[trARPES] Fwd: Re: METIS: current status and to-do list

Laurenz Rettig rettig at fhi-berlin.mpg.de
Fri Jun 29 10:04:38 CEST 2018




-------- Forwarded Message --------
Subject: 	Re: METIS: current status and to-do list
Date: 	Thu, 21 Jun 2018 14:01:19 +0200
From: 	Martin Ellguth <ellguth at surface-concept.de>
To: 	Ralph Ernstorfer <ernstorfer at fhi-berlin.mpg.de>, 
Elena.Arbelo at specs.com <Elena.Arbelo at specs.com>, 
Marko.Wietstruk at specs.com <Marko.Wietstruk at specs.com>, Michael Kallmayer 
<kallmayer at surface-concept.de>, Thomas Berg <berg at surface-concept.de>, 
oelsner at surface-concept.de <oelsner at surface-concept.de>, Schönhense, 
Prof. Dr. Gerd <schoenhe at uni-mainz.de>
CC: 	Laurenz Rettig <rettig at fhi-berlin.mpg.de>



Dear Ralph,

I am working on the list of issues and so far have solutions for A1, A2, 
A7, A12, B14, B15.
A8 is a small fix, but best done interactively (i.e. either TeamViewer 
or service at your site ---
the extent of necessary software updates will eventually require a visit 
at your site, anyways).
B18 does not require a solution since the independent time histogram is 
already provided in form of the
1D Custom Projections in the current software version.

A3 is a big task and I cannot predict how much time it will take (could 
be anything from 2 weeks to several months)
but I think it is important to fix this first, since it will potentially 
change parts of the EPICS interface as well (i.e. some
names of process variables) which might require adaptations of software 
that you build on top of the TDC EPICS ioc.
Issues B16, B17 depend on the fix for A3.

A4 is something I was not able to reproduce yet. Does this occur for 
live histograms and accumulated histograms?

There won't be any fixes for A5, since the behaviour can be avoided by 
first starting the servers and
only starting Control System Studio afterwards.

I believe A6 can also be avoided by a proper sequence of booting up the 
METIS components. In particular,
the high-voltage supplies require 1-2 minutes of boot-up time, before 
the corresponding EPICS server can
connect to them. Even though the HV crates may become visible in the 
network earlier than 1 minute after boot-up,
launching of the device servers should be really delayed by 2 minutes 
after powering-on the HV crates.

A9 (manual) will not be available in short time, but in the meantime, I 
can prepare some document that explains
the custom cuts.

A10: the hdf5 file should be self-explanatory after the last patches 
that I had sent (i.e. the Streams have
names X, Y, t, MasterRstCtr, ADC, State Input). The range of values 
available for the individual event data
fields in the hdf5 files follows from the bit widths that the 
intermediate software layer (libsctdcDeviceWrapper) uses.
I will prepare a document which describes how these bit widths can be 
adapted.

The computer freezes (D29) could be due to a bug in the AMD Ryzen CPU 
firmware in combination
with using a Linux OS. There are customer reports with a similar 
description (sudden freezes approximately twice a week):
https://community.amd.com/thread/225795
For the next service visit, I would try the latest BIOS update and see 
if afterwards the BIOS setup
offers a parameter "Power Supply Idle Control" that can be set to 
"Typical Current Idle", which the users in the
linked forum thread reported as fixing the freezing issues.

Since the fix to A3 is rather urgent, I propose to dedicate attention to 
the remaining points of your list only
after I have prepared a solution to the A3 issue.

Best regards,
Martin



Am 21.06.2018 um 09:45 schrieb Ralph Ernstorfer:
>
> Dear all,
>
> we are curious about your thoughts on the various items on our list. 
> In addition, we would like to discuss a timeline on which the urgent 
> items are addressed as some issues are truly inconvenient and slow our 
> progress.
>
> Please let us know if some aspects aren't described clear enough.
>
> Cheers,
>   Ralph
>
>
> Am 14.06.2018 um 18:33 schrieb Ralph Ernstorfer:
>>
>> Dear all,
>>
>> we have gained some practical experience with the METIS by now and 
>> collected first data with the fs XUV (22 eV) pulses. Some of the data 
>> looks very nice already, see attachment. The short visit of Gerd and 
>> Hajo during their BESSY beam time was extremely helpful. We are still 
>> far from truly mastering this instrument, though.
>>
>> We also gained some experience with the software. While a lot of 
>> things work fairly nicely, there still is a number of issues ranging 
>> from bugs to aspects that are inconvenient to a wish list of 
>> features. We collected these in the attached document. We are aware 
>> that it's a fairly long list, but we have sorted it according to 
>> category and severeness of the issues.
>>
>> We noticed a count rate dependent electron artifact during the site 
>> acceptance test. It is also described in the attachment.
>>
>> Besides software and data acquisition, there is an issue with the 
>> magnetic shielding. There is indications that magnetic fields enter 
>> the spin filter replacement tube, deflecting the electrons 
>> vertically. When using 22 eV photon energy, we have not found an 
>> alignment yet where the electrons propagate on the optical axis of 
>> the objective lens and the subsequent lenses (A-F), arrive centered 
>> on the detector without being distorted in both imaging modes. This 
>> was already noticed during the factory acceptance test (distortions 
>> of the CHESSY sample images), i.e. it does not arise from our lab 
>> environment. Do you have suggestions for improving / fixing this issue?
>>
>> Cheers,
>>   Laurenz and Ralph
>>
>>
>>
>>
>>
>>
>> -- 
>> Ralph Ernstorferernstorfer at fhi-berlin.mpg.de
>> Research Group Structural and Electronic Surface Dynamics
>> ERC project FLATLAND
>> Fritz Haber Institute
>> Faradayweg 4-6                              Tel: +49 30 8413-5117
>> 14195 Berlin                                Fax: +49 30 8413-5387
>> Germany
>> http://w0.rz-berlin.mpg.de/pc/ernstorfer/
>
> -- 
> Ralph Ernstorferernstorfer at fhi-berlin.mpg.de
> Research Group Structural and Electronic Surface Dynamics
> ERC project FLATLAND
> Fritz Haber Institute
> Faradayweg 4-6                              Tel: +49 30 8413-5117
> 14195 Berlin                                Fax: +49 30 8413-5387
> Germany
> http://w0.rz-berlin.mpg.de/pc/ernstorfer/
> ---------------------------------------------------------------------- 
> Das FHI verarbeitet, speichert und loescht Daten im Rahmen seiner 
> Geschaeftstaetigkeit gemaess der Datenschutz-Grundverordnung (DSGVO) 
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-- 
Dr. Martin Ellguth
SURFACE CONCEPT GmbH
Am Sägewerk 23a
D-55124 Mainz


----------------------------------------------------------------------
Das FHI verarbeitet, speichert und loescht Daten im Rahmen seiner
Geschaeftstaetigkeit gemaess der Datenschutz-Grundverordnung (DSGVO)
[General Data Protection Regulation (GDPR)] der Europaeischen Union.

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