)$^{155,154,152m2,152m1,152g,150m,150g,149,148,147,146}$Eu, $^{nat}$Sm(d,x)$^{153,145}$Sm and $^{nat}$Sm(d,x)$^{151,150,149,145,144,143}$Pm up to 50 MeV. The cross-sections were measured by the stacked-foil irradiation technique and high resolution $γ$-ray spectrometry. The results were compared with results of nuclear reaction codes ALICE-D, EMPIRE-D and TALYS (from TENDL libraries). Integral yields of the products were calculated from the excitation functions.
Activation cross-sections are presented for the first time for natGd(d,xn)161,160,156(m+), 154,154m1,154m2,153,152(m+),151(m+)Tb, natGd(d,x)159,153,151Gd and natGd(d,x)156Eu reactions from their respective thresholds up to 50 MeV. The cross-sections were measured by the stacked-foil irradiation technique and by using high resolution gamma-ray spectrometry. The measured values were compared with the results of theoretical models calculated by the computer codes ALICE-D, EMPIRE-D and TALYS (data from TENDL library). Integral yields of the reaction products were deduced from the excitation functi…
Natural silver targets have been irradiated by using a 50 MeV alpha-particle beam in order to measure the activation cross sections of radioisotopes in the 40-50 MeV energy range. Among the radio-products there are medically important isotopes such as $^{110m}$In and $^{111}$In. For optimizing the production of these radioisotopes and regarding their purity and specific activity the cross section data for every produced radioisotope are important. New data are measured in this energy range and the results of some previous measurements have been confirmed. Physical yield curves have been calcul…
Inclusive energy spectra of the complex fragments (3 $\leq$ Z $\leq$ 5) emitted in the reactions $^{12}$C (77 MeV)+ $^{28}$Si, $^{11}$B (64 MeV)+ $^{28}$Si and $^{12}$C (73 MeV)+ $^{27}$Al (all having the same excitation energy of $ \sim$ 67 MeV), have been measured in the angular range of 10$^\circ$ $\lesssim θ_{lab} \lesssim$ 60$^\circ$. The fully energy damped (fusion-fission) and the partially energy damped (deep inelastic) components of the fragment energy spectra have been extracted. It has been found that the yields of the fully energy damped fragments for all the above reactions are in…
Activation cross sections for proton induced reactions on Sm are presented for the first time for $^{nat}$Sm(p,xn)$^{154,152m2,152m1,152g,150m,150g,149,148,147,146,145}$Eu, $^{nat}$Sm(p,x)$^{153,145}$Sm, $^{nat}$Sm(p,x)$^{151,150,149,148g,148m,146,144,143}$Pm and $^{nat}$Sm(p,x)$^{141}$Nd up to 65 MeV. The cross sections were measured via activation method by using a stacked-foil irradiation technique and high resolution gamma ray spectroscopy. The results were compared with results of the nuclear reaction codes ALICE, EMPIRE and TALYS (results taken from TENDL libraries). Integral yields of t…
We present a probable experimental signature of collective enhancement in the nuclear level density (NLD) by measuring the neutron and the giant dipole resonance (GDR) $γ$ rays emitted from the rare earth $^{169}$Tm compound nucleus populated at 26.1 MeV excitation energy. An enhanced yield is observed in both neutron and $γ$ ray spectra corresponding to the same excitation energy in the daughter nuclei. The enhancement could only be reproduced by including a collective enhancement factor in the Fermi gas model of NLD to explain the neutron and GDR spectra simultaneously. The experimental resu…
Experimental information on fragment emissions is important in understanding the dynamics of nuclear collisions and in the development of transport model simulating heavy-ion collisions. The composition of complex fragments emitted in the heavy-ion collisions can be explained by statistical models, which assume that thermal equilibrium is achieved at collision energies below 100 MeV/u. Our new experimental data together with theoretical analyses for light particles from Sn+Sn collisions at 270 MeV/u, suggest that the hypothesis of thermal equilibrium breaks down for particles emitted with high…
Cross-sections for ${}^{nat}Pb(p,xn){}^{201-207}Bi$, ${}^{204}Pb(p,1-4n){}^{201-204}Bi$ and ${}^{206}Pb(p,3n){}^{204}Bi$ reactions have been determined in the astrophysical energy range $20-30 \, MeV$. The analysis were performed by $γ$-spectroscopy associated with half-lives measurements. The results were compared with previously experimental data, when available, and with theoretical calculations performed using TALYS code. We report a possible new $γ$ transition from ${}^{204m}{Pb}$ and other theoretical discrepancies, probably due overestimation of the Coulomb barrier and neutron binding e…
Excitation functions were measured in the 31 - 49.2 MeV energy range for the natPd(d,xn)111,110m,106m,105,104g,103Ag, natPd(d,x) 111m,109,101,100Pd, natPd(d,x), 105,102m,102g,101m,101g,100,99m,99gRh and natPd(d,x)103,97Ru nuclear reactions by using the stacked foil irradiation technique. The experimental results are compared with our previous results and with the theoretical predictions calculated with the ALICE-D, EMPIRE-D and TALYS (TENDL libraries) codes.
Excitation functions were measured by stacked-foil activation technique for the $^{150}$Nd(p, xpyn) reaction using 97.65$%$ enriched $^{150}$Nd target. Measurement up to $\sim$50$%$ above barrier and down to 18$%$ below the barrier was performed using proton beam energy (E$_p$) of 7 - 15 MeV from VECC Cyclotron. The yield of suitable $γ$ rays emitted following the decay of relevant evaporation residues was determined using a 50$%$ High Purity Germanium (HPGe) detector.(p,n) cross section was found to follow the expected trend with a maximum value of 63.7(4.9)mb at E$_p$ $\sim$ 8.6 MeV. (p,2n) …
Cross-sections of deuteron induced nuclear reactions on lead were measured up to 50 MeV using the standard stacked foil irradiation technique and high resolution $γ$-ray spectrometry. Experimental cross-sections and derived integral yields are presented for the $^{nat}$Pb(d,x)$^{206,205,204,203,202}$Bi, $^{203cum,202m,201cum}$Pb and $^{202cum,201cum}$Tl reactions. The experimental data were compared with the results from literature and with the data in the TENDL-2013 library (obtained with TALYS code). The cross-section data were analyzed also with the theoretical results calculated by using t…
The total bremsstrahlung flux-averaged cross-sections <$σ$(E$_{γmax}$)> for the photonuclear reactions $^{nat}$Ni($γ$,xn)$^{57}$Ni and $^{nat}$Ni($γ$,xn)$^{56}$Ni have been measured in the range of end-point energies E$_{γmax}$ = 35...94 MeV. The experiments were performed with the beam from the NSC KIPT electron linear accelerator LUE-40 with the use of the activation and off-line $γ$-ray spectrometric technique. The calculation of the flux-average cross-sections <$σ$(E$_{γmax}$)>$_{th}$ was carried out using the partial cross-section values $σ$(E) computed with the TALYS1.95 code and bremsst…
Activation cross sections of the natEr(d,x)163,165,166,167,168,170Tm and natEr(d,x)171,161Er nuclear reactions have been measured in the 32-50 MeV energy range, above 40 MeV for the first time. The activation method with stacked foil irradiation technique and gamma-ray spectroscopy were used. The experimental cross sections were compared with the theoretical predictions in the TENDL-2015 library.
Due to potential level of energy intensity 178m2Hf is an extremely interesting isomer. One possible way to produce this isomer is irradiation of nat-Ta or nat-W samples with high energy protons. Irradiation of nat-Ta and nat-W samples performed for other purposes provides an opportunity to study the corresponding reactions. This paper pre-sents the 178m2Hf independent production cross sections for both targets measured by the gamma-ray spectrometry method. The reaction excitation functions have been obtained for the proton energies from 40 up to 2600 MeV. The experimental results were compared…
An electrically cooled Broad Energy Germanium (BEGe) detector has been characterized in the energy range E$_γ$ $\sim$ 0.122 - 7 MeV by utilizing the $γ$- rays emitted by a short-lived resonance state in $^{15}$O populated through $^{14}$N(p,$γ$) reaction and standard radioactive source ($^{152}$Eu). The experimental results have been reproduced through simulations with GEANT4 code, including vendor specified detector geometry along with the detailed construction of the target holder flange, to delineate the effects of the holder at various energies and detector position. Later the efficiency w…
Cross sections for the formation of 225,227-Ac, 223,225-Ra, and 227-Th via the proton bombardment of natural thorium targets were measured at a nominal proton energy of 800 MeV. No earlier experimental cross section data for the production of 223,225-Ra, 227-Ac and 227-Th by this method were found in the literature. A comparison of theoretical predictions with the experimental data shows agreement within a factor of two. Results indicate that accelerator-based production of 225-Ac and 223-Ra is a viable production method.
[Background] Alpha-nucleus optical potentials are basic ingredients of statistical model calculations used in nucleosynthesis simulations. While the nucleon+nucleus optical potential is fairly well known, for the alpha+nucleus optical potential several different parameter sets exist and large deviations, reaching sometimes even an order of magnitude, are found between the cross section predictions calculated using different parameter sets. [Purpose] A measurement of the radiative alpha-capture and the alpha-induced reaction cross sections on the nucleus 115In at low energies allows a stringent…
Double differential cross sections (DDCS) for light charged particles (proton, deuteron, triton, 3He, alpha) and neutrons produced by a proton beam impinging on a 238U target at 62.9 MeV were measured at the CYCLONE facility in Louvain-la-Neuve (Belgium). These measurements have been performed using two independent experimental set-ups ensuring neutron (DeMoN counters) and light charged particles (Si-Si-CsI telescopes) detection. The charged particle data were measured at 11 different angular positions from 25 degrees to 140 degrees allowing the determination of angle differential, energy diff…
In the frame of a systematical study of light ion induced nuclear reactions on hafnium, activation cross sections for proton induced reactions were investigated. Excitation functions were measured in the 38 to 65 MeV energy range for the $^{nat}$Hf(p,xn)$^{180g,177,176,175,173}$Ta, $^{nat}$Hf(p,x)$^{180m,179m,175,173,172,171}$Hf, $^{177g,173,172,171,170,169}$Lu and $^{nat}$Hf(p,x)$^{169}$Yb reactions by using the activation method, combining stacked foil irradiation and off line gamma ray spectroscopy. The experimental results are compared with earlier results in the overlapping energy range, …
We have studied neutron response of PARIS phoswich [LaBr$_3$(Ce)-NaI(Tl)] detector which is being developed for measuring the high energy (E$_γ$ = 5 - 30 MeV) $γ$ rays emitted from the decay of highly collective states in atomic nuclei. The relative neutron detection efficiency of LaBr$_3$(Ce) and NaI(Tl) crystal of the phoswich detector has been measured using the time-of-flight (TOF) and pulse shape discrimination (PSD) technique in the energy range of E$_n$ = 1 - 9 MeV and compared with the GEANT4 based simulations. It has been found that for E$_n$ $>$ 3 MeV, $\sim$ 95 \% of neutrons have t…
The production of nuclear bremsstrahlung photons (E$_γ>$ 30 MeV) has been studied in inclusive and exclusive measurements in four heavy-ion reactions at 60{\it A} MeV. The measured photon spectra, angular distributions and multiplicities indicate that a significant part of the hard-photons are emitted in secondary nucleon-nucleon collisions from a thermally equilibrated system. The observation of the thermal component in multi-fragment $^{36}$Ar+$^{197}$Au reactions suggests that the breakup of the thermalized source produced in this system occurs on a rather long time-scale.
During the runs of the PS 179 experiment at LEAR of CERN, we photographed an event of antiproton-Ne absorption, with a complete pi+ -> mu+ ->e+ chain. From the vertex of the reaction a very slow energy pi+ was emitted. The pi+ decays into a mu+ and subsequently the mu+ decays into a positron. At the first decay vertex a muon neutrino was emitted and at the second decay vertex an electron neutrino and a muon antineutrino. Measuring the pion and muon tracks and applying the momentum and energy conservation and using a classical statistical interval estimator, we obtained an experimental upper li…
Excitation functions for the production of the 181,182m,182g,183,184g,186Re and 183,184Ta radionuclides from proton bombardment on natural tungsten were measured using the stacked-foil activation technique for the proton energies up to 40 MeV. A new data set has been given for the formation of the investigated radionuclides. Results are in good agreement with the earlier reported experimental data and theoretical calculations based on the ALICE-IPPE code. The thick target integral yields were also deduced from the measured excitation functions. The deduced yield values were compared with the d…
Experimental data from the reaction of an 8.0 GeV/c pi- beam incident on a 197Au target have been analyzed in order to investigate the integrated breakup time scale for hot residues. Alpha-particle energy spectra and particle angular distributions supported by a momentum tensor analysis suggest that at large excitation energy, above 3-5 MeV/nucleon, light-charged particles are emitted prior to or at the same time as the emission of the heavy fragments. Comparison with the SMM and GEMINI models is presented. A binary fission-like mechanism fits the experimental data at low excitation energies, …
The 48Ti on 40Ca reactions have been studied at 300 and 600 MeV focusing on the fusion-evaporation (FE) and fusion-fission (FF) exit channels. Energy spectra and multiplicities of the emitted light charged particles have been compared to Monte Carlo simulations based on the statistical model. Indeed, in this mass region (A about 100) models predict that shape transitions can occur at high spin values and relatively scarce data exist in the literature about coincidence measurements between evaporation residues and light charged particles. Signals of shape transitions can be found in the variati…
The experiment of Ar+Au reactions at 30 MeV/u have been performed using the Compact Spectrometer for Heavy IoN Experiments (CSHINE) in phase I. The light-charged particles are measured by the silicon stripe telescopes in coincidence with the fission fragments recorded by the parallel plate avalanche counters. The distribution properties of the azimuth difference $Δϕ$ and the time-of-flight difference $ΔTOF$ of the fission fragments are presented varying the folding angles which represents the linear momentum transfer from the projectile to the reaction system. The relative abundance of the lig…
New experimental excitation functions for proton induced reactions on natW are presented in the 32- 65 MeV energy range. The cross sections for natW(p,xn)186,184,183,182m,182g,181Re, naW(p,x)178W, natW(p,x)183,182,180m,177,176,175Ta, 175Hf, 177Lu were measured via an activation method by using a stacked-foil irradiation technique and high resolution gamma-ray spectrometry. The results were compared with predicted values obtained with the nuclear reaction model code TALYS (results taken from TENDL-2014 and TENDL-2015 on-line library). Production routes of the medically relevant radionuclides 18…
In the frame of a systematical study of light ion induced nuclear reactions on platinum, activation cross sections for deuteron induced reactions were investigated. Excitation functions were measured in the 20.8 - 49.2 MeV energy range for the natPt(d,xn)191,192,193,194,195,196m2,196g,198g,199Au, natPt(d,x)188,189,191,195m,197m,197gPt and natPt(d,x)189,190,192,194m2Ir reactions by using the stacked foil irradiation technique. The experimental results are compared with previous results from the literature and with the theoretical predictions in the TENDL-2014 and TENDL-2015 libraries. The appli…
Experiments to determine the yields and bremsstrahlung flux-averaged cross-sections <$σ(E_{γmax})$> of photonuclear reactions on the natural Mo targets were performed on the beam from the NSC KIPT electron linear accelerator LUE-40 with the use of the $γ$-activation technique. The bremsstrahlung end-point energies were in the range $E_{γmax}$ = 35...80 MeV. The bremsstrahlung quantum flux was calculated with the program GEANT4.9.2 and, in addition, was monitored using the $^{100}$Mo$(γ,n)^{99}$Mo reaction. Calculations of the yields and average cross-sections <$σ(E_{γmax})$> for photonuclear r…
A stack of thin Nb foils was irradiated with the 100 MeV proton beam at Los Alamos National Laboratory's Isotope Production Facility, to investigate the $^{93}$Nb(p,4n)$^{90}$Mo nuclear reaction as a monitor for intermediate energy proton experiments and to benchmark state-of-the-art reaction model codes. A set of 38 measured cross sections for $^{\text{nat}}$Nb(p,x) and $^{\text{nat}}$Cu(p,x) reactions between 40-90 MeV, as well as 5 independent measurements of isomer branching ratios, are reported. These are useful in medical and basic science radionuclide productions at intermediate energie…
Accurate multiplicities of prompt fission neutrons emitted in neutron-induced fission on a large energy range are essential for fundamental and applied nuclear physics. Measuring them to high precision for radioactive fissioning nuclides remains, however, an experimental challenge. In this work, the average prompt-neutron multiplicity emitted in the 239Pu(n,f) reaction was extracted as a function of the incident-neutron energy, over the range 1-700~MeV, with a novel technique, which allowed to minimize and correct for the main sources of bias and thus achieve unprecedented precision. At low en…
Cross sections for the 168Yb(alpha,gamma)172Hf and 168Yb(alpha,n)171$Hf reactions were measured by means of the activation method using alpha particles with energies between 12.9 MeV and 15.1 MeV. The spectroscopy of the gamma rays emitted by the reaction products was performed using three different HPGe detector types, namely clover-type high-purity germanium detectors, a low-energy photon spectrometer detector, and a coaxial high-purity germanium detector. The results were compared to Hauser-Feshbach statistical model calculations. Within certain assumptions, astrophysical conclusions could …
