Subject: Minutes of the February 26/02 DRAGON Meeting

Members Present: DAH, LB, AC, CJ, SE, DO, MC, PM, DG
Meeting was Chaired by DAH, recorded by MC

Minutes of the last meeting on February 19/02 were adopted with minor 
corrections.

Business Arising out of the Minutes :
SE wanted to correct the statement made as contained in the first 
paragraph about energy loss in the gas target: SRIM calculation did not
enter the determination of the pressure profile. SE also pointe out that
the transmission of the DRAGON was only tested for lower energies of the
22Mg.

DAH while reporting  the status of the hardware jobs undertaken commented
"More things broken than were fixed" in the last week.
List of jobs accomplished : 1) Cryo temp. Calib  2) Ordering spare IG
heads, O'rings  3) mounting of Pb plates to cover the Tank Hoops
4) Fixing/replacing NMR scope.
Problems still to be addressed about Ion Pumps and the Scaling programme. 
DAH also reported that safety fence lockup with Keys is expected to 
be commissioned by April, but the Area Safety Unit is delayed by East
Target Station work.

DO suggested that needle valves with vernier should replace the present 
Nupro valves on the roughing and venting lines of the Final slit box. He
is to contact the Varian people.

PM described the filament problem with the IG21 etc. as well as that the
last turbo (in the final Box) cannot be controlled from Epics.

CJ reported the analyses she had done. She presented the results where the 
Elastic counts were normalised with the FC4 rdg.,run time,ch.state,energy,
atomic number and pressure for the various runs  covering 21Ne, 21Na and
24Mg beams at various energies. There was lack of  consistency 
between the various runs at higher energies, particularly in the
early 21Na runs.  She also showed  Shawn's 
analysis results for 21Na runs at E=200 to 211 KeV/u which appeared to be 
more consistent. However the 21Ne runs at higher energies viz. E=750 and 823 
to 850 KeV/u exhibit relatively better consistency.

DAH summarised these results as follows : 1. There should be a stringent 
check list in future runs to avoid inconsistencies. 2. Doubts still exist 
whether the whole beam in FC4 is going thru the target.3. General warning  
with regard to placing too much reliance on Elastic Monitor alone. 
4. Details about the Masks set in for Data Acquisition should be looked into 
to see whether Strip/Elastic Detectors  every genuine count was
registered. (There is a known problem at very low rates.)

LB presented the draft of 21Na(p,gamma) work at 822 KeV/u resonance. Several 
copies were distributed among the members. He also mentioned that a bit of 
text to be still added to the draft. He also commented that the gamma 
efficiencies should also be looked into in more details with appropriate 
branching ratios.

SE rported the  progress of the analyses done so far by AC & SE. They looked 
thru all the runs. Problems with Elastics persist though in some runs they 
observed consistency as well. It is expected that more details will be 
presented in the next weekly meeting.

LB observed that different target profile shapes should be tried to see 
which one gives better consistency. DAH suggested that target profile be 
convoluted with total widths of the resonances. Maybe a full Monte Carlo 
simulation is needed.

SE suggested that the energy loss in the target needs to be measured again 
precisely to minimise the error bars. Some mistrust of the SRIM/TRIM 
calculations was expressed. The changes from 21Ne to 21Na do not exactly
match with SRIM results.