So obviously there are xenon short-arc lamps (like XBO), all of which run on weird ballasts and sometimes DC. This is technically HID, but at the higher pressure end which requires higher voltages to ignite and runs at very very high pressures compared to everyday HID technologies like MV, MH, or HPS.

I know this would almost certainly have to be a pulse-start system, but if you just fill an empty mercury vapor discharge tube (without starting probes) with xenon, or maybe a pulse-start metal halide discharge tube (without refractive coating), I feel like you would have an HID technology that is much like pulse-start metal halide but possible cheaper and it warms up faster. I don’t know if maybe these lamps would be able to be made to run on standard PSMH gear, but it would be cool if that was also possible. Obviously it would have an outer envelope and screw base for easier handling, just like normal HID lamps.

Was this ever attempted? If not, why?

As far as I know, I have seen that the metal halide lamps used in car headlights are often called “xenon” or “HID” lamps. I do have a few of those lamps in my collection and they seem to require an extremely high ignition pulse voltage of around 30kV or so.

@WorldwideHIDCollectorUSA
As far as I know, they just use xenon as their starter gas (instead of mercury vapor) so they get some extent of instant brightness when they first turn on. They also do require a very high voltage pulse because they are under very very high pressure, like xenon short arc except that there are halide salts inside. These are sometimes called “xenon-metal halide” or “XMH”, but in the automotive world they usually just say “xenon” even if it is inaccurate.

There are some long-arc xenon lamps intended for continuous or quasi-continuous mode. Including that weird DKsT ballast-less multikilowatt Soviet series. The problem with pure xenon fill lamps is very poor efficiency just about of good quality halogens. So while the light quality is very good, it is economically unfeasible to use a xenon lamp for general lighting, despite Soviets and Russians tried to prove otherwise up to quite recent years

In the numbers, 20kW DKsT 20000 tube is said to output 600klm of light, that is piss poor 30lm/W. Using modern metal halides the same light output can be achieved with just 3-4 of 2kW lamps, much easier to use and I bet having much better optical control in their luminaires allowing for even more savings.

The problem with xenon discharge is that it radiates significant energy in near-IR, making huge efficiency loss.

@RRK
Wow, I didn't know that. Since it has such bright white, I would have assumed that the majority of the light is in the visible spectrum, but I suppose a significant portion is not. So essentially MH is better than xenon in practically all cases. Interesting.

I think that most xenon super high pressure xenon lamps fall under the IEC definition of IHID Lamps. Regarding the xenon long arc lamps, there are very few pictures on the site even of them. See additional data here:
https://www.lamptech.co.uk/Documents/Brochures/Osram%20-%20Liste%20XQO%20-%201969-I%20DE.pdf
https://www.lamptech.co.uk/Documents/Brochures/Osram%20-%20Liste%20XBF%20-%201969-X%20DE.pdf

@RRK
 So essentially MH is better than xenon in practically all cases. Interesting.

That is, for general lighting application!

Xenon lamps rule for optical applications like movie projectors or floodlights, and a great multitude of all imaginable types of xenon long-arc lamps are used as flashlamps.

An interesting kind of quasi-stationary xenon lamps called XOP, somewhere in between of stationary and pulsed types, typically quenched by a SCR control, is quite widely known for white light strobes in showbiz.

 

As an overall lamp, the Xenon alone is rather inefficient, that is why, along its cost (expensive gas by itself, the fill is under high permanent pressure which makes the lamp difficult to ensure safety, related to that is more difficult handling, again due to safety concerns,...) and driving complexity (needs high voltages for ignition).
But it does excel in two areas:
As a high pressure source, it is able to concentrate all the light output into very small spot, which makes the following optics way more efficient when precise beam control is needed (projection applications, light cable coupling,...). So much, the overall system becomes significantly more efficient in generating the precise beam than other technologies, hence its popularity there. Moreover because in such systems the lamp cost, even when seems very high vs other lamps, is just small fraction of the overall system cost (this equipment uses to be very expensive regardless of the light source type).
Second advantage is the instant light output ability, which makes the applications like photo flash also very efficient - because the instant response, it does not need to be lighted longer than really needed for the exposure itself, so way less power gets wasted when the light source needs power before and after the main exposure (like incandescent needs to be first wArmed up to full brightness for about a second to take an exposure for 1/10 of a second; the Xe flash needs to be lighted just for the 1/10 of a second, so with similar general efficacy it means 10x less energy needed).
Plus the Xe allo9ws very huge peak power in very tiny package (the very cheap and tiny disposable camera flashes used to operate at 100's W of peak power, allowing very short exposure times, so sharp image even when the things were moving). By the way this is still a feature not attainable by LEDs, however an advanced image processing was able to go around this limitation in modern camera implementations (more sensitive sensors, using multiple partially exposed images and then aligning the pictures on each other in SW in order to get the required total equivalent exposure).
Also the car headlight bulbs (in fact a hybride between Xe discharge and MH) was utilizing the fact the Xe is able to deliver the light instantly, so even when it needed power boost to compensate for the lower efficacy, it was able to cover the time before the main halide fill evaporates and takes over.

But unless the application really benefits from these properties, it does and did not make sense to use it.

Also: Short arc xenon lamps maintains their high pressure even when cold, and can explode like a hand grenade even when cold.
Because of this, people that working in screening films at cinema theater, wiring special clothing for use with xenon lamps, and the lamps comes with special boxes, and are be released from them only during installation.