Facilities of the Department of Physics and Astronomy at Austin Peay State University include a newly established NASA-funded $500K Materials Fabrication and Characterization Lab, the APSU Observatory, and a dedicated computer cluster. Detailed descriptions are below.
HORIBA XploRa Confocal Raman Microscope - A high performance Raman spectrometer which is coupled to a research grade optical microscope, allowing both standard optical microscopy and detailed chemical analysis on a single system. Technical specifications: spatial resolution < 1 micron; spectral resolution 1.1-1.8 cm-1 depending on the laser source; spectral range 100-4000 cm-1; two excitation lasers (532 and 785nm). Detector – 1024 pixels, high sensitivity air cooled CCD.
MBraun Thermal Evaporator - The MBraun is a recipe driven, PC controlled (both power and temperature via Lab View) stand-alone Thermal Evaporator. This system is capable of monitoring pressure, power and thickness. The MBraun is fully interlocked for safety, capable of recovering from power interruptions, and capable of co-evaporation or sequential evaporation of metals or organics. Technical specifications: Sample Holder: up to 4”, rotating at 3 RPM. Dry scroll pump and turbo molecular pump. Base Pressure: 2 x 10-6 Torr. Sources: Dual crucible evaporator with auto shutters, programmable evaporation route. Automatic control of deposition rate and thickness.
HORIBA Fluorolog-3 Spectrofluorometer - This FL3-11 system has two single-grating spectrometers in the excitation and emission positions, a T-sample compartment, and a photomultiplier tube (PMT) with a photon counting system, controlled by a computer. The PMT spectral range is from 250 nm to 800 nm.
The steady-state excitation source is a broadband 450 W Xenon lamp with emission from the UV to near-IR. With this excitation source, luminescence emission and excitation spectra from 250 – 800 nm can be measured.
This FL3-11 system is also equipped with a Time-Correlated Single-Photon Counting system (TCSPC), including a HORIBA FloroHub station and fixed-wavelength “Plug and Play” interchangeable pulsed NanoLEDs and SpectraLEDs. Wavelengths of 280, 320, 370, and 390 nm are available from standard optical pulse durations from 200 ps to 2 ns. Lifetime from 200 ps to 10 μs can be measured using this TCSPC and lifetime from 10 μ to 10 ms can be measured operating in the MCS mode using pulsed SpectraLED.
PremiScan/400/MB Optical Parametric Oscillator (OPO) - OPO's have a broad tuning range that only dye lasers can approach; however, the dye laser requires the use of many different dyes to access the same wavelength range. An OPO exploits the non-linear behavior of certain crystals when irradiated by an intense light source. When a non-linear crystal is illuminated by an intense pump beam, it will emit two other waves called the idler and signal in a process called three-wave mixing. The premiScan OPO delivers the high efficiencies and beam quality throughout its entire tuning range. By using a seamless two-crystal swapping design, the premiScan optimizes the efficiencies at the wings without compromising performance in the center of the range. The premiScan/400/MB OPO offers a peak signal energy of 120 mJ, a tuning range of 410-2630 nm and linewidth of 3-7.5 cm-1.
The system also includes a high-efficiency, angle-tuned, temperature stabilized harmonic generator, a pair of mounted 355 nm dichroic beam splitters and back reflection protection.
Quanta-Ray Pro-230-10 Nd:YAG laser (ash-lamp pumped laser) - This acts as the pump laser for the OPO above and can also be used for Pulsed Laser Deposition (the Department also has a small vacuum chamber that can be tasked for this purpose). The laser produces pulses at a rate of 10Hz, with pulse energies of 1250 mJ at its fundamental wavelength of 1064 nm. This laser has a short term energy stability of ±2% over time scales of one hour and a long term power drift under 3% over eight hours. The system also includes a water-cooled beam dump for internal use in the Quanta-Ray Pro-230-10 Nd:YAG laser.
Hitachi model TM-1000 SEM with EDS-elemental analysis - Specification: Accelerating Voltage – 15 kV; Detector – Solid State Backscattered Electron Detector (BSE); Magnification: 20 - 10.000 X (Digital Zoom : 4 X); Specimen Stage – X = 15mm / Y = 18mm; Maximum Sample Size – 70mm in diameter; Maximum Sample Height – 20 mm high; Pressure Mode – Standard Mode/Charge-up reduction mode; Evacuation System – Turbo Molecular Pump (TMP) & Diaphragm PUMP.
Computational facilities - The Austin Peay State University interdepartmental computing cluster consists of 32 compute nodes (each with 2 quad core Intel Xeon L5420 processors [8 total cores running at 2.50 GHz] and 16 GB of ram [4 nodes have been upgraded to 32 GB]) connected to each other by switched gigabit ethernet. The nodes are managed by a head node which has 2 quad core Intel Xeon L5420 processors [8 total cores running at 2.50 GHz], 32 GB of ram, and 26 TB of disk space which is shared via NFS with the compute nodes. Installed software includes NWChem, ECCE, and Gaussian.
Computational research at APSU is a multi-disciplinary endeavor involving faculty from several departments including Physics and Astronomy, Mathematics, and Chemistry.
Astronomy facilities - The Department of Physics & Astronomy operates the APSU Observatory which consists of a 0.5m Ritchey-Chretian telescope on a German equatorial mount housed within a 16' dome as well as a storage facility. The telescope is equipped with a large format imaging camera (Apogee Ulta U16000) with Sloan Digital Sky Survey-ugriz filters. A set of Johnson-Cousins UBVRI-filters and a small set of Balmer-alpha redshifted filters are also available.
In addition, the Department has recently joined the WIYN 0.9m Consortium at the Kitt Peak National Observatory in Arizona. The 0.9m WIYN telescope is equipped with a large format imaging system and several filter sets. APSU gets about 16 nights per year on this system.