Re: Amptek SiPIN vs FastSDD - Recommendations?
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Soren,
I would agree with Charles
on the SiPin detector on the basis of cost vs resolution. The Si-Pins that we
see on ebay are 25mm^2 which is the lowest resolution version of these
detectors. An SDD has much better resolution and count rate but at a price. A
6mm^2 Si-Pin has about the same resolution as a 25mm^2 SDD but the SDD has a
10x better count rate while maintaining the resolution.? SDD¡¯s are useful in
high count rate high resolution situations and excel down in the lower energies
and at lower peaking times. At the higher energies where broadening is a factor
the two are getting to be comparable.
For a hobbyist application
the excitation source is really weak so the count rates are low and a Si-Pin
can use a higher peaking time to get better resolution while not worrying low
energy noise and about count rate limitations. And the price is much better and
does the job needed.
The digital stacks are tailored
to the detector at the factory and aren¡¯t interchangeable without a new software
flashcode as I understand it, Geo will know more about that.
Dud
?
From:
[email protected] [mailto:[email protected]] On
Behalf Of Charles David Young
Sent: Thursday, December 3, 2020
10:54 AM
To: XRF
Subject: Re: [XRF] Amptek SiPIN vs
FastSDD - Recommendations?
?
I'll just relate my experience with the Amptek SiPIN that I have been
using for a year or so.? It is great for helping me identify
minerals.? Even if I had the budget for an SDD I doubt I would go that
way.
You on the other hand may have an application where the SDD would have
serious advantages.? If you can justify the expense then by all means, go
for it.
You might give us an idea of your application.? If you don't have
anything specific and are just interested in learning about XRF then I would go
with the Amptek SiPIN.
?
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On Thu, Dec 3, 2020 at 10:41 AM Soren <justinhuber@...> wrote:
I'm a bit new to the world of XRF and am currently using an old
scintillator probe and some NIM modules - but the resolution isn't great.
I've been looking at some Amptek setups on eBay and have been corresponding
with GEO and it was recommended that I post this question on the forum:
There are several complete Amptek systems for sale on eBay. (I hope this
question doesn't encourage someone to buy them before I do!) I'm trying to
understand the tradeoffs.
SiPIN system
- 25mm
SiPIN detector
- PA230
preamp
- DP5/PC5
stack for power and pulse processing.
This is one of the systems that Geo posted pictures of in June and
July. It would seem that the electronics are current model products.
FastSDD system
- 25mm Fast SDD - 500um - 0.5mm Be Window
- PA230 - looks to be an early model of the PA230 Board
- Red PCB vs. normal Green/Blue PCB with fewer parts
- DP5X - looks to be a simpler integrated version of the
DP5/PC5 board combo.
I've studied the pictures of the PA boards for which I could find pictures to
see how they have evolved over time. I've seen about four different versions,
which increase in complexity. But I'm not sure if this is a function of product
development over time or that one board may be designed for SiPIN vs SDD.
Anyway, I wonder if
anyone has some insight into the tradeoffs between the two complete systems
mentioned SiPIN vs FastSDD. One has the obviously better detector (SDD). The
other seems to have the better backend electronics (SiPIN) and is cheaper. I'd
love to have anyone's expertise if figuring out which may be the better option.
BTW, if anyone is curious, here are some of the patents which seem to show the
inner workings of some of the Amptek Systems:
- US6,587,003B2 - Charge Sensitive Preamplifier
with Pulsed Reset Source - the secret sauce in low noise preamplifiers,
besides a good FET and OpAmp, is using a pulsed reset instead of a large
drain resister, which adds noise. This approach is explained in Amptek's
Reset Preamplifier Application Note.
- US7448802 - Integrated X-Ray Source Module - The
X-ray source that Amptek sells appears to be made by Newton Scientific -
this is the schematic of the inner electronics which could be useful for
someone trying to repair one of these units. The reference for U10 which
is the main controller IC is conspicuously absent - but it looks to be the
UC1872/2872/3872 made by Unitrode
- US7949099 - Compact High Voltage X Ray Source -
you can also look at how the tubes themselves are put together.
NOTE: These designs are
still under patent protect so I would not recommend that someone actually build
any of these - but they could be useful for repair.
Thanks so much for your help.
All the best,
Soren
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