THE FAST XRAY MONITOR FXM BASED ON YAP:CE SCINTILLATOR YTTRIUM ALUMINUM PEROVSKITE ACTIVATED BY CERI

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THE FAST X-RAY MONITOR (FXM) BASED ON YAPCE
SCINTILLATOR (YTTRIUM ALUMINUM PEROVSKITE
ACTIVATED BY CERIUM)FOR THE CORONAS-PHOTON
SATELLITE PROJECT
E. Fedorovykh
Astrophysics Institute at Moscow
Engineering-Physics Institute, RUSSIA
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Instrument FXM

• Goals of experiments
• Fast monitoring of hard X-ray Solar radiation in
  the energy range of 20 600 keV with
  2 3 ms time resolution
• Registration of Solar flare X-ray radiation
  temporal profile in 6 differential and 2 integral
  energy sub-bands.

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FXM block-diagram

• Instrument FXM consists of
• detection block FXM-D,
• high-voltage source
• block HVS-5,
• electronic block FXM-EM.
• Blocks FXM-D, HVS-5 are installed on an
  extendable platform.
• Block FXM-EM is installed in a pressure
  compartment.

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Detection block FXM-D
FXM-D onboard CORONAS-PHOTON

• Overall dimensions 366x204x122 mm,
• Weight 5 kg.

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Detection block FXM-D
Collimator (field of view 6)
Light-emitting diode board
PMT
Discriminator block
Divider
Preamplifier
Scintillator YAPCe
Stabilization block
Ø70mm
10mm
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Properties of YAPCe
Thickness of crystal 10 mm
YAPCe yttrium aluminum perovskite with cerium,
YAlO3(Ce)
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Energy spectra of YAPCe
Counts
Counts
Channel
Channel
Energy spectrum of the radioactive source Am241.
The crystal thickness was 10 mm.
Energy spectrum of the radioactive source Cs137.
The crystal thickness was 10 mm.
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Detection block FXM-D
Stabilization block The measurement channel is
stabilized using precise impulses from the light
source (light-emitting diode) placed in the
collimator in front of the crystal. The system
stabilization reaction time is 0,1 s. This system
controls the PMT power supply. This helps one to
avoid the influence of output characteristics at
high count rate.
Discriminator block Signals from preamplifier
separated according to their amplitude into six
differential channels. Two integral channel are
provided too.
Output waveform Rise time 38 ns Fall time 116 ns
500 mV
100 ns
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High voltage source block HVS-5
Block HVS-5 is adjustable high voltage source
with range from 900 V to 1900 V. Controlling is
realized by external control signal 0 - 10 V,
generated in the stabilization block.

• Overall dimensions 225x190x57 mm,
• Weight 2 kg.

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Electronic block FXM-EM

• Block FXM-EM realize following functions
• low voltage supply to FXM-D and HVS-5 blocks
• change of data acquisition time interval
  (temporal resolution) by means of control code
  words (UKS)
• counting of events in FXM-D channels, recording
  to data frames and transfer to the Scientific
  data acquisition and registration system (SSRNI).

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Conclusion
At present FXM has passed almost all
preflight tests. Flight model is under making
now. FXM Web-page http//iaf.mephi.ru
/coronas-photon_brm.htm