exotic nuclei structure and reaction noyaux exotiques ... - IPN - IN2P3

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X direction (mm) Y direction (mm) Figure 2 : Vertical section of the 130 kV Pegase platform with the main elements umn including the ion source, the lens, the Wien filter, and which duplicates the Orion facility working at the Tandem terminal since 1993 at around 10 MeV. The focusing of the new equipment will be, however, much improved in order to reach the micron objective. This set up is then connected to a diagnostic chamber containing deflection plates, a collimator holder with different size collimators and a Faraday cup. The collimator position is precisely adjustable and the Faraday cup measures the intensity of the beam selected by the Wien filter and passing through the collimator chosen by the user at the platform level. All the power supplies and the electronics are set on this platform, driven and controlled via about thirty optical fibers. The acceleration occurs after the diagnostic chamber through an accelerator gap made of 2 tubes one of which is a “trumpet” calculated by J. Arianer (fig 2) In the first experiments, we use the focusing properties of this gap. The future focusing beam line incorporates a “Russian” quadruplet with weak aberrations [7] which permits to obtain one µm beam spot (fig 3). This PEGASE project submitted in July 2007 by E.A. Schweikert to the NSF was accepted in February 2008. The realization started at the end of June 2008 and was finished at the end of November 2009 when the platform was transferred to the Texas A&M University, after it was delivered and tested at the IPN in October. The IPN tests went up to 100 kV and gave a total beam intensity of 300 nA. The transmission is better than 80 %. A selected Au 400 4+ beam was accelerated at 480 keV with a 1 nA intensity. The first gold nanodroplets beam at 35 km/s was obtained on October the 22 nd . The first experiments started in February 2010, at Texas A&M University, the Pegase platform being connected to a Time-of-Flight mass spectrometer. The first secondary ions spectra have been obtained from a silicon wafer and a CsI target. These first experiments permitted to test the transmission of the cluster beams and simultaneously the ToF mass spectrometer and the first stage of the electron emission microscope. 10 5 0 5 10 0 500 1000 1500 2000 Beam line distance from the source (mm) Figure 3: An example of simulation of the Pegase Beam line from the LMISource to the Russian quadrupoles with the full cluster beam. There are clearly two focussing points one behind the 130 kV acceleration lens (Pegase first step) and the other behind the Russian quadrupoles After these tests the experiments in progress concern the measurement of the massive cluster energy losses. At Orsay with 200 keV/atom massive cluster ions we showed that there was no pronounced coherent effect after the passage through 25 nm of matter, the zone close to the surface where the coherent effect is strongest is thus negligible with respect to the total range [8]. 101
But at 80 keV total energy ( 200 eV/atom) we observed a full coherent effect [9] with a projected range increased by a factor of almost 6 to 8 because of the clearing the way effect (the first cluster atoms entering in the solids push away the target atoms and so open an easy path for their followers). It is thus important to control in the range from 40 keV to 400 keV of total energy what is the contribution of the coherent motion on the energy loss, the part of the clearing the way effect versus the friction processes (effect of the charge at the surface Coulomb explosion etc) observed between 200 keV per charge and 4 MeV per charge [2]. The targets are carbon foils of 5, 10, 15 nm. The reference of these measurements are the 20-100 keV beams of Au 1-5 [10]. The secondary ion and electron emission are measured from the backside of the target and simultaneously we measure the velocity of the projectiles or fragments by time of flight. The first results show that the massive cluster passes through 15 nm of carbon at 80 keV per charge and produces an ion emission of carbon clusters; It is important to notice that an atomic ion with the same velocity is stopped by 3 nm of carbon and that 15 nm is the range of atomic gold at 27 keV or Au 3 at 80 keV; this has been controlled experimentally. These measurements will allow to establish the transition between coherent effect and independent atomic interaction and also to know the energy deposited in the first 10 nm of matter which contributes to the secondary emission from the solid. References [1] S. Bouneau, et al , Nucl. Instr. And Meth. B225, 579-589, 2004. [2] A.Tempez, et al, Rapid Comm; in Mass Spectrom. 18 371- 376, 2004. [3] C. Guillermier, et al, Applied Surface Science 252, 6529- 6532, 2006. [4] C. Guillermier, et al, Int. Journal of Mass Spect., Volume 263, Issues 2-3, 5, 298-303, 2007. [5]C.Guillermier, et al, Int. Journal of Mass Spect., 275, 86-90, 2008. [6]S. Della-Negra, et al, Surface and Interface Analysis, accepted, 2010. [7]A.D.Dymnikov and S.Y. Yavor.,Sov. Phys. Techn. Phys., 8- 7, 639, 1964. [8]S. Bouneau, et al,. Nucl. Instr. And Meth. B 251, 383-389, 2006. [9] S. Della-Negra, M. Pautrat, G. Rizza, In preparation [10]H.H. Andersen, et al, Nucl. Instr. and Meth. B212, 56, 2003. 102
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EXOTIC NUCLEI STRUCTURE AND REACTIO
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in the spectra by analyzing their t
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were taken from ref. [5]. Concernin
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keV -ray with the particles and the
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the 605.9 keV line of the 74 Zn 2+
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Figure 2 a n d analysis. Figure 2 s
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ing particles was thus obtained by
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First p-p p collisions in the ALICE
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Quarkonia physics with ALICE IPNO P
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NA50 updated puzzle IPNO Participat
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Status of the HADES experiment (I):
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Status of the HADES experiments (II
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Status of the HADES experiment (III
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Hadron physics in pbar-p p annihila
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Hadron Electrodynamics IPNO Partici
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G0 experiment at Jefferson Lab. IPN
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GEp-III and GEp-2 at Jefferson Lab
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Exotic low mass narrow baryons from
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The PVA4 parity violation experimen
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Etude des Distributions de Partons
Page 41 and 42: Latest Results from GRAAL IPNO Part
Page 43 and 44: Persistence of the Polarization in
Page 45 and 46: The northern site of the Pierre Aug
Page 47 and 48: The Pierre Auger southern Observato
Page 49 and 50: In figure 4 we plot the differentia
Page 51 and 52: THEORETICAL PHYSICS Research in the
Page 53 and 54: transfer reaction, the 34 Si(d, 3 H
Page 55 and 56: Collective excitations with SKYRME
Page 57 and 58: Pairing and nuclear incompressibili
Page 59 and 60: Pairing properties in nuclei and in
Page 61 and 62: Evaporation-residue residue cross s
Page 63 and 64: Extending the VMI model: normal and
Page 65 and 66: Alpha particle condensation in nucl
Page 67 and 68: Collective Modes in Ultracold Trapp
Page 69 and 70: Exploring key unknown neutrino prop
Page 71 and 72: Relic astrophysical and cosmologica
Page 73 and 74: After a term by term Borel resummat
Page 75 and 76: Chiral expansions of the π 0 lifet
Page 77 and 78: IPNO Participation: H. Sazdjian Eff
Page 79 and 80: fer is used to extract f + (0). We
Page 81 and 82: cleon. The spectrum becomes strongl
Page 83 and 84: A pseudo Coulombian potential in D=
Page 85 and 86: The many-body problem with an energ
Page 87 and 88: The rotational spectrum and the att
Page 89 and 90: Z-identification of very heavy nucl
Page 91: The Pegase project, a new solid sur
Page 95 and 96: Isospin effects on fragment and par
Page 97 and 98: Radial collective energy and fragme
Page 99 and 100: Latent heat of the phase transition
Page 101 and 102: Alpha-particle particle condensatio
Page 103 and 104: Fluo X: Deexcitation time measureme
Page 105 and 106: ENERGY AND ENVIRONMENT The increasi
Page 107 and 108: toe/cap/y which energy access inequ
Page 109 and 110: nides. A global comparison can be p
Page 111 and 112: 3D coupling of Monte-Carlo neutroni
Page 113 and 114: Fission cross sections of actinides
Page 115 and 116: Studies and synthesis of specific m
Page 117 and 118: Chemistry and Electrochemistry of T
Page 119 and 120: function of temperature. The recent
Page 121 and 122: global electron number of the redox
Page 123: (D 0 /D)-1 ln complexes of Pa(V). I
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exotic nuclei structure and reaction noyaux exotiques ... - IPN - IN2P3

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