Production of antideuterons and heavier antinuclei

A short review on measured production rates for antideuterons and other light antinuclei (³H,³He,⁴He) is given. The physics interest in experiments with these particles is described. The main items are the production mechanisms, antideuteron-atoms, antideuteron-induced possible quark/gluon phase transitions and the study of the properties (masses, magnetic moments, ...) of these particles. The paper finishes with the discussion of production schemes for low energy antideuterons. It turns out that with small modifications of the present -production facility at CERN more than 10⁷ antideuterons/day could be stored and used for experiments.     

Breeding of antideuterons in the AIC at FAIR

We present here a proposal to make use of the antiproton ion collider AIC of FAIR to breed cold antideuterons using the pionic fusion reactions $\overline{pp} \to \overline{d}\pi^{-}$ . An antideuteron yield of 1.4% per pair of antiprotons is reached. With a luminosity L?=?5.2×10²⁸ cm^???2 s^???1 the expected antideuteron production rate is 23 s^???1. Methods for improving the antideuteron yield and production rate are indicated.     

Facility for preparation of gas mixture in muon catalyzed fusion experiments

A facility is described that allows safe handling of high tritium gas activity as dozens kilocuries in a regular laboratory environment. It is used to make and deliver into the target a mixture of specific isotopic composition with the contamination requirement of 10^-7 v.f. for Z>1 elements, and recover it upon completion of operation. With this facility, efforts have been accomplished to investigate into the muon catalyzed fusion on two targets – liquid tritium and high-pressure tritium types. Also, the operation range was 0.1–120 MPa for pressure and 20–800 K for temperature and the amount of tritium used was about 100 kCi. The facility showed reliability in operation without indications of radiation beyond the safety level. This revised version was published online in August 2006 with corrections to the Cover Date.     

Observation of antideuteron production in electron-positron annihilation at 10 GeV center of mass energy

The production of antideuterons has been observed in electron-positron annihilations at center-of-mass energies around 10 GeV. Antideuterons have been identified unambiguously by their energy loss in the drift chamber, their time-of-flight and the pattern of their energy deposition in the shower counters of the ARGUS detector. The production rate in the momentum range (0.6?1.8) GeV/c is (1.6_?0.7^+1.0) × 10^?5 per hadronic event.     

激光柱形腔靶的X射线温度和X射线转换效率

本文根据实验和数值模拟给出的信息,解析研究激光加热柱形腔靶(简称“腔靶”)X射线温度与激光转换的X射线能之间的定标规律,推断了1989年在神光激光器上做的系列腔靶实验,对于每束激光能量为300—500J,脉冲宽度为0.7—1.0ns,波长λ为1.06μm的高斯型激光源,双束靶的X射线转换效率约为(50—55)%,X射线温度为(1.5—1.7)×10⁶K。 关键词：     

Deuteron and antideuteron production in Au+Au collisions at square root of s(NN)=200 GeV

The production of deuterons and antideuterons in the transverse momentum range 1.1相似文献   

Performance of the far‐IR beamline of the 6 MeV tabletop synchrotron light source

The performance of the far‐infrared (FIR) beamline of the 6 MeV tabletop synchrotron light source MIRRORCLE‐6FIR dedicated to far‐infrared spectroscopy is presented. MIRRORCLE‐6FIR is equipped with a perfectly circular optical system (PhSR) placed around the 1 m‐long circumference electron orbit. To illustrate the facility of this light source, the FIR output as well as its spectra were measured. The optimum optical system was designed by using the ray‐tracing simulation code ZEMAX. The measured FIR intensity with the PhSR in place is about five times higher than that without the PhSR, which is in good agreement with the simulation results. The MIRRORCLE‐6FIR spectral flux is compared with a standard thermal source and is found to be 1000 times greater than that from a typical thermal source at ～15 cm^?1. It is also observed that the MIRRORCLE‐6FIR radiation has a highly coherent nature. The broadband infrared allows the facility to reach the spectral range from 10 cm^?1 to 100 cm^?1. MIRRORCLE‐6FIR, owing to a large beam current, the PhSR mirror system, a large dynamic aperture and small ring energy, can deliver a bright flux of photons in the FIR/THz region useful for broadband spectroscopy.     

Search for cosmic-ray antideuterons

We performed a search for cosmic-ray antideuterons using data collected during four BESS balloon flights from 1997 to 2000. No candidate was found. We derived, for the first time, an upper limit of 1.9 x 10(-4) (m2s sr GeV/nucleon)(-1) for the differential flux of cosmic-ray antideuterons, at the 95% confidence level, between 0.17 and 1.15 GeV/nucleon at the top of the atmosphere.     

Toward improving the accuracy of testing the equivalence of the inertial and the gravitational mass under terrestrial conditions

An experiment aimed at testing the equivalence of the inertial and the gravitational mass is considered in which use is made of a facility including a vacuum chamber with two coupled oscillators (a pendulum and dynamical damper that form a vibrational system featuring two degrees of freedom) and falling onto the Sun. The layout of the facility and its basic parameters are presented. The pendulum and the dynamical damper have the same natural frequency, which is equal to the frequency of their rotation about the Sun. This frequency is dependent on the date of the experiment and can be calculated on the basis of the time equation. In the proposed facility, the amplitude of oscillations of the damper is 1.2×10^?5 rad, which is much greater than the value of 10^?7 rad previously achieved in the experiment that tested the equivalence principle to the highest precision of about 10^?12. This precision can be considerably improved. The result is presented that was obtained from a measurement during the solar eclipse in Moscow on August 11, 1999.     

Sura-wind radar: Studies of nonlinear effects using VHF-wave occultion of the ionosphere

We present experimental results on reception of VHF signals of the transmitting facility “Sura” of the Radiophysical Research Institute by the NASA spacecraft WIND. The experiments were performed during daytime during the summer seasons 1997–1998. The dependence of power and spectral characteristics of the VHF radio waves on the power of the sounding radiation is analyzed. We find that, in a wide range of effective powers of the VHF radiation from about 40 kW to 160 MW, the phenomena observed in the radiation received onboard WIND (such as focusing, scintillations, or frequency deviations of signals) does not usually depend on the operation mode of the “Sura” facility. At the same time, broadening of the radiation pattern of the facility and decrease of the mean level of the received signal by about 6 dB toward the direction of maximum of the radiation pattern were observed at the peak radiation power of the facility. The experimental results are compared to present concepts on effects of self-focusing instability and nonlinear defocusing of VHF radio waves in the ionospheric plasma. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 42, No. 8, pp. 799–809, August 1999.     

Large angle production of stable particles heavier than the proton and a search for quarks at the CERN intersecting storage rings

Measurements have been performed on production of particles with mass 1.5 GeV/c² and charge $\text{?}\text{2}\text{3}$ for θ_lab = 62.5° and $\text{s}\text{= 53}\text{GeV}$. At p_T = 0.7 GeV/c the relative rate of production of antideuterons to π^? is (5 ± 1) × 10^?5. The deuteron to antideuteron ratio is 3.7 ± 1.2. No new stable particle has been amongst 0.7 × 10⁸ charged particles entering our detector.     

First principles study of nuclear quadrupole interactions in the molecular solid BF3 and the nature of binding between the molecules

The LPCTrap facility is coupled to the low-energy beam line LIRAT of the SPIRAL source at GANIL (France). The facility comprises an RFQ trap for beam preparation and a transparent Paul trap for in-trap decay studies. The system has been tested for several ion species. The Paul trap has been fully characterized for ⁶Li⁺ and ²³Na⁺ ions. This characterization together with GEANT4 simulations of the in-trap decay setup (Paul trap and detection system) has permitted to predict the effect of the size of the ion cloud on the decay study of ⁶He⁺.     

Study on the RF Power Necessary to Ignite Plasma for the ICP Test Facility at HUST

An Radio‐Frequency (RF) Inductively Coupled Plasma (ICP) ion source test facility has been successfully developed at Huazhong University of Science and Technology (HUST). As part of a study on hydrogen plasma, the influence of three main operation parameters on the RF power necessary to ignite plasma was investigated. At 6 Pa, the RF power necessary to ignite plasma influenced little by the filament heating current from 5 A to 9 A. The RF power necessary to ignite plasma increased rapidly with the operation pressure decreasing from 8 Pa to 4 Pa. The RF power necessary to ignite plasma decreased with the number of coil turns from 6 to 10. During the experiments, plasma was produced with the electron density of the order of 10¹⁶m^–3 and the electron temperature of around 4 eV. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Does a high energy antideuteron beam provide a crystal ball for studying two-particle properties of nuclei?

The problem of annihilation of fast antideuterons in complex nuclei is analyzed semi-quantitatively in the framework of a simple probabilistic model. Sensitivity of the annihilation cross section to two-particle nuclear distribution is scrutinized.Dedicated to Professor Ivan Úlehla on the occasion of his sixtieth birthday.     

Dosimetry and spectrometry at accelerator based neutron source for boron neutron capture therapy

An innovative accelerator-based neutron source for boron neutron capture therapy has started operation at the Budker Institute of Nuclear Physics, Novosibirsk. This facility is based on a compact vacuum insulation tandem accelerator designed to produce proton current up to 10 mA. Epithermal neutrons are proposed to be generated by 1.915 MeV protons bombarding a lithium target using ⁷Li(p,n)⁷Be threshold reaction.In the article, techniques to detect neutron and gamma-rays at the facility are described. Gamma radiation is measured with NaI and BGO gamma-spectrometers. The total yield of neutrons is determined by measuring the 477 keV γ-quanta from beryllium decay. For the rough analysis of the generated neutron spectrum we used bubble detectors. As the epithermal neutrons are of interest for neutron capture therapy the NaI detector is used as activation detector. We plan to use a time-of-flight technique for neutron spectra measurement. To realize this technique a new solution of short time neutron generation is proposed.     

The LPCTrap experiment: measurement of the ��-��?angular?correlation in 6He+ decay using a transparent Paul trap

The LPCTrap experiment is devoted to the precise measurement of the ??-?? angular correlation parameter, a _?|? , in the pure Gamow-Teller decay of ⁶He⁺. This experiment is motivated by the search of the presence of tensor type contributions in the weak interaction. The radioactive source is confined in a transparent Paul trap installed at LIRAT, the low energy beam line of the SPIRAL facility. The ??-?? correlation is studied by measuring the time of flight of the recoil ions detected in coincidence with the ?? particles. During the last experiment, a total of 4 × 10⁶ coincidence events have been recorded which would enable to determine the coefficient with a statistical uncertainty of 0.5%. The status of the analysis is presented in this contribution.     

Pionic Fusion Study of the halo analogue state6Li

The isobaric analogue state of the ground state of the halo nucleus⁶He,⁶Li* has been studied in a pionic fusion experiment at the CELSIUS storage ring facility in Uppsala, Sweden. This was the first of two proposed experiments with the aim to study the high momentum part of the wave functions of the halo nuclei⁶He and⁶Li (0⁺, T=1). The Li nuclei were produced in inverse kinematics reactions with alpha particles incident on a deuterium cluster jet target. The⁶Li ions were detected in a zero-degree spectrometer situated in the fourth quadrant of the CELSIUS ring. The measurement was done for three different beam energies corresponding to 5.4, 2.2 and 1.5 MeV above threshold in the c.m. The cross-sections slowly increase with beam energy from 95 nb at the lowest energy to about 250 nb at 5.4 MeV above threshold.     

TUNKA-133: A new array for the study of ultra-high energy cosmic rays

A new array for studying ultra-high energy cosmic rays was inaugurated in 2009 in the Tunka Valley, about 50 km from Lake Baikal. Having an area of 1 km², the new facility allows us to study cosmic rays with energies of 10¹⁵–10¹⁸ eV via the a unified method for registering Cherenkov radiation from extensive air showers (EASes) and is making a substantial contribution to understanding the origin of ultra-high energy cosmic rays. We describe the current state of the experiment, the new methodological approach, our initial results, and the plans for further development of the array.     

激光加热充氖靶丸的压缩实验研究

在神光(10¹²W)激光器上,用充Ne靶丸开展了内爆压缩实验研究。结果表明:实现了激光加热靶丸的对称性内爆压缩,芯部电子密度达10²³cm^-3,平均内爆速度为3.3×10⁷cm/。 关键词：