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

Posted: Sun Dec 30, 2018 6:43 am
by Harald_Consul
I have found an old (1980s or 1990s) Rigaku scintillation tube probe on ebay (which afaik is good quality equipment). The price is attractive.

However the problem is, the seller can neither provide the specifications nor the correspending meter for it. Also the manufacturer Rigaku does not provide any service for the item any more (no manuals, no design plan), as the item is to old.

Is there a possibility to figure out the specs of the old scintillation probe by reverse engineering or alike? I mean in a sensible time horizon of days (not months).

Thanks in advance

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

Posted: Sun Dec 30, 2018 9:49 am
by Dennis P Brown
Most tubes are fairly easy to find data on once one knows the tube type (required operating voltages) - that might require opening the unit. Read out units tend to be very similar but my experience is rather limited.

Just an aside: most scintillation counters do not work for neutrons.

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

Posted: Sun Dec 30, 2018 2:30 pm
by Harald_Consul
No neutron detection, I know.

Due to an old Rigaku journal article from 1991 the tube specs are
  • Tube voltage: 50kV
  • Tube current: 300mA
A little bit strange. However, Rigaku staff personal should know their tube very well.

I hope they mean 50kV DC. Otherwise, it would be hard to generate for me.

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

Posted: Sun Dec 30, 2018 4:03 pm
by Richard Hull
That sounds more like an x-ray tube!!!! An industrial one, at that!

True scintillation probes never run much over 1500 volts at 100ua.... More normal, 900 volts.

Richard Hull

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

Posted: Mon Dec 31, 2018 1:02 am
by Robert Dwyer
It says in the article you posted that this is an x-ray tube not a scintillator. Good luck powering it, but I still suggest you dont try as 50kv 300ma x-ray tube is lethal.

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

Posted: Wed Jan 02, 2019 2:55 pm
by Harald_Consul
Are you really sure, that the technical description

X-ray tube Cu
Tube voltage: 50kV
Tube current : 300 mA

does really apply to the detector tube, and not the x-ray generation tube? I mean a differential x-ray spectroscope works like this, that some material gets x-radiated by one x-ray tube and another detector tube looks at the x-waves, that have passed through the material, right?

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 a ion gun.

I thought I could operate with the 3 kV or less from the power supply of a Turn-Key Helium-3 He-3 Neutron Counter. The unit can also get equipped with a x-ray detector tube (without beryllium window).

But reverse engineering in high-voltage would be too dangerous, even for me.

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

Posted: Wed Jan 02, 2019 4:57 pm
by Dennis P Brown
As Richard and others pointed out, scintillation tubes generally require no more than 3 kV excitation (more often, less) and use a very small micro-amp current. A 50 kV, 300 ma supply even for a fusor would be massive (i used a 32 kV, 35 ma supply and had to water cool my fusor due to heat issues.) That grade of supply is what powered old massive x-ray tubes. Those specifications just aren't for a detector. But even if you have an x-ray detector (and it would never require those power levels), that is is only of marginal use for fusors - to check safety issues for 30 kV and up fusors. Absolutely no detector exists that requires 50 kV and 300 ma to operate. Besides, most such tubes (x-ray generating) used copper as its target electrode just as you indicate for the tube type - Cu.

If you can build or obtain a negative (DC) power supply that can output 50 kV with current capabilities over 50 ma, you have an excellent and very powerful fusor supply. Can be used for an ion gun too but the x-ray danger is very serious and lethal if not properly shielded. Issues of reverse electron flow are also serious and dangerous issues for x-ray generation up stream from the target.

The article mentions they use plastic films that provided visible light outputs (fluorescence from the IP and PET films) as well as a scintillation tube (maybe for x-ray detection or possibly just visible detection from the films - not clear from the paper.) These types of detectors are not useful for particle detection at all.

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

Posted: Wed Jan 02, 2019 9:08 pm
by Robert Dwyer
The radiation safety aspect of operating such a supply cannot be overstated. At 50kv and 300ma the amount of x-rays produced in a typical fusor will be copious and lethal. At 50kv 5ma, I was producing a measured dose of 2mrem/hr 4 feet away from my device. Assuming you aren't running a a true ion beam device (in hard vacuum), scaling that dose up 60x is 120mrem/hr. That is a dose I wouldn't be comfortable being around, and almost certainly would require some type of liscense. Locking lead bricks are minimum for shielding (IMO), with a LOT of distance being your friend.

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

Posted: Wed Jan 02, 2019 11:53 pm
by Richard Hull
I think this is a dead duck. He will not get the x-ray tube, since he thought it was a scintillation tube.

Richard Hull

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

Posted: Thu Jan 03, 2019 3:04 pm
by Harald_Consul
Ok, nearly everyone of us is conform with, that 50kV is the typical operation voltage of an old Copper (CU) x-ray generation tube . So, we do not need to talk about those 50 kV any more, I guess. (Sorry for the somekind misleading introduction.)

What is exactly the difference between a differential x-ray spectroscopy detector tube (which is the design of the Rigaku tube) and a scintillation tube? When I search Ebay for scintillation detectors, most of them are offered as spectroscopy detector tubes. So, the main difference between them is the measurement accuracy for the designated kind of measuring?

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

Posted: Thu Jan 03, 2019 5:56 pm
by Bruce Meagher
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

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

Posted: Fri Jan 04, 2019 3:27 am
by Dennis P Brown
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.

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

Posted: Fri Jan 04, 2019 6:57 am
by Harald_Consul
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]

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

Posted: Fri Jan 04, 2019 3:50 pm
by Harald_Consul
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

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

Posted: Fri Jan 11, 2019 1:19 pm
by Bruce Meagher
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

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

Posted: Sun Jan 13, 2019 2:48 pm
by Harald_Consul
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.

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

Posted: Mon Jan 14, 2019 2:55 pm
by Harald_Consul
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 ;-) ).

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

Posted: Tue Jan 15, 2019 1:13 am
by John Futter
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

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

Posted: Tue Jan 15, 2019 2:54 am
by Bruce Meagher
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 x-rays 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

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

Posted: Tue Jan 15, 2019 8:21 am
by Dennis P Brown
Read both of Bruce Meagher's posts carefully. He is 100% correct.

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

Posted: Tue Jan 15, 2019 2:47 pm
by Harald_Consul
Unfortunately - as I told before - I've already purchased the x-ray scintillitor tube. Mainly because of two reasons:
  • I have got a small budget, thus I am dependent on maximum-universal measuring insruments.
  • All those 50kV warning postings jared on my nerves.

By the way, where have all those 50kV warning postings gone? (Cleared by moderation without leaving back a trace? I am not offending against the way of moderation. It's just been surprising to see postings disappear without any trace. I am just used to, the cleaning moderation would leave back an empty posting. The mod is free to delete this text within these brackets, if desired.)

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

Posted: Tue Jan 15, 2019 10:49 pm
by Michael Bretti
Harald,

I would strongly suggest you research more into the fundamentals of beam systems, beam optics, and beam instrumentation to save yourself a lot of frustration and money pursuing methods that will not yield results you are looking for. While you can reverse the polarity of a gun and use it as an electron beam source (with some modifications), electron and ion beams behave differently under the same conditions, there is no way you could optimize your ion beam output by looking at an electron beam from the same device. They are just not equivalent. X-ray yields can also be very different based on even just target material, so looking at just x-ray output alone will not be necessarily useful for optimizing a beam. A beam can of course be optimized for x-ray output, but that does not mean it is optimized in all aspects.

You also wouldn't need to look at the x-rays at all either - as mentioned in other responses, a simple Faraday cup is incredibly valuable and powerful, and will yield current readings, for both ion and electron beams. At this level, your beam accelerating voltage and current is also very low overall, so you wouldn't be producing anything much of use from beam-target interactions besides neutrons if running a deuterium beam into a self-loading target with high enough voltage/current. If you are measuring the voltage input into your gun, and you know the beam current on a Faraday cup, that will give you a lot of information to start with.

Also as mentioned, you can use methods such as wire scanners for beam profiling measurements. Ion beam profiling can also be measured using direct scintillation screens with a properly positioned camera as well. If you want to get into more in-depth and complex optimization, stuff like pepperpots with scintillation screens can be used for measuring emittance of the beam. A retarding field energy analyzer or an energy analyzer magnet can be used for measuring the energy distribution of the beam. Time-of-Flight methods can also be used for beam energy as well. There are of course a huge range of diagnostics that can be pursued depending on what you are trying to measure. However, besides a simple Faraday cup, or a direct scintillation screen, other methods become much more complex and involved to implement, especially on a budget.

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

Posted: Wed Jan 16, 2019 8:17 am
by Harald_Consul
That's been very helpful Michael. Thanks.

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

Posted: Sat Feb 02, 2019 9:53 am
by Harald_Consul
Ok guys. Here comes the next episode of how figure out (hack) the signal of the Rigaku scintillation tube probe.

First of all, this is NOT a standard "universitary" scintillation probe, where the original photo multiplier signal goes directly on the signal cable. This is a scintillation probe with an integrated pre-amplifier inside!! (Which is the type of scintillation probe type you want, to process a raw signal in some kind of hacking approach.)


DSCN4532_Ausschnitt_50pc.JPG

On left side you see the voltage divider. On the right side you the little preamplifer board.



Let's have a closer look at the out pins of the preamplifer board, now.

DSCN4542_Ausschnitt_50pc.JPG

To keep it simple and stupid, I am simply labeling the external pins of the preamplifier board from left to right as
  • A: light blue
  • B: orange
  • C: white
  • C: dark blue + thin black
  • E: another black connected to the ground of the high voltage cable
The original signal from photo multiplier tube is another (sixth) pin F not visible in the photo.



Third, let's have a closer look on the 5 pole cable, now.

DSCN4533_Ausschnitt_50pc.JPG

The cable contains
  • light blue
  • orange
  • thick black, which contains white + dark blue inside
  • thin black (which is unvisible in the opposite perspective)
The big red cable is the high voltage cable, which is connected to the BNC plug.


Last for completeness only, a look at the 5-pin connector again (which already has been posted before)

Rigaku2_Pic_Plugs2.jpg

On the left you see the high voltage BNC plug. On the right you see the - much more interesting - the 5-pin connector, which is the end of the 5 pole cable in the previous photo.


Happy guessing on which cable has which electrical assignment now.

Some thoughts from me:

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

Posted: Sun Feb 03, 2019 7:24 am
by Harald_Consul
Some further thoughts from me:
  • The external 5 pole connection of the preamplifer board fits to the preamplified positive going signal scheme in https://www.crystals.saint-gobain.com/s ... _70421.pdf page 3 and 4 (page count as labeled)
  • Concluding from this the five poles would be
    • -24 V OR +24 V FET bias voltage (I cannot figure out from the manual: sometime they speak from -24 V and sometime they speak from +24 V)
    • +12 V operating voltage
    • -12 V operating voltage
    • Ground
    • Signal Out
  • Maybe the preamplifier does work like one of the three FET biasing circuits metioned in the Circuits today FET biasing article? How can I check this?