is it normal to have this much dead pixel on the brand new canon ra?

NCamerin wrote:

Kameratrollet wrote:

Different temperature what I found after a quick look. 15 vs 29 degrees C.

Not sure what you meant, that the temperature is the cause of the increment of white pixels?

We didn't have any problem until basicly 26th May where suddenly begining appear white pixels all over the frame and on Auguat 1st was worst.

Unfortunately, this issue of "stuck" and "hot" Pixels affects every model and every brand of camera.  The solution is to do what everyone else does by using "Dark Frame Subtraction" when there are too many pixels to conveniently edit individually.  I'd say quite a few of the stuck pixels on my EOS Ra are white with some being red, blue or green.  If you see a white pixel with extremely dark (black) pixels surrounding it like a halo or a "cross" shape with the white pixel in the center, then it can sometimes indicate a pixel that is beyond stuck/hot and is closer to "permanently jammed" whilst not quite being truly dead.  This may often not be repaired using the usual methods.
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To see if it's a serious issue or not, do the Sensor Clean with the lens OFF the camera and the body cap in place.  Then try taking a picture using "normal" daylight exposures and ISO settings (eg 1/80 second with ISO 200 etc).  Try to photograph something with a darker, smoother texture to make it easier to spot any errant pixels. If the pixels that appeared to be problematic in your long-exposure shots with high ISO settings are still visible in these tests, then you can be sure that there's an issue with the sensor.  But it's unlikely.
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If those same pixels are showing up with normal daylight settings, you could contact Canon.  It's possible they may or may not be able to assist because the EOS Ra is a limited edition camera and has only recently (2 months ago?) been discontinued (perfectly normal... it will probably be another 7+ years before another is released).
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It's normal to expect some (dozens?) of hot pixels to occur.  Even with a new camera.  My EOS 6D looked like it was snowing with over a THOUSAND mostly white pixels the first time I used it for Astro.  The touchup took forever to clone them all out.   A simple "manual sensor clean" using only the menu setting solved it and almost all of those white pixels vanished.  The temperature in the air at the time can affect their appearance or disappearance.  Cameras tend to generate stuck pixels on the sensor as time goes on and the camera gets older by several years.  The hot pixels are simply not producing the color and tonal values expected.  I'd say my EOS Ra produces around 20 or more (35?) hot pixels which often disappear when a so-called "Manual sensor clean" is applied.  Remember you need to remove your lens and put your body cap onto the camera when doing this.  If you leave the lens on when conducting this procedure, the results will be somewhat less effective.