lens: m lens simulations, analysis, and results
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LENS: m LENS Simulations, Analysis, and Results. B. Charles Rasco Louisiana State University on behalf of the LENS Collaboration. Why Low-Energy Neutrino Spectroscopy (LENS)?. To get n e energy information from the sun!. - PowerPoint PPT PresentationTRANSCRIPT
LENS: mLENS Simulations, Analysis, and Results
B. Charles RascoLouisiana State University
on behalf of the LENS Collaboration
Why Low-Energy Neutrino Spectroscopy (LENS)?
Compare the photon luminosity of the sun to the luminosity of pp and CNO n energy output from the sun.
Measure the CNO n in order to get a direct measure of the metalicity of the sun.
To get ne energy information from the sun!
Why LENS?
497 keV
115 keV
What signal are we looking for?
Ee = En-QEn
(See R. Bruce Vogelaar’s Presentation J9-5)
ne + 115In ® 115Sn* + b-
Use 115In because reaction has a low Q value (~115 keV)In-loaded (~8% - 10 tons of Indium) liquid scintillator (LAB)
In order to identify the electrons and gammas above background good position and time resolution are required.
One way to accomplish position resolution is with a 3D segmented detectorsuch as a scintillation lattice detector. LENS is a 60x60x60 scintillation lattice detector.
Phys. Rev. Lett. 37, 259 (1976).
What is a Scintillation Lattice?
Thin Container Filled with Liquid ScintillatorContainer Index of Refraction = n1 (Could be air)
Liquid Scintillator Index of Refraction = n2 > n1
What is a Scintillation Lattice?
(Though this animation just shows a Scintillation Plane)
We call this a Scintillation Lattice
What Is LENS?
(See Z. Yokley’s Presentation - J9-6)
mLENS - 6x6x6 – 3” Cubes – Now miniLENS - 9x9x9 – 3” Cubes – Under Construction
LENS – mLENS and miniLENS will show the way...
4 m Water Tank
mLENS and miniLENS
(See D. Rountree’s Presentation J9-7)
What Was Measured?
~.5 mCi 137Cs Source Located Near Center Bottom of mLENS
for ~ 1 hour
Background Runfor ~ 1/2 hour
Longer Background Runfor ~ 1 week
~.5 mCi 137Cs Source
All Runs Triggered on Center Four Top PMT
Trigger PMT
Y=2 Plane
Y=3 Plane
Y=4 Plane
Y=5 Plane
PMT All Approximately Normalized byPrevious Measurements
Background Subtracted 137Cs Data
Raw 137Cs Source (662 keV g)
Background Subtracted 137Cs Source
Background
Normalized Over This Region
40K (1460 keV g)(Compton Edge or Full E Deposit?)
Thorium (2.6 MeV g)(Compton Edge or Full E Deposit?)
Low E Bump
137Cs (Compton Edge or Full E Deposit?)
Simulation of 137Cs Source at Bottom of mLENS
Relative height of low energy bump to high energy bump depends on the trigger level.
Low Trigger Threshold Medium Trigger Threshold High Trigger Threshold
Simulation of 137Cs Source at Bottom of mLENS
Low Trigger Threshold
Low Energy Peak is a Low EnergyDeposit in the Plane. Most LikelySeveral Mostly Forward Compton
Interactions (The Most Probable to Happen) in a Single Cell as the g
Crosses the Plane.
High Energy Peak is a Mixture of theFull Energy Deposit, Full Energy Minus Loss in the Outer Acrylic Shell, and the Compton Edge
Deposit in the Plane.
High Trigger Comparison of Simulation and First 137Cs Measurements
Background Subtracted 137Cs
Simulated 137Cs
Measured data is proportionally normalized, not linearly normalized.
Simulated Number of PE / Proportionally Scaled Channel Number
VT -- R. Bruce Vogelaar, Mark Pitt, Camillo Mariani, S. Derek Rountree, Laszlo Papp, Tristan Wright, Joey Heimburger, Lillie Robinson, Zach Yokley
LSU -- Jeff Blackmon, B. Charles Rasco, Liudmyla Afanasieva, Kevin Macon, Matt Amrit
BNL -- Minfang Yeh BNL
NCCU -- Diane Markoff
UNC -- Art Champagne
The LENS Collaboration
BACKUP SLIDES
Prediction for 3 Plane mLENS with Low Trigger
Measurement with Low Trigger Threshold
And What it Translates to Measuring
Sum Y=2+3+4 PlanesSum Y=2 PlaneSum Y=3 PlaneSum Y=4 Plane
Prediction for 3 Plane mLENS with High Trigger
Measurement with High Trigger Threshold
And What it Translates to Measuring
Sum Y=2+3+4 PlanesSum Y=2 PlaneSum Y=3 PlaneSum Y=4 Plane