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BARC

Proportional counter for soft X ray/ gamma ray energy Spectroscopy


The X ray proportional counting system is useful for measurements of soft X-rays/gamma rays from isotopic sources as well as X-ray generator. Detector is based on a gas filled proportional counter and can be operated in sealed and flow type operation. It counts the number of X-rays as well as capable of recording an energy spectrum of the source with 10% of FWHM energy resolution at energy of 14.4 keV. X-ray proportional counters show high resolution performance at X-ray energies < 50 keV. This feature makes these detectors ideal for X-ray fluorescence spectroscopy, thin film thickness gauging and Mossbauer studies. Pulse mode operation also enables to record small variation in X-ray energy as essential for Mossbauer experiments. It can be also used in X-ray diffraction experiments with step scan method to record x-ray intensity verses 2Θ angular distribution of diffracted X-rays. is useful for measurement of X ray energy spectrum, intensity of X rays.

Parties with experience and interest in building nuclear radiation detectors / sources are invited.

SPECIFICATIONS
  1. Cathode 2S Al 6061 T6
  2. Anode 25 µm diameter, Tungsten
  3. Fill gas: Ar + CH4 (9:1) at 1 bar
  4. 100% detection efficiency for < 50 keV
  5. Dynamic range 3 to 50 keV
  6. Energy Resolution 10-12 % of FWHM at 14.4 keV energy
  7. Be window 250 µm thick transmission ~99 % for X ray energy 10-50 keV
  8. Low background: 3-4 counts/minute
  9. Anode bias plateau length~ 400 V
  10. Anode Bias ~1800 V
  11. Count rate capability: 104 CPS
  12. Dead time: 1 µsec
APPLICATIONS
  1. Detector is capable of measuring intensity and an energy spectrum of the X-rays/gamma ray source with 10-12 % of FWHM energy resolution at energy of 14.4 keV. X-ray proportional counters show high resolution performance at X-ray energies < 50 keV.
  2. This feature makes these detectors ideal for X-ray fluorescence spectroscopy, thin film thickness gauging and Mossbauer studies. Pulse mode operation also enables to record small variation in X-ray energy as essential for Mossbauer experiments.
  3. It can be also used in X-ray diffraction experiments with step scan method to record x-ray intensity verses 2 Θ angular distribution of diffracted X-rays. is useful for measurement of X ray energy spectrum, intensity of X rays.
  4. The gas filled detectors show good efficiency at the lower energy range and eventually no high energy noise is observed as compared solid state detectors.

Proportional counter for soft X ray/gamma ray energy Spectroscopy is useful for measurements of intensity and energy spectrum of soft X-rays/gamma rays from isotopic sources as well as X-ray generator.

  1. Detector is based on a gas filled proportional counter and can be operated in sealed mode
  2. Detector consists of a gas filled coaxial cylindrical cathode, fine anode (25 µm diameter, W) and Be window with 99% transmission for soft X ray.
  3. It is useful for recording an energy spectrum of the X-rays/gamma ray source with 10% of FWHM energy resolution at energy of 14.4 keV. X-ray proportional counters show high resolution performance at X-ray energies < 50 keV.
  4. Detector calibrated with known source energies is useful for measurement of energy of unknown sources and variation in energy spectrum caused by experimental conditions.
  5. Proportional counting mode ensures good signal to noise ratio, better counting accuracy and good energy resolution.
  6. A simple data acquisition system consists of preamplifier, amplifier, counter scalar and multichannel analyzer to record the data.

Detector is capable of measuring intensity and an energy spectrum of the X-rays/gamma ray source with 10-12 % of FWHM energy resolution at energy of 14.4 keV. X-ray proportional counters show high resolution performance at X-ray energies < 50 keV. This feature makes these detectors ideal for X-ray fluorescence spectroscopy, thin film thickness gauging and Mossbauer studies.


Proportional counter for soft X ray/gamma ray energy Spectroscopy is useful for measurements of intensity and energy spectrum of soft X-rays/gamma rays from isotopic sources as well as X-ray generator.

  1. Detector is based on a gas filled proportional counter and can be operated in sealed mode
  2. Detector consists of a gas filled coaxial cylindrical cathode, fine anode (25 µm diameter, W) and Be window with 99% transmission for soft X ray.
  3. It is useful for recording an energy spectrum of the X-rays/gamma ray source with 10% of FWHM energy resolution at energy of 14.4 keV. X-ray proportional counters show high resolution performance at X-ray energies < 50 keV.
  4. Detector calibrated with known source energies is useful for measurement of energy of unknown sources and variation in energy spectrum caused by experimental conditions.
  5. Proportional counting mode ensures good signal to noise ratio, better counting accuracy and good energy resolution.
  6. A simple data acquisition system consists of preamplifier, amplifier, counter scalar and multichannel analyzer to record the data.

PRINCIPLE OF OPERATION

Gas filled proportional counters are commonly used in detection of X-rays, as they can be built in any size and shape, have relatively good energy, high efficiency, good uniformity over the sensitive volume, shows no radiation damage and very low intrinsic background as compared to the solid state and scintillation detectors.

The detection process used for low energy photon (Ep) in the range of 3 keV to 50 keV, is its complete absorption of photon by an inner shell electron. The secondary effects used for detection process are:

  1. The photoelectric effect in which photoelectron is emitted. (hv)
  2. Photoelectron carries the energy of photon, less the binding energy of electron, Eb
  3. Energy of photoelectron is hv- Eb, it ionizes the gas medium
  4. The ionization of gas leading to production of electron and positive ion pairs.
  5. Primary charge of electrons, carried the energy information of photon, drifts to anode and avalanche formation occurs.
  6. Secondary charge cloud forms electrical pulse on the feedback capacitor of charge sensitive preamplifier

SPECIFICATIONS

  1. Cathode 2S Al 6061 T6
  2. Anode 25 µm diameter, Tungsten
  3. Fill gas: Ar + CH4 (9:1) at 1 bar
  4. 100% detection efficiency for < 50 keV
  5. Dynamic range 3 to 50 keV
  6. Energy Resolution 10-12 % of FWHM at 14.4 keV energy
  7. Be window 250 µm thick transmission ~99 % for X ray energy 10-50 keV
  8. Low background: 3-4 counts/minute
  9. Anode bias plateau length~ 400 V
  10. Anode Bias ~1800 V
  11. Count rate capability: 104 CPS
  12. Dead time: 1 µsec
APPLICATIONS
  1. Detector is capable of measuring intensity and an energy spectrum of the X-rays/gamma ray source with 10-12 % of FWHM energy resolution at energy of 14.4 keV. X-ray proportional counters show high resolution performance at X-ray energies < 50 keV.
  2. This feature makes these detectors ideal for X-ray fluorescence spectroscopy, thin film thickness gauging and Mossbauer studies. Pulse mode operation also enables to record small variation in X-ray energy as essential for Mossbauer experiments.
  3. It can be also used in X-ray diffraction experiments with step scan method to record x-ray intensity verses 2Θ angular distribution of diffracted X-rays. is useful for measurement of X ray energy spectrum, intensity of X rays.
  4. The gas filled detectors show good efficiency at the lower energy range and eventually no high energy noise is observed as compared solid state detectors.
REQUIREMENTS FOR COMMERCIAL PRODUCTION

Infrastructural Requirements

  1. About 500 sq feet (~ 25 x 20 sq. ft) roofed area with proper cleanliness, dust proof with controlled temperature (25±1°C) and humidity (<55%) with continuous power.

EQUIPMENTS

  1. Workshop facility for Al machining such as milling machine, lathe machine and turning machine, Al brazing
  2. Wire mounting assembly with uniform tension
  3. Vacuum System with diffusion pump/Turbo Molecular Pump with Rotary backing, vacuum and pressure gauge.
  4. Pinching tool for 3.2 mm dia Cu tube (~40 kg fine control pressure)
  5. Flame solder station (torch) with LPG and air compressor
  6. Metallic manifold with 6 valve terminals for mounting detector and fill gas cylinder
  7. Outgassing oven ~ 70 °C
  8. Ar + CH4 (P-10) Gas cylinder and gas regulator
  9. Test setup with HV, preamplifier, amplifier, counter scalar, MCA and oscilloscope
  10. X-ray sources for calibration Co57 (6.3 and 14.4 keV) or 55Fe (5.9 keV)

Consumables

  1. Raw material Al tubes and rods
  2. tungsten wire
  3. Tungsten spring
  4. Ceramic feed through
  5. P10 gas
  6. Process chemicals (trichloroethylene, NaOH solution, alcohol, acetone, silicon grease)
  7. Liquid Nitrogen for vacuum system

MANPOWER REQUIREMENT

  1. One M.Sc. (Physics) or equivalent degree with experience in handling radiation sources and test electronics.
  2. Two technicians trained in turning, fitting, vacuum pump handling and thin wire handling/ soldering.

Electrical Power Requirement:

  1. 220 V, 50 Hz, Single phase, 15 A

Precautions

  1. Test area should be covered by personnel radiation monitoring badges.
Application Procedure
BARC Technologies
A completely assembled X ray proportional counter
BARC Technologies
Energy spectrum of 57Co gamma ray source
BARC Technologies
Schematic of detector test setup for data acquisition