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Magnetic disturbance

R

Robert Macy

Jan 1, 1970
0
The magnets they use for that are usually the rubber, refrigerator type
that are barely magnetic.  I can't imagine they will mess up this
equipment unless they are pretty close to it.  I assume the vault itself
has restricted access.

One of my friends used to sell magnets for health.  She claimed that she
cured people with them and truly believed in them.  They cost a lot of
bucks too and were pretty worthless magnets.  It is amazing how easy it
is to fool otherwise intelligent people with a little techno-babble.

Rick

now for the 'non-scientific' answer.

ANY device that constantly reminds the wearer will have a positive
effect.

so magent, copper, woven seaweed, doesn't matter what it's made of.
Just the fact that the wearer is constantly reminded will produce
positive 'anecdotal' information.
 
J

Joerg

Jan 1, 1970
0
Jamie said:
The education and common sense level of those that apply for jobs these
days are amazingly low. But we need to have business as usual.

There is generally no problem with those that operate the equipment,
it's those that aren't usually in that area, like material handers,
brain dead salary, people on tour and the general no nothing grease
monkeys and contractors.

The best one's are the truck drivers when they drop a load or back
straight into a vault wall. Cracks in the containment walls are not
generally a good thing.

IMHO the best diagnostic avenue is a makeshift "magnetic pulse catcher".
Could be made with a scope that triggers upon exceeding a prescribed
good-bad band. The Instek GDS-series has that, at least my GDS-2204
does. In this case meaning it'll trigger when the normally flat
horizontal line wiggles either way. Hang a loop with burden resistor
onto it and wait until the next event. There would be a recording
afterwards. The shape of the pulse should give some good pointers of
what it could be. For example, if you see a brief burst of 60Hz cycles
you'd know :)

Just a thought, in case you guys haven't purged the facility of larger
CRT monitors: Those have degaussing coils. Some come on every time their
power is cycled, others come on at random. Fridge de-icing loops can
also cause some grief because sometimes they consist of a somewhat
resistive wire run around its door frame, meaning a loop many feet in
diameter.
 
M

Martin Brown

Jan 1, 1970
0
I was in work today and spent about 2 hours zeroing the sensor array
around each vault to get proper readings at the computer. What ever
happen the other day sort of corrected it self as for the E-Beam,
but the sensor array we have hanging around each vault did not fully
come back into zero alignment for what ever reason.

You enjoy talking in riddles it seems.

Difficult to comment sensibly without knowing what sensor technology you
are using and whether or not active shielding is involved.

One possibility is that one of your machines is going haywire and taking
the rest down. Or you are being affected by externally sourced radio
frequency interference that is wrecking the beam steering.
The sensors are something we constructed as a way to detect the
surroundings with in the critical areas of the E-beam to keep people,
metal objects and equipment from being place in proximity of the vault.

I presume the application is electron beam lithography but it would make
it a lot easier if you clarified this. Synchrotron radiation sources
also use electron beams as a means to an end.
If you disturb the area around too much in the area where the E-beam
is housed, it will cause the beam to steer off and if bad enough cause
heating in the aperture, which isn't a good thing because it can also
cause .001" thick titanium window to heat unevenly and thus start a leak.

Heating of the aperture can propagate up the drift tube and bellows
which all have gaskets that leak when slightly aggravated.

So, we try to force the system to shut down at the slightest hiccup so
there won't be hours or lost time and repair work.

Why are you so coy about describing what sort of kit it is?

An academic institution would by now have a simple crude primitive
magnetic field disturbance detector knocked up out of fishing line a
mirror and a magnet. Laser pointed at the mirror and the whole assembly
protected from drafts with a glass tube. Simples.

http://www.heliophysical.org.uk/files/5.pdf

Sophisticated gear can have complicated modes of failure. At present you
have no idea what caused your stuff to go AWOL and the way you are going
you will be every bit as mystified the next time it happens too.
 
J

Jamie

Jan 1, 1970
0
legg said:
There are many ways to carry out a beam scanning function, so this
isn't really a good way to describe the nature of the victim
equipment. Is it microwave radar, laser, atomic particle - what type
of beam technology is being disturbed?

The different units may be independant, but they will still share
power and probably communications. If they are directed at the same
target, this is also a common factor. If they run on the same
software/firmware revision, in the same time zone, that's also a
commonality. The longer-term effects suggest SW that is not
particularly error tolerant.

If the 'flux differential array sensors' that went screwy at the same
time were indeed multiple and independent of the misbehaving
equipment, then it might mean something. If they're just parts of the
misbehaving equipment, their output is meaningless.

RL

If you don't know what an E-Beam is, then I won't bother.

Jamie
 
J

Jamie

Jan 1, 1970
0
Robert said:
now for the 'non-scientific' answer.

ANY device that constantly reminds the wearer will have a positive
effect.

so magent, copper, woven seaweed, doesn't matter what it's made of.
Just the fact that the wearer is constantly reminded will produce
positive 'anecdotal' information.

We have inductive loops attached to the walls, spaced closely to form
an array. These loops are all driving via Atmega processors to generate
a pulse and fast compactors attached to the inputs.

They daisy chain together and the end unit will connect via serial to
the PC.

The program in each does not generate its own ID however, the values
for each zone are appended to a packet and the size of the packet and
CRC are recalculated. We have an input assigned to the uC indicating
it is the first unit via jumper, so it'll start TXing immediately and
the others will wait for a packet to arrive and then send it to the
next, etc.

The first unit will pause sending for the maximum time it would take
all 16 devices to send if they were implemented or if some error
resulted in the link some how.

With this kind of configuration, you are able to see moving objects as
they pass by the wall.

We don't use a BFO method because it is far to unstable but found that
using time constant on L works very well. The mosfet switches are used
to energize the coils. THe gate is driven via a bjt from the uC for the
on state and for the off state a pull down R is present at the gate to
allow for a slow turn off, we did this to avoid the wheeling voltages
and not use diodes, so far it seems to work


I use the atmega due to high IO count, so each uC can accumulate many
zones which will keep the lag down.

Also to add to that, when sampling in the group of IO's we need to
stagger loops, meaning, we can't energize a loop adjacent for obvious
reasons.

There are other little details we do with this system but I won't get
into that.
Jamie
 
J

Jamie

Jan 1, 1970
0
Paul said:
Jamie wrote:




Where are you located (part of the world, building occupancy type, etc.)?

Could be geomagnetic, or some guy next door doing some welding.
The E-beam processing is far from any form of known electrical
disturbance and it's housed in its own building attached to the main
structure..

Long before I was there, it was required it had to be built on a
cement slab to insure nothing below it was there. In the main building
we have transformer vaults but nothing goes under this building for the
E-Beam. Also it had something to do with environmental laws.

We are located in the center of CT, Northeast US.. I know Maine just
recently had an earth quake but as for as I know, we had no issues with
that here. Actually, the only think that happen was my dog getting
scared of something at the time it happen and insisted she had to come
in. I let her in and I noticed her tail was between her legs, she was
afraid of something, I had no idea what it was at the time.

There was reports of ground shakes, I didn't feel anything myself,
most likely too wrapped up with other things :0

Jamie
 
R

rickman

Jan 1, 1970
0
Relatively benign quackery, like homeopathy, in that it does nothing at
all.

It's not benign when it sucks money out of people's pockets. She loaned
me a six inch square pad to try on my back, she *insisted* in fact, and
when it didn't work she really wanted it back as it cost $100!

More recently she moved to the Sedona, AZ area and I don't see much of
her. She may be a wacko, but I might visit her some day.

Rick
 
P

Phil Allison

Jan 1, 1970
0
"Martin Brown"
Jamie said:
You enjoy talking in riddles it seems.


** Jaime is a fake name, the guy is " Maynard A. Philbrook" - a radio ham -
his call sign is KA1LPA .

He is an utter idiot and an egomaniac.

He haunts usenet purely to BIG NOTE himself.

Why are you so coy about describing what sort of kit it is?


** So he can keep control over the discussion, same as any troll does.

You sound like smart guy, stop wasting your time with the idiot.


..... Phil
 
J

Jamie

Jan 1, 1970
0
Paul said:
Perhaps someone is entering an EM railgun into the annual pumpkin chucking
contest.
Ha, quit.

It does not take much to whack out the system from the top side of
the vault, it's not protected that well and is cordoned off when in
operation.

I suppose some atmospheric abnormally could disrupt it. I know near
by strikes from
T showers does nothing to it, at least not enough for it to get
spassed out.

Talking about pumpkins, I stopped at a place today and got talking to
the clerk and he mention how he has this young labrador mix, he let him
out side for a bit and the lab chewed up half of the pumpkin he put the
the steps.. So any one that has dogs, beware, I guess some of them like
pumpkins.


Jamie
 
J

Jamie

Jan 1, 1970
0
Jeff said:
Try downloading data from the USGS National Geomagnetism Program at:
<http://geomag.usgs.gov>
Skimming the various strip chart graphs shows some rather radical
short term variations. Where are you and what was the date and time
of the event so I can play with the numbers? Looks like the real time
graphs only go back 4 days.
This happen in the middle of last week.. and I did check one of those
sites. As best as I understood it, it does look like some red hot spot
was over our area just about at that time. That is, if I read the image
and data correctly.

It's really weird and not the first time this has happen.

But, can't let that get in our way, even though it force a lot of work
on the machine operators to pull back the product they were running
though it to make sure it got a proper dose. Some of the products run
through it takes 2 people just to pick up one end.

Jamie
 
J

Jamie

Jan 1, 1970
0
Phil said:
"Martin Brown"




** Jaime is a fake name, the guy is " Maynard A. Philbrook" - a radio ham -
his call sign is KA1LPA .

He is an utter idiot and an egomaniac.

He haunts usenet purely to BIG NOTE himself.






** So he can keep control over the discussion, same as any troll does.

You sound like smart guy, stop wasting your time with the idiot.


.... Phil
Phil, you're embarrassing yourself, again..

The offer is still open to come to the states for some good drugs
to get you docile and subservient. You'll work out well for a door stop.

Phil I got to say, you are way off base about what you think you know
about me and it's so funny it makes me laugh and the guys at work get a
kick out of it when they see the posts you make. Just another
poor sap from down under that has lost their way.

Jamie
 
J

Jamie

Jan 1, 1970
0
Jeff said:
That would be Weds Oct 24th.




If true, that probably answers your question.




Plan your disasters carefully.




I thought you were doing wafer fab, not electron beam welding.

hell no, we do cross linking of insulating materials. Other people
use the same type of equipment to irradiate food, tires etc...

I don't know how much energy is involved with wafer fabrication but
we can go up in the range of 2.5 Mev on a couple of the machines with
a large scanning area. One of those machines are fed with paired 750MCM
feeds from the buss, that is each phase has a pair of 750MCM, the other
machines use paired 500MCM

We met up with some one about 5 years ago now, that has a unit that
requires a dedicated feed from the electric company, lots of power
there. They irradiate anything for any one accept petroleum, that is
done with a proton accelerator.


We do custom electronics for other operations in the business too,
everything we do stays in the circle of the company. We do not
design anything for commercial applications out side of what we do there
or what ever one of our other locations may need.

Out side of that, I do get into designing electronics that is not
related to my job. The last big adventure I got into was redoing an
eddy current heat treating process inverter system, that was fun. snack
toy money.


Jamie
 
B

Bill Sloman

Jan 1, 1970
0
  hell no, we do cross linking of insulating materials. Other people
use the same type of equipment to irradiate food, tires etc...

   I don't know how much energy is involved with wafer fabrication but
we can go up in the range of 2.5 Mev on a couple of the machines with
a large scanning area.

E-beam wafer fab work doesn't involve a lot of energy. It's just
exposing an electron-sensitive resist, typically for less than a
microsecond. The standard Cambridge Instruments set-up was built
around their S-250 electron microscope, which only went up to 40kV -
there was some interest in getting it up to 100kV, but I don't know if
it got anywhere.

While you gained from the finer focus, you lost from the spread of the
high-energy secondaries in the silicon under the resist.

<snip>
 
B

Bill Sloman

Jan 1, 1970
0
Egads, a major power user.  It's going to take a rather large magnetic
field to move such a high power electron beam.  I was thinking in
terms of electron beam lithography in a wafer fab, which is probably
more sensitive to magnetic fields than your monster.

It's not power that matters, but voltage. The faster the electron is
travelling, the harder it is to bend it's path.

And you bend the path of each electron by the same amount. A moving
electron does constitute a current, but not a large one.
 
J

Jamie

Jan 1, 1970
0
Bill said:
It's not power that matters, but voltage. The faster the electron is
travelling, the harder it is to bend it's path.

And you bend the path of each electron by the same amount. A moving
electron does constitute a current, but not a large one.

We didn't have any issues with the electrons impacting on a non
intended target. It was a problem with the aperture heating up due to
some disturbance that forced the steering out of alignment enough to
abend the system. On top of that, it saturated the sensor array we have
attached on the out side of the protected vault walls.

btw, we have a storm coming in on us and they called me this morning
to notify me of them canceling operations at our facility. So i'll be here
to aggravate every one, including you.


Jamie
 
J

Jamie

Jan 1, 1970
0
Jeff said:
Egads, a major power user. It's going to take a rather large magnetic
field to move such a high power electron beam. I was thinking in
terms of electron beam lithography in a wafer fab, which is probably
more sensitive to magnetic fields than your monster.

Well, maybe a CME (coronal mass ejection) landed some charged
particles on your wiring adding a DC component to whatever you're
using to feed the ray guns. It wouldn't take much DC on the power
lines to create a magnetic field inside the building:
<http://www.spaceweather.com/archive.php?view=1&day=24&month=10&year=2012>
Well, there was a solar flare on the 23rd, but no CME. Ok, I give up.
True but, the units we have do not all come off the same transformers
and they are located far from the location.

Even though we are generating lots of energy, still does not actually
take that much to move the beam, when the train passes by behind the
building we can notice a slight shift in the machine that is closes to
the tracks, steering is critical. On the original machine, which is
still in operation, focus coils have been added but not for focusing and
a couple of small permanent magnets are position just above the scan horn
to correct for an obstruction in the structure so the beam will scan in
a straight line.

We are thinking of using a DDS type system to generate a AB pattern so
we can create custom steering for problems like these. The manufacture
of the machines told us they once tried to engineer a multpoint ramp
signal generator ref for the scan amps but didn't have much success with
it at the time. I guess they had an array of 10 turn pots to set each
point into a summing circuit from a digital IO mux chip.

Playing with present DDS technology at the board level would be a
first for me ;)

Have a good day.
Jamie
 
G

George Herold

Jan 1, 1970
0
I once took one of those super space magnets [so strong they can make
a Canadian dime stand on its edge through your hand] and held it close
to my old [favorite] monitor and wow what great color changes. only to
find the effects became permanent! not even ON/OFF cycling did a
thing. Then I remembered how energetic the fields from my cheap pencil
sharpener were, held it close to the screen, sharpened a pencil, and
voila! degaussed the nickel layer on the monitor making the color
better than before! whew!  I was very looky I didn't permanently bend
or break that film, too.

I got myself into the same situation years ago. I finally thought to use
my big Weller soldering gun as a degausser.- Hide quoted text -

- Show quoted text -

I've used a variac and coil to deguass things. (tweezers and small
tools.)

George H.
 
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