sub-microsecond -particle...
TRANSCRIPT
-
CHE9, 2017
Sub-microsecond α-particle emitters
Anton S̊amark-Roth
On behalf of theTASCA E115 Collaboration
October 10, 2017
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Outline
1 α decay
2 Experiment and set-up
3 Correlation analysis
4 Nuclear structure
5 Outlook
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 2
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Geiger-Nuttall LawThe very short-lived
4 5 6 7 8 9 10Qα (MeV)
−5
0
5
10
15
20log 1
0t 1
/2(s)
Po218
Rn222
Ra226
Th232U238
Pu244
Cm248
Cf250
Fm252
No254 Sg266Hs270
Half-life vs Q
Geiger-Nuttall law:log10 t1/2 = a ·
√Qα + b
Ref. PyNE with ENSDF
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 3
http://pyne.io/
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Geiger-Nuttall LawThe very short-lived
100 110 120 130 140 150 160 170Neutron number
10−6
10−4
10−2
100
102
104t 1
/2(s)
Chemistry limit∼ 0.5 s
Analogue limit ∼ 5 µsPo
AtRn
FrRa
AcTh
PaU
Np
Pu
AmCm
Cf
Fm
Es
MdNoLr
RfDb
Sg
Bh
Hs
Mt
Ds
Rg
Cn
Nh
Fl
Half-life vs Neutron numberRef. PyNE with ENSDF & XUNDL
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 4
http://pyne.io/
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
The Chart of Nuclides
Ref. Interactive Nuclide Chartwith NuBASE 2012
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 5
http://people.physics.anu.edu.au/~ecs103/chart/
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
The Chart of Nuclides
Ref. Interactive Nuclide Chartwith NuBASE 2012
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 6
http://people.physics.anu.edu.au/~ecs103/chart/
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
The 2012 E115-experiment
The reaction: 48Ca+243Am→291Mc∗. Here transfer background . . .
TASCA-separator. Source: Phys. Rev. C, 83:054618.A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 7
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Correlation analysisPixel by pixel correlated events
Event
1 Pixel2 Time3 Beam ON/OFF
4 Silicon detector particle energies (Full energy and reconstructed)5 Germanium detector photon energies (x rays and γ rays)
Aim: Select the data for just one decay path, i.e. 219Ra-215Rn.
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 8
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
“imp-α1-α2” correlated events
7.2 7.4 7.6 7.8 8.0 8.2 8.4
(MeV)1
αEnergy of
8.60
8.65
8.70
8.75
8.80
8.85
8.90
8.95
9.00
(M
eV
)2
αE
nerg
y o
f
0
2
4
6
8
10
12
14
0
10
20
30
40
50
Co
un
ts
7.2
1
7.5
3
7.9
0
7.6
8
7.9
8
0 5 10 15 20 25 30 35 40
Counts
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 9
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
“imp-α1-α2” correlated events
7.2 7.4 7.6 7.8 8.0 8.2 8.4
(MeV)1
αEnergy of
8.60
8.65
8.70
8.75
8.80
8.85
8.90
8.95
9.00
(M
eV
)2
αE
nerg
y o
f
0
2
4
6
8
10
12
14
0
10
20
30
40
50
Co
un
ts
7.2
1
7.5
3
7.9
0
7.6
8
7.9
8
0 5 10 15 20 25 30 35 40
Counts
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 10
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
“imp-α1-α2” correlated events
7.2 7.4 7.6 7.8 8.0 8.2 8.4
(MeV)1
αEnergy of
8.60
8.65
8.70
8.75
8.80
8.85
8.90
8.95
9.00
(M
eV
)2
αE
nerg
y o
f
0
2
4
6
8
10
12
14
0
10
20
30
40
50
Co
un
ts
7.2
1
7.5
3
7.9
0
7.6
8
7.9
8
0 5 10 15 20 25 30 35 40
Counts
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 11
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
“imp-α1-α2” correlated events
7.2 7.4 7.6 7.8 8.0 8.2 8.4
(MeV)1
αEnergy of
8.60
8.65
8.70
8.75
8.80
8.85
8.90
8.95
9.00 (
Me
V)
2α
En
erg
y o
f
0
2
4
6
8
10
12
14
0
10
20
30
40
50
Co
un
ts
7.2
1
7.5
3
7.9
0
7.6
8
7.9
8
0 5 10 15 20 25 30 35 40
Counts
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 12
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
“imp-α1-α2-α3” correlated events
7.2 7.4 7.6 7.8 8.0 8.2 8.4
(MeV)1
αEnergy of
8.60
8.65
8.70
8.75
8.80
8.85
8.90
8.95
9.00
(M
eV
)2
αE
nerg
y o
f
0
2
4
6
8
10
0
10
20
30
40
50
Co
un
ts
7.2
1
7.6
8
7.5
3
7.6
5
7.9
0
7.9
8
0 5 10 15 20 25 30 35 40
Counts
8.70
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 13
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
“imp-α1-α2-α3” correlated events
7.2 7.4 7.6 7.8 8.0 8.2 8.4
(MeV)1
αEnergy of
8.60
8.65
8.70
8.75
8.80
8.85
8.90
8.95
9.00 (
Me
V)
2α
En
erg
y o
f
0
2
4
6
8
10
0
10
20
30
40
50
Co
un
ts
7.2
1
7.6
8
7.5
3
7.6
5
7.9
0
7.9
8
0 5 10 15 20 25 30 35 40
Counts
8.70
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 14
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Decay level scheme 219Ra-215Rn
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 15
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Decay level scheme 219Ra-215Rn
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 16
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Decay level scheme 219Ra-215Rn
7.2 7.4 7.6 7.8 8.0 8.2 8.4
(MeV)1
αEnergy of
8.60
8.65
8.70
8.75
8.80
8.85
8.90
8.95
9.00
(M
eV
)2
αE
nerg
y o
f
0
2
4
6
8
10
0
10
20
30
40
50
Counts
7.2
1
7.6
8
7.5
3
7.6
5
7.9
0
7.9
8
0 5 10 15 20 25 30 35 40
Counts
8.70
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 17
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Decay level scheme 219Ra-215Rn
7.2 7.4 7.6 7.8 8.0 8.2 8.4
(MeV)1
αEnergy of
8.60
8.65
8.70
8.75
8.80
8.85
8.90
8.95
9.00
(M
eV
)2
αE
nerg
y o
f
0
2
4
6
8
10
0
10
20
30
40
50
Counts
7.2
1
7.6
8
7.5
3
7.6
5
7.9
0
7.9
8
0 5 10 15 20 25 30 35 40
Counts
8.70
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 18
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Decay level scheme 219Ra-215Rn
7.2 7.4 7.6 7.8 8.0 8.2 8.4
(MeV)1
αEnergy of
8.60
8.65
8.70
8.75
8.80
8.85
8.90
8.95
9.00
(M
eV
)2
αE
nerg
y o
f
0
2
4
6
8
10
0
10
20
30
40
50
Counts
7.2
1
7.6
8
7.5
3
7.6
5
7.9
0
7.9
8
0 5 10 15 20 25 30 35 40
Counts
8.70
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 19
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Decay level scheme 219Ra-215Rn
7.2 7.4 7.6 7.8 8.0 8.2 8.4
(MeV)1
αEnergy of
8.60
8.65
8.70
8.75
8.80
8.85
8.90
8.95
9.00
(M
eV
)2
αE
nerg
y o
f
0
2
4
6
8
10
0
10
20
30
40
50
Counts
7.2
1
7.6
8
7.5
3
7.6
5
7.9
0
7.9
8
0 5 10 15 20 25 30 35 40
Counts
8.70
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 20
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Decay level scheme 219Ra-215Rn
0 50 100 150 200 250 300 350 400Photon energy (keV)
0
2
4
6
8
10
12
14
16
Co
un
ts
Rn
x r
ays
215
13
0
31
6
7.2 7.4 7.6 7.8 8.0 8.2 8.4
(MeV)1
αEnergy of
8.60
8.65
8.70
8.75
8.80
8.85
8.90
8.95
9.00
(M
eV
)2
αE
nerg
y o
f
0
2
4
6
8
10
0
10
20
30
40
50
Counts
7.2
1
7.6
8
7.5
3
7.6
5
7.9
0
7.9
8
0 5 10 15 20 25 30 35 40
Counts
8.70
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 21
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Decay level scheme 219Ra-215Rn
0 50 100 150 200 250 300 350 400Photon energy (keV)
0
2
4
6
8
10
12
14
16
Co
un
ts
Rn
x r
ays
215
13
0
31
6
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 22
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Decay level scheme 219Ra-215Rn
0 50 100 150 200 250 300 350 400Photon energy (keV)
0
2
4
6
8
10
12
14
16
Co
un
ts
Rn
x r
ays
215
13
0
31
6
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 23
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Decay level scheme 219Ra-215Rn
0 50 100 150 200 250 300 350 400Photon energy (keV)
0
2
4
6
8
10
12
14
16
Co
un
ts
Rn
x r
ays
215
13
0
31
6
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 24
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Decay level scheme 219Ra-215Rn
0 2 4 6 8 10 12s)µt (
0
2
4
6
8
10
Counts
1α-
2αt∆
Exponential fit
7.2 7.4 7.6 7.8 8.0 8.2 8.4
(MeV)1
αEnergy of
8.60
8.65
8.70
8.75
8.80
8.85
8.90
8.95
9.00
(M
eV
)2
αE
nerg
y o
f
0
2
4
6
8
10
0
10
20
30
40
50
Counts
7.2
1
7.6
8
7.5
3
7.6
5
sum
(a+
ce)
7.9
8
0 5 10 15 20 25 30 35 40
Counts
8.70
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 25
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Decay level scheme 219Ra-215Rn
0 2 4 6 8 10 12s)µt (
0
2
4
6
8
10
Counts
1α-
2αt∆
Exponential fit
7.2 7.4 7.6 7.8 8.0 8.2 8.4
(MeV)1
αEnergy of
8.60
8.65
8.70
8.75
8.80
8.85
8.90
8.95
9.00
(M
eV
)2
αE
nerg
y o
f
0
2
4
6
8
10
0
10
20
30
40
50
Counts
7.2
1
7.6
8
7.5
3
7.6
5
sum
(a+
ce)
7.9
8
0 5 10 15 20 25 30 35 40
Counts
8.70
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 26
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Decay level scheme 219Ra-215Rn - Comparison with previous work
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 27
-
Outlook
• Evaluate the constructed decay level scheme on the basis of Geant4simulations.
• Use theoretical models to calculate the structural- and α-decay properties of219Ra & 215Rn:
• Large scale shell model calculations.• Contemporary α-decay models developed in Lund.
• Establish a final interpretation of the Ra-219 & Rn-215 decay path.• Study three other odd-even isotopes in the same region.
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Decay level scheme 219Ra-215Rn - Comparison shell model calculations
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 29
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Half-lifet1/2 of Ra-219
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 30
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Fast Sampling ADCsPile-ups
0 500 1000 1500 2000 2500 3000 3500 4000Channel
500
0
500
1000
1500
2000
Volta
ge (a
rb. u
nit.)
Digital Analogue
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 31
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Gaussian fits Ra-219
7.5 7.6 7.7 7.8 7.9 8 8.1-particle (MeV)αEnergy of
0
5
10
15
20
25
Counts
Total fit
Individual Gaussians
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 32
-
α decay Experiment and set-up Correlation analysis Nuclear structure Outlook
Coincident photons Ra-219
0 20 40 60 80 100 120 140 160 180 200 220 2400
1
2
3
4
5
6
7
8
9
10
Co
un
ts
Rn
x r
ays
215
13
0300 400 500 600 700 800 900 1000
Photon energy (keV)
0
2
4
6
8
10
12
14
16
Co
un
ts
31
6
A. S̊amark-Roth, Che9 2017. Sub µs α-particle emitters 33
decayExperiment and set-upCorrelation analysisNuclear structureOutlook