Sphenix-tpc-l mailing list

[Evgeny Shulga <mohaas33 AT gmail.com>]

Hello,
Almost all antistatic sheets are attached with tape but some are not and it is usually unexpected, 

I am just asking to keep consistency,

GEMs with deflections usually have no issues with the currents, at the end, the question is about the uniformity of the fields.

Cheers,

Evgeny

Department of Particle Physics and Astrophysics

Weizmann Institute of Science

E-mail: evgeny.shulga AT weizmann.ac.il

About me:  cern.ch/eshulga 

Phone: +972536120793

Address: 234 Herzl St. PO Box 26, Rehovot 7610001 Israel

On Wed, Apr 28, 2021 at 6:17 PM Klaus Dehmelt <klaus.dehmelt AT stonybrook.edu> wrote:

Hi Evgeny,

I am afraid we cannot do anything against the non-taping of the antistatic sheets on top of the GEMs. I understand that they are flying in the LFT, however, if we tape them to the other sheets we will have a hard time getting them off and destroy them quickly.

We have to see how the GEMs with deflections will behave once assembled in a module. At this time I assume they behave properly when applying a voltage to them.

Cheers,

Klaus

********************************************

Klaus Dehmelt

Stony Brook University

Dept. of Physics and Astronomy

Stony Brook, NY 11794-3800, USA

Office C-108

Phone +1 631 632 8115

E-mail klaus.dehmelt AT stonybrook.edu

My Webpage

*********************************************

On Tue, Apr 27, 2021 at 1:49 PM Evgeny Shulga <mohaas33 AT gmail.com> wrote:

Hi Klaus,

Is the picture showing that a part of the Kapton is ripped off? Was this the only one or are there more?

_______

The picture should show that the surface of the GEMs is not flat (attached is the picture with highlights)

There are a few such GEMs in this batch, for example:

https://sphenix.physics.sunysb.edu/TPC-data/R1.GF-G2.R1-G2-10.2021-04-07_04:10:52.R1_G2_10.jpg

I am not sure what you mean by that not all plastic foils on top of the GEMs are taped. Are you saying that the protecting plastic sheets are loosely laid on the GEMs? 

_______

Yes the protecting plastic sheets are loosely laid on the GEMs and those are electrostatically attached to the paper foam and then fall on top of the GEM

What is LFT? I found with a Google search -liver function test-

_______

LFT is a Laminar Flow Table, I wanted to emphasize that the space is limited and if the plastic which is covering the GEMs is electrostatically attached to the upper foam-protecting sheet it is an issue for handling

Cheers,

Evgeny

Department of Particle Physics and Astrophysics

Weizmann Institute of Science

E-mail: evgeny.shulga AT weizmann.ac.il

About me:  cern.ch/eshulga 

Phone: +972536120793

Address: 234 Herzl St. PO Box 26, Rehovot 7610001 Israel

On Tue, Apr 27, 2021 at 7:35 PM Klaus Dehmelt <klaus.dehmelt AT stonybrook.edu> wrote:

Hi Evgeny,

is the picture showing that a part of the Kapton is ripped off? Was this the only one or are there more?

I am not sure what you mean by that not all plastic foils on top of the GEMs are taped. Are you saying that the protecting plastic sheets are loosely laid on the GEMs? What is LFT? I found with a Google search -liver function test- :-)

Cheers,

Klaus

********************************************

Klaus Dehmelt

Stony Brook University

Dept. of Physics and Astronomy

Stony Brook, NY 11794-3800, USA

Office C-108

Phone +1 631 632 8115

E-mail klaus.dehmelt AT stonybrook.edu

My Webpage

*********************************************

On Tue, Apr 27, 2021 at 3:14 AM Evgeny Shulga <mohaas33 AT gmail.com> wrote:

Hello,

Yesterday during the meeting I have mentioned that there are foils with "depression"

Attached is the photo of such case

More over not all the plastic foils on top of the GEMs are taped - that is very unpleasant in our LFT conditions

Cheers,

Evgeny


Department of Particle Physics and Astrophysics

Weizmann Institute of Science

E-mail: evgeny.shulga AT weizmann.ac.il

Phone: +972536120793

Address: 234 Herzl St. PO Box 26, Rehovot 7610001 Israel

   

On Sun, Apr 25, 2021, 10:11 PM Klaus Dehmelt <klaus.dehmelt AT stonybrook.edu> wrote:

Hello everyone,

we will meet tomorrow, Monday, April 26 at 11 AM EDT for our bi-weekly sTPC meeting. You can find a tentative agenda here. The agenda is protected with babar1008.

Please let us know if you want to present.  

Since we will be losing BlueJeans access in a couple of weeks we will switch over to ZOOM. The ZOOM coordinates are:

Time: Apr 26, 2021, 11:00 AM EDT
Join Zoom Meeting
https://stonybrook.zoom.us/j/92612427215?pwd=TVFQUHBZd2JOb0lnNjJyS3htYncwZz09

Meeting ID: 926 1242 7215
Passcode: 777724

Cheers,

Klaus

********************************************

Klaus Dehmelt

Stony Brook University

Dept. of Physics and Astronomy

Stony Brook, NY 11794-3800, USA

Office C-108

Phone +1 631 632 8115

E-mail klaus.dehmelt AT stonybrook.edu

My Webpage

*********************************************