[G14_run] Test on the eloss package

[Dr. A.M. Sandorfi]

Reinhard,
The energy loss is all in the Neodymium, Titanium and copper of the
solenoid, and in the Aluminum walls of the magnet can, 80K heat shield and
the IBC vacuum can. The loss in the target itself is almost nothing.
Andy


On 4/10/14, 8:52 AM, "Reinhard Schumacher" <schumacher at cmu.edu> wrote:

> Haiyun et al,
> 
> Using 500 MeV/c as a benchmark, Eugene's program gives energy losses of
> 10.0 MeV for protons and 1.5 MeV for pions.  How thick does this imply
> the target material is?
>                    protons        pions
> all plastic       1.6  cm        0.76 cm
> all aluminum      0.74 cm        0.22 cm
> 
> This shows that the program is internally inconsistent for what it
> returns for pions and protons at a given momentum.  But also, the
> material thickness the numbers imply seems like a lot:  is the HDIce
> target at 90 degree really the equivalent of 1.6cm of plastic or .74cm
> of aluminum?  That seems very thick.
> 
> Reinhard
> 
> ___________________________________________________________________
> Reinhard Schumacher         Department of Physics, 5000 Forbes Ave.
> Carnegie Mellon University, Pittsburgh, PA 15213, U.S.A.
> phone: 412-268-5177         web: www-meg.phys.cmu.edu/~schumach
> ___________________________________________________________________
> 
> On 04/09/2014 10:37 PM, Dr. A.M. Sandorfi wrote:
>> Thanks Haiyun,
>> This provides a direct comparison with my earlier direct calculation,
>> tracking the Eloss through sequential layers.
>> 
>> For protons:
>> - 65 MeV kinetic energy corresponds to 355 MeV/c momentum, for which your
>> Eloss plot gives 22 MeV for delta_E. It should be 27 MeV.
>> - at the upper end of your plot, 1000 MeV/c, or 433 MeV kinetic energy, the
>> delta_E seems to be a little under 4 MeV. This is closer, but still too low.
>> The delta_E shouldn't be less than 5.
>> 
>> Still the pion Eloss seems to be off the most.
>> Andy
>> 
>> 
>> 
>> 
>> 
>> 
>> On 4/9/14, 6:08 PM, "Reinhard Schumacher"<schumacher at cmu.edu>  wrote:
>> 
>>> Hello Haiyun,
>>> 
>>> Nice work.  Your proton band looks like it gives higher energy loss for
>>> protons at a given momentum than Dao's and the others'.  At 300 MeV/c,
>>> your plot shows ~30 MeV energy loss, while Dao's shows ~10 MeV.  For
>>> pions the behavior is less clear: both your calculation and his give
>>> less than 2 MeV energy loss at 300 MeV/c, which is very likely too
>>> small.  So this leads to the questions:
>>> 
>>> 1) Why do you get higher, probably closer to correct, energy losses for
>>> protons?
>>> 
>>> 2) Why does the program give unrealistically small energy losses for
>>> everybody?
>>> 
>>> Reinhard
>>> 
>>> ___________________________________________________________________
>>> Reinhard Schumacher         Department of Physics, 5000 Forbes Ave.
>>> Carnegie Mellon University, Pittsburgh, PA 15213, U.S.A.
>>> phone: 412-268-5177         web: www-meg.phys.cmu.edu/~schumach
>>> ___________________________________________________________________
>>> 
>>> On 04/09/2014 05:16 PM, Haiyun Lu wrote:
>>>> Dear g14ers,
>>>> 
>>>> I did a straight test on the eloss package of g14. I made up some events
>>>> of proton and pi-. They are at fixed vertex position at (0,0,-7.5),
>>>> which is the center of the target. They are at the fix polar angle, 90
>>>> degree, which is perpendicular to the beam line. The azimuthal angle and
>>>> the momentum are variable. Then I plot the energy loss versus the
>>>> momentum for proton and pi-. I attached a file "eloss_test.png". There
>>>> are two bands in the histogram. The upper one is for proton and the
>>>> lower one is for pi-.
>>>> 
>>>> Best regards,
>>>> Haiyun
>>>> 
>>>> 
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>> 
>>