Laser cooling problem....

[Schrecken_Licht]

I just bought a CW YAG laser from Chris (Heuuersciences) and I'm having a problem getting a pump that's powerful enough to circulate water thru the laser.  When I bought the laser I also bought a water fountain pump (of the sort that you would use in a small fish pond or outdoor fountain) to circulate the water.  

However, last night I was all ready to go and fire the thing up, and darned if it didn't not light up!  Well, the emission light comes on so the unit is getting power, but the lightbulb that pumps the laser won't come on (it uses a .5 or 1kw quartz light bulb).    

Chris said the problem is likely (other than the bulb being bad or loose - I did check it to be sure it didn't come loose in shipping) that my pump isn't putting out enough flow or pressure.  He said it requires about 35 pounds of pressure for the laser to start.

Now I'm no expert on pumps - heck, I don't even have a fountain or fish pond, or even a fish tank!  So, anyone have any idea of what sort of pump I can get that will push enough water to allow this laser to work?  Every pump I've seen thus far is rated at how many gallons per hour (and sometimes how high it can lift the water), but not pressure....so how would I know if a given pump is powerful enough? The pump I have is rated at 70gph and a 12" lift, BTW.  Apparently not enough....

I had thought about running it off tap water, but that just won't be practical, for many reasons....even though the water pressure is more than enough.

Any ideas?

BTW, here is a pic of the (non-working) laser with the cover removed:

 

[JLSE]

I have a couple of these lying around. They are nice little pumps that run on 120ac or 48vdc. The can produce a good  pressure, but im not sure of the GPM or exact PSI.  They are approx. 6in long and really torque'y  

PM me if interested.

* They are much stronger than typical fountain or aquarium pumps. I also have a 300$ 12vdc monster that is 12in long or so, it was originally for soda or beer dispensing

 

[FrothyChimp]

I don't recommend using tap water for cooling. I'm sure the cavity uses flow tubes for cooling so the water actually surrounds the pump lamp. You need to use de ionized water so you don't get a short across the water. Tap water contains ions such as metals and treatment chemicals like chlorine and fluorine. As ions, they will conduct current. This can damage the lamp or the circuitry.