FRIB Introduction to NSCL and the research done

FRIB Introduction to NSCL and the research done here - Nuclear Physics • Molecules, Atoms, and Atomic Nuclei • The science of Isotopes – What are isotopes? – How do we make isotopes, make new elements, etc. ? – Strange examples: Halo Nuclei – Isotopes in Astronomy • Introduction to NSCL and The Facility for Rare Isotope Beams (FRIB) Slide 1

Molecules FRIB • Molecules – the smallest unit of any substance consisting of more than one atom • Examples: Methane, Octane, d-Glucose • Molecules can be created or modified by chemical reactions Slide 2

Companies make and market molecules FRIB http: //www. sigmaaldrich. com/chemistry/chemical-synthesis-catalog. html Slide 3

Some of what you can buy… FRIB Slide 4

Details… FRIB Product Catalog > Chemical Synthesis > Building Blocks > Organic Building Blocks > Alkanes > Acyclic Slide 5

Atoms FRIB • The Methane molecule is made of one carbon and four hydrogen atoms • Atoms are made of electrons and a nucleus with protons and neutrons (mostly) • Chemistry – atoms are unchangeable (mostly – in fact this is what we do) • The number of protons in the atomic nucleus (atomic number) determines the chemical element Slide 6

Periodic Table of the Elements FRIB Slide 7

Atomic Nuclei FRIB • A representation of an Oxygen Atomic Nucleus 6 fm (0. 00000006 m) If this nucleus was the size of a basketball the atom would stretch to Detroit. http: //www. scri. fsu. edu Slide 8

FRIB Atoms of elements come in several forms: Isotopes • Isotopes of Beryllium Neutron number The sum of neutron and proton numbers is called the mass number (often written as A) Slide 9

FRIB Nuclear Science Wall Chart – Resource for Classes http: //www. lbl. gov/abc/wallchart/index. html Slide 10

FRIB Back to Nuclei: Truth in advertizing – Neutrons and protons are not fundamental particles • Neutrons and protons are made of quarks (mostly) 6 fm This picture is also too simplistic http: //www. scri. fsu. edu 11 Slide

Multiple choice FRIB • Which of the following statements is most correct concerning where oxygen atoms come from? – – – They are mostly human made from when coal is burned They are made in natural chemical reactions They were made in the Big Bang They are made in the cores of stars like the Sun They are made when stars explode • We can ask a similar question about all the elements. • For example, where do gold atoms come from? Slide 12

What is a rare isotope? FRIB Rare isotopes have unusual nuclei (exotic) Normal Nucleus: 6 neutrons 6 protons (carbon) 12 C Stable, found in nature Exotic Nucleus: 16 neutrons 6 protons (carbon) 22 C Radioactive, at the limit of nuclear binding Characteristics of exotic nuclei: Excess of neutrons or protons, short half-life, neutron or proton dominated surface, low binding Slide 13

How do we make rare isotopes? FRIB Lithium-7 3 protons, 4 neutrons Suppose we want to study Lithium-11 3 protons, 8 neutrons Slide 14

Creation of new isotopes FRIB 18 -Oxygen Collision 11 -Lithium A 18 -Oxygen nucleus is accelerated to a velocity of about 100, 000 miles per second. Slide 15

Production of rare isotopes FRIB Nucleus Factory Produced by W. Benenson and W. R. Richards Slide 16

In-Flight Production of Rare Isotopes Example: NSCL’s CCF FRIB Example: 86 Kr → 78 Ni K 500 ion sources coupling line K 1200 86 Kr 14+, 12 Me. V/u A 1900 production stripping target 140 Me. V/u foil focal plane p/p = 5% 86 Kr 34+, wedge Slide 17

FRIB Facility for Rare Isotope Beams FRIB Slide 18

FRIB Linear Accelerator details FRIB Tunnel Floor ~40 ft below grade Grade (ground) level Slide 19

FRIB Production and Separation of Isotopes – The Rap Version • Rare Isotope Rap (full version is 5 minutes) by Kate Mc. Alpine • http: //www. youtube. com/watch? v=677 Zm. PEFIXE • Kate also did the LHC Rap • Short version Slide 20

FRIB How a Fragment Separator Works – Rare Isotope Rap http: //www. youtube. com/watch? v=677 Zm. PEFIXE Kate Mc. Alpine, CERN Slide 21

Schedule for FRIB Completion FRIB • 2010 – Approval of the conceptual design, start of preliminary design • 2011 – Approval to start final design • 2013 – Final design approved, start of construction • 2018 – Project is complete Slide 22

The Chart of the Isotopes FRIB Number of Protons How many protons can a nucleus hold? Isotope Predicted limits of stability How many neutrons Number of Neutrons can a nucleus hold? Slide 23

Isotope Chart – Chart of Nuclides FRIB Yellow – synthesized for experiments Green – possible range of undiscovered isotopes Slide 24

FRIB Some Isotopes are very “Exotic” Halo Nuclei Slide 25

Element 112 Copernicium, Cn FRIB • Officially named in 2009 • “The idea was to go backwards, to honor someone who was not greatly honored in his lifetime. ” – Sigurd Hofmann • Hofmann wanted to highlight the contribution of nuclear chemistry to other fields, astrophysics in particular. • Element was first produced at GSI in 1996 by fusion of zinc and lead. Zeitschrift für Physik A 354, 229 -230 (1996) Slide 26

Atomic Number FRIB Detailed View of Superheavy Element Region Produced at DUBNA by 48 -calcium + target Neutron Number Physics. World. com Slide 27

What are the limits of atomic number? FRIB • We don’t know. Atomic numbers greater than 300 are possible. • These nuclei are refereed to as hyperheavy nuclei (as opposed to superheavy nuclei from around 102 to 124) • The repulsion of the protons in the nucleus will likely lead to unusual shapes Nue neverforum Toroidal Nuclei Bubble Nuclei (hollow inside) • How will we make them? We don’t know, but with better nuclear models we will better understand the likelihood of their existence. Slide 28

History of Element Discovery FRIB 1700+ Rise of modern chemistry – Dalton’s Atomic Theory Babylonia Egypt Democritus – idea of atoms Copper Age Slide 29

FRIB The history of element discovery 12002000 Chemistry Dalton’s Atomic Theory Cavendish, Priestly, Scheele, … Mendeleev’s Periodic Table Particle Accelerators Time of the Alchemists Slide 30

What are the future possibilities? FRIB • We do not know. So far we have “discovered” 118 elements. (The last six have not been officially sanctioned. ) • This is one of the questions we can address at FRIB with an advanced capability to produce new neutron-rich isotopes – Better nuclear models to understand what the limits are – Production of more neutron-rich heavier nuclei • FRIB is a modern equivalent to the Philosopher’s Stone (no religious or mystical connotation intended) 50 Years form now (maybe not likely but dreaming)… FRIB Slide 31

Where Atoms Made? The Challenge FRIB • We would like to understand where the atoms are made. • This is part of a larger problem to understand the chemical history of the Universe • To do this we need to – Model elemental synthesis by stars and galactic processes – Model the development and evolution of galaxies – Produce and study the isotopes (and their reactions) that are important for this modeling (this is the main part we use our accelerators to do) Slide 32

FRIB Making atoms - Stellar evolution of massive stars • Stars with more than 8 times the mass of our Sun develop multiple burning layers • Hydrogen to helium • Helium to carbon • Carbon to oxygen, neon, magnesium • Oxygen to neon • Neon to magnesium • Magnesium to Silicon • Silicon to Iron • Iron is the most bound nucleus and has no exothermic nuclear reactions Slide 33

Forefront of Observational Astronomy: High Resolution Telescopes FRIB • The measurement of elemental abundances is at the forefront of astronomy using large telescopes Hubble Space • Large mirrors enable high resolution spectroscopic studies in a short time (Hubble, LBT, Keck, …) • Surveys have provided large data sets (SDSS, LAMOS, Sky. Map, HERMES, LSST, Gaia, …) Large Binocular Telescope • Future missions: JWST - “is specifically designed for discovering and understanding the formation of the first stars and galaxies, measuring the geometry of the Universe and the distribution of dark matter, investigating the evolution of galaxies and the production of elements by stars, and the process of star and planet formation. ” Slide 34

FRIB Where do atoms come from? A hint from stellar spectra • Stellar absorption spectra “young” star T=4800 K; elements like our sun Intensity (relative) • Not all stellar absorption spectra of the same surface temperature are identical old star T=4700 K; only 1/10, 000 heavy elements Slide 35

FRIB About Half of Heavier Elements must be made in an r-Process (Click on image to start animation) Nuclear physics shapes the characteristic final abundance pattern for a given r-process model Slide 36

FRIB 37 Slide 37