Transcript 150Nd Project - IDEA project

150Nd
Project
• Nd crystals used so far
• News about NdGaO3
• Scintillating Bolometers
• Conclusions & Prospect
Stefano Pirro, IDEA Meeting -Orsay April 14 , 2005
Two Crystal compounds
Compound
Density
[g/cm3]
Melting
Point [Cº]
Deby
Temp. [K]
Nd Fraction
[%mass]
NdF3
6.51
1377
n.a.
71
NdGaO3
7.57
1605
676
55
NdGaO3
Good “theoretical” candidate
16 g sample
200 g sample
The small sample was tested at sea level @ Milano-Bicocca and Firenze
The big sample was tested deep underground @ LNGS
Stefano Pirro, IDEA Meeting -Orsay April 14 , 2005
NdGaO3 Milano-Bicocca Test
Paramagnetic heat capacitance
PTFE supports
1.3x1.3x1.3 cm3
Final temperature 38.5 mK
Stefano Pirro, IDEA Meeting -Orsay April 14 , 2005
NdGaO3 Firenze Test
The main difference was in the choice of the thermal conductance between crystal and
Cryostat. The choice was a hard contact in order to cool down the crystal to lower
temperatures with respect the ones reached in Milano.
Nylon wires
1.5 cm2 thermalization surface Cu-NdGaO3
Mixing chamber Temperature: 20 mK
Stefano Pirro, IDEA Meeting -Orsay April 14 , 2005
NdGaO3 LNGS Test
3x3x3 cm3
200 g
PTFE supports (low conductance)
Two different set-up were used
Low conductance set-up
High conductance set-up
Stefano Pirro, IDEA Meeting -Orsay April 14 , 2005
NdGaO3 LNGS
After 10 days the temperature reached was ~34 mK
After 70 days the temperature reached is ~16 mK
We see thermal pulses, but some Serious doubts arise
on the identification of actual particle pulses
Injected thermal energy of ~ 1300 keV
Stefano Pirro, IDEA Meeting -Orsay April 14 , 2005
New Run Hall C
We mounted the small NdGaO3 Crystal. The aim is to see if,, due to the smaller mass, we are
Able to recognize actual particle pulses.
The run started Friday 8 April. The temperature is slowly decreasing and is now around 30 mK.
Stefano Pirro, IDEA Meeting -Orsay April 14 , 2005
Innovative Techniques
Several tests were made in the R&D cryostat @LNGS during the lasts months
The idea is to move towards a active background rejection
Double readout heat - light
100Mo
Nuclei with Q-Value above the
208Tl
3034 keV
-  line
48Ca
4271 keV
116Cd
2802 keV
We developed suitable bolometric light detectors with a Energy resolution of 3050 eV
Stefano Pirro, IDEA Meeting -Orsay April 14 , 2005
Light detector
PbMoO4
SrMoO4
MgMoO4
CaMoO4
Stefano Pirro, IDEA Meeting -Orsay April 14 , 2005
Large-Surface Light detector
Stefano Pirro, IDEA Meeting -Orsay April 14 , 2005
Scatter Plots
PbWO4
CaMoO4
SrMoO4
Stefano Pirro, IDEA Meeting -Orsay April 14 , 2005
First “LARGE” mass high RESOLUTION scintillating bolometer for DBD
150 g of CdWO4
Stefano Pirro, IDEA Meeting -Orsay April 14 , 2005
Conclusions
• Neodimuim-based Detectors/Bolometers shows clearly the
difficulties of this compound
• There is, nevertheless, some hope to have some new results
• The use of the enriched Nd is, in my opinion, one of the last chance
• The “new” implementation of scintillating bolometers clearly
shows the easy feasibility of a “new” powerful experiment
• Lot of effort is needed in order to identify a suitable scintillating
compound
Stefano Pirro, IDEA Meeting -Orsay April 14 , 2005