Intense deuteron beam investigation by activation yield-ratio technique

In this work, the intense deuteron beam from a plasma focus device is investigated by the activation yield-ratio technique. It is shown that boron-carbide (B₄C) and boron-nitride (BN) are complimentary targets for high energy deuteron beam studies. For deuteron spectra of the form dNd/dE∝E−n, when deuteron spectra decrease relatively gradually (n<6) BN is a better choice, while for the case of very rapidly decreasing deuteron spectra (n>6), B₄C is more suitable.     

用IR研究H~+辐照对Mo涂层的影响

在不锈钢基体上采用离子束混合技术及电子束处理方法进行Mo薄膜沉积,沉积后的试样再进行氢离子注入.分别对氢离子注入前后的样品进行500~4000波数范围内IR分析,研究了氢离子辐照前后涂层的红外光谱振动吸收峰的变化,对Mo涂层的抗氢机理进行了探讨.     

Preservation and control of the proton and deuteron polarizations in the proposed electron-ion collider at Jefferson Lab

We propose a scheme of preserving the proton and deuteron beam polarizations during acceleration and storage in the proposed electron-ion collider at Jefferson Lab. This scheme allows one to provide both the longitudinal and transverse polarization orientations of the proton and deuteron beams at the interaction points of the figure-8 ion collider ring. We discuss questions of matching the polarization direction at all stages of the beam transport including the pre-booster, large booster and ion collider ring.     

Optical and Structural Modifications in Heavy Ion Irradiated Polystyrene

Samples of polystyrene (PS) have been irradiated with ⁶⁴Cu (50 and 120 MeV) and ¹²C (70 MeV) ion beams (fluence=10¹¹ to 10¹³ ions cm^?2) in order to study the induced modifications using UV‐VIS and FTIR spectroscopy. UV spectra of irradiated samples reveal that the optical band gap decreases from 4.36 to 1.46 eV in PS. The decrease in optical band gap is more pronounced with the Cu‐ion beam due to high electronic energy loss as compared to the C ion beam. The effect of low energy (50 MeV) Cu ions on the optical properties of PS is larger than that due to high energy (120 MeV) Cu ions. The correlation between the optical band gap and the number of six member carbon rings inside the largest carbon clusters embedded in the network of polystyrene is discussed. FTIR spectra reveal the formation of hydroxyl, alkene, and alkyne groups in the Cu‐ion irradiated PS. Changes in the intensity of the absorption bands on irradiation with C‐ion relative to pristine samples have also been observed and are discussed.     

Irradiation effect of yttria-stabilized zirconia by high dose dual ion beam irradiation

Yttria-stabilized zirconia （YSZ） is irradiated with 2.0-MeV Au2＋ ions and 30-keV He＋ ions. Three types of He, Au, Au ＋ He （successively） ion irradiation are performed. The maximum damage level of a sequential dual ion beam implanted sample is smaller than single Au ion implanted sample. A comparable volume swelling is found in a sequential dual ion beam irradiated sample and it is also found in a single Au ion implanted sample. Both effects can be explained by the partial reorganization of the dislocation network into weakly damaged regions in the dual ion beam implanted YSZ. A vacancy-assisted helium trapping/diffusion mechanism in the dual ion beam irradiated condition is discussed. No phase transformation or amorphization behavior happens in all types of ion irradiated YSZ.     

Nanoporous structures of polyimide induced by Ar ion beam irradiation

The surface morphology evolution of polyimide (PI) that was treated with an Ar ion beam was explored using a hybrid ion beam system. A hole-like nanostructure formed on PI during the Ar ion beam treatment at a lower fluence, but PI formed 3D porous nanostructures with a mean diameter of ∼90 nm at a higher fluence. The chemical binding energy and the composition of the Ar ion irradiated PI were analyzed using FT-IR and XPS spectra, which revealed that the polymer chain scissioning increased with increasing Ar ion treatment duration, i.e., fluence. The surface hardness and the elastic modulus of PI increased from 1.17 to 1.62 GPa and 4.06 to 5.41 GPa, respectively, with respect to the Ar ion beam treatment duration.     

Laser plasma acceleration of quasi-monoenergetic beams of light multicharged ions

Experimental results on the spectra of residual impurity ions from a plasma created on the surface of a tungsten target that is irradiated by a femtosecond laser pulse and is subjected to preliminary pulsed laser cleaning are reported. It is shown that deep modulation corresponding to the formation of a quasi-monoenergetic ion beam appears in the energy spectra of protons and light multicharged carbon ions in this case. The position of a “dip” at the scale of velocities closely correlates with the position of the front of heavier ions.     

Modification in the transport and morphological properties of solid polymer electrolyte system by low-energy ion irradiation

The poly(ethylene oxide) (PEO)-based solid polymer electrolyte (SPE) systems consisting of NaBr as a dopant salt are prepared. The stable PEO:NaBr system with 3 wt% of NaBr was subjected to low-energy ion beam irradiation to bring in morphological modification. The irradiated samples are studied using complex impedance spectra to evaluate electrical conductivity and relaxation process in the system. The studies show an increase in conductivity by one order magnitude in the irradiated systems. The dielectric loss tangent (tanδ) curves show a single peak due to strong coupling of ion transport with segmental motion. The resultant relaxation time τ exhibits a continuous decrease indicating increase in segmental dynamics as a result of increased amorphous content in the system. The temperature-dependent studies also indicate that the irradiated systems are more disordered/amorphous compared to pure systems. This fact is further supported by XRD, by observing an increase in peak width associated with reduction in peak intensity. The Raman spectra also support the change in morphology of the system by the appearance of disordered-longitudinal acoustic mode band.     

CLUSTER EFFECTS IN DEUTERIUM CLUSTER ION IMPLANTATION ON SOLIDS

Atomic and nuclear cluster effects of (D⁺₃) were studied by alternative implantation of deuterium cluster ion beam and isolated deuteron (D⁺) beam on metal targets. The beam energy was adjusted from 10keV/d to 100keV/d in experiment. The atomic cluster effect was shown by the enhancement of X-ray emission induced by cluster deuterion. The average ratio of X-ray intensity induced by each cluster deuteron to that induced by each isolated deuteron is about 2.6 in the experimental energy region. The nuclear cluster effect is shown by the difference of D-D fusion rates induced by two kinds of deuterons under the same experimental conditions. The ratio of the D-D fusion rates induced by the two kinds of deuterons is energy dependent.     

Deuteron NMR spectra of NH3D+ Ions

A theory of deuteron nuclear magnetic resonance (NMR) spectra is outlined for NH₃D⁺ ions. Dipolar interactions among all five spins in the ion contribute to the shape of the deuteron spectra. Dimensions of the ammonium ion can be derived from the structure of the single-crystal spectra. The analysis of the spectra supplies ways to distinguish between cases of rigid, tunnelling or reorienting protons. Single-crystal spectra of partially deuterated ammonium perchlorate measured at 5 K provide examples of the applicability of the theory. Distances between nuclei are derived. Evidence is provided for tunnelling and reorientation of protons in NH₃D⁺ ions. Deuteron spectra indicate that NH₃D⁺ ions exhibit a diverse mobility. There exist ions with immobile deuterons which populate one position in the crystal unit cell (isotopic ordering), while the deuterons in the remaining ions reorient about C₃ axes parallel to the N-D bond orientation of the rigid ones. The contribution of the latter increases with increasing temperature.     

Deuteron beam polarimetry at the nuclotron

The scheme of the deuteron beam polarization measurements at Nuclotron are presented. A deuteron beam polarimeter based on the spin-asymmetry measurements in the dp-elastic scattering at large angles in center-of-mass system has been constructed at the internal target station at the Nuclotron of JINR. This polarimeter is planned to use for the measurements of the vector and tensor components of deuteron beam polarizations at the energies 270–2000 MeV simultaneously. Details on the low energy polarimeters are also discussed.     

The ALTO project at IPN-Orsay

The availability of both a tandem deuteron beam and a linac electron beam, the latter converted into Bremsstrahlung, at the new ALTO facility at IPN-Orsay offers a unique opportunity to compare the performance of a laser ion guide under different regimes. The ALTO accelerator has delivered its first electron beam at the end of 2005 and a design for a gas-cell prototype is being studied.     

Proposal of the experiment on the investigation of the (d, p) reaction at the extracted deuteron beam of the U-70 accelerator

The experiment on the investigation of the A(d, p)X reaction at the extracted deuteron beam created at the Serpukhov U-70 accelerator is proposed. Precise measurements of the momentum spectra of protons emitted in the (d, p) reaction at an initial deuteron momenta of 20–40 GeV/c can give unique information on the deuteron short-range structure. A manifestation of contribution of nonnucleonic degrees of freedom in the deuteron is entirely possible over this energy range. The text was submitted by the authors in English.     

Development of a system for monitoring the shape,position, and intensity of the extracted relativistic ion beam at the Nuclotron-M accelerator complex at JINR

Test samples of detectors and electronics for them constructed for the purpose of monitoring the “intense” relativistic ion beams extracted from the accelerator of the Nuclotron-M accelerator complex in real time are described. The system was tested in a series of acceleration runs with deuteron beams with an intensity of up to 10¹⁰ 1/s and beams of carbon nuclei. The system allows one to perform multiple measurements of the two-dimensional distribution of the beam intensity in the plane perpendicular to it and the beam position in this plane during the beam dump and measure the two-dimensional distribution of the target irradiation dose after each beam dump.     

Measurement of tensor polarization of a deuteron beam passing through matter

The results of measurements and the handling procedure of data on the tensor polarization of the deuteron beam arising as the beam passes through matter obtained at the Nuclotron during the June 2008 run using an extracted unpolarized 5 GeV/c deuteron beam are described. The effect observed is compared with calculations made in the framework of the Glauber multiple-scattering theory.     

Beam transportation lines for the NICA project

A heavy-ion collider, i.e., the Nuclotron-based Ion Collider Facility (NICA), is being developed at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. The aim of this project is to construct a new accelerator complex for conducting experiments with colliding ion beam (at the first stage of the project) and with polarized proton and deuteron beams (at the second stage). The NICA accelerator complex will consist of two linear accelerators, two synchrotrons, two collider rings, and beam transportation lines. The magnetic lattice and diagnostic and correction systems for the NICA beam transportation lines are described in this report.     

氘核与聚变中子耦合输运方法及应用

对加速器驱动中子发生器的数值模拟包括离子输运、聚变反应、中子输运等。由于核反应截面远低于带电粒子输运的库仑截面,且核反应平均自由程远大于靶厚度,直接蒙卡抽样难以抽到聚变反应。在MCNPX程序基础上,采用“强迫”聚变方法,即每个入射氘核必发生一次聚变反应,聚变反应处氘核的真实状态(位置、能量和方向)以抽样产生,并以此状态来确定聚变中子的出射状态,实现了氘核与聚变中子的耦合输运模拟计算。研究结果表明,该方法能够给出氘核输运对聚变中子能谱和角分布的影响,中子产额计算结果符合预期。     

Carbon ion beam-induced variation in orientation of crystal planes of polycrystalline Zn nanowires

In the present work, polycrystalline Zn nanowires are synthesised within polymeric templates by the electrochemical deposition technique. Free-standing Zn nanowires with diameters 100, 200, 400 nm were synthesised on copper substrate acting as cathode, using this technique. The synthesised nanowires were irradiated with 40 MeV C⁴⁺ ion beam for various fluencies at Inter University Accelerator Centre, New Delhi, India. The effect of carbon ion beam on the grain size and preferred orientation of crystal planes of Zn nanowires were studied. The Rigaku X-ray diffractometer was used for X-ray diffraction (XRD) spectra of pristine and irradiated Zn nanowires. Post irradiation XRD analysis showed variation in the intensity of peaks, indicating the change in the orientation of crystal planes of the material. The preferred orientation of the crystal lattice planes in the polycrystalline material was found using texture analysis. To quantitatively investigate the degree of preferred orientations, the texture coefficients (TC) were calculated. The variation of TC was used to demonstrate the effect of irradiation on preferred orientation.     

Effect of 160 MeV Ni ion irradiation on PbS quantum dots

PbS quantum dots of average size 10 nm are encapsulated in a matrix (polyvinyl alcohol (PVA)) following chemical route. They are irradiated with 160 MeV Ni¹²⁺ ion beam with fluences 10¹²-10¹³ ions/cm². Red shift in the absorption response in the optical absorption spectra reveal size enhancement of the quantum dots after irradiation and was confirmed by transmission electron microscopy (TEM). Photoluminescence (PL) study was carried out with excitation wavelength 325 nm on both unirradiated and irradiated samples at different fluences and fluence-dependent surface states and excitonic emission is observed in the PL study. The Huang-Rhys coupling constant decreases significantly after swift heavy ion (SHI) irradiation and shows a decreasing trend with increase in ion fluence.     

Luminescent Properties of Sapphire Single Crystals Irradiated with a Pulsed Fe10+ Ion Beam

Optics and Spectroscopy - The optical and luminescent properties of sapphire single crystals irradiated by a pulsed Fe10+ ion beam with an energy of 200 keV are studied. The results of measurements...