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Next Generation Electron Momentum Spectrometer for Small Spot ARPES and Momentum Microscopy

The KREIOS 150 MM is a new generation of electron spectrometers for high performance ARPES and PEEM. The unique lens systems combines and immersion lens for PEEM operation with a hemispherical energy analyzer scanning system for unrivaled ARPES measurements. Its lens system aquired the fill half sphere of the electron emission for ultimate angular acceptance of 180°.

The KREIOS 150 MM comes with a special lens system for momentum microscopy, showing a constant energy map or a real space map on the detector. Integrated deflectors allow changing the microscopy spot without moving the sample. The lens system features apertures to refine the k-space into high contrast and dark field PEEM, as well as field apertures to select a spatial region for µ-ARPES down to 2 µm field of view. The kinetic energy up to 1500 eV allows XPS and XPEEM measurements. With the new CMOS detector the KREIOS 150 is the most performing ARPES analyzer available. Due to the design of the KREIOS lens system and hemisphere, no artificial aberration correction is needed. Instead a second hemisphere can be upgraded to enhance the energy resolution or the electron transmission.

With a 2D CMOS detector is shows outstanding performance in countrate, linearity and a true pule counting mechanism. It combines a state of the art lens system with a proven hemipshere design for highest transmission and resolution.

This analyzer features the mometum microscopy mode for data aquisition. For enhanced energy resolution or transmission a special MM Twin version is available. For Spectroscopy, the KREIOS 150 can be used fully in spectroscopy mode.


  • Ultimate Acceptance Angle
  • Momentum Microscopy Mode
  • µ-ARPES with down to 2 µm
  • PEEM Operation with < 50 nm resolution
  • 0.008 Å-1 momentum resolution
  • large Field of View




Kinetic Energy Range

0-1500 eV

Pass Energies

1-200 eV Continously Adjustable

Magnetic Shielding

Double µ-Metal Shielding

Energy Dispersion


Lens Modes

PEEM Mode, Momentum Resolved Mode

Measurement Modes

Snapshot Mode, Sweeping Mode


2D CMOS Detector with Spin Option


8 positions for apertures and slits

Energy Window

13% of Pass Energy

Electric Isolation

> 3.5 keV, 29 keV on lens system



Working Pressure

10-11 to 10-7 mbar

Energy Resolution

< 25 meV in MM Mode
< 10 meV in Spectroscopy Mode

Angular Resolution

< 0.1° for 0.1 mm emmission spot for He I


0.008 Å-1 for 0.1 mm emmission spot @ He I

Acceptance Angle

±90° full cone

Lateral Resolution

50 nm

Smallest Acceptance Spot

2 µm

Detector Channels

1285 x 730 (with Channel Binning)

Field of View

2µm (with aperture) to 200 µm
special PEEM mode with 1000 µm

Working Distance

4-10 mm

Mounting Flange

DN150CF (8" OD)


  1. (2023) Performance of a photoelectron momentum microscope in direct- and momentum-space imaging with ultraviolet photon sources

    Chuang, T.-H., Hsu, C.-C., Chiu, W.-S., Jhuang, J.-S., Yeh, I.-C., Chen, R.-S., Gwo, S. & Wei, D.-H.
    J. Synchrotron Rad.
    Read more
  2. (2022) Fermiology and Origin of Tc Enhancement in a Kagome Superconductor Cs(V1 − xNbx)3Sb5

    Kagome metals AV3Sb5 (A=K, Rb, and Cs) exhibit a characteristic superconducting ground state coexisting with a charge density wave (CDW), whereas the mechanisms of the superconductivity and CDW have yet to be clarified. Here we report a systematic angle-resolved photoemission spectroscopy (ARPES) study of Cs(V1xNbx)3Sb5 as a function of Nb content x, where isovalent Nb substitution causes an enhancement of superconducting transition temperature (Tc) and the reduction of CDW temperature (TCDW). We found that the Nb substitution shifts the Sb-derived electron band at the Γ point downward and simultaneously moves the V-derived band around the M point upward to lift up the saddle point (SP) away from the Fermi level, leading to the reduction of the CDW-gap magnitude and TCDW. This indicates a primary role of the SP density of states to stabilize the CDW. The present result also suggests that the enhancement of superconductivity by Nb substitution is caused by the cooperation between the expansion of the Sb-derived electron pocket and the recovery of the V-derived density of states at the Fermi level.

    Takemi Kato, Yongkai Li, Kosuke Nakayama, Zhiwei Wang, Seigo Souma, Fumihiko Matsui, Miho Kitamura, Koji Horiba, Hiroshi Kumigashira, Takashi Takahashi, Yugui Yao and Takafumi Sato
    PHYSICAL REVIEW LETTERS 129, 206402 (2022)
    Read more


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