1. Letter of Intent: XXXXI
Alex Murphy
Study of Reactions Important to Synthesis of 44Ti in Core Collaspe Supernovae
TRIUMF EEC July 8th 2005
…good evening from Edinburgh

2. Core Collapse Supernovae
Science Case
‘Easy’ to make
Supernovae are…
Some of the most powerful explosions in the Cosmos
Some of the most scrutinised objects in the Universe
Responsible for production of many heavy elements
Responsible for shaping our local distribution of stars
There is consensus on the basic mechanism
But! The best simulations still don’t explode!
Extremely complex
Need a good diagnostic
SN1987A
44Ti !
M1 – The Crab
TRIUMF EEC July 8th 2005

3. Core Collapse Dissociation back to n, p, and a
Massive star (>10–12 M)
Stellar evolution  onion-skin-like structure
At maximum of BE/A, thermal support lost  Core collapses
Shock wave passes through Si layer above core
Dissociation back to n, p, and a
…Nuclear statistical equilibrium…
…Alpha-rich freeze out
Dominant site for 44Ti production
Key reactions to be studied*
40Ca(a,g) – E1024
44Ti(a,g)
44Ti(a,p) – This work
45V(p,g) – This work
Triple a
* (The et al ApJ 504 (1998) 500)
TRIUMF EEC July 8th 2005

4. 44Ti production
Amount ejected sensitively depends on location of the ‘mass cut’
Material that ‘falls back’ is not available for detection
44Ti yield a sensitive diagnostic of the explosion mechanism
Thus, VERY useful for models to make comparisons against
What’s more, it’s (relatively) easily observed
Gamma-Ray observation
1.157 MeV
INTEGRAL & other missions
Meteoritic data
Enrichment of 40Ca in type X grains
Timmes et al. (1996)
TRIUMF EEC July 8th 2005

5. Proposed research Take advantage of unique future ISAC beams
44Ti(a,p)47V – direct measurement
Gas/implanted target
Trilis, CSB
LEDA/CD
Not measured before at astrophysical energies - extrapolation of previous results suggests it’s eminently feasible 10^7 pps).
45V(p,p)45V – resonant elastic scattering
Knowledge of 46Cr, precursor to 45V(p,g)46Cr
CH2 target
Unmeasured. SM/TES suggests ‘feasible’ 10^7 pps).
45V(p,g)46Cr
DRAGON
Use (p,p) as guide.
Coordinated
approach
TRIUMF EEC July 8th 2005

6. UK Grant application A request has been made to UK’s EPSRC
specifically based on this work, at this facility
Request is for 33 months of PDRA + Travel
Panel meets 27/7/05
Referees’ reports…
Very positive feedback.
Confident this will be funded
TRIUMF EEC July 8th 2005

7. Purpose of this LoI… Proposed research requires:
Charge state booster
Laser ion source (TRILIS)
Development of 44Ti and 45V beams
Many thanks for your time…
And sorry I couldn’t e there
And many thanks to Marialuisa!!!!
TRIUMF EEC July 8th 2005