Advanced Materials

FOLGAT AG has long-year proofed and long-term joint operation partnership with the Institute for Single Crystals of the National Academy of Sciences of Ukraine

Business management Technology development team Business Efficiency Field of Applications
  • 25 years experience at FSU and Ukraine market
  • 17 years experience at International scintillator market
  • 15 years experience of International large scale project management in Japan, Europe, USA
  • 3 Dr. Sci and 9 Ph.D Scientists and Technologists.
  • U.S. and PCT patents “umbrella”
  • 30 years experience in crystal growth R&D and production
  • 2 key person from the top level of “scintillator development community”
  • The technology allows the growth of single crystals dia 500 mm and 500 mm height
  • Technical platform (capacities) to grow up to 25 tons of crystal per year
  • Unique technology   Þ   uniform crystal   Þ    perfect product
  • Own raw material source
  • Crystal processing and detector assembling infrastructure
  • Industrial & Security Applications
  • Microelectronics Screening
  • Nuclear and HE Physics
  • Medical Imaging

 

Products and Services 

Single Crystals Scintillation Detectors Plastic Scintillators Devices
  • NaI(Tl)
  • CsI(Na)
  • CsI(pure)
  • LiI(Eu)
  • Stilbene
  • Detection:
  • Alpha
  • Beta
  • Gamma
  • Neutrons
  • Standard
  •  Assemblies
  •  X-ray
  •  Well-type
  •  Ruggedized
  •  Custom-made
  • PST based
  • Ultrafast
  • Radiation hard
  • Molded
  • Casted
  • Shifters
  • Spectrometers
  • Gamma cameras (SPECT)            

Introduction

Common scintillators used for radiation detection include inorganic crystals, organic plastics and liquids. However, many materials scintillate at some level; scintillation of liquid xenon and neon plays a role in some ultra-low-background experiments. Most scintillators for common use are either inorganic crystals or plastics, the most common being thalium-doped sodium iodide crystals, which have a high radiation-to-light conversion efficiency. However, organic liquid scintillating fluids are well-suited for detecting very low energy particle radiation such as beta radiation from tritium by simply immersing the sample to be tested in the scintillation fluid, thereby negating detector absorption problems due to the very short mean free paths associated with low energy particles. 

Types of Scintillators

  1. Inorganic crystals
  2. Plastic scintillators
  3. Organic crystals
  4. Liquid scintillators

Single Crystals

    Alkali - Halide Scintillators

NaI(Tl) 
The necessity to use NaI(Tl) crystals in sealed units is counterbalanced by the fact that they have the greatest light output among all the scintillators and a convenient emission range coinciding with a maximum efficiency of photomultipliers with bialkali photocatodes. Moreover, large-size NaI(Tl) crystals can be produced at a low cost.

CsI(Na)
CsI(Na) is a good alternative for NaI(Tl) in many standard applications because it has a high light output (85% of that of NaI(Tl)), the emission in a blue spectral region coinciding with the maximum sensitivity of the most popular PMT with bialkali photocatodes, and hygroscopicity substantially lower than that of NaI(Tl).

CsI(Tl)
Since the maximum of emission spectrum is at 550 nm, photodiodes can be used to detect the emission. Because a scintillator-photodiode pair can be used, it is possible to reduce significantly the size of the detection system, to do without a high-voltage power supply, and to use the detection system in magnetic fields.

CsI(CO3)
We offer a new scintillation material, CsI(CO3). The light output in gamma-excitation is 60% that of NaI(Tl). The decay time varies from 1.4 to 3.4 ms depending on the dopant concentration. These characteristics allow CsI(CO3) to be used in combination with other scintillators in phoswich detectors. CsI(CO3) has an afterglow of 0.05% after 5 microSec.

Undoped CsI
The decay time is ~10 ns. Undoped CsI can be effectively used for experiments in medium- and high-energy physics.

Selector Guide for Alkali Halide Scintillators

Material Important properties Applications comments
NaI(Tl) Very high light output, good energy resolution General scintillation counting, monitoring, health physics, environmental high temperature use
CsI(Tl) Non-hygroscopic, rugged, long wavelength emission Particle - & high energy physics, general detection, photodiode readout, phoswiches
CsI(Na) High light output, rugged Geophysical
CsI(pure) Fast, non-hygroscopic, radiation hard High energy physics (calorimetry)
CsI(CO3) Medium decay time, low afterglow Gamma-detection, phoswich detectors
LiI(Eu) High neutron cross-section, high light output Thermal neutron detection and spectroscopy

 

Physical Properties of Alkali Halide Scintillators

........... NaI(Tl) CsI(Na) CsI(Tl) CsI(undoped) CsI(CO3) 6LiI(Eu)
Density [g/cm3] 3.67 4.51 4.51 4.51 4.51 4.08
Melting point [K] 924 894 894 894 894 719
Thermal expansion coefficient [K-1] 47.4x106 49x106 49x106 49x106 49x106 40x106
Cleavage plane <100> none none none none <100>
Hardness (Mho) 2 2 2 2 2 2
Hygroscopic yes yes slightly slightly yes very
Wavelength of emission maximum [nm] 415 420 550 310 405 470
Refractive index at emission maximum 1.85 1.84 1.79 1.95 1.84 1.96
Light output [% of NaI(Tl)](for gamma rays) 100 85 45 5-6 60 30-35
Primary decay time [microSec] 0.23 0.63 1 0.01 2 1.4
Afterglow (after 6 microSec) [%] 0.3-5 0.5-5 0.1 - 0.06 -
Lower wavelength cutoff [nm] 300 300 320 260 300 425

 

    Plastic Scincillators

Plastic scintillators are a solid solution of luminophors (luminescent additives), in a transparent polymer (polystyrene (PST)). Many characteristics of plastic scintillation materials (light output, transparency to own emission, decay time, radiation resistance) can be varied by changing their composition. Polystyrene-based scintillators Scintillators with a polystyrene matrix are used to detect alfa-, beta, and gamma- radiation, and fast neutrons. Plastic scintillators are prepared by bulk polymerization in aluminium (size up to 3.5 m) or glass cast and by pressure molding technique.

  • fast plastic scintillation material: decay time from 0.9 to 0.5 ns, light output 55-50% of anthracene;
  • plastic scintillation material having the slow decay component: decay time from 300 to 400 ns, light output 45-40% of anthracene;
  • radiation hard plastics (UPS-92RH with dia.16x10 мм has 50 % of the initial light output after irradiation at 18 МRad);
  • plastic scintillation material of elevated radiation resistance;
  • scintillation polystyrene with the light scattering additive;
  • scintillation material for dosimetry;
  • scintillation polystyrene containing soluted organic compounds of heavy elements (Pb -12%, Sn -10%).
Properties Polystyrene (PST)
Density [g/cm3] 1.06
Refractive index 1.06
Absorption coefficient [cm-1] 0.01-0.003
Softening temperature [K] 355-360
Hygroscopic no
Wavelength of emission maximum [nm] 430
Light output [% of anthracene] 5
H/C ratio 1.0
Decay time [ns] 2-3

 

Selector Guide for Plastic Scintillators

Scintillators Important properties Applications comments
UPS-89, UPS-923A, UPS-90, UPS-96 Very high light output, good transparency, short decay time General purpose, particle detection
UPS-92S Slow decay time Phoswiches
UPS-91F Ultra fast decay time High energy physics, calorimetry
UPS-92RH Radiation hard High energy physics, calorimetry
UPS-96M Pressure molding technique, very cheap High energy physics, calorimetry

 

Physical Properties of Plastic Scintillators

Scintillators Light output % anthracene Wavelength of max. emiss., nm Rise time, ns Decay time, ns Light attenuation length, cm Analoges
UPS-89 65 418 0.9 2.4 360 NE102A
UPS-923A 60 425 0.9 3.3 400 BC400, NE114
UPS-90 50 418 1.0 3.5 400 NE110
UPS-92S 44 380 0.9 380-450 350 BC412, NE115
UPS-91F 39-45 390 0.7 0.6-0.4 350 PilotV, BC422Q
UPS-92RH 60 425 - 3.5 - SCSN81
UPS-96M 55 418 1.0 3.5 25 none
UPS-97G 60 425 0.9 3.3 60 BC444
UPS-971 55 425 0.9 - 400 none
UPS-972 44 435 0.9 - 400 none
UPS-973 45 445 0.9 - 400 none

 

PRESENTATION

Our Address

Melsunger Str.9, D-60389, 

Frankfurt am Main, Germany

tel: +496995297164, fax: +496995297165

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