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Homemade X-ray machine question

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James

Wed May 04 2011, 05:22PM

Registered Member #3610 Joined: Thu Jan 13 2011, 03:29AM
Location: Seattle, WA
Posts: 506

Photographic paper and film both vary, but film seems to be about 10x faster in practice. I have not tried direct exposure on paper, but 4mA with a fast intensifier screen does provide nice results for a 5-15 second exposure.

There must be somewhere over there that sells photo developing chemicals. I got the stuff I use from Adorama in the US, I think I paid about $8 per bottle, a bit less than a liter.

magnet18

Wed May 04 2011, 07:44PM

Registered Member #3766 Joined: Sun Mar 20 2011, 05:39AM
Location:

Posts: 624

è¬æ˜•å“² wrote ...

I test MacGyver's method.But I use some overdue vitamin pills and ammonia.It works but ofcourse very low quality.(not with X-ray,With ordinary negative film)

This is the very first time I develop photo.

But my dad was VERY VERY angry about the smell of ammonia.

Can I use baking soda or Na2Co3?

So photographic paper cannot detect X-ray?

Is he allergic to ammonia? the fumes are pretty much harmless other than possibly a mild headache.
Try it in the bathroom with the exhaust fan on.

hsieh

Thu May 05 2011, 12:02AM

Registered Member #1412 Joined: Thu Mar 27 2008, 04:07PM
Location: Taipei Taiwan
Posts: 278

magnet18 wrote ...

Is he allergic to ammonia? the fumes are pretty much harmless other than possibly a mild headache.
Try it in the bathroom with the exhaust fan on.

He worried that I might harm my health.

My dad seems to be sensitive to smell.My mom secretly told me that even the smell of her body lotion made him angry.

I will try baking soda or Na2Co3 and do my experiment when no one at home.

I think developing film or photographic paper using household items or food itself can be a project.I will start a new thread when I made it to work

Wolfram

Thu May 05 2011, 05:43AM

Registered Member #33 Joined: Sat Feb 04 2006, 01:31PM
Location: Norway
Posts: 971

Do not use baking soda. All the sites that I've found on developing with orange juice or coffee suggest that sodium carbonate works, and baking soda doesn't.

hsieh

Thu May 05 2011, 03:13PM

Registered Member #1412 Joined: Thu Mar 27 2008, 04:07PM
Location: Taipei Taiwan
Posts: 278

I downloaded some of my favorite antique B&W photo,turn them into negative using software,and do my experiment using coffee and sodium carbonate.

It works,but the image quality is poor.But I know nothing about developing photo and this is my first(and probably the last)try.So I'm surprise I can see the image.After some google,I understand that even if I use commercially made developer,There is still many factors that can affect the quality,Needless to say developer made from coffee.

I now have to prepare for an important exam so probably don't have time to try more experiment about homemade developer or amateur radiography.

Fraggle

Thu May 05 2011, 03:51PM

Registered Member #1526 Joined: Mon Jun 09 2008, 12:56AM
Location: UK
Posts: 216

Lol if he thinks that`s bad you are going to be in deep trouble when he finds out you`re powering an X-RAY TUBE (!) in the house :o)
It`s probably going to be less effort to find something fluorescent and use a digital camera than messing about with diy film developing and such

James

Thu May 05 2011, 05:08PM

Registered Member #3610 Joined: Thu Jan 13 2011, 03:29AM
Location: Seattle, WA
Posts: 506

I found that developing film and paper was the easy part, but then the supplies are cheap and readily available here. If you have a safelight to work under, you can watch the image form. The timing and temperature are only critical if you're developing a bunch of photographs and want them to all have matching contrast.

Proud Mary

Thu May 05 2011, 06:48PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Anders M. wrote ...

The numbers from RadPro are based on theoretical calculations with a lot of unrealistic assumptions. To quote from the RadPro website: "It should always overestimate the amount of shielding required because e-max for the tube head is used when in reality the device produces an entire energy spectrum from lower energies up to e-max.". I think overestimate is a mild word in this case, as assuming all of the energy is at e-max is quite a bold assumption.

You may be interested to see the 'rule-of-thumb' X-ray tube dose rate formula used by the University of Glasgow Radiation Protection Service:*

D = 670ZVI/dÂ² mGy/s (assuming a 1mm Be filter)

Where D is the dose rate in mGy/sec
Z is the Atomic Number of the target
V is the applied tube voltage in kV
I is the tube current in mA
d is the distance from the source

*

uzzors2k

Thu May 05 2011, 08:17PM

Registered Member #95 Joined: Thu Feb 09 2006, 04:57PM
Location: Norway
Posts: 1308

Using the above formula I got a dose rate of 2,88mGy/hr, or roughly a whole year's dose per hour. The assumptions I used are listed below. Shield attenuation was calculated using tables from

The dose rate formula assumes you're standing in the main x-ray beam, unless I'm mistaken.

X-ray tube output fluence (1mm Be)

Target Atomic Number 74
Tube Voltage 50 kV
Tube current 4 mA
distance 1000 mm

Dose rate 9,92 mGy/sec

Attenuation of Pyrex (5mm, 50kV) 7,41E-001
Attenuation of lead (1mm, 50kV) 1,09E-004

Total dose rate 0,8 ÂµGy/sec
2,88 mGy/hr

Wolfram

Thu May 05 2011, 09:01PM

Registered Member #33 Joined: Sat Feb 04 2006, 01:31PM
Location: Norway
Posts: 971

Uzzors wrote ...

Using the above formula I got a dose rate of 2,88mGy/hr, or roughly a whole year's dose per hour. The assumptions I used are listed below. Shield attenuation was calculated using tables from

The dose rate formula assumes you're standing in the main x-ray beam, unless I'm mistaken.

X-ray tube output fluence (1mm Be)

Target Atomic Number 74
Tube Voltage 50 kV
Tube current 4 mA
distance 1000 mm

Dose rate 9,92 mGy/sec

Attenuation of Pyrex (5mm, 50kV) 7,41E-001
Attenuation of lead (1mm, 50kV) 1,09E-004

Total dose rate 0,8 ÂµGy/sec
2,88 mGy/hr

I don't really think any of these calculations can give a realistic result, as the radiation from an x-ray tube is a spectrum, and all the calculations I've seen so far only take into account the attenuation at a single wavelength. If you choose the highest energy, then the calculated attenuation will be much too low, as the average x-ray photon energy is supposedly a third of the maximum energy. And if you choose the average energy to calculate attenuation, the calculated attenuation will be too high, as the attenuation of the higher energies is often much lower. Ideally one would choose some point in-between these two exteremes, but the whole situation becomes very complex when you take into account characteristic radiation of the tube and the k-edges of the shielding materials. This is why I prefer to trust the attenuation table I linked to earlier over these calculations.

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