From bardelli@fi.infn.it Wed Sep 26 20:40:57 2007 Date: Fri, 21 Sep 2007 11:32:44 +0000 (UTC) From: Bardelli Luigi To: "Lazarus, IH (Ian)" Cc: Thomas Davinson , Bardelli Luigi Subject: RE: FW: Si simulations (Huelva discussion) Dear Ian, I send you in attachment two files, one referrering to the simulation with plasma switched off and one with plasma switched on. The two files are text files that provide the *current* output from the detector before the application of any preamplifier, so that you can plug them into your favourite preamp simulator :-) (I suppose you should insert in your simulation something like a transient current generator). Beware that these signals refere to a standard silicon readout (no strips at the moment sorry). After decompression (gzip), the file format is as follows: FIRST LINE : sampling period (float, ns) SECOND LINE : number of samples (integer) following lines: one sample for line (float) The signals have been delayed by 100 ns in order to have a better visualization. You will notice some fluctuactions on the signal with plasma: this is due to the fact that the simulation has been run in "low accuracy" mode (to save time...). I have started some higher accuracy runs: I expect that the higher accuracy runs will have more or less the same shape but a longer risetime (but the order of magnitude should be correct). Some final remarks: since the simulation of heavy ions is a very interesting topic from my point of view also, may I ask you to keep me informed of your discussions/developments? I am also in the process of writing a paper on this code, so any suggestions and/or discussion is very welcome from my side. If you need some kind of reference you may use L.Bardelli et al, "Simulation and study of current signals and plasma effects in silicon detectors for heavy ions experiments", Proceedings of the IWM2005 conference, ISBN 88-7438-029-1. Keep in touch! Luigi On Fri, 21 Sep 2007, Lazarus, IH (Ian) wrote: > > Thanks very much Luigi. > > We expected that the plasma would have a significant effect > and your simulation confirms it. > > Does your simulation tell you anything about the pulse > shape as well as calculating the 10-90% time? > > If pulse shapes are available (perhaps as tables of charge or > voltage against time?) we would find them useful for electronics > simulations. > > For example it would be very interesting to have a file of values > for charge against time at the input of your idealised charge preamp > to test the response of our ASIC design to a realistic pulse. > > (If the code produces a table like this at the charge preamp output > rather than its input, we could calculate the input charge shape > ourselves > if you could send the idealised preamp output pulse shape and the > circuit > diagram of the simulated preamp.) > > We have a project meeting next week (27th) so we will certainly discuss > your simulation results there and maybe come up with some other > questions. > > Thanks very much for your help. > > best regards, > > Ian > > ------------------------------------------- > Ian Lazarus > Nuclear Physics Group, STFC, Daresbury Lab, > Daresbury Science & Innovation Campus, > Keckwick Lane, Warrington WA4 4AD, England > > Office +44 (0)1925 603433 > Mobile +44 (0)7825 420895 > Email I.H.Lazarus@dl.ac.uk > URL http://npg.dl.ac.uk > ------------------------------------------- > > >> -----Original Message----- >> From: Bardelli Luigi [mailto:bardelli@fi.infn.it] >> Sent: 21 September 2007 11:34 >> To: Lazarus, IH (Ian) >> Cc: Thomas Davinson; Bardelli Luigi >> Subject: RE: FW: Si simulations (Huelva discussion) >> >> Dear Ian and Thomas, >> thank you for the replies. I have run my simulation with >> the following >> parameters: >> >> det. thick.: 1mm >> bulk type : n >> det. Vdepl : 200 V >> det. Vappl : 250 V >> front inj. >> >> Since the simulation needs a non-zero electric field in the >> detector, I have used an applied voltage of 250V, i.e. 50V >> over depletion. >> The simulated readout system is a standard one (i.e. without >> strips): as far as I know this can influence the shape of the >> collected signal, but not its duration (that is due to the >> charge drift only). >> >> I remind you that my detector simulation is still a work in >> progress, partially tested only for light ions (Z< ~30), so >> please consider any "result" as very very preliminary. >> >> Here are the numbers that I got for a U ion, 17GeV, using an >> ideal charge preamplifier (i.e. rise-time: 0 ns...) >> >> 10-90% risetime, with plasma switched off: about 43 ns 10-90% >> risetime, full simulation (i.e. with plasma): about 380ns >> 100% collection time, full simulation (i.e. with plasma): >> about 700 ns >> >> Let me know if you need additional info or tests Regards >> Luigi >> >> >> ,------------------------------------------------------------------. >> | Luigi Bardelli | >> |------------------------------------------------------------------| >> | INFN Sezione di Firenze | >> | Tel: +39-055-457-2693 | >> | -2710 | >> | -2714 | >> | Fax: +39-055-457-2676 | >> | E-Mail: bardelli@fi.infn.it | >> `------------------------------------------------------------------' >> ** Please avoid sending me Word or PowerPoint attachments. >> ** See http://www.gnu.org/philosophy/no-word-attachments.html >> >> > > ,------------------------------------------------------------------. | Luigi Bardelli | |------------------------------------------------------------------| | INFN Sezione di Firenze | | Tel: +39-055-457-2693 | | -2710 | | -2714 | | Fax: +39-055-457-2676 | | E-Mail: bardelli@fi.infn.it | `------------------------------------------------------------------' ** Please avoid sending me Word or PowerPoint attachments. ** See http://www.gnu.org/philosophy/no-word-attachments.html [ Part 2, "" Application/OCTET-STREAM (Name: ] [ "bardelli_aida_u_noplasma.txt.gz") 6.6KB. ] [ Unable to print this part. ] [ Part 3, "" Application/OCTET-STREAM (Name: ] [ "bardelli_aida_u_withplasma.txt.gz") 47KB. ] [ Unable to print this part. ]