Hauke,
As I explained last night, the NIKHEF flange is
incompatible with the present chamber because of
oring locations and cold head flanges. What I am
doing right now,
is to modify the Bates top flange to have angle
movement simalar to the NIKHEF flange and
additional translation under vacuum. This will get
rid of any alignment problems.
I used the optical plummet this morning to take
measurements and have started the modifations and
should finish late friday nite.
Ernie
Hauke Kolster wrote:
>
> Hello everybody.
> Today we have continued to map out the position of the ABS nozzle in
> respect
> to the skimmer. We have collected about 8 data points that showed a
> picture
> that is consistent with a misalignment of about 1mm of the nozzle after
> pumping and cooling of the nozzle. One can clearly see the loss of beam
> due
> to the overlap of the nozzle and the skimmer. However the overall signal
> in the target chamber remained small.
>
> Unfortunately at about 9 pm we discovered that the glass tube coolant
> in the
> dissociator leaked into the dissociator can (the one that contains the
> rf cicuit)
> and we had to pull the dissoiator to protect the other chambers from a
> spill.
> This sets us back for some time but also enables us to make the
> decision for
> an alternative solution on the dissociator top flange. Ernie and I
> agreed today
> to use the original top flange from Amsterdam. This flange enables a
> tilt of the
> rf can and also results in a motion of the nozzle in respect to the
> skimmer
> under roughing vacuum conditions so that an alignment of the nozzle can
> be
> done much faster. With the new pushers we have control over a x-y motion
> and a tilt as well as the distance from the skimmer in much shorter
> time. The
> time estimate is that the flange can be modified by Friday evening and
> all
> components back in the ABS during the weekend. The alignment of the ABS
> through the theodolite is still set up so that the top flange and the
> plummet
> can be adjusted within a much shorter time now.
>
> In the meantime the dissociator will be cleaned and critical parts
> replaced
> to get good initial conditions for the upcoming run. Ernie's estimate
> was that
> the ABS should be operational by the beginning of next week so we can
> pick up the studies to find sufficient target density.
>
> The target field is operationl for the longitudinal and transverse
> direction
> and can be set to L: 250A, T: 500A for an spinangle of 45 deg in the
> cell center. The resulting field is in the order of 375 Gauss. For the
> exact
> calibration please contact Vitaly Ziskin.
>
> I have already tuned the MFT 12-23 transition and written two short
> macros
> that control the injection states for polarized running:
> MFT off: states 1 and 2, average injected polarization P_e = 0.7, P_z =
> 0.15
> MFT on: state 1 only, average injected polarization; P_e = 1, P_z = 1
> After taking into account that there are molecules injected in the cell
> (P=0)
> and also relaxation effects one can expect a polarization of:
> MFT off: P_e = 0.5, P_z = 0.25
> MFT on: P_e= 0.6, P_z = 0.6
> as a realistic number.
>
> Hauke
>
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