סמינר ארצי בפיזיקה גרעינית

29 באפריל 2019, 14:30 
Hebrew University, Ross building, Seminar room 
סמינר ארצי בפיזיקה גרעינית

PROGRAM

 

14:30 - 14:45  Refreshments

 

14:45 - 15:45  "European Nuclear Physics Long Range Plan: New Opportunities in Nuclear Physics with High Power Lasers and Monochromatic and Brilliant Gamma Beams", Sydney Gales, IFIN-HH/ELI-NP and IN2P3/CNRS

Abstract:

The European Nuclear Physics Long Range Plan was published last year and its main conclusions will be briefly presented. A new research facility based on High Power Laser Beams (HLPS) and monochromatic and brilliant Gamma Beam System (GBS) called “Extreme Light Infrastructure-Nuclear Physics”, ELI-NP, is currently under construction at Magurele, Bucharest, Romania. Its mission covers scientific research at the frontier of knowledge involving two domains. The first one is to use HPLS to produce secondary accelerated electrons, ions and gamma rays to probe the structure of nuclei and study nuclear reactions under extreme conditions. 

The second is based on a Compton–backscattering high-brilliance and intense low-energy gamma beam (<20 MeV), a marriage of laser and accelerator technology which will allow us to investigate nuclear structure and reactions as well as nuclear astrophysics with unpreceded resolution and accuracy.

Ultra-intense laser fields, reaching up to 1022 W/cm2, are now able to produce typical radiation formerly used in nuclear facilities, as demonstrated in laboratories across the globe. Such power densities are comparable to stellar environment conditions. High power laser probes will allow to study isomer properties in plasmas, to investigate laser induced multi step reactions, such as fission-fusion, to reach extremely neutron rich nuclei, and shed new light in the understanding of the r-process. Possible applications of HPLS in Nuclear Medicine and Nuclear Energy will be discussed.

The new Multi-MeV GBS at ELI-NP will be used to study key questions in Nuclear Structure and Reactions like detailed structure of the dipole response in very heavy nuclei, search for new low-spin modes or to investigate reactions relevant to nucleosynthesis. Brilliant Multi-MeV Gamma Beams may also be used to develop new imaging technics. Nondestructive investigations based on gamma rays can be successfully applied to nuclear security and counter terrorism. In this presentation the research domain at reach with these new probes as well as the related applications will be illustrated through selected examples.

 

 

15:45 - 16:15  Coffee Break

 

16:15 - 17:15  "Development of the radioactive neon trapping program at SARAF, and precision measurements with stable isotopes", Ben Ohayon, The Hebrew University

Abstract:

The last decade witnessed an explosion of applications of experimental methods from the field of Atomic Molecular and Optical (AMO) physics to low-energy nuclear physics observables, with motivation spanning nuclear-structure, nuclear-astrophysics, and searches for physics Beyond the Standard Model (BSM). Ground (and isomeric) state properties such as Q-values, charge radii and nuclear moments, are routinely extracted by applying penning and multiple reflection mass-spectrometry, and a multitude of laser spectroscopic techniques [1,2]. The use of atom and ions traps is crucial for extracting information - such as branching ratios, waiting times, and angular correlations - on the low-energy fragments emerging from a nuclear decay [3]. In fact, determinations of beta-decay correlations to the level of few pro-mil are competitive and complementary with high-energy searches [4].

In this talk I review the development, current status, and future outlook for the Neon Atom Trap (NeAT) program at the SARAF particle accelerator [5]. I will cover the creation of substantial amounts of 23Ne at SARAF [6], the application of new methods for manipulating and detecting atoms with laser radiation [7-11], and our intended detection scheme. The determination of the energy spectrum of daughter ions recoiling from nuclear beta-decay, on the order of 100 eV, necessitates the application of kinematic reconstruction methods usually applied in the fields of physical-chemistry. We have recently demonstrated the first implementation of a Magneto-Optical-Trap Velocity-Map-Imaging (MOT-VMI) device [12]. This novel experimental scheme constitutes a true "Nuclear decay Microscope", which is capable of a complete, event-by-event reconstruction of 3D angle, Mass, and energy distributions of recoil ions from beta decay of ultracold, trapped neon isotopes.

[1] K Blaum, Jens Dilling, and Wilfried Nörtershäuser. Precision atomic physics techniques for nuclear physics with radioactive beams. Physica Scripta 2013 [2] Daniel Rodríguez et. al. MATS and LaSpec: High-precision experiments using ion traps and lasers at FAIR. EPJ 2010 [3] J A Behr and A. Gorelov.  β-decay angular correlations with neutral atom traps. JPG 2014 [4] M González-Alonsoa O Naviliat-Cuncic, N Severijns. New physics searches in nuclear and neutron decay. PPNP 2019 [5] I Mardor et. al. The soreq applied research accelerator facility (saraf): overview, research programs and future plans. EPJA 2018 [6] Y Mishnayot et. al. in preparation.
[7] BO, and G Ron. New approaches in designing a Zeeman slower. JINST 2013 [8] BO, E Wåhlin, and G Ron . Characterization of a metastable neon beam extracted from a commercial RF ion source. JINST 2015 [9] BO, and G Ron. Investigation of different magnetic field configurations using an electrical, modular Zeeman slower. RSI 2015 [10] BO, G Gumpel, and G Ron. Measurement of the Ne transition isotope shift using a single, phase-modulated laser beam. PLB 2017 [11] BO, H Rahangdale, AJ Geddes, JC Berengut, and G Ron. Isotope shifts in 20, 22 Ne: Precision measurements and global analysis in the framework of intermediate coupling. PRA 2019 [12] BO, H Rahangdale, J Chocron, R Kosloff, O Heber, G Ron. Imaging recoil ions from optical collisions between ultracold, metastable neon isotopes. arXiv:1904.05672

 

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