Bulletin of the American Physical Society
2015 Annual Spring Meeting of the APS Ohio-Region Section
Volume 60, Number 3
Friday–Saturday, March 27–28, 2015; Kent, Ohio
Session F3: Heavy Ion Experiment II |
Hide Abstracts |
Chair: Rosi Reed, Wayne State University Room: KSU Student Center 315 |
Saturday, March 28, 2015 11:35AM - 11:50AM |
F3.00001: Lambda Polarization at the STAR BES Isaac Upsal Non-central heavy ion collisions provide a system with non-zero total angular momentum which can be transferred, in part, to the fireball via baryon stopping. It has been predicted that this angular momentum will lead to a net spin of emitted particles through coupling with the bulk material. Due to its parity violating decay the $\Lambda$ is self-analyzing, which allows us to associate the daughter proton decay direction with $\Lambda$ spin. Ultimately this allows us to use them as a probe of net-particle spin. In this talk we will present preliminary measurements of net $\Lambda$ polarization from STAR BES program. [Preview Abstract] |
Saturday, March 28, 2015 11:50AM - 12:05PM |
F3.00002: Status of the Silicon Detector of the STAR Experiment at RHIC Jonathan Bouchet The Heavy Flavor Tracker (HFT) is a new state-of-the-art detector fully installed at the STAR experiment at the Relativistic Heavy Ion Collider (RHIC) in January 2014. It consists of two layers of ultra thin sensors equipped with active pixel technology (MAPS) surrounded by two outer layers of conventional silicon pads and strips. The HFT provides excellent track pointing resolution which allows for measurements of heavy quark production with greater precision. In this talk I will report on the HFT physics as well as the overall performances during RHIC-run 14. [Preview Abstract] |
Saturday, March 28, 2015 12:05PM - 12:20PM |
F3.00003: A compound crystal with film scintillator for electron detection George McKinney, Warren McDonald Yttrium Aluminum Garnets (YAG) and Yttrium Aluminum Perovskite (YAP) are widely used as electron detectors. This application requires a top conducting layer which hinders their application at low electron energies. We have developed a layer of zinc tungstate which delivers conductivity large enough to prevent charging while still being an efficient scintillator. For better coupling between the two systems we have studied their optical properties. Ce doping is an essential element in YAP and YAG in order for them to be efficient scintillators. We have studied the Ce content and we show that higher Ce content leads to reabsorption in the YAP scintillators. These details were revealed by using photoluminescence emission and excitation spectroscopy. The absorption spectrum for the YAG scintillators coincides with the excitation for the main emission lines. The optical studies of the zinc tungstate films and a single crystal have shown that the films are more efficient light emitters. We have integrated the zinc tungstate films with YAG scintillators and we will report on the performance of this compound scintillator. It is expected that it will perform well at low and high electron energies, which makes it a very cost effective platform for electron detectors. [Preview Abstract] |
Saturday, March 28, 2015 12:20PM - 12:35PM |
F3.00004: Thin film scintillators Warren McDonald, George McKinney, Marian Tzolov Scintillating materials convert energy flux (particles or electromagnetic waves) into light with spectral characteristic matching a subsequent light detector. Commercial scintillators such as yttrium aluminum garnet (YAG) and yttrium aluminum perovskite (YAP) are commonly used. These are inefficient at lower energies due to the conductive coating present on their top surface, which is needed to avoid charging. We hypothesize that nano-structured thin film scintillators will outperform the commercial scintillators at low electron energies. We have developed alternative thin film scintillators, zinc tungstate and zinc oxide, which show promise for higher sensitivity to lower energy electrons since they are inherently conductive. Zinc tungstate films exhibit photoluminescence quantum efficiency of 74{\%}. Cathodoluminescence spectroscopy was applied in transmission and reflection geometries. The comparison between the thin films and the YAG and YAP commercial scintillators shows much higher light output from the zinc tungstate and zinc oxide at electron energies less than 5 keV. Our films were integrated in a backscattered electron detector. This detector delivers better images than an identical detector with commercial YAG scintillator at low electron energies. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700