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THEMIS 1000 2D-DLD

Time-of-Flight Electron Energy Analyzer for ARPES and 2D DLD Detector and 1000 mm Drift Tube

The SPECS THEMIS is a time-of-flight analyzer, ideally suited for pulsed light sources with high repitition rates. The electron dispersion is done by the different travel time through the drift tube, when a bunch of electrons is emissted from a short laser pulse. Depending on the kinetic energy window, an ultra high resolution in the sub-meV range can be detected. 

The detection system is the 2D DLD detector with x and y detection for angular resolved data and integrated 240 ps time resolution. The native repition rate is 5-8 MHz and an optional frequency entension to 50-80 MHz is available. 

The THEMIS 1000 comes with a 1000 mm drift tube. The lens system, beeing identical to the PHOIBOS 225, fits into a DN150CF flange. 

KEY FEATURES

  • Parallel Energy and Angular Detection
  • Up to ±15° Acceptance Angle
  • 2D DLD Detector with 240 ps Time Resolution
  • Up to 3500 eV Kinetic Energy
  • 1000 mm Drift Tube

MADE FOR THESE METHODS

1

SPECIFICATIONS

THEMIS 1000 2D-DLD
Performance
Energy Resolution

< 0.2 meV (theoretical, 100 ps time resolution)

Angular Resolution

< 0.1°

k-Resolution

0.1 A-1

Acceptance Angle

±15°, ±7°, ±4° and ±3°

Lateral Resolution

< 35 µm

Smallest Acceptance Spot

N/A

XPS Count Rates UHV

N/A

Detector Channels

800x800 (with Channel Binning)

Operation
Kinetic Energy Range

0-3500 eV

Pass Energies

N/A

Energy Dispersion

time -of-flight

Lens Modes

Transmission Mode, Angular Resolved Mode

Measurement Modes

Snapshot Mode, Sweeping Mode, Fixed Energy Mode

Detector

2D DLD Detector

Slits/Apertures

N/A

Energy Window

N/A

Electronics

HSA + for THEMIS

Working Pressure

10-11 to 10-7 mbar

Mounting
Working Distance

53.3 mm

Mounting Flange

DN150CF (8" OD)

Magnetic Shielding

Double µ-Metal Shielding

Electric Isolation

> 7 keV

PUBLICATIONS

  1. (2022) Electron pair emission from surfaces: Some general experimental considerations

    We discuss some experimental facets of electron pair emission from surfaces using two different experimental
    approaches. In the first case the instrument consists of a pair of hemispherical analyzers which are operated
    with continuous primary beams of electrons or photons. The second instrument employs a pair of time-of-flight
    spectrometers which require a pulsed excitation source. A key experimental quantity is the ratio of ‘true’ to
    ‘random’ coincidences which can be determined in different ways. Regardless of the type of instrument the
    primary flux has to adopt a much smaller value than in single electron spectroscopy. We describe different
    approaches to obtain the relevant count rates, in particular the concept of operating with a delayed coincidence
    circuit. We also address the question on how to compare the two types of spectrometer in terms of their
    performance.



    R. Kamrla, W. Widdra, C.-T. Chiang, and F.O. Schumann
    Journal of Electron Spectroscopy and Related Phenomena 257 (2022) 147185
    Read more
  2. (2020) Laser-based double photoemission spectroscopy at surfaces

    The recent development of double photoemission (DPE) spectroscopy at surfaces using laserbased
    high-order harmonic generation in combination with time-of-flight electron spectroscopy
    is reviewed. Relevant experimental conditions including the solid angle for collecting photoelectron
    pairs, the energy and angular resolutions, as well as the repetition rate and the photon
    energy range of light sources are introduced. As examples, we provide an overview of laser-based
    DPE results on the noble metals Ag and Cu as well as transition metal oxides NiO and CoO. The
    DPE energy and angular distributions of photoelectron pairs are compared with emphasis on the
    possible indications of electron-electron interaction. Potential further developments including
    femtosecond time-resolved DPE experiments are outlined.



    C.-T. Chiang, A. Trützschler, M. Huth, R. Kamrla, F. O. Schumann, und W. Widdra,
    Progress in Surface Science 95 (2020) 100572
    Read more
  3. (2014) Electron pair emission detected by time-of-flight spectrometers: Recent progress

    We present results for electron coincidence spectroscopy using two time-of-flight (ToF) spectrometers. Excited by electron impact, the energy and momentum distribution of electron pairs emitted from the Cu(111) surface are resolved and a spectral feature related to the Shockley surface state is identified. By combining the two ToF spectrometers with a high-order harmonic generation light source, we demonstrate double photoemission spectroscopy in the laboratory that required synchrotron radiation in the past. Utilizing this setup, we report results for (γ,2e) on NiO(001) on Ag(001) excited with light at 30 eV photon energy.



    M. Huth, C.-T. Chiang, A. Trützschler, F.O. Schumann, J. Kirschner,W. Widdra
    Appl. Phys. Lett. 104, 061602
    Read more

SPARE PARTS

1
Product image
Product description
Article No.
 
DN40CF 4-fold SMB Feedthrough for DLD

Spare electrical feedthrough for all DLD detectors. Connection flange for the ACU unit

2100011768

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