Hall C Safety Stand down March 20, 2009
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Transcript of Hall C Safety Stand down March 20, 2009
Hall C Safety Stand downMarch 20, 2009
• Stephen Wood: Overview and Safety Overview• Mike Spata: Beamline overview• Kellner: Schedule and safety rules• Manzlak: Physics Division EH&S comments• Neil Wilson: Tool Safety• Bill Vulcan: Electrical work
E05-115 HES/HKS
2
Building blocks of ordinary matter
Protons Neutrons
Quarks
u u d
u d d
3
Chart of Isotopes
Neutrons
Pro
tons
Black squares:Stable or nearly stable
Exploiting “Chart”:Medical isotopesNuclear Power
Exploring and extending“Chart” still an active field:
AstrophysicsFRIB @ MSU
Exploring a third dimension
Protons Neutrons
4
Quarks
u u d
u d d
u d s
Lambda Particle
(a hyperon)Strange quark
e + p e + K+ + Producing Lambdas
N
Z
Nutron #Pro
ton#
L, S hypernuclei
Nu ~ Nd ~ Ns
Nu
mb
er o
f s
qu
ark
s
0
1
2
LL, X hypernuclei
Normal Nuclei (World of u,d quarks)
World of u, d, s quarks
Extend building blocks of the World from u,d to u,d,s!
Neutron#
K+ detection At very forward angle (~ 0 deg.) Detected by High resolution Kaon Spectrometer (HKS)
Hypernuclear productionby the (e,e’K+) reaction (E05-115)
e’
K+
e- Beam from CEBAF
Target nucleus
Eg
e’ detection Should be at extremely forward angles Detected by High resolution Electron Spectrometer (HES)
L is free from nucleons’ Pauli exclusion Probe to deep inside of nucleus
L is L in deep inside of nucleus? or should be treated as (uds)?
Extend nuclear force to baryon force
Simulation
-B L [MeV]
Evolution of 12LB spectra
E89-009~300h x 0.6mA
E01-011~120h x 30mA
E05-115~24h x 30mA
Cou
nts/
150
keV
-BL (MeV)
Accidental coincidence
coun
ts/
100k
eVYear 2000 Year 2005 Year 2009 summer!
Much sharper spectra than possible with pion or kaon beams
Hypernuclear investigation in wide mass range at JLab Hall C
Light Hypernuclei (s,p shell)
A
1 20 50 200 1057
Elementary Process
Single-particle potential
Distinguishability of a L hyperon
U0(r), mL*(r), VLNN, ...
Neutron/Hyperon star,
Strangeness matter
Baryon-baryon interaction in SU(3)LS coupling in large isospin hypernucleiCluster structure, Fine structureNeutron rich hypernuclei
E05-115 6,7Li 10,11B 12C (40Ca) 52Cr 89Y
3rd Generation Experiment
E01-011 7Li 12C 28Si
E89-009 12C
Medium - Heavy hypernuclei
1st gen.:
2nd gen.:
9
2.344 GeV
CEBAF Electron beam
To the beam dump
7.5deg tilt
HES
HKS
Target
e-
K+
HKS + HES + New Splitter (dedicated system to hypernuclear study)
Fully optimized for (e,e’K+) hypernuclear spectroscopy
10
One beam in – 4 “beams” out
Kaon and electron need to be detected at small scattering angles.
Splitter magnet separates negative electron and positive kaon.
Splitter magnet also bends primary beam. Beam needs to be send to dump. Either bend beam after splitter (the way it was done last time, or bring beam in at an angle.
ElectronsPhotons
K+
e-