Prospects to
measure
8
B
production
VLADIMIR KRAVCHUK
Laboratori Nazionali di
Legnaro, Italy
EUROnu week in Strasbourg
1
-
4 June 2010
CONTENTS
1.
INTRODUCTION
2.
CROSS
-
SECTION MEASUREMENTS AND PRECISION
3.
ANGULAR DISTRIBUTION
4.
DIRECT OR REVERSE KINEMATICS?
5.
EXPERIMENTAL SET
-
UPS
a) Internal options: LNL
-
TANDEM/CN, Legnaro
i) LNL
-
CN
ii) LNL
–
TANDEM RIPEN+PHOSWICH SET
-
UP
iii) LNL
–
TANDEM EXOTIC+RIPEN SET
-
UP
b) External options
i) LNS
–
TANDEM MAGNEX+EDEN SET
-
UP Catania, Italy
ii) IUAC
–
15 MV PELLETRON HYRA+NAND SET
-
UP, New Dehli, India
iii) JINR
–
U400 CYCLOTRON AKULINA+DEMON SET
-
UP, Dubna, Russia
iv) JYU
–
K130 CYCLOTRON SET
-
UP TO BE STUDIED, Jyvaskyla, Finland
6.
TARGETS
7.
CONCLUSION
1. INTRODUCTION
In the article of Rubbia et al. the
8
B
nucleus is considered as a neutrino
source producing relatively high
-
energy neutrinos:
The reaction proposed for the
8
B
production is:
with the decay time of 0.77 s. In the
same article the plot of the total
cross section of the indicated process
is demonstrated as a function of
3
He
incoming energies together with the
incoming energies for the reverse
kinematics:
The optimum energy for collisions
suggested in the article of Rubbia et
al. is ~20 MeV for Li ions on He
target.
C. Rubbia et al., Nucl. Instr. and
Meth. A 568 (2006) 475
-
487
2. CROSS
-
SECTION MEASUREMENTS
AND PRECISION
and references therein
1. What precision in the cross
-
section measurements is
required for the project?
3. ANGULAR DISTRIBUTION
Angular distribution is measured only until
E(
3
He)=5.7 MeV
2. Presumably there is a need to measure
the angular distribution. What angular
resolution is required? This information
will help in the choice of the set
-
up and
geometry.
3. Do wee need to perform theoretical
calculations (using presumably DWBA
code) for the possible comparison with
the experimental results and for the
extension in the whole energy range of
interest?
4. DIRECT OR REVERSE
KINEMATICS?
D. Neuffer, Nucl. Instr. and
Meth. A 585 (2008) 109
-
116
LISE++ Kinematics Calculations
1)
8 MeV
3
He (16 MeV
6
Li)
–
intermediate
case;
2)
10 MeV
3
He (20 MeV
6
Li)
–
optimum
energy according to the articles of Rubbia
et al. and Neuffer;
3)
5.5 MeV
3
He (11 MeV
6
Li)
–
energy with
the maximum reaction cross
-
section from
the data in literature.
For each of the energy cases described
above 4 calculations were performed:
two
-
body direct kinematics
3
He +
6
Li
-
>
8
B +
1
n
;
elastic scattering direct kinematics
3
He +
6
Li
-
>
3
He +
6
Li
;
two
-
body reverse kinematics
6
Li +
3
He
-
>
8
B +
1
n
;
elastic scattering reverse kinematics
6
Li +
3
He
-
>
6
Li +
3
He
.
4. What projectile energy shall
we use in our measurements?
5. EXPERIMENTAL SET
-
UPS
a) Internal options
–
LNL, Italy
i) CN / RIPEN array
DIRECT KINEMATICS
-
CN
3
He beam can arrive up to an energy
of 11 MeV (pulsed 2 ns);
-
Part of the RIPEN array could be used
for the neutron detection
-
Non
-
coincident measurement
-
Li target is available
-
Could be considered as a test
measurement
5. EXPERIMENTAL SET
-
UPS
a) Internal options
–
LNL, Italy
ii) TANDEM / RIPEN
-
PHOSWICH array
REVERSE KINEMATICS
-
TANDEM
6
Li beam is available
around energy of 20 MeV (pulsed
~
1 ns);
-
The RIPEN array could be used for
the neutron detection in
coincidence with the PHOSWICH
array for the
8
B detection
-
The high elastic count rate is not a
problem for the PHOSWICH
detectors
-
The RIPEN array has to be
equipped with the electronic
modules
RipeN
Ri
velatori
pe
r
N
eutroni a LNL
12.7cm x 12.7 cm
24 BC501 cylindrical Liquid Scintillators
Digital electronics
: under test
Acqiris
:
DC271A
–
1GS/s
–
4 Ch
–
8 Bit
RipeN
@
LNL
Ongoing tests
n
g
g
n
n
g
4 MeV p + Li pulsed beam @ CN Van de Graaf accelerator
Sampled signal
ToF
RipeN
@
LNL
Ongoing tests
n
137
Cs
60
Co
88
Y
g
All 24 detectors working!
Good n
-
g
di獣物浩湡瑩潮
Light response
Discrimination threshold
Source Tests
Bit
-
resolution
Sampling rate
Acquisition rate
PSA algorithm
(developed by
T. Marchi)
Preliminary
digitized electronics:
Acqiris card
g
n
䅭
-
䉥
keVee
g
n
Am
-
Be
PHOSWICH
array at LNL
IMF
(Z
IMF
from 3 up to
~12)
5. EXPERIMENTAL SET
-
UPS
b) External options
i) MAGNEX / EDEN Set
-
up, LNS Catania, Italy
REVERSE KINEMATICS
-
6
Li beam is available around
energy of 20 MeV (pulsed
~
1 ns);
-
The EDEN array could be
used for the neutron
detection coupled to the
MAGNEX array for the
8
B
detection
-
The
target chamber
,
equipped with multiple
entrance ports which are
double
-
valved to allow
rotation of the spectrometer
without breaking vacuum in
the chamber
-
The entrance
position
-
sensitive start detector
(PSD), providing the Start
signal for the TOF and
measuring the particle
angles.
-
The
focal plane detector
(FPD), which identifies the
particles. It measures ion
position, direction (angle),
energy
-
loss, charge and
mass
EDEN Calibration
R. Ghetti et al., Nucl. Instr. and
Meth. A 516 (2004) 492
-
501
5. EXPERIMENTAL SET
-
UPS
b) External options
ii) HYRA / NAND Set
-
up, IUAC New Dehli, India
REVERSE KINEMATICS
Hy
brid
R
ecoil Mass
A
nalyzer
(HYRA)
N
ational
A
rray of
N
eutron
D
etectors
(NAND)
5. EXPERIMENTAL SET
-
UPS
b) External options
iii) AKULINA / DEMON Set
-
up, JINR Dubna, Russia
REVERSE KINEMATICS
DEMON Neutron detection array
5. EXPERIMENTAL SET
-
UPS
b) External options
iv) JYU, Jyvaskyla, Finland
DIRECT KINEMATICS
6. TARGETS
The people of the LNL
-
EXOTIC set
-
up are using
3
He gas targets. The composition of the
target is the following: the 2.2 micron entrance HAVAR (heat treatable Cobalt base
alloy that provides very high strength, Co
-
42%, Cr
-
19.5%, Ni
-
12.7%) window with the
diameter of 16 mm, 5 cm of the gas cell, exit window with the same characteristics of
the entrance one. If we decide to use 5 cm (obviously using a cooling procedure), we
can just borrow one of the existing targets from the EXOTIC set
-
up. In case we want to
use less then 5 cm, we can realize a new target with a guidance of the EXOTIC set
-
up
users. The
3
He gas targets are provided by Padova and the cost of the one is estimated
to be ≤ 5 KEuro.
Schematic drawing of the gas target(s)
7. CONCLUSION
A. Personally we see a more feasible internal option ii) by using the
RIPEN set
-
up at the LNL 3rd experimental hall with the detection set
-
up
consisting of the PHOSWICH array for the
8
B detection in coincidence
with the neutrons detected by the RIPEN array.
B. The choice of kinematics is reverse in this case, ~20 MeV pulsed
6
Li
beam can be provided by the LNL TANDEM accelerator and as a target
3
He gas target (already existing or realized in a decent time) can be
used.
C.
The question here is a timescale, as the RIPEN array should be
equipped with electronics for 24 detection modules.
D. If the timescale for the RIPEN developed is considered to be long, the
internal option i) and external option i) (Catania) could get high priority.
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