Subject: FYI: Gun trips and raith computer shut downs experienced today
From: James Conway <jwc@snf.stanford.edu>
Date: Wed, 01 Dec 2004 18:06:47 -0800
Wed, 01 Dec 2004 18:06:47 -0800
Greetings:

For your information and benefit:

1. Today we have been observing FE-gun emission instability and an 
increase in amplitude of  fluctuations through our session this 
afternoon.  Beam Currents were observed varying from 0.1550 to 0.1568 
through a three minute period of measurements. 10 kV 30 um aperture 5.12 
mm WD.

This is to be expected as we approach the end of the FE-Gun's useful life.
We experienced this before just before the gun went down  last year.

During our write the EHT also tripped off and we had to abort the run 
and restart the gun again once. No EHT trip event was recorded on the 
LEO server but the raith software caught this and alerted us as a FATAL 
error.

Users are requested to record all gun trips and emission variability 
observed into the run logbook in the results and comments section and in 
the CORAL report problems section.

2. For the third time this week upon inserting a USB stick into the 
front USB port on the RAITH computer the computer powered down 
abruptly.  I am continuing to evaluate this problem to determine where 
the exact problem may be.

Users are requested to report all computer crashed for any means onto 
CORAL make comment.

Thank you,

James Conway
12012004:1801




Greetings:

For your information and benefit:

1. Today we have been observing FE-gun emission instability and an increase in amplitude of  fluctuations through our session this afternoon.  Beam Currents were observed varying from 0.1550 to 0.1568 through a three minute period of measurements. 10 kV 30 um aperture 5.12 mm WD.

This is to be expected as we approach the end of the FE-Gun's useful life.
We experienced this before just before the gun went down  last year.

During our write the EHT also tripped off and we had to abort the run and restart the gun again once. No EHT trip event was recorded on the LEO server but the raith software caught this and alerted us as a FATAL error.

Users are requested to record all gun trips and emission variability observed into the run logbook in the results and comments section and in the CORAL report problems section.

2. For the third time this week upon inserting a USB stick into the front USB port on the RAITH computer the computer powered down abruptly.  I am continuing to evaluate this problem to determine where the exact problem may be.

Users are requested to report all computer crashed for any means onto CORAL make comment.

Thank you,

James Conway
12012004:1801