Modern Status of High Pressure Xenon
Gamma-ray Spectrometers and their
Applications.
Valery Dmitrenko1, Nobuyuki Hasebe1,2,3
1National Research Nuclear University
Moscow Engineering Physics Institute (MEPhI)
Moscow, Russia
2Department of Physics, School of Advanced Science and Engineering,
Waseda University, Tokyo, Japan
3Research Institute for Science and Engineering,
Waseda University, Tokyo, Japan
Aprile 04, 2017
Khon Kaen, Thailand
HPXe2003
High Pressure Xenon: science, detectors and applications
XeSAT2005
Applications of Rare Gas Xenon to Science and Technology
Contents
1. Introduction.
2. Xenon gas – perfect material for gamma-ray spectrometers.
3. Xenon gamma-ray spectrometers: design, principles of
operation.
4. Spectrometric and operating characteristics of Xenon gammaray spectrometers.
5. Applications of Xenon gamma-ray spectrometers.
6. Advanced developments of Xenon gamma-ray spectrometers.
7. Conclusion.
Main disadvantages of High Purity Germanium (HPGe) and
NaI gamma-ray spectrometers.
• HPGe gamma-ray spectrometers:
• Operation only at low temperature (require liquid nitrogen or
mechanical cooler);
• Difficulties for application in field conditions, space
experiments and so on;
• Limited sensitive volume;
• High cost.
• Gamma-ray spectrometers on base of NaI:
• Low energy resolution.
Xenon gas general characteristics
Element
Valence electron configuration
Atomic number


  2.36   F  W 
E 

Xe
5s2 5p6
54
1
2
Atomic weight (g/mol)
131.3
F - Fano Factor
W - mean energy for ion-electron pair production
Atomic radius (nm)
0.218
E - energy of gamma-ray
Ionizing potential (eV)
12.13
Standard density (kg/m3)
5.851
Condensing temperature at
normal pressure (°C)
-108.10
Congelation temperature (°C)
-111.85
Critical temperature (°C)
Heat capacity at 0° C
(J/(kgmoldegree)
Abundance in the air (%)
16.59
20808.4
10-5
For Gas:
For Liquid:
F = 0.2
at density 0.6 g/cm3 (60 bar)
F = 0.04
W = 20 eV
at density 0.6 g/cm3 (60 bar)
W = 15.6 eV
E = 1 MeV
E = 1 MeV
GXe = 0.5 %
LXe = 0.2 %
Ionization chamber for laboratory research
1 - signal electrode;
2 - ceramic insulators;
3 - guard ring;
4, 5 - shielding grids;
6-
207Bi
gamma-ray
source;
7 - ceramic rods;
8 - negative electrode;
9 - feedthroughs;
10 - gas input.
Drift velocity of electrical charge in Xenon gas as function of electric field
for different concentration of H2 and Xenon density 0.6 g/cm3
5
Drift Velocity, 10 cm/sec
9
2%
1.5%
1%
0.6%
0.26%
Pure Xe
8
7
6
5
4
3
2
1
0
0
2000
4000
6000
Electric field, kV/cm
8000
The W/W0 ratio as function of Xenon gas density
1
W 0 = 21 .5 eV
0. 9
W - mean energy for ionelectron pair production;
W /W
0
W0 - mean energy for ionelectron pair production
in Xe gas at the normal
pressure.
H ig h Pre ssu re Xe
0. 8
0. 7
L iq u id X e
0. 6
0
1
3
2
D e n s ity , g/ c m
3
Energy resolution of ionization chamber for laboratory research
as function of electric field for different densities of Xenon gas
8
Energy resolution, %
7
6
 = 0,60 g / cm
3
 = 0,88 g / cm
3
 = 1,42 g / cm
3
5
4
3
2
1
0
1
2
3
4
Electric field, kV / cm
5
6
The intrinsic energy resolution as function of Xenon gas density
for different gamma-ray energies
20
Energy resolution, %
18
1
2
3
4
5
16
14
12
-
122 keV
166 keV
393 keV
836 keV
1275 keV
1
2
10
8
3
6
4
4
5
2
0
0,2
0,4
0,6
0,8
1,0
1,2
3
Density, g / cm
1,4
1,6
Xenon purification system
Preliminary
purification
Fine
purification
1- vessel for unrefined
Xenon;
2 - vessel for preliminary
Ca
purified Xenon;
3 - vessel for H2 storage;
4 - vessel for purification
and storage of finally
1
2
3
4
purified Xe;
5
5 - vessel for storage of
finally prepared mixture
of Xe + H2.
Electro-spark titanium purifier of Xenon gas
1
Xe
2
1- ceramic feedthrough;
3
2 - vessel;
3 - signal electrode
4
5
7
6
output;
4 - titanic high-voltage
electrode;
5 - titanic electrode;
6 - flange;
7 - signal electrode.
Requirements to Xenon gas and intensity of electric field to reach high
spectrometric characteristics of Xenon gamma-ray spectrometers.
1. Xenon gas density has not to exceed 0.5 g/cc.
2. It is necessary to use Xenon + Hydrogen mixture (or another)
to increase the drift velocity of electrons. Percentage of
Hydrogen has not exceed 0.5%.
3. Life time of electrons in gas has to be not less than 1 - 2 msec.
4. Intensity of electric field in the drift volume has to be higher
than 2 kV/cm.
PARALLEL-PLATE IONIZATION CHAMBER “KSENIA”
MAIN PARAMETERS
Energy range
FWHM at 662 keV
0.1÷5 MeV
23 keV
Xenon density
0.6 g/cm³
Sensitive volume
1000 cm³
Diameter
250 mm
Length
300 mm
Weight
5 kg
Voltage
± 24 V
Power
5W
1 – vessel, 2 – cathodes, 3 – drift electrodes, 4 – ceramic insulator, 5 – shielding grid,
6 – anode, 7 – flange, 8 – metal-ceramic feed-through.
Gamma-ray telescope “KSENIA”
(Orbital station “MIR”, 1991 - 2000)
MAIN PARAMETRS
Xenon density
0.6 g/cm³
Concentration of hydrogen
0.26 %
Pressure of a Xenon at 23° С
55 atm
Drift electric field
2.6 кV/cm
Maximum electron drift time
15 μs
Energy range
0.1÷5 МeV
Sensitive volume
1000 cm³
Sensitive area
100 cm²
Energy resolution (662 кeV)
3.5±0.25%
Energy resolution (1 МeV)
(2.0±0.2)%
Photopeak efficiency (662кeV)
(4.5±0.2)%
Photopeak efficiency (1.33МeV)
(1.5±0.1)%
Power consumption
15 W
Weight
80 kg
Schematic diagram of HPXe detector
with shielding grid
1. Charge sensitive amplifier.
2. Valve.
3. High voltage power supply.
4. Metal-ceramic feedthrough.
5. Cylindrical ionization chamber.
6. Anode.
7. Thermal insulation.
8. Vessel.
9. aluminum housing.
1
2
3
4
5
6
7
8
9
Principle of gamma-ray spectrometer operation based
on ionization chamber filled with High Pressure Xenon
Shielding grid
Charge-sensitive
pre-amplifier
Anode
Cathode
Linear shaping amplifier +
Amplitude-digital converter
High Pressure Xenon Detector – 2 (HPXeD-2)
MAIN PARAMETERS
Energy range (50-5000) keV
FWHM at 662 keV
14 keV
Density of Xe
Sensitive volume
Diameter
Length
Total mass
Voltage
0.4 g/cm³
2000 cm³
120 mm
300 mm
9 kg
=24 V or ~220 V
Power consumption
10 W
Gamma-ray source
137Cs
14000
Counts
12000
10000
8000
6000
4000
2000
0
0
200
400
Energy, keV
600
800
Gamma-ray source
133Bа
50000
Counts
40000
30000
20000
10000
0
0
100
200
300
Energy, keV
400
500
133Ва
spectrum comparison, measured by
HPGe, CZT, NaI and HPXe gamma-ray spectrometer
ADVANTAGES OF HPXe DETECTORS
RADIATION STABILITY
20
9
7
6
1. After activation.
2. Before activation.
15
-1
Counts (sec )
-1
Counts (sec )
NaI
1. After activation.
2. Before activation.
Xe
8
5
4
3
1
2
2
1
1
10
5
2
0
0
0
200
400
600
800
1000
Energy (keV)
Spectra from High Pressure Xenon
Detector (120 mm, L=500 mm,
M= 1.8kg) before and after activation
by Pu-Be neutron source (T=66 hours,
fluence= 1.5*10¹º neutrons).
0
500
1000 1500 2000 2500 3000 3500 4000
Energy (keV)
Spectra from NaI detector ( 80
mm, L=50 mm, M=0.9 kg) before and
after activation by Pu-Be neutron
source (T= 66 hours, fluence =
1.5*10¹º neutrons).
ADVANTAGES OF HPXe DETECTORS
Linearity
Vibrostabitity
40
500
K
450
Channel
400
137
350
Cs
60
Co
300
250
133
Ba
200
150
100
226
50
0
200
400
600
Ra
800
Energy resolution, %
550
7
6
5
4
3
2
1
1000 1200 1400
Energy, keV
662 keV
1.332 MeV
40
45
50
55
60
65
70
Acoustic noise, dB
75
80
ADVANTAGES OF HPXe DETECTORS
THERMOSTABILITY
200
Generator
Channel
175
137
150
Cs
125
100
0
50
100
150
Temperature, C
200
ADVANTAGES OF HPXe DETECTORS
Channel (511 keV)
Energy resolution, % (511 keV)
LONG PERIOD OF OPERATION
Years
Years
ADVANTAGES OF HPXe DETECTORS
PRE
AMP
Ge
CSA
HPXe
NaI (Tl)
Cryostat
Ge
HPXe
NaI(Tl)
0.1- 0.4
1.5 - 3
5-8
0.1
1
Energy resolution at Eg=1 MeV, %
HPXe
-196
Ge
-200
NaI(Tl)
-150
-100
-50
+20 - +180
-20 - +60
0
50
100
150
200
o
Operation temperature, C
< 107 n/cm2
8
2
6
2
< 10 n/cm
< 10 n/cm
10
0
10
1
10
Ge
HPXe
NaI(Tl)
2
10
3
10
4
10
5
Radiation stability, neutron/cm2
10
6
10
7
10
8
RADIATION CUSTOMS CONTROL OF PASSENGERS
Portal monitor ВНИИЭМ-ПМ
(equipped with 2 liters HPXe detector)
Detection time of radionuclide
(662 keV, 50 kBq)……………….. 1 sec.
Identification time of radionuclide
(662 keV, 50 kBq) ....................... 5 sec.
Software
50000
Ba-133
Counts
40000
30000
20000
10000
0
0
100
200
300
400
500
Energy, keV
Scanning spectrum of variable energy interval.
Software
Sensitivity of the gamma-detector as
function of a scanning interval
14 keV
16 keV
20 keV
24 keV
28 keV
36 keV
46 keV
14
12
E0  x / 2
K  x 

E0  x / 2
N0
2E 2
e

K(x)
10
( E  E0 )2
2 E 2
 E0  x / 2

 E
    e dE 
 E0  x / 2

1
2
dE
8
6
4
2
0
10
20
30
40
50
x keV
60
70
80
90
100
Software
Minimum detecting time of the source 137Cs (75 kBq)
as function of distance from Xenon Gamma-ray Detector.
11
10
1000 keV
100 keV
20 keV
9
8
Time, sec
7
6
5
4
3
2
1
0
0
25
50
75
X, cm
100
125
150
Movable security checkpoint
for river and sea ports
Movable security checkpoint
for river and sea ports
RADIATION CUSTOMS CONTROL OF LUGGAGE
295 (19,3%)
Ra (1600 years)
226
351 (37,6%)
10
Counts, 1/sec
609 (46,1%)
1
768 (4,9%)
1120 (15,1%)
1238 (5,8%)
1377 (4%)
1764 (15,4%)
0,1
0,01
A clock
500
1000
1500
2000
Energy, keV
238 (43,3%)
Th (1,4*10
232
510 (22,6%)
10
10
years)
Counts, 1/sec
583 (84,5%)
727 (10,3%)
911
968
1
2614 - 1022 (100%)
0,1
200
Camera lens
400
600
800
1000
1200
Energy, keV
1400
1600
1800
RADIATION CUSTOM CONTROL OF TRANSPORT CONTEINERS
WITH DECLARED RADIONUCLIDES
140 keV
Mo
99
Counts, 1/sec
740 keV
10
778 keV
1
I
12
Counts, 1/sec
100
131
10
8
364 keV
6
284 keV
4
636 keV
0,1
722 keV
2
0,01
200
400
600
800
1000
Energy, keV
1200
1400
0
100
200
300
400
500
Energy, keV
600
700
800
Control for gaseous radionuclide pollution
from nuclear reactors
1000
from
1294 keV
700
600
Counts
3. Air-ejector ventilation
Ar
800
2. Main airway of special
ventilation.
41
900
1. Atmosphere manifold
operation
500
400
300
200
research hall.
100
4. Operation research hall.
0
500 600 700 800 900 1000 1100 1200 1300 1400 1500
5. Vertical ventilation
Energy, keV
experimental channel.
10000
85
6. Concrete protection.
8000
7. Reactor.
m
Kr
88
Kr
9. Horizontal ventilation
Counts
135
8. Moderator – water.
6000
138
above reactor space.
Xe
41
4000
experimental channel.
10. Air-ejector ventilation
Xe
Ar
87
Kr
2000
0
200
400
600
800
1000
Energy, keV
1200
1400
Control of KCl concentration in process
of potassium chloride fertilizer manufacturing
2.0
1.8
3
Counts (10 )
1.6
1.4
200 keV
1.2
1.0
1.46 MeV
0.8
0.6
0.4
0.2
0.0
0
200
400
600
800 1000 1200 1400 1600
Energy, keV
580 000
1.
2.
3.
4.
5.
6.
Waterproof container
HPXe detector
Lead collimator
Drain
KCl and NaCl solution
Rotor
Counts
575 000
570 000
565 000
560 000
555 000
550 000
70
80
90
100
110
Temperature, 0С
120
EXPERIMENT “SIGNAL”
ON SOLAR MISSION “INTERGELIOPROBE”
Прибор «Сигнал»
38
SOLAR MISSION “INTERGELIOPROBE”
TRAJECTORY
39
PERSPECTIVE FIEIDS OF APPLICATION
• RADIOACTIVE WAIST RECICLING AND STORIGE
Хранилище
Детектор
рентгеновский тамограф
• MEDICINE
Measurement of douse radiation of a patient with taking
into account of gamma-ray spectrum distribution.
• PREVENTIOM OF RADIOLIGICAL TERRORISM.
- Installing of gamma-ray spectrometers on ventilation
systems and water supply stations.
- Control for shipping of radioactive sources at the airports,
tracks and cars terminals, railroad stations and so on.
центральный кондиционер
Advanced gamma-ray detectors technology
Xenon gamma-neutron detector
Gamma-ray detector filled on
with Xenon+Helium-3 mixture.
Interaction of neutrons with
Helium-3 through reaction:
4
2,0x10
4
Counts
1,5x10
Thermal neutrons
137
Cs
3
2
4
1,0x10
3
5,0x10
0,0
200
400
600
Energy, keV
800
1000
He 10 n13H 11p
Energy yield of this reaction
is 765 keV,
Interaction Cross-section of
thermo neutrons with 3Не - 5327
barn.
Advanced gamma-ray detectors technology
Thin-walled vessel of xenon gamma-ray detector
The wall of the body was made of 0,8 mm stainless steel covered with 2.5 mm of
synthetic fiber (Kevlar) and successfully tested under pressure more than 400 atm.
Advantage of construction:
Total mass three times smaller;
Compton scattering in the wall decreased ;
Energy range widened to low energies.
Manufacturing technology of thin-walled housing
of Xenon gamma-ray detector
- The thickness of the steel housing 0.5 mm.
-The outer shell material: carbon fiber, Kevlar
or fiberglass. Thickness 2 mm.
-This housing can withstand the pressure
more than 400 atmospheres.
Electrical signals from HPXe detector
under high acoustic impact
Electrical signals from the HPXe detector
from 137Cs gamma-ray source at the level of the acoustic impact of ~ 90 dB
Methods of mathematical processing
electrical signals from HPXe gamma-ray detector
1) Digitalization and memorizing the signal.
Continuous storing digitized electrical signals.
Thus in addition to the wanted signal, and
stored voltage values before and after its arrival,
which makes it possible to implement a number
of mathematical operations.
2) Finding the beginning of the pulse.
By setting the required amplitude threshold
determined by the timestamp, which is
attached to all further calculations
3) rejection of superimposed signals.
This consists of each signal in the study for
the presence therein of two or more pulses
that are close in time of arrival.
Methods of mathematical processing
electrical signals from HPXe gamma-ray detector
4) Compute baseline subtraction.
By approximating the linear dependence of digitized voltage values before and after the
arrival of the useful pulse baseline is calculated, which is then subtracted from the
corresponding value of the desired signal.
5) Analysis of pulse front time.
At this stage, the calculation and analysis of the pulse edge time, and if it does not fall in the
desired range of values (time corresponding to desired signals), this impulse is excluded
from further processing. If the rise time corresponds to the desired signal, this value is used
to correct the amplitude of the total in the integration the pulse.
6) The integration of the pulse and the spectrum set.
After subtracting the baseline occurs useful signal integration within the established time
limits. Then, the amplitude distribution (spectrum) is formed on the basis of the obtained
integral values.
7) Calculation of the dead time of the spectrometer.
The time during which each pulse is processed, and the spectrometer does not register the
following event, is summed, and the value of "dead time“ is taken into account in the
processing of the spectra.
Xenon gamma-ray detector with a wall thickness
of 0.5 mm stainless steel
- For a detector with a wall thickness of 0.5 mm fraction of absorbed gammarays with energy 59.5 keV (241Am) is three times smaller than for the detector
with a wall thickness of 3 mm stainless steel.
- The range of detected gamma-rays extended to 30 keV-3 MeV.
The energy resolution of HPXe detector with
the digital processing of electronic pulses at acoustic impact
Using the digital pulse processing instead of analog allowed to make HPXe gammaray detector practically insensitive to the acoustic impact of up to 90 dB.
The results of the gamma-ray lines detection of with energies 662 keV and 1133 keV
differ slightly.
The energy resolution of HPXe gamma-ray detector
with digital pulse processing
The values obtained for the energy resolution of HPXe gamma-ray detector, in
particular the value of (1,7 ± 0,1)% or 11,2 keV for the 662 keV gamma-line
are by far a record for this type of equipment.
Contribution to energy resolution in case
using analog and digital signal processing
Contribution to energy resolution in
case using analog signal processing.
It shows data for the energy 662 keV.
The resulting energy resolution –
15,3 keV (2,3 %).
Contribution to energy resolution in
case using digital signal processing.
It shows data for the energy 662 keV.
The resulting energy resolution –
11,3 keV (1,7 %).
CONCLUSIONS
• Xenon gamma-ray spectrometers have high spectrometric
and performance characteristics and in many cases can
successfully compete with existing gamma-ray
spectrometers.
• Numerous testes of Xenon gamma-ray spectrometers
carried out at different organizations confirmed the
reasonability to use them more widely.
• there are some perspective in further developing of
spectrometric and performance characteristics of Xenon
gamma-ray spectrometers.
• THANK YOU FOR YOUR ATTENTION
МОБИЛЬНАЯ УСТАНОВКА ДЛЯ
СОРТИРОВКИ РАО
РАДИОАКТИВНЫЙ КОСМИЧЕСКИЙ МУСОР
55
РАДИОАКТИВНЫЙ КОСМИЧЕСКИЙ МУСОР
Распределение космического мусора на высотах от 100 до 2000 км
56
Gamma-ray telescope "Xenia"
1. anode,
2. shielding grid,
3. cathode,
4. drift electrodes,
5. ceramic isolator,
6. stainless still vessel,
7. high-voltage feethrough,
8. flange.