High resolution x-ray spectroscopy using germanium microcalorimeters

Conference · Wed Jul 26 04:00:00 EDT 1989

OSTI ID:5828118

Silver, E; Labov, S; Goulding, F; Madden, N; Landis, D; Beeman, J; Pfafman, T; Melkonian, L; Millett, I; Wai, Y

We are developing cryogenically-cooled microcalorimeters for high resolution x-ray spectroscopy. Using neutron transmutation-doped (NTD) germanium thermistors as the x-ray absorber, we have achieved an energy resolution of 70 eV at a temperature of 0.3 K. There is strong evidence for incomplete conversion of x-ray energy into thermal energy when the photon is absorbed in the bulk of the NTD germanium. We believe that the nonthermal energy component manifests as ionization, none of which is converted to thermal energy within the measurement time of the system. As in an ionization detector, the division between ionization and thermal energy is statistically uncertain and leads to a lower limit to the energy resolution measured using either the thermal or ionization signal. Complete conversion to thermal energy with no loss to ionization appears to occur when the x-ray is absorbed by the metallic contacts. This will be discussed in the context of our most recent 0.3 K experiments. 20 refs., 11 figs.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5828118
• Report Number(s): UCRL-101721; CONF-890836-14; ON: DE89017784
• Country of Publication: United States
• Language: English

Related Subjects

440300* -- Miscellaneous Instruments-- (-1989)
47 OTHER INSTRUMENTATION
640101 -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ADIABATIC DEMAGNETIZATION
CALORIMETERS
ELEMENTS
ENERGY RESOLUTION
GERMANIUM
MEASURING INSTRUMENTS
METALS
RESOLUTION
SEMICONDUCTOR DEVICES
SPECTROSCOPY
THERMISTORS
ULTRALOW TEMPERATURE
X-RAY SPECTROSCOPY