welcome to the charms see – tea sunday, october 11, 2015 release of light alkalis (li, na, k) from...
TRANSCRIPT
![Page 1: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/1.jpg)
Welcome to the
CHARMS See – TeaFriday, April 21, 2023
Release of Light Alkalis (Li, Na, K) From ISOLDE Targets
Strahinja Lukić, 18.10.2005
![Page 2: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/2.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
2
Outline
Release of nuclides from ISOLDE targets
Release measurement technique
Results
![Page 3: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/3.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
3
Release of Nuclides from ISOLDE Targets
Nuclide production
Thermal diffusion
Effusion
Ionization
Extraction by 60 kV field
Losses to chemical reactions, leaks, radioactive decay...
Proton beam
![Page 4: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/4.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
4
Typical ISOLDE Target
20 cm
![Page 5: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/5.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
5
Ion-Sources Surface
Hot transfer line made of a metal with high work function (W, Ta)
Plasma Electron beam ionizing a gas
mixture (Ar+Xe)
Hot or cold transfer line
Laser excitation and ionization using
characteristic wavelengths in 2-3 steps
Chemical selectivity
Surface Ion-Source
EXTRACTION ELECTRODE
http://isolde.web.cern.ch/ISOLDE/
![Page 6: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/6.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
6
ISOLDE Facility LayoutTransmission Losses
http://isolde.web.cern.ch/ISOLDE/
![Page 7: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/7.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
7
Release Measurement Using the Tape Station
Proton beam pulses are spaced by 14 - 20 s
Ion beam implanted on a tape at a certain time after the p+ bunch Timing and duration controlled by a
deflector magnet
Tape carries the ions to the detector (1s)
Detection of β, α, γ or n during a specified time
Detector
![Page 8: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/8.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
8
The Release Curve
![Page 9: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/9.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
9
Yield and In-Target Rates
The release curve is established for a long lived isotope and applied to the shorter lived isotopes of the same element
The decay losses can be deduced and in-target production rates calculated
But, losses to leaks and chemical reactions impossible to estimate → yields are not always reproducible
![Page 10: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/10.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
10
Cross-sections
Production cross-sections can be estimated assuming that: All the nuclides are produced in primary reactions
(approximately correct for Li, Na and K)
Production cross-sections are constant along the target despite the proton energy loss (approximately correct for 1 GeV protons ? Energy loss ~50 MeV, xs variation ~20-30% ?)
mol
atottg
M
Nd
tot
i eCP
110242.6]/1[ 12
![Page 11: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/11.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
11
Some Results
Order of magnitude good except data from specific targets
Shape of the distribution approximately good (steeper than in ABRABLA results)
![Page 12: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/12.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
12
Some Results
Very few data, incompletely documented
Order of magnitude good
Shape of the distribution approximately good
![Page 13: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/13.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
13
Other Results - K
Too few data for potassium in the segment that was treated
Order of magnitude good except in the same specific targets as for sodium
![Page 14: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/14.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
14
Other Results - Li
Very difficult element for ISOL Small atom - leaks through solid materials
Fast diffusion – faster than the measurement system?
No sufficiently long-lived isotope – difficult to establish the release curve.
Extrapolate the release curve parameters from K and Na?
![Page 15: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/15.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
15
Other Results - Li
Estimated release curves extremely long (not logical for Li) → apparently high decay losses → high xs
Using parameters extrapolated from sodium doesn't seem to work
Possible errors because of the time-dependent background (He)
8Li produced in U-Carbide
![Page 16: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/16.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
16
Other Results - Li
No experimental data to compare to.
![Page 17: Welcome to the CHARMS See – Tea Sunday, October 11, 2015 Release of Light Alkalis (Li, Na, K) From ISOLDE Targets Strahinja Lukić, 18.10.2005](https://reader034.vdocuments.mx/reader034/viewer/2022051018/56649ea95503460f94bad8af/html5/thumbnails/17.jpg)
18-10-2005 Release of the Light Alkalis From ISOLDE Targets
17
Conclusions
The method seems to work although it would be difficult to use it for independent cross-section measurements.
The main problem - unpredictable losses
Yield data are scarce, at least in the period that was treated (1993 – 2002)
Systematic measurement of the time-dependent background could help, particularly for lithium