J. Plasma Fusion Res. SERIES, Vol.3 (2000) 274-276

Distance-Monitoring of Absorption dose on Materials
under lon lrradiation
KALANTARYAN Oganes V., KONONENKO Sergey I.* and MURATOV Vladimir I.
Kharkov State University, Svobody Sq., 4, 310077, Kharkov, (Jkraine(Received: 18 January 2000 / Accepted: 28 September 2000)

Abstract

It was obtained that ionluminescence spectra of SiO2 changed essentially under the proton
bombardment. The relation between the light intensity and the implantation dose was determined. Thenovel method for monitoring proton dose (up to 3 x l02l particles/cm3) in quartz was proposed.

Keywords:
ionluminescence, defects, band, silica, irradiation dose, hydrogen

1. Introduction

In visible range the luminescence spectra of silica(induced by different sources) consists of two widebands. The first band maximum lays near 455 nm ofwavelength. This radiation is related with one of theintrinsic silica defects, namely, E'-centers [6]. The
second band has maximum, which is near 645 nm. Its
nature is determined by other intrinsic silica defects
which are non-bridging oxygen centers [7]. The opticalproperties of silica significantly change in the presenceof hydrogen in a sample. It was shown in [8] thatabsorption of light bands with maximums at 4,75 eY
and 2,0 eV was decreased essentially by implanted

The powerful flux of the high-energy particles
bombards the structural elements inside a thermonuclear

reactor during a steady-state fusion [1]. Properties ofdifferent materials are well known to change underirradiation. This fact is explained by forming andannealing of the defects of different types and transition

to steady-state. [2,3]. These processes increase if thematerials are irradiated by ions. The projectile energy isspent for production and annealing of the defects andluminescence generation. The light parameters aredetermined by projectile characteristics and give theinformation about absorbed irradiation dose and materialproperties.

hydrogen. Usually these absorption bands wereassociated with non-bridging oxygen centers.

In the previous investigations [2,3] the silica

The silica is one of the widely used materials inparticular in devices with high irradiation conditions(e.g. as windows or parts of electronic components inluminescence was studied only for irradiation doses lessthan l0r8 particles/cm3 and for a few wavelengths. Notespace). It is applied as passivating layer whilethat the samples were preliminarily irradiated bydifferent kinds ofthe particles and after that the opticalradiation was excited in them bv ultraviolet sourcesmanufacturing of ion implanted semiconductor [4]. Alsoit was used as the window and guide material for input
and output of optical radiation for fusion reactors (seefor example [5]). It is necessary to note that the opticalproperties of silica glass are changed by irradiation
essentially [4].

mostly.

This paper presents the results of experimental
study of luminescence spectra during ion bombardment

aCorresponding author's e-mail: kononenko@ pem.kharkov.ua.
274@2000 by The Japan Society of Plasma
Science and Nuclear Fusion ResearchKalantaryan O.Y. et al., Distance-Monitoring of Absorption dose on Materials under Ion Irradiation

with implanted doses up to 3 x l02r particles/cm3,
specifically, the relation between ionluminescence
spectrum parameters and absorption doses was1).

Such spectra were observed earlier for pure silica
when excitation of different type was applied. The mostintensive (the first) band had maximum at 460 nm . Its

investigated.

presence was associated with defects of E'-center (the2. Experimental Setup

break of the short-life bond between Si and O). The
second band had the maximum at 650 nm and wassituated on the long wave side of the first band. The
radiation in this band was associated with non-bridging

The setup for a study of the luminescence inducedby proton bombardment of the bulk silica samples wasdescribed in detail in [9]. The pure silica targets werebombarded by the proton beam with energy of 210420
keV and current density up to 30 1tNcm2. The residual
gas pressure up to l0-a Pa was maintained in the vacuum
chamber by the magnetic-discharge pump. The sample
was set at the angle of 3ff with respect to the beam (alloxygen centers.

angles were measured against the perpendicular to theThe ionluminescence spectra changed when theproton dose increased. The intensity of the long wave
side of the first band grew (see Fig. 1, curve 2). The
intensity of the short wave side and position of themaximum did not change. As the result of full width on

target surface). The face offlexible light guide under thehalf-maximum (FWHM) increased from 500 nm

chosen direction collected the silica optical radiation.
Quartz condenser projected the light from the back of(nonirradiated silica) to 508 nm (for the dose -3 x l02r
particles/cm3). The ratio of intensities in the point withthe light guide on the entrance slit of the grating

wavelength of h = 620 nm to those in the first band
maximum increased flrom 5.6 x l0-2 to 7.3 x l0-2. The
intensity of the second band decreased and becamealmost indistinguishable at the background of the firstmonochromator. Detection of the luminescence wascarried out using the photomultiplier detector in thewavelength range of 40G-700 nm.
The observation angle changed from 0" to 60" by of
the light guide face. The optical channel of the setup
was calibrated by incandescence spectrum-metric lamp.
The luminescence spectra were corrected according toband. These results were obtained for proton energy of
210 keV.

4. Discussion
The changes in spectrum depended on thethe spectral sensitivity and were normalized to the beam

implanting dose strongly. These effects can be used forthe monitoring of absorption proton dose. The mostsignificant changes of spectra with the growth of dosewere observed at the wavelength of 650 nm. The
ionluminescence intensity at the wavelength 650 nm
was a sum of the longwave side radiation of the firstcurrent.

3. Results
The typical luminescence spectrum of nonirradiatedsilica under ion bombardment is shown in Fis. I (curveband and the radiation maximum of the second band.
The intensity of the first band in this point increased
with dose growth but the maximum magnitude of thesecond band decreased. As the result, the intensity at

10-8;

650 nm decreased because the rate of the second process
was higher that of the first process. The measurement of+6

changes of intensity at this wavelength allows

f;+-20rm

monitoring the absorbed dose. So, we can determine theimplantation dose on the basis of the analysis of thelight intensity growth at 620 nm because the light yieldof the first band in this point changed most significantly.
However, we think that efficiency of this method

4s0 500 5$ 6m 650 7tn

can be improved using the ratio of luminescenceintensity at 650 nm to that at 620 nm. In this case themethod becomes more sensitive because the first value

Vthdqgth, trnrl
Fig.1 The ionluminescence spectra of SiO. under
proton bombardment: curve 1 - nonirradiatedincreases and the second value decreases. Moreover,these wavelengths are close to each other; thus, ansample, curve 2 - the sample irradiated withabsorbed proton doses of 3 x 1021 particles/cm3.

275

Kalantaryan O.Y. et al., Distance-Monitoring of Absorption dose on Materials under Ion Irradiation

115

5. Gonclusions

l14

It was obtained that the ionluminescence spectra of

1'3

SiO2 changed under the proton bombardment. The
relation between light intensity and implantation dose up
to 3 x 102r particles/cm3 was determined. The novel
method for monitoring the proton dose in quartz wasl'2v lrl

proposed.

I0'9

Acknowledgments

0'8

The authors are grateful to Prof. A. Shishkin andMember of National Academv of Science of Ukraine V.

101520253035

Storighko for help.

4partict.r/"-3]
Dose I tO
Fig.2 The proton dose dependence ofthe coefficient K:

References

curve 1 - the proton energy was 420 keV; curve 2 the proton energy was 210 keV.

tll M. Fujiwara, Annual Report of NIFS, 3, (Sept.
1998).

[2] L.H. Abbu-Hassan et a/., Nucl. Instr. and Meth.

influence of optical channel dispersion on the819t20,927 (t987).
[3] F. Jaque et al., Nucl. Instr. and Meth. 182/183, 781

measurements is negligible.

It was obtained that the dependence of the ratio offl98r).

[4] P.J. Chandler et al.,Rad.Eft.42,45 (1979).
[5j M. Shoji, Annual Report of NIFS, 32, (Nov. 1999).
[6] F.J. Feigl et a/., Sol. Stat. Commun., 14, 225

the luminescence intensities at 650 nm to that at 620 nm(coefficient R) upon the absorption dose had similar
behavior for studied proton energy and the different
observation angles. We calculated the coefficient K = Rl/, where / was the mean path of proton in SiO2 andplotted the curves of dose dependence ofI( for different
energies of particles (see Fig. 2). The energy loss data(r974\.

t7l A.R. Silin er al., Tochechnie defecty i elementarnie
vozbuzhdeniya v kristallicheskom i stekloobraznom
SiO2, (Zinatne, Riga, 1985).

[8] S.M. Brekhovskih et al., Radiacionnie centri v

was taken from [10] and quartz density from [11]. The
magnitude ofK depended only on the proton density inneorganicheskih steklah (Energoizdat, Moskva,

silica sample but was practically independent of1988).

t9l O.V. Kalantaryan et al.,Poverk,hnost 5, 45 (1992).
[0]' O.F. Nemets et al., Spravochnik po yadernoy
fizike, (Naukova dumka, Kiev, 1975).
[ 1] Tablitsi fizicheskih velichin. Pod red. LK. Kikoina,(Atomizdat, Moskva, 1976).
[2] Y. Ueda et al., Annual Report of NIFS, 78, (Sept.

projectile energy and observation angles (see Fig. 2).
The expecting high particle flux of the LHD projectis up to 1017 particles/cm2 s [12]. In this case, dose up to3 x 102r particles/cm3 will be accumulated during theirradiation time equal to 3 x lOa s.

1998).

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