LENS m LENS Simulations Analysis and Results B

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 ne energy information from the sun! 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.

Why LENS? What signal are we looking for? Ee = En-Q En 497 ke. V 115 ke. V Phys. Rev. Lett. 37, 259 (1976). ne + 115 In ® 115 Sn* + b. Use 115 In because reaction has a low Q value (~115 ke. V) 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 3 D segmented detector such as a scintillation lattice detector. LENS is a 60 x 60 scintillation lattice detector. (See R. Bruce Vogelaar’s Presentation J 9 -5)

What is a Scintillation Lattice? Thin Container Filled with Liquid Scintillator Container Index of Refraction = n 1 (Could be air) Liquid Scintillator Index of Refraction = n 2 > n 1

What is a Scintillation Lattice? We call this a Scintillation Lattice (Though this animation just shows a Scintillation Plane)

What Is LENS? (See Z. Yokley’s Presentation - J 9 -6)

m. LENS and mini. LENS m. LENS - 6 x 6 x 6 – 3” Cubes – Now mini. LENS - 9 x 9 x 9 – 3” Cubes – Under Construction 4 m Water Tank LENS – m. LENS and mini. LENS will show the way. . . (See D. Rountree’s Presentation J 9 -7)

What Was Measured? Trigger PMT ~. 5 m. Ci 137 Cs Source Located Near Center Bottom of m. LENS for ~ 1 hour Background Run for ~ 1/2 hour Y=5 Plane Y=4 Plane Longer Background Run for ~ 1 week Y=3 Plane Y=2 Plane All Runs Triggered on Center Four Top PMT ~. 5 m. Ci 137 Cs Source PMT All Approximately Normalized by Previous Measurements

Background Subtracted Low E Bump 137 Cs (Compton Edge or Full E Deposit? ) 137 Cs Data Raw 137 Cs Source (662 ke. V g) Background Subtracted 137 Cs Source Background Normalized Over This Region (1460 ke. V g) (Compton Edge or Full E Deposit? ) 40 K Thorium (2. 6 Me. V g) (Compton Edge or Full E Deposit? )

Simulation of 137 Cs Source at Bottom of m. LENS Low Trigger Threshold Medium Trigger Threshold High Trigger Threshold Relative height of low energy bump to high energy bump depends on the trigger level.

Simulation of 137 Cs Source at Bottom of m. LENS Low Trigger Threshold Low Energy Peak is a Low Energy Deposit in the Plane. Most Likely Several 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 the Full 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 137 Cs Measurements Background Subtracted 137 Cs Simulated Number of PE / Proportionally Scaled Channel Number Measured data is proportionally normalized, not linearly normalized.

The LENS Collaboration 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

BACKUP SLIDES

Prediction for 3 Plane m. LENS with Low Trigger Sum Y=2+3+4 Planes Sum Y=2 Plane Sum Y=3 Plane Sum Y=4 Plane Measurement with Low Trigger Threshold And What it Translates to Measuring

Prediction for 3 Plane m. LENS with High Trigger Sum Y=2+3+4 Planes Sum Y=2 Plane Sum Y=3 Plane Sum Y=4 Plane Measurement with High Trigger Threshold And What it Translates to Measuring