Bolometer projects

1
New technology detectors for space and
Earth-based applications

• HESA consortium develops new technology
  detectors for X-ray
• cameras of future space telescopes, which will be
  able to observe the
• earliest black holes and galaxies in the Universe
  13 billion years ago
• Developed technology is also useful for new
  types of X-ray and
• infrared cameras in industrial and medical
  applications.

2
Superconducting hot-spot bolometers
Detectors for sub-mm wavelength cameras
Room temperature bolometer

• Air-bridge structure fabricated from niobium, a
  superconductor below 9 K
• Sensitivity ten times better than state of the
  art at 4K

• Imaging micro-bolometer array
• Works in room temperature
• ten times better than previous infrared detectors

3
Applications of sub-mm bolometers

• Remote, planetary atmospheric sensing (ESA)
• Solar observations (flare eruptions, similar to
  X-rays)
• Concealed weapon detection
• Detection of shallow buried landmines
• Passive imaging of targets in poor weather
• Early detection of skin cancers
• Signature analysis of biological and chemical
  weapons

4
TES X-ray calorimeters (TES Transition Edge
Sensor)

• Enables detailed analysis of
• material composition and even chemical state by
  very high
• resolution X-ray spectroscopy
• Applies superconducting detectors
• - Operates at very low temperatures
• (below 0.1 K, almost absolute zero)

5
X-ray calorimeter applications
Analysis of materials through X-ray fluorescence
Detectors for future X-ray satellites (XEUS)
- micro-analysis of elements and detection of
chemical shifts of compounds

• Detection of the first black holes in
• the Universe
• Age determination of early galaxies by accurate
  determination of red-shift
• Studies of the evolution of early black holes in
  the Universe

Scanning electron microscope
Electron beam
TES-based X-ray spectrometer
Characteristic X-ray radiation
Impurity particle
Integrated circuit being fabricated
6
SQUID-based detectors for medical diagnostics and
brain research

• Magnetoencephalography (MEG) brain scanner
• measures electrical currents in brain (neural
  currents) with super-sensitive SQUID detectors
• device by Neuromag, SQUIDs by VTT

• Magnetic Resonance Imagers (MRI)
• - New SQUID detectors enable 3D-imaging of human
  brain with a million times weaker magnetic field
  than traditional MRI
• - Hydrogen (water) content in brain tissue is
  measured (MRI), but also phosphorus can be
  measured (fMRI, functional MRI)

7
Other related development areas by HESA

• Thallium bromide and its application for hard
  X-ray detectors (Department of Chemistry/Universit
  y of Helsinki, Metorex International)
• Development of microscale diffractive grids for
  infrared wavelength filtering (Department of
  Physics, University of Joensuu, Metorex
  International)
• Development of detector control electronics for
  XEUS X-ray instruments (Patria new Technologies)

8
More information

• Juhani Huovelin, Docent, Helsingin yliopisto
• tel. [phone]
  juhani.huovelin_at_helsinki.fi
• Heikki Sipilä, CTO, Metorex
• tel. [phone], heikki.sipila_at_metorex.fi
• Heikki Seppä, Professor, VTT
• tel. [phone], heikki.seppä_at_vtt.fi