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Corinne Louchart – LH2 target test NUSTAR meeting – 28/02/2012
Results of the LH2 target test
HISPEC-DESPEC meeting 28th February 2012
Corinne Louchart, CEA Saclay
Corinne Louchart – LH2 target test NUSTAR meeting – 28/02/2012
Characteristics of the LH2 target:
� 20 mm thickness (for the test), 60 mm thickness also developed
� 65 mm diameter
� 125 µm of mylar for the entrance window
� 250 µm of mylar for the exit window
Exit window
Entrance window
The LH2 target
Filling of liquid hydrogen (test in CEA Saclay)
Corinne Louchart – LH2 target test NUSTAR meeting – 28/02/2012
Installation on the roof
� control – command
� H2 and N2 gas tanks
� cables and gas pipes from roof to vault
Corinne Louchart – LH2 target test NUSTAR meeting – 28/02/2012
Installation in S4
� target installation ~ 1h
� pumping time ~ 10h
� cooling time ~ 15h
Operation time: ~ 24 h
De-installation time: ~ 12 h
Corinne Louchart – LH2 target test NUSTAR meeting – 28/02/2012
In-beam test set-up
Beam of 54Cr at 130MeV/u
� 7 hours of beam time
� 400 000 particles per spill (10 s)beam
RIS
ING
TPC TPC TPC
MUSIC MUSIC
START STOP
LYCCA Si
LYCCA CsI
Hecto
r
No target DSSD
Corinne Louchart – LH2 target test NUSTAR meeting – 28/02/2012
Identifications
Energy CsI (MeV)
En
erg
y D
SS
D (
MeV
)
� MUSIC 2 used
Z
A/Q
Beam selection
54Cr
Z selection
Cr
Ti
Corinne Louchart – LH2 target test NUSTAR meeting – 28/02/2012
IdentificationsT
oF
(a
.u.)
Total kinetic Energy (MeV)
54Cr
52Cr
48Ti
Mass
� absolute mass obtained via E = γmc2
� Mass resolution ≈ 1.0 (FWHM)
Cr isotopes
Corinne Louchart – LH2 target test NUSTAR meeting – 28/02/2012
Ge time gate
Ge time (a.u.)
54Cr
Corinne Louchart – LH2 target test NUSTAR meeting – 28/02/2012
Background versus detector position
Cos(ααααγγγγ)
54Cr
En
erg
y (
keV
)
Energy (keV)Energy (keV)
Corinne Louchart – LH2 target test NUSTAR meeting – 28/02/2012
Energy spectra
2+→ 0+
@ 834 keV
4+→ 2+ and
Contamination 53Cr
Energy (keV)
Co
un
ts (
10
keV
/bin
)
Energy (keV)
Co
un
ts (
10
keV
/bin
)
5/2-→ 3/2-
@ 1007 keV
� E resolution ≈ 30 keV (FWHM)
� S/B ≈ 2
7/2-→ 3/2-
@ 1288 keV
Contamination 52Cr
Inelastic scattering (p,p’)
Knockout -1n0+
2+
4+
6+
8+
10+
12+
834.8 keV989 keV
1398.6 keV
1459.1 keV
2042.5 keV
2101.2 keV
1006 k
eV
3/2-
1973.6
keV
1/2-
5/2-
7/2-
5/2-
7/2-1289.6
keV
530.2
keV
564 k
eV
H.J. Wollersheim et al.
NIM A 537 (2005) 637-657
55Ni + 9Be @171 MeV/u
Corinne Louchart – LH2 target test NUSTAR meeting – 28/02/2012
Energy (keV)
Co
un
ts (
10
keV
/bin
)
Energy (keV)
Co
un
ts (
10
keV
/bin
)
2+→ 0+
@ 887 keV
4+→ 2+
@ 1310 keV
2+→ 0+
@ 1436 keV
4+→ 2+
@ 932 keV
Energy spectra
Knockout -2p -4n
Knockout -2n
0+
2+
4+
1434.1 keV
935.5 keV
0+
2+
4+
983.5 keV
1312.1 keV
H.J. Wollersheim et al.
NIM A 537 (2005) 637-657
55Ni + 9Be @171 MeV/u
Corinne Louchart – LH2 target test NUSTAR meeting – 28/02/2012
Conclusions
To be done (In-beam test analysis):
� Addback for Ge clusters
� Estimate efficiencies via G4 simulations
� Cross section estimates
� Technical article/report to be written
Conclusion:
� PRESPEC H2 target operational
� Available thicknesses: from 20 to 60 mm
� In-beam validation successful
� Inelastic, n and p knockout measured
� S/B up to 3 for -2n knockout
� Mass ID: ∆A/A=1 FWHM (preliminary)
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