In our laboratory we have access to the following instruments:

Laser ablation and solid-particle beam apparatus

The apparatus is used to synthesize small solid particles that are analogues of cosmic dust grains. Laser ablation of a solid target is performed in the presence of a quenching gas in the first of three differentially pumped chambers. The vaporized matter condenses into small grains which are carried away by the quenching gas that flows through a nozzle into the second chamber where it expands. The free expansion, seeded with the grains that have stopped growing, is sampled by a skimmer to form a beam of solid particles in the third chamber. The particles can be collected in this chamber or directed toward a fourth chamber (see below) where they can be processed by exposure to heat or VUV photons and also studied by FTIR absorption spectroscopy.

Nd:YAG laser (532 nm; Continuum Surelite)

Photograph coming soon.

 

Processing and spectroscopy chamber

Photograph coming soon.

This vacuum chamber is equipped with a He closed-cycle cryocooler fitted with a high-temperature interface, which allows us to bring and keep the sample holder to any temperature between 10 and 800 K. The chamber is coupled to an FTIR spectrometer by means of mirrors placed in an evacuated optical path. Supplementary ports are used to connect the chamber to the laser ablation and solid-particle beam apparatus (see above), to a UV/vis spectrophotometer via optical fibers, or to mount a H2 lamp to irradiate the samples with VUV photons. The chamber is also used to carry out FTIR matrix-isolation spectroscopy.

Closed-cycle He cryocooler (ARS DE-204SL)

FTIR spectrometer (Bruker VERTEX 80v)

H2 lamp

 

He droplet experiment

Differentially pumped 5-stage He cluster/ droplet beam apparatus

Liquid helium-cooled supersonic jet source

Quadrupole mass spectrometer

Nd:YAG laser (1064 nm, 532 nm, 355 nm; Continuum NY81-20) + dye laser (Lambda Physik Scanmate 1)

Atomic hydrogen source (HABS; MBE-Komponenten)

 

Matrix isolation spectroscopy

Closed-cycle He cryocooler ARS DE-204SL for sample cooling (6.5 K)

Vacuum chamber, turbomolecular pump

UV-VIS-NIR spectrometer with optical fibers (Jasco V-670 EX)

Nd:YAG laser (1064 nm, 532 nm, 355 nm, 266 nm; Continuum Minilite II) for laser vaporization

Sources for thermal evaporation

 

Supersonic-jet cavity ring-down spectrometer

Vacuum chamber containing heated pulsed valve or laser ablation source

Nd:YAG laser (1064 nm, 532 nm, 355 nm; Continuum Surelite II-20) + dye laser (Continuum ND6000) + SHG stage (Continuum UVT-1) for cavity ring-down spectroscopy

Photomultiplier (Hamatsu H6780-04) as optical detector

Digital oscilloscope (Tektronix TDS3052)

Nd:YAG laser (1064 nm, 532 nm, 355 nm, 266 nm; Continuum Minilite II) for laser vaporization

Nd:YAG laser (1064 nm, 532 nm, 266 nm; Continuum NY61-20) for laser vaporization (at higher fluence)

 

Synthesis of carbon particles and molecules

Flow reactor

cw CO2 laser (Laser Photonics, model 150, wavelength: 10.6 µm; power: 50 W)

High-performance liquide chromatograph (Jasco system with delivery pumps PU-2080 Plus and diode array detector MD-2010 Plus)

 

Cluster beam apparatus

The flow reactor is mounted into the source chamber of a molecular beam machine. A pulsed CO2 laser (Urenco ML104, laser pulse energy: 40 mJ, repetition rate: 20 Hz) initiates the pyrolysis of the reactant gases (SiH4 and GeH4 with total flow rate: 15.5 sccm; helium buffer gas: 1100 sccm). A mechanical size selection of the clusters is achieved with a chopper. The size of the synthesized nanocrystals is determined in situ by time-of-flight mass spectrometry. The sample collection in the cluster beam is performed on substrates like mica, SiO2, and polymers.

ArF excimer laser (Lambda Physik OPTex PRO; 193 nm for ionization)

 

Atomic force microscope

Multimode AFM (Veeco) with controller (Digital Instruments Nanoscope III)

Stereo microscope (Carl Zeiss Stemi 2000-C) with CCD camera (Spindler & Hoyer 230 C) and monitor

 

Other facilities

Through cooperations with other institutes of the Physics Department of the University of Jena, we have also access to the following instruments:

At the Astrophysical Institute:

Fourier transform IR spectrometer

Raman microscope spectrometer

UV-VIS-NIR spectrometer

VUV spectrometer

At the Institute of Materials Science and Technology:

High-resolution transmission electron microscope (HRTEM): JEOL JEM 3010 with LaB6 cathode operating at an acceleration voltage of 300 kV and equipped for energy-dispersive X-ray (EDX) spectroscopy