Application of heavy charged particle spectrometry 1) Identification of superheavy elements by means of alpha decay sequence 2) Study of hot and dense nuclear matter by means of charged particle spectrometry Table of isotopes in the range of superheavy elements Heavy ion collision with ultrarelativistic energy

Problem: very small cross-sections production only single nuclei – necessary unambiguous identification Energy : 1) sufficient for overcoming of Coulomb barrier 2) as small as possible, to obtain “relatively stable“ compound nucleus Decay of alpha decay sequence → alpha particles contain information about energy differences between following nuclei Production possibilities: 1) Neutron capture – up to Z = 100 (earlier decay then neutron capture) 2) Reaction of light nucleus on heavy target 3) „Cold“ fusion of heavy nucleus – projectile A ~ 40, E EX ~ 10 MeV 4) „Hot“ fusion of heavy nucleus – usage of 48 Ca (Z = 20) E EX ~ 40 MeV Production of superheavy elements Drop model: 1) stability decreases with increasing proton number 2) excess of neutrons increases with increasing proton number Existence of „more stable“ superheavy elements made possible by existence of magic numbers - shell structure ↔ shell model Competition of volume energy (strong nuclear interaction) and coulomb energy Stability island – Z = 114 and N = 184 – depends on potential form, significant uncertainty

Detection of superheavy elements at GSI Darmstadt Identification of single cases of superheavy element production and decay : 1)Capture of all alpha from decay sequence and determination of their energy 2)Identification of fission Velocity filter: Electric deflectors and dipole magnets: F el = q·EF mag = q·v·B Choice of incurred compound nucleus: Right choice E a B  for v CM is F TOT = F el – F mag = 0 dipole magnets electric deflectors TOF rotated target quadrupole magnets Stopping of beam svazek SHIP device Elements 107 – 112 device SHIP at GSI Darmstadt: fusion reaction on Pb, Bi nuclei: usage of separation, separation of compound nucleus, implantation to active volume of detector and identification by means of alpha decay sequences Rotated target (Pb, Bi) low thaw point intensive beam – nuclei/s

TOF spectrometer: Suppression of residual background: Start – transition detectors, thin carbon foils (electron production) and mikrochannel plates Stop – 16 silicon strip detectors ΔE = 14 keV for alpha from 241 Am Efficiency 99,8%, resolution 700 ps Coverage: 80% of 2π HPGe detectors – photons from deexcitation of excited nuclei transition detectory stop detector (silicon) Cross sections až ~ pb, single nucleus per tens days Very intensive beams during many months

107 Bh Bohrium 108 Hs Hassium 109 Mt Meitnerium 110 Dm Darmstadtiumu 111 Rg Roentgenium 112 Cp Copernicium Fusion per low energies: Results from GSI confirmed also by Japanese laboratory RIKEN First identified decays of named element with present second highest Z Further – fusion by means of higher energies: (112, 113, 114, 115, 116, 117, 118) Problem – sequence ends by unknown isotopes, rather long decay time (problem with identification by means of coincidences) Year 2006 – join – looks OK Reaction: 48 Ca Pu → Z = 114, A = 292 Excitation function for C+Pu reaction

Map of superheavy elements Cold fusion Hot fusion Stability island Neutron number Proton number

108 Hassium – one from last element chemically studied Oxid of ruthenium RuO 4 Oxid of osmium OsO 4 Oxid of hassium HsO 4 Chemical analysis of single atoms Nucleus decays early than new is produced Study of volatility → oxides of VIII group are very volatile Known isotopes of hassium First produced hassium nucleus Production of more stable Hs isotopes Narrow channel with decreasing temperature from -20 o C up to -170 o C → the more volatile the further molecules will flight before adsorption Hs with A ~ 288 will be maybe very stable Nucleon Decay number halftime only elements in this column can be octavalent Element density [g/cm 3 ] melting point [ o C] boiling point [ o C] stiffness [Mohs]

Study of hot and dense nuclear matter by means of charged particles production Effort to build 4π detectors of charged particles Example of FOPI spectrometer at GSI Darmstadt Determination of nuclear matter temperature – spectrum Scheme of FOPI spectrometer Display of event detected by FOPI spectrometer Spectrometer of charged particles FOPI Relativistic heavy ion collisions→ Big number of produced charged particles Determination of pressure – particle collective flow Determination of nuclear matter equation of state

Introduction of transfer mass m T : and rapidity y:and then: Target region Y REL  -1Collision region Y REL  0 Projectile region Y REL  +1 Relative rapidity: Y REL = (Y - Y PRO /2)/(Y PRO /2) Y PROJ – projectile rapidity Identification of charged particles Spectra of charged particles (Ni+Ni a Au+Au experiments with beam energy 1 GeV/A)

T wo A rm P hoton S pectrometer Detection of gamma, neutrons and charged particles 384 BaF 2 detectors with plastic veto – distinguishing of neutral and charged particles cooperation with TOF plastic wall - collision characteristic: Beam energy: 10 MeV GeV (GSI Darmstadt, KVI Groningen GANIL Caen, CERN)

Collective flow of nucleons N = N 0 ( 1 + A·cosφ + B·cos(2·φ)) Relative rapidity: Y REL = (Y - Y PRO /2)/(Y PRO /2) Y PROJ – projectile rapidity Target region Y REL  -1Collision region Y REL  0Projectile region Y REL  +1 A – magnitude of asymmetry in the collision plane B – magnitude of asymmetry perpendicular to it (eliptical flow) A < 0, B = 0A = 0, B < 0A > 0, B = 0

Bounce off particles to the Reaction plane: Squeeze out of particles perpendicular to reaction plane Experimental data – dependency of collective flow on nucleons number – agreement of hydrodynamical models Dependence of collective flows on rapidity (origin of nukleons) Target region Collision region Target region Projectile region

Application at material research - scattering, channeling, ion reaction... Tandetrom 4130 MC at NPI ASCR is used for material research – from H up to Au, energies from hundreds keV up to tens MeV Usage ions for modification and studies of structure of surface layers of solid materials Different types of silicon semiconductor detectors of charged particles Usage of ion accelerators for relatively low energies in the range from keV up to MeV Spectrometers of charged nuclei – often semiconductor silicon detectors

RBS (Rutheford Backscattering Spectroscopy) - spectrometry of charged pasrticles back scattered by Rutheford scattering – layers from nm up to μm – spectrometry of scattered ions by semiconductor detectors. Change of energy given by momentum change and ionisation losses – profiles of impurities distribution materials are determined – mainly heavy nuclei RBS channeling – channeling of charged particles – crystal structures – determination of distinctive directions of crystal axes and impurities – slight turning of crystal sample ERDA (Elastic Recoil Detection Analysis) – detection of atoms knocked on by ions – mostly lighter nuclei, from hydrogen up to nitrogen – possibility of control changes of surface properties – study of hydrogen amount at polymers – connection with measurement of ion time of flight ERDA incident ion scattered ion detector RBS Elastic scattering ions: incident ion reflected ion detector

Ion reaction with nuclei PIGE (Particle Induced Gamma ray Emission) PIXE – (Particle Induced Gamma ray Emission) Ion litography and ion beam machining – preparing of microelectronical a optoelectronical components and microscopic mechanical devices. Sprockets produced by ion litography method at photoresistive material Ion implantation – modification of surface material layers Material modification and working AMS – accelerator mass spectroscopy – impurity of elements with concentration – often for carbon dating Ion microprobe – very narrow and intensive ion beam – usage – scanning of object surface with micrometer accuracy see gamma spectroscopy