The BOREXINO detector, located in the Gran Sasso National Laboratory in Italy, has been designed for real-time spectroscopy of low energy solar neutrinos. Extremely low background rates required to successfully accomplish this goal triggered a very extensive R&D program focused on developments of novel background reduction and assay techniques. This has been achieved and, in many cases, these techniques are still the most sensitive world-wide. Extremely low background of the BOREXINO detector made it possible to probe almost entire spectrum of the solar neutrinos in real-time. Radon, as one of the main background sources, needed special considerations and developments, described briefly in this paper.

1.
G.
Alimonti
 et al.,
Nucl. Instrum. Methods A
600
(
2009
)
586
.
3.
G.
Bellini
 et al.,
Phys. Rev. Lett.
,
101
(
2008
)
091302
.
4.
G.
Bellini
 et al.,
Phys. Rev. Lett.
,
107
(
2011
)
141302
.
5.
G.
Bellini
 et al.,
Phys. Rev. D
,
89
(
2014
)
112007
.
6.
G.
Bellini
 et al.,
Phys. Rev. D
,
82
(
2010
)
033006
.
7.
G.
Bellini
 et al.,
Phys. Rev. Lett.
,
108
(
2012
)
051302
.
8.
G.
Bellini
 et al.,
Phys. Lett. B
,
722
(
2013
)
295
.
10.
11.
M.
Agostini
 et al.,
Phys. Rev. Lett.
,
115
(
2016
)
231802
.
12.
R.
Wink
 et al.,
Nucl. Instr. Meth. A
,
329
(
1993
)
541
.
13.
W.
Rau
,
G.
Heusser
,
Appl. Rad. Isot.
,
53
(
2000
)
371
.
14.
G.
Heusser
 et al.,
Appl. Rad. Isot.
,
52
(
2000
)
691
.
15.
H.
Simgen
 et al.,
Nucl. Instr. Meth. A
,
479
(
2003
)
407
.
16.
M.
Balata
 et al.,
Nucl. Instr. Meth. A
,
370
(
1996
)
605
.
17.
M.
Giammarchi
 et al.,
Int. J. Mod. Phys. A
,
29
(
2014
)
1442008
.
18.
G.
Zuzel
,
M.
Wojcik
,
BOREXINO general meeting
,
Perugia
,
Italy
,
6
8
May,
1998
.
19.
G.
Zuzel
,
H.
Simgen
,
Appl. Rad. Isot.
,
67
(
2009
)
889
.
21.
W.
Kutschera
 et al.,
Nucl. Instr. Meth. B
,
92
, (
1994
)
241
.
22.
Bundesamt
für Strahlenschutz
,
Umweltradioaktivität
und Strahlenbelastung
,
Jahresbericht
, (
2001
)
63
.
23.
G.
Zuzel
,
H.
Simgen
and
G.
Heusser
,
Appl. Rad. Isot.
,
61
(
2004
)
197
.
24.
H.
Simgen
 et al.,
Int. J. Mod. Phys. A
,
29
(
2014
)
1442009
.
25.
M.
Wojcik
 et al.,
Nucl. Instr. Meth. A
,
449
(
2000
)
158
.
26.
M.
Wojcik
,
G.
Zuzel
,
Nucl. Instr. Meth. A
,
524
(
2004
)
355
.
27.
G.
Zuzel
 et al.,
Nucl. Instr. Meth. A
,
498
(
2003
)
240
.
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