The development of radioactive beam facilities makes possible the study of weakly bound nuclei far from stability and close to the drip lines. A vast variety of nuclei is now available, therefore a new research ground is open for the discovery of phenomena previously unexpected. Complementary studies with stable weakly bound nuclei can assist such studies. Examples for $^6$He and $^6$Li are discussed.
{"title":"Weakly bound Nuclei","authors":"A. Pakou","doi":"10.12681/hnps.3340","DOIUrl":"https://doi.org/10.12681/hnps.3340","url":null,"abstract":"The development of radioactive beam facilities makes possible the study of weakly bound nuclei far from stability and close to the drip lines. A vast variety of nuclei is now available, therefore a new research ground is open for the discovery of phenomena previously unexpected. Complementary studies with stable weakly bound nuclei can assist such studies. Examples for $^6$He and $^6$Li are discussed.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115428324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Perdikakis, A. Spyrou, M. Kokkoris, C. Zarkadas, A. Karydas, S. Harissopulos, S. Kossionides
An alternative method for the detection of beryllium in light element matrices is proposed, implementing the use of a deuteron beam at energies from 1 to 2.1 MeV and the $^{9}$Be(d,n$gamma )^{10}$B reaction. A HP GE detector of 20{%} relative efficiency was used to detect the 718 keV gamma ray of $^{10}$B. The minimum detection limits obtained for beryllium, are compared to those taken with other NRA techniques (PIGE, heavy-ion and charged-particle spectroscopy) in complex matrices containing high concentrations of light elements. The absolute $gamma $-ray yield of the reaction is also compared to absolute $gamma $-ray yields from literature.
{"title":"Beryllium determination in non-optimal matrices using the $^{9}$textbf{Be(d,n$gamma )$}$^{10}$textbf{B}","authors":"G. Perdikakis, A. Spyrou, M. Kokkoris, C. Zarkadas, A. Karydas, S. Harissopulos, S. Kossionides","doi":"10.12681/hnps.3347","DOIUrl":"https://doi.org/10.12681/hnps.3347","url":null,"abstract":"An alternative method for the detection of beryllium in light element matrices is proposed, implementing the use of a deuteron beam at energies from 1 to 2.1 MeV and the $^{9}$Be(d,n$gamma )^{10}$B reaction. A HP GE detector of 20{%} relative efficiency was used to detect the 718 keV gamma ray of $^{10}$B. The minimum detection limits obtained for beryllium, are compared to those taken with other NRA techniques (PIGE, heavy-ion and charged-particle spectroscopy) in complex matrices containing high concentrations of light elements. The absolute $gamma $-ray yield of the reaction is also compared to absolute $gamma $-ray yields from literature.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":" 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120829113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Kozik, Z. Majka, R. Planeta, P. Staszel, A. Wolanin-Statek, M. Smoluchowski, S. Kowalski, W. Zipper, J. Cibor, E. Kozik, N. Nicolis
An effective way for the investigation of nuclear matter under the extreme conditions of high density and temperature is the study of nuclear fragmentation, realized in intermediate-energy heavy-ion collisions. The potential energy accumulated in the compression zone of the collision is converted into collective flow of matter in the later stages of the reaction. During the expansion of the system, fragments are formed in a clusterization process. In the final stage of the reaction, the fragments are moving along Coulomb trajectories and may deexcite by particle emission or secondary break-up.In order to verify the influence of the collective energy on the experimental energy spectra and extract quantitative information on the thermal and collective components, a model simulation was developed. In this procedure, the evolution of the disintegrating system in a multifragmentation process was described after the freeze-out stage with a Monte-Carlo approach. A reconstruction procedure for the fragment kinetic energies has shown the possibility to obtain the thermal and collective components from measured fragment spectra. In the present work, we scrutinize the model simulation for the evolution of the disintegrating system by testing the sensitivity of the collective expansion energy extraction on the model assumptions concerning the freeze-out characteristics, such as the size and shape of the freeze-out volume. Furthermore, thermal aspects of the early stage of the expansion are tested with an examination of the relationship between the assumption of the degree of thermalization of the emitting source and the extracted value of the collective energy.
{"title":"Influence of Model Assumptions on Radial Flow Investigations in Heavy-Ion Collisions","authors":"T. Kozik, Z. Majka, R. Planeta, P. Staszel, A. Wolanin-Statek, M. Smoluchowski, S. Kowalski, W. Zipper, J. Cibor, E. Kozik, N. Nicolis","doi":"10.12681/hnps.3343","DOIUrl":"https://doi.org/10.12681/hnps.3343","url":null,"abstract":"An effective way for the investigation of nuclear matter under the extreme conditions of high density and temperature is the study of nuclear fragmentation, realized in intermediate-energy heavy-ion collisions. The potential energy accumulated in the compression zone of the collision is converted into collective flow of matter in the later stages of the reaction. During the expansion of the system, fragments are formed in a clusterization process. In the final stage of the reaction, the fragments are moving along Coulomb trajectories and may deexcite by particle emission or secondary break-up.In order to verify the influence of the collective energy on the experimental energy spectra and extract quantitative information on the thermal and collective components, a model simulation was developed. In this procedure, the evolution of the disintegrating system in a multifragmentation process was described after the freeze-out stage with a Monte-Carlo approach. A reconstruction procedure for the fragment kinetic energies has shown the possibility to obtain the thermal and collective components from measured fragment spectra. In the present work, we scrutinize the model simulation for the evolution of the disintegrating system by testing the sensitivity of the collective expansion energy extraction on the model assumptions concerning the freeze-out characteristics, such as the size and shape of the freeze-out volume. Furthermore, thermal aspects of the early stage of the expansion are tested with an examination of the relationship between the assumption of the degree of thermalization of the emitting source and the extracted value of the collective energy.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127347596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Patronis, P. Assimakopoulos, S. Dababneh, M. Heil, F. Kaeppeler, D. Karamanis, P. Koehler, R. Plag
The neutron capture cross section of the unstable isotope $^{135}$Cs was measured relative to that of gold by means of the activation method. The sample was produced by ion implantation in a high resolution mass separator and irradiated with quasi-monoenergetic neutrons at 30 keV and 500 keV, using the $^{7}$Li(p,n)$^{7}$Be reaction. After the irradiations at the above energies, one more irradiation with thermal neutrons was used for defining the sample mass and for measuring the half-life of $^{136}$Cs. The neutron capture cross section was determined as 164 $pm$ 10 mbarn and 34.8 $pm$ 3.0 mbarn at 30 keV and 500 keV, respectively, and were used to normalize the theoretically derived cross section shape.
{"title":"The $^{135}$Cs(n,$gamma$) cross section at 30 and 500 keV","authors":"N. Patronis, P. Assimakopoulos, S. Dababneh, M. Heil, F. Kaeppeler, D. Karamanis, P. Koehler, R. Plag","doi":"10.12681/hnps.3346","DOIUrl":"https://doi.org/10.12681/hnps.3346","url":null,"abstract":"The neutron capture cross section of the unstable isotope $^{135}$Cs was measured relative to that of gold by means of the activation method. The sample was produced by ion implantation in a high resolution mass separator and irradiated with quasi-monoenergetic neutrons at 30 keV and 500 keV, using the $^{7}$Li(p,n)$^{7}$Be reaction. After the irradiations at the above energies, one more irradiation with thermal neutrons was used for defining the sample mass and for measuring the half-life of $^{136}$Cs. The neutron capture cross section was determined as 164 $pm$ 10 mbarn and 34.8 $pm$ 3.0 mbarn at 30 keV and 500 keV, respectively, and were used to normalize the theoretically derived cross section shape.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122412178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Stamoulis, K. Ioannides, A. Vlachogianni, C. Papachristodoulou
The Radiochronology Center has been established in 1999 as a member of the Horizontal Laboratories network of the University of Ioannina. Recently it has added to its activities the development of a tritium measurements laboratory as part of the Radiochronology Center. The laboratory is equipped with a super low level background liquid scintillation counter, which is capable to measure very low concentrations of tritium for applications in radioprotection, dating and hydrology.For the aims of the present continuing study rainwater samples are collected monthly. Each sample is distilled and then it is passed through an electrolysis process to increase the tritium concentration. Five mL of the enriched sample are mixed with 15 mL of a scintillation cocktail, specially designed for tritium measurements and its beta activity is measured for 200 min. The LLD of tritium in the samples is estimated 3 Bq/L or 27 TU.Our preliminary results show that, during the measuring period tritium concentration increased with time. The tritium values are correlated with the cosmic ray neutron flux data at ground level, available for Greece in the same period. The measured tritium concentrations in rainwater, which range from 36 ± 8 to 64 ± 8 TU, may be used for local hydrology studies.
{"title":"Correlation of Tritium Concentration in Rainwater with Cosmic Rays: Preliminary Results","authors":"K. Stamoulis, K. Ioannides, A. Vlachogianni, C. Papachristodoulou","doi":"10.12681/hnps.3348","DOIUrl":"https://doi.org/10.12681/hnps.3348","url":null,"abstract":"The Radiochronology Center has been established in 1999 as a member of the Horizontal Laboratories network of the University of Ioannina. Recently it has added to its activities the development of a tritium measurements laboratory as part of the Radiochronology Center. The laboratory is equipped with a super low level background liquid scintillation counter, which is capable to measure very low concentrations of tritium for applications in radioprotection, dating and hydrology.For the aims of the present continuing study rainwater samples are collected monthly. Each sample is distilled and then it is passed through an electrolysis process to increase the tritium concentration. Five mL of the enriched sample are mixed with 15 mL of a scintillation cocktail, specially designed for tritium measurements and its beta activity is measured for 200 min. The LLD of tritium in the samples is estimated 3 Bq/L or 27 TU.Our preliminary results show that, during the measuring period tritium concentration increased with time. The tritium values are correlated with the cosmic ray neutron flux data at ground level, available for Greece in the same period. The measured tritium concentrations in rainwater, which range from 36 ± 8 to 64 ± 8 TU, may be used for local hydrology studies.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"196 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123073237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The electron screening effect in the d(d,p)t reaction has been studied for deuterated metals, insulators, and semiconductors, i.e. 58 samples in total. As compared to measurements performed with a gaseous D2 target, a large effect has been observed in most metals, while a small (gaseous) effect is found e.g. for the insulators, semiconductors, and lanthanides. The periodic table provides the ordering of the observed small and large effects in the samples. An explanation of the large effects in metals is possibly provided by the classical plasma screening of Debye applied to the quasi-free metallic electrons. The data also provide information on the solubility of hydrogen in the samples.
{"title":"Metals, the plasma of the poor man?","authors":"C. Rolfs","doi":"10.12681/hnps.3342","DOIUrl":"https://doi.org/10.12681/hnps.3342","url":null,"abstract":"The electron screening effect in the d(d,p)t reaction has been studied for deuterated metals, insulators, and semiconductors, i.e. 58 samples in total. As compared to measurements performed with a gaseous D2 target, a large effect has been observed in most metals, while a small (gaseous) effect is found e.g. for the insulators, semiconductors, and lanthanides. The periodic table provides the ordering of the observed small and large effects in the samples. An explanation of the large effects in metals is possibly provided by the classical plasma screening of Debye applied to the quasi-free metallic electrons. The data also provide information on the solubility of hydrogen in the samples.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124993158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Kokkoris, R. Vlastou, C. Papadopoulos, X. Aslanoglou, S. Kossionides, R. Grötzscheld
A method for determining the energy loss and mean dechanneling distance of light charged particles traveling along a low index axis of a crystal in the backscattering geometry, is presented. The method is based on nuclear resonance reactions which act as a marker for the range in the backscattering spectra. Computer simulations based on the assumption of an exponential rate of dechanneling of the incoming particles in the crystalline material, are in good agreement with measured spectra. The results of applying this method to protons and alphas in crystals of Si, SiO2, SiC and MgO are discussed and possible improvements are indicated.
{"title":"Measurements of Energy Loss of Charded Particles Travelling in Crystalline Materials along the Channeling Directon","authors":"M. Kokkoris, R. Vlastou, C. Papadopoulos, X. Aslanoglou, S. Kossionides, R. Grötzscheld","doi":"10.12681/hnps.3361","DOIUrl":"https://doi.org/10.12681/hnps.3361","url":null,"abstract":"A method for determining the energy loss and mean dechanneling distance of light charged particles traveling along a low index axis of a crystal in the backscattering geometry, is presented. The method is based on nuclear resonance reactions which act as a marker for the range in the backscattering spectra. Computer simulations based on the assumption of an exponential rate of dechanneling of the incoming particles in the crystalline material, are in good agreement with measured spectra. The results of applying this method to protons and alphas in crystals of Si, SiO2, SiC and MgO are discussed and possible improvements are indicated.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"2013 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133543311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The rate of a heavy lepton (muon or tau) capture by nuclei as well as the heavy lepton to electron conversion rate can be calculated when the heavy lepton wavefunction is known. Analytical calculation of the wavefunction of any of these leptons around any nucleus is not feasible owning to their small Bohr radii, on the one hand, and to the finite nuclear extend on the other. A new numerical calculation algorithm is proposed hereby, which makes use of the concept of neural networks. The main advantage of this new technique is that the wave function is produced analytically as a sum of sigmoid functions.
{"title":"A Study of $tau^-$ and $mu^-$ in the Field of Nuclei Using Neural Network Techniques","authors":"N. Panagiotides, T. S. Kosmas","doi":"10.12681/hnps.3352","DOIUrl":"https://doi.org/10.12681/hnps.3352","url":null,"abstract":"The rate of a heavy lepton (muon or tau) capture by nuclei as well as the heavy lepton to electron conversion rate can be calculated when the heavy lepton wavefunction is known. Analytical calculation of the wavefunction of any of these leptons around any nucleus is not feasible owning to their small Bohr radii, on the one hand, and to the finite nuclear extend on the other. A new numerical calculation algorithm is proposed hereby, which makes use of the concept of neural networks. The main advantage of this new technique is that the wave function is produced analytically as a sum of sigmoid functions.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125807593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-08-13DOI: 10.1088/0305-4470/37/32/005
M. Grypeos, C. Koutroulos, K. Oyewumi, Th. A. Petridou
The quantum mechanical hypervirial theorems (HVT) technique is used to treat the so-called "uncertainty" relation for quite a wide class of central potential wells, including the (reduced) Poeschl-Teller and the Gaussian one.It is shown that this technique is quite suitable in deriving an approximate analytic expression in the form of a truncated power series expansion for the dimensionless product $P_{nl}equiv _{nl}_{nl}/hbar^2$, for every (deeply) bound state of a particle moving non-relativistically in the well, provided that a (dimensionless) parameter s is sufficiently small. Numerical results are also given and discussed.
{"title":"The HVT Technique and the \"Uncertainty\" Relation for Central","authors":"M. Grypeos, C. Koutroulos, K. Oyewumi, Th. A. Petridou","doi":"10.1088/0305-4470/37/32/005","DOIUrl":"https://doi.org/10.1088/0305-4470/37/32/005","url":null,"abstract":"The quantum mechanical hypervirial theorems (HVT) technique is used to treat the so-called \"uncertainty\" relation for quite a wide class of central potential wells, including the (reduced) Poeschl-Teller and the Gaussian one.It is shown that this technique is quite suitable in deriving an approximate analytic expression in the form of a truncated power series expansion for the dimensionless product $P_{nl}equiv _{nl}_{nl}/hbar^2$, for every (deeply) bound state of a particle moving non-relativistically in the well, provided that a (dimensionless) parameter s is sufficiently small. Numerical results are also given and discussed.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116590338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-01-23DOI: 10.1142/9789812701848_0044
J. Vergados
In this paper we review the theoretical issues involved in the direct detectionof supersymmetric (SUSY) dark matter. After a brief discussion of the allowedSYSY parameter space we focus on the determination of the traditional neutralinodetection rates, in experiments which measure the energy of the recoiling nucleus,such as the coherent and spin induced rates and the dependence of the rate onthe motion of the Earth (modulation effect). Then we examine the novel featuresappearing in directional experiments, which detect the recoiling nucleus in a givendirection. Next we estimate the branching ratios for transitions to accessibleexcited nuclear levels. Finally we estimate the event rates leading to the atomionization and subsequent detection of the outgoing electrons.
{"title":"Some Issues Related to the Direct Detection of Dark Matter","authors":"J. Vergados","doi":"10.1142/9789812701848_0044","DOIUrl":"https://doi.org/10.1142/9789812701848_0044","url":null,"abstract":"In this paper we review the theoretical issues involved in the direct detectionof supersymmetric (SUSY) dark matter. After a brief discussion of the allowedSYSY parameter space we focus on the determination of the traditional neutralinodetection rates, in experiments which measure the energy of the recoiling nucleus,such as the coherent and spin induced rates and the dependence of the rate onthe motion of the Earth (modulation effect). Then we examine the novel featuresappearing in directional experiments, which detect the recoiling nucleus in a givendirection. Next we estimate the branching ratios for transitions to accessibleexcited nuclear levels. Finally we estimate the event rates leading to the atomionization and subsequent detection of the outgoing electrons.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129010433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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