Presentation on theme: "Numerology (P. Baudrenghien) For each ring: Convention 1: The 400 MHz RF defines 35640 buckets, spaced by one RF period, and numbered from 1 to 35640 Convention."— Presentation transcript:
Numerology (P. Baudrenghien) For each ring: Convention 1: The 400 MHz RF defines 35640 buckets, spaced by one RF period, and numbered from 1 to 35640 Convention 2: Bucket 1 is the first bucket after the 3 s long abort gap (defined from bucket 34442 to 35640) For 25 ns operation the bunches will occupy buckets 1, 11, 21 etc. with gaps occurring every PS or SPS kicker gap. For 43 bunch operation the bunches will occupy buckets 1, 811, 1621, etc. (see LHC-OP-ES-0003 rev 1.0 for the different schemes).
LHC filling schemes Why t 3 and t 4 ? When should we use one or the other?
Injection Request Request name Next injection ring Next injection beam type Next injection bunch Int Next injection particle type Is active Injection Bunch configuration Configuration name First Bucket number Bunch pattern Pattern name Description Number of PS batches Number of bunches per PS batch Total number of bunches Bunch spacing n 1 n 1 Bunch pattern Injection Bunch config Injection scheme composed of injection requests Injection Scheme Scheme Name n n Injection Scheme Entry Injection Order Next Injection Delay
Next injection To inject a beam into LHC : –Next injection Ring –Next injection RF bucket (the first bucket filled by the injection) –Number of PS batches ------------------------------------- –Next Injection Beam Type : divided into 4 groups in the telegram NIBNCH : number of bunches NIBSP : bunch spacing (ns) NIBIN : bunch intensity (*10E9) NIPTY : particle type (0=protons, 1=ions) Should we add this field into the injection request sent to the CBCM? These telegrams groups will be set together with ring bucket and number of batches by the CBCM (No need to set it from the application) These groups won’t be editable (i.e. sequencer can’t change it) OP has to check that the beam in the injector corresponds to what is requested
Next Injection Do we have to publish extra information? –I.e. the injection sequencer set a RF FESA class with the next filled buckets Active injection request –The injection that is being executed (from the request to the CBCM to the injection quality check validation) –Accessible through LSA client API Is it needed to know before we start injecting what is the expected bunch configuration after the injection process?
Circulating bunch config Information about circulating bunch configuration exists : –In a table in LSA DB An array of filled buckets is published from this table. (ACCCON_SYS.ANYDATA_QUEUE/LHC_CIRC_BUNCH_CONF_B1) Extra information needed to be published : –The SPS batch number for each bunch –The bunch intensity CirculatingBunchConfiguration -beam number -bunch number -bucket number 1-2 1 to 2808 (number of bunches for 25ns nominal scheme) 1 to 35640 : total number of buckets –In the telegram groups As for injection beam type, the circulating beam type groups (BTC1 and BTC2) will be replaced by 4 groups per beam –C1BNCH : number of bunches –C1BSP : bunch spacing (ns) –C1BIN : bunch intensity (*10E9) –C1PTY : particle type (0=protons, 1=ions)
Replaced by C1BNCH C1BSP C1BIN C1PTY Replaced by C2BNCH C2BSP C2BIN C2PTY
Circulating bunch configuration Telegram and database have to be updated after each injection and after a beam dump –Who, how? –Should it be updated as well if a part of the beam is lost? Depends if it represents –What we have in the LHC –Or what we aim to have in the LHC