Re: MGDRAW Directional Cosines

Vasilis,

Thanks for your response..

This approximation is likely OK for high energy heavy particles (such as
protons, muons), but I assume multiple scattering between track-segment
endpoints can occur and consequently the values for the directional
cosines determined using the end point difference for low energy
electrons will deviate significantly from the original incoming direction.

John

On 1/9/2012 9:23 AM, Vasilis Vlachoudis wrote:
> Hi John,
> the C[XYZ]TRCK variables contains the direction cosines, at the end of the
> step of the direction to follow next.
> The individual direction cosines from each segment you can find them from
> the difference [XYZ]TRACK(I) - [XYZ]TRACK(I-1)
>
> Vasilis Vlachoudis
> Dep EN, CERN=
> CH-1211 GENEVA 23
> SWITZERLAND
> Phone: +41-22 767 9851
> GSM: +41-76 487 4378
> Fax: +41-22 766 9644
>

> On 1/6/2012 12:27 PM, John Clem wrote:
>> Hi All,
>>
>> I have a question concerning the data stored in the TRACKR common
>> specifically when accessed through MGDRAW (USERDUMP card is set to
>> WHAT(1)=100). It is my understanding from the user manual the
>> parameter NTRACK is the number of track segments while MTRACK is the
>> number of energy loss events along the track. XTRACK, YTRACK, ZTRACK
>> represents the end point of the ith track segment with 0 < i < NTRACK
>> while DPTRCK(3,j) represents the momentum loss vector of the jth
>> deposition track as 1 < j < MTRACK.
>> The current objective is to extract the directional cosines for every
>> start and end point of a track segment. Now the question: Are the
>> directional cosines parameters CXTRCK, CYTRCK, CZTRCK associated with
>> the "i=0" starting point of the track segment(s)? If so, is it then
>> correct to assume that subsequent end points directional cosines can
>> be determine from the momentum loss vector DPTRCK?
>>
>> Thanks, John
>>
>>

-- 
>>  John Clem
>>  Research Associate Professor
>>  Bartol Research Institute
>>  Department of Physics and Astronomy
>>  217 Sharp Lab
>>  University of Delaware
>>  Newark, DE 19716
>>  off 302-831-4354
>>  cell 302-388-1218