Tuesday Nov. 8, 2005
DRAGON meeting 14:00

Attendance: LB, PM, GR, CV, MT, JDA, DH, CD, LF, CR, JP, AH, DF, DO, AP
(recorder)

Previous meeting's minutes:  no changes

DH: ISAC EPICS1 will be rebooted tomorrow (Wed.).

Acceptance tests:

JP: -using the strong (10^5 Bq) Gd source pointing out the exit window of
the
gas target, centred to about 0.5 mm or so in the target
-separator is set to 3.182 MeV 2+ alphas
- rate at DSSSD observed is much lower (3x) than expected from calcs.,
shape of
the hit pattern is 'grotty'
-took source out to do an absolute flux calibration, ie placed source
(pointing
at DSSSD) in final slits box, fully opened slits...saw 1/3 of expected
activity
at DSSSD
-looks like about 17 mrad acceptance
- changed strengths of DRAGON fields to simulate different
energies...seems that
alpha energies are few % low

JP will go to Safety to examine the source....will put source back into
gas
target to repeat tests in more detail.
DH: we could also look at the quality of the focus at the mass slits...

LB: would be nice to have the DSSSD at the mass slits...
DH: Perhaps after CV's run?  ED1 had been conditioned to 171 kV before
these
transmission exercises...CV wants 173 or so.

E989:

CR: no real comments.  Mini-meeting after this meeting.  CR corrects his
~20%
error mentioned in his ACOT talk...it should be less...

LF is working on beam normalization, the most "laboroius" part.

JDA: We should make sure to write all collaborators in future talks.
MT: should talks go on the website?

The peanut gallery says yes.

E1027:

JC has disappeared.  DO says there are dewers, tools in the
mass-separator
room...PM will go look at this with DO.

MT: 2 targets were made (300 uCi, and ~200uCi), after tweaking the
alignment we
had good transmission onto the foil, then we just ran...

LF: targets are in the collection station (which is isolated)...plan is
eventually to move them into the target chamber to be used in Seattle...

JDA: Don't do anything until JC arrives!

MT will give a summary at the ISAC forum tomorrow.

E1024:

CV presents more details on the resonances seen in previous DRAGON
studies,
compares these with resonances as reported in the literature...shows
target
z-position for several runs...CSB seems to affect position of resonance
in the
target (by 6 cm)???  CV shows a plot of expected beam energy
resolution...using
SRIM to model the gas target (4 torr He) and the 100 nm SiN CSB, we
should be
seeing resolution ~2-3x better than the 6.8 keV/u we had been seeing.

JDA: Is there a better way of going about this expt?

DH: Are we seeing some resonances twice (ie due to overlapping energies)
in the
previous DRAGON studies?

LB: excitation functions are difficult with DRAGON...

DH: other than the strong resonance, it will be difficult to see if our
energy
bites agree/disagree with the literature, as the literature has problems.

CV: The plan: we'll work our way down in energy to see the resonances,
trying
for <25% overlap of the beam energy error bars.

E1024 starts Nov. 17 for beam development, tuning begins on Nov. 21.

JDA:alternatives? Ca target?

DH: better to deliberately oxidize a Ca target so we know its stopping
power?

Ca target talk ensues.

JDA: well, let's do CV's expt as it stands....look at the data...maybe a
new,
big resonance will appear.

CV will handle protocol for changing beam energy, training session for
replacing
CSB - maybe have next DRAGON meeting in ISAC hall as CSB needs replacing
anyway?

AOB:

JDA:  Need to finalize what we want with respect to electronics...discuss
with JC