Raith Status report 01052005:1230 hours System access delayed through Friday.
jwc at snf.stanford.edu
Wed Jan 5 13:51:21 PST 2005
Greetings Raith Users:
There will be a delay in the previously announced schedule
to return the system to users access through Friday Noon.
Users with reservations for RAITH on the CORAL schedule before Noon
Friday should remove their reservations and reschedule for a later time.
Over the holiday we completed a 200 hour bake out of the System after
the PM routine was performed just before the shut down. We replaced the
Field Emission Gun tip, aperture plate, and performing many cleanings
and inspection routines of various sub-systems on the RAITH.
Completed thus far were the following:
1. Replaced the FE- Gun and multi-hole aperture plate with new parts.
2. System Administration to both the LEO and RAITH computers,
updating all windows patches and antivirus software definitions.
Swept the system of viruses and spy ware. NO Viruses found.
Backed up the system to HD.
3. Load Lock and transfer arm and track maintenance as scheduled.
Also tensioned the bands to this section
4. Inspection and Cleaning of the System Chamber and Piezo control
kinetic mounts. Check exchange positions for transfer arm.
5. Pole Piece removed inspected and cleaned.
6. Realigned the laser interferometer optimizing the laser signal to
12 Volt Peak to Peak, an optimal value.
7. Stage Motor Controller: Calibrated the X/Y Sin-Cosine control
board and checked the motors for current draw values. Tested the
motor controller power supply output voltage.
8. Exchanged the loaner Water Chiller with our repaired unit.
9. Performed an overnight bake out and a brief 'dry' run up of the
FE- gun up to 20 keV without the EHT voltage applied to evaluate
the cleanliness of the anode and aperture plates and FE-gun to
evaluate arcing concerns.
The extended bake out of the system completed 1800 hours December 25,
2004 and upon cooling the gun section reached 9.8 E -011 mBar. Upon
arrival yesterday I observed 1.8 E - 010 mbar vacuum. This is wonderful
vacuum level to start conditioning the FE-Gun and performing the service
run up greatly reducing the chance of FE-Gun arcing during the service
Yesterday afternoon we started the service and conditioning run up of
the FE-Gun. While one minor EHT trip event was encountered as we
initially brought the Fe-Gun on line, the rest of the ramp to 1000 Volts
went smoothly and we were able to maintain good vacuum. We will be
continuing this work, resuming this afternoon, and we plan to perform a
very slow and cautious run up to 10 KeV level before we start alignments
to the mechanical position of the FE-Gun, check out the E/O section of
the system, and finally performing all the usual calibrations and
adjustments of the gun, aperture(s), and stigmation centering functions.
After ~24 hours of beam time at this level I hope to be able to qualify
the system and hand off access to users late this week.
NOTE: There remain a number of issues still to be addressed to
effectively eliminate all the issues we encountered in the last quarter
of the year mainly related to image drift on image acquisition during
Write Field alignment; leakage and alignment of the Raith beam Blanker;
and elimination of the extra shot spots on reduced scan fields. The
remain a few other nagging concerns related to Single Pixel Line
resolution and circularity of Circle and dot shot features written with
the system we hope will be eliminated by the FE-Gun exchange and PM of
the SEM column.
I expect this work to take much of the week to complete but will offer
some access to RAITH Champions scheduled on the system after Friday Noon
and through the weekend. But with the caveat that only those whom are
willing to evaluate their results and promptly return to me their
measurements will get access to the system until I have finished all
outstanding action items.
FYI: I am writing up a document that describes the PM routine task and
will add this to my System Qualification Process Control Monitoring
(PCM) testing documentation previously posted and also in RAITH Notebook
No. 2 in the Lab.
Thank you for your support!
Previous announcement WED DEC. 8, 2004:
Greetings RAITH Users:
We will be taking the system off line from Monday December 13, 2004 at
10 00 AM through January 5, 12 00 hours.
The coral schedule has been blocked out for this period. Please do not
attempt to make reservation during this period.
We will make every effort to have the system back up completing all
adjustments to the system, and have the system performance qualified, by
NOON January 5, 2005 if all goes well through the PM, shutdown, start up
and qualification testing period.
Should unforeseen circumstances cause additional delays I will be
posting to this email discussion list the afternoon of January 4, 2005.
Please stay tuned.
Thank you for your support!
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