How to figure out the specs of old Rigaku scintillation tube probe?

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Bruce Meagher
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Re: How to figure out the specs of old Rigaku scintillation tube probe?

Post by Bruce Meagher » Thu Jan 03, 2019 10:56 pm

Harald,

It would have helped if you included a picture or a link to the detector you were considering. A quick eBay search turned up a Rigaku scintillator detector such as this <https://www.ebay.com/itm/153324151509>. Is this similar to what you were considering? I’ve included a couple images below because the eBay link will expire. This appears to be a scintillator detector and not an x-ray tube.

The first question you should answer is what is your intended use of a "scintillator" detector? Knowing what you are trying to measure would allow others to offer opinions on the appropriateness of a particular detector. I’d hazard a guess this is a small NaI(Tl) detector with a beryllium window coupled to a photomultiplier tube used to capture low energy photons (based on the images and its intended use). If you’re planning on doing elemental analysis by x-ray fluorescence this might be just the detector to get you started. Not knowing the exact material, size, or any specs of the detector makes it a fishing expedition. The fact Rigaku makes XRD and XRF equipment suggests their detectors will be optimized for low energy photons. Purchasing it and tearing it apart will remove the mystery.

Taking a random part off a system and trying to reverse engineer it can be an easy or a monumental task. Having little experience with the design and operation of the particular part puts it more on the difficult side. If you have a good familiarity with photomultiplier tubes and preamps then reverse engineering this particular part might not be all that difficult.

Bruce
Attachments
Rigaku 1.jpg
Rigaku detector
Rigaku 2.jpg
Riga detector window

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Dennis P Brown
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Re: How to figure out the specs of old Rigaku scintillation tube probe?

Post by Dennis P Brown » Fri Jan 04, 2019 8:27 am

As I posted previously, and found from the article you provided, it stated that some units used a simple scintillation detector. Other units, I have to assume, then used visible light detectors - either single element or maybe multiple elements (likely silicone diode array(s) found in cameras) that were used to detect the visible light created by fluorescence from the x-rays hitting the IP or PET films in the spectrometers. If the company cannot or does not provide information on the unit you have, providing a picture is, as Bruce suggests, a good idea to help people here determine the detector type.

Harald_Consul
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Re: How to figure out the specs of old Rigaku scintillation tube probe?

Post by Harald_Consul » Fri Jan 04, 2019 11:57 am

Ok. Here come the pictures (assembled from two independent ebay offers of the same article):

Rigaku_Pic_Total1.jpg
Rigaku_Pic_Front2.jpg
Rigaku_Pic_Plugs1.jpg
Rigaku_Pic_Plugs2.jpg
Rigaku_Pic_Plugs3.jpg

Desired inention/ purpose of the detector:
Harald_Consul wrote: Beryllium window detection tubes like the Rigaku tube are perfect broad band particle dectors (alpha, beta, gamma radiation and protons, I guess). It would be perfect to optimize the design of an ion gun.
[edit]
It would also be helpful, if you described how to figure out the electrical wiring of the plugs of your scintillation tube using low voltage from a multimeter or so, assuming the case you have lost the manual.
[/edit]

Harald_Consul
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Re: How to figure out the specs of old Rigaku scintillation tube probe?

Post by Harald_Consul » Fri Jan 04, 2019 8:50 pm

I have decided on the successor Rigaku detector tube model 211080W now, which Bruce had figured out.

I first thought, it would be too expensive for me, but the seller gave me 33% discount. 400 USD for such a detector tube is a very good deal.

I will power it with the BERTAN PMT-20C/N-1 OPTION 1; 0 to 2KV HIGH VOLTAGE POWER SUPPLY. This guy also gave me 25% discount.

Just still need to know about the wiring of of the sensor connector, which has one pin more than the M8 4-pin sensor connector.

Rigaku2_Pic6.jpg

Bruce Meagher
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Re: How to figure out the specs of old Rigaku scintillation tube probe?

Post by Bruce Meagher » Fri Jan 11, 2019 6:19 pm

Harald,

I’ll be following your efforts with much interest. I would imagine you’ll have to do a complete teardown to really understand what you have purchased. There is no way of knowing the signals on the connectors unless you reverse engineer the electronics inside (or get a schematic from Rigaku). If this is truly an NaI(Tl) detector you’ll want to know the size and the condition of the crystal. They are hydroscopic and can crack if mishandled. If you purchased this as “used" on eBay you should be able to return it if the crystal is damaged.

As for the intended use I don’t think these would be useful for optimizing an ion source. I do not believe protons of low energy will penetrate the window material (you'll need the thickness and stopping power tables to confirm). The maximum counting rates for NaI detectors are on the order 1e6 counts/second which would correspond to a tiny ion current. I would also think hitting a detector with an ion beam of much power would quickly destroy the window.

It could be very useful for general counting and maybe even some spectroscopy work depending on the crystal size.

Good luck!

Bruce

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Re: How to figure out the specs of old Rigaku scintillation tube probe?

Post by Harald_Consul » Sun Jan 13, 2019 7:48 pm

Oooh f***, I didn't consider the scintillator crystal is hygroscopic!! In Germany most incoming parcels get desinfected with some glue liquid as a biological warfear counter measure (German Angst, you know). I really hope this won't damage the crystal.

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Re: How to figure out the specs of old Rigaku scintillation tube probe?

Post by Harald_Consul » Mon Jan 14, 2019 7:55 pm

From my (unaware) point of view there basically may be the follwing approaches to measure the power of a ion beam by a scintillator:
  1. Using a scintillator for alpha radiation [with Cesium iodide (CsI) or zinc sulfide (ZnS) crystal]
  2. Using a dummy target, that will produce gamma radiation, when bombarded with ions, and measuring with a scintillator for gamma radiation
  3. As no. 2, but slowing down the gamma radiation with lead or sonmething to x-ray radiation and then measuring with a scintillator for x-ray
  4. Reversing the polarity of the ion gun and producing an electron beam instead (for optimizing the design, only), beaming it onto a dummy alu-foil (tin-foil) target producing x-ray bremsstrahlung, then measuring with a scintillator for x-ray

No 4. is what I have got currently on my mind (until you tell me better ;-) ).

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Re: How to figure out the specs of old Rigaku scintillation tube probe?

Post by John Futter » Tue Jan 15, 2019 6:13 am

Harald
We use beam profile monitors at work to know the shape and position of our ion beams
look them up they are a bent peice of wire that rotates within the ion beam tube and present a differing position target to the beam without taking out much beam energy so you can leave them in while running
I tried to attach a PDF but the new rules are inane
lookup tupb005.pdf

Bruce Meagher
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Re: How to figure out the specs of old Rigaku scintillation tube probe?

Post by Bruce Meagher » Tue Jan 15, 2019 7:54 am

I believe an NaI scintillator is the wrong device for optimizing a low energy ion beam. IMO, the very first step would be measuring the beam current with a faraday cup and an electrometer. Alpha’s from #1 will not make it through your window (edit: I assume you mean helium ions from an ion source not alpha particles from a nuclear decay). What gamma’s can be produced from a few keV ion beam in any material and with what yield? I claim #3 would produce no usable x-rays based on the answer to #2.

John and Andrew have done extensive work with ion sources so take note of their suggestions.

Bruce
Last edited by Bruce Meagher on Wed Jan 16, 2019 9:23 am, edited 1 time in total.

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Dennis P Brown
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Re: How to figure out the specs of old Rigaku scintillation tube probe?

Post by Dennis P Brown » Tue Jan 15, 2019 1:21 pm

Read both of Bruce Meagher's posts carefully. He is 100% correct.

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